Weather, Transfer Switch, Misc. Stuff and The Great Solar System Build

This is what I woke up to the other morning. Sigh… It’s March. It should be getting warmer out. Instead we get this???

The weather here in Wisconsin can get interesting, to say the least. Mostly it’s fairly pleasant up here, but sometimes things get weird. Like blizzards in May. Or the Great Frog Storm of 1956. (That one was scary.) This winter has been remarkably mild with very little snow. Well very little snow until now. I think we got more snow in the first 2 weeks in March than we did during the rest of the winter combined. Now we’re under a storm warning for tomorrow and could get another 5 – 8 inches of snow. Sigh…

But let’s get on with this. I’m sure you have better things to do than listen to me rambling along. I know I do. (Looks at calendar… Well no, it seems I don’t have better things to do. Never mind.)

I thought I was done talking about solar and power systems and all of that for a while. I should have known better because here we go again. That transfer switch I was talking about last time is now installed and working. The kit had everything necessary and installing it is pretty simple. It took maybe an hour to install the whole thing. (Do I really need to include the disclaimer telling you not to go fiddling around with your house’s electrical service because you can get killed if you don’t know what you’re doing?)

Circuit tracers aren’t hugely expensive, this is the one I have and it sells for about $50. If you have kids they make great circuit tracers. “DAD! What did you do??? The Playstation shut down and I didn’t save my game!!!”

It took some time to track down what breakers powered what. A variety of electricians have been in that panel fiddling with things in the years we’ve lived here and not all of them were careful about labeling what they hooked to what, it seems. I was upset by that because these guys are supposed to be professionals. You don’t just shove a new breaker into a panel, hook it to something and leave it unlabeled. Or, even worse, change an existing circuit and then not note down what was changed. I ended up spending a good hour with a circuit tracer running around the house testing outlets and lights before I could even start installing the transfer switch. Fortunately only two or three were mislabeled but that was still concerning. I got out my little label making thingie to make nice, neat labels, only to find my label making thingie didn’t work. (Yeah, it’s been one of those weeks so far. The label maker, the mislabeled circuits, a crimping tool designed to crimp MP4 connectors doesn’t actually crimp things…)

With the transfer switch set up I can change between grid power and the Blutetti with just the flip of a switch. And the transfer switch doesn’t care where it gets power from so I can plug in either the Bluetti or our big Generac gas powered generator.

Planning and Research Problems

If you’ve been following this discussion that started with the Bluetti solar generator thing you know MrsGF and I have decided to put in a relatively large solar power system that can handle much of our electrical needs. We aren’t going “off grid” as they call it because with the weather we get here in Wisconsin it would be difficult, even impossible, to rely on solar for all of our electrical needs. But we could make a significant dent in our electric bill if we manage to pull this off.

But there are problems.

Now we could do something like look at some of the “plug ‘n play” systems from Bluetti, Ecoflow, Generac and others but all of those have serious issues. When it comes to the solar generator people like Bluetti and Ecoflow, the problem is that while they have some pretty nice systems that are fairly easy to install that can handle almost the whole house, you’re locked into those companies for the entire lifetime of the system. You can only use their batteries, their accessories, their adaptors, etc. If something goes wrong with the system the only thing you can do is pack the whole thing up and ship it back to the company which will, maybe, you hope, fix it and maybe, you hope, actually ship it back to you and that it will actually work when it arrives. And that will take weeks at least, maybe even months. And during that time your entire solar energy system is shut down. And let’s be honest, all of the systems from those companies are breathtakingly overpriced when you look at what you actually get for your money.

There are problems with the big brand names like Generac and Tesla as well. Once again you’re at the mercy of a single vendor for all of your equipment. You might be lucky and be in an area that is served by an installer/dealer who can help you when something goes wrong, and something will go wrong eventually, but even so you’re still tied to a single vendor for everything. And even worse, the systems from these companies are eye wateringly expensive for what you get.

And then there are the problems with almost all of the commercial “solar contractors” out there.

If your goal is to gain some independence from the grid you aren’t going to get it from most of the commercial solar contractors out there. What most of them are selling are systems intended to generate power that is sold directly back to the utility, not to make you independent from the grid. They have little, if any, battery backup capability. And with a system like that you are entirely at the mercy of the utility company. They could decide tomorrow to change the rates, add in bogus “connection fees”, even shut you down entirely.

So if you want a system that gives you some independence from the grid, that doesn’t lock you into a single vendor who could very well disappear tomorrow, want to do it as economically as possible, and want a system that is relatively easy to repair when things go wrong, you’re pretty much stuck with trying to build it yourself.

Which brings me to…

The Great Solar System Build

Oh, brother, talk about hyperbole. Sheesh…

Over the next few weeks (or months, because I’m not only lazy I am also a procrastinator of the first order) I’m going to document in excruciating and incredibly boring detail our efforts to build a reasonably large home solar power system from the ground up, complete with system specifications and why we chose those specifications, the search for equipment, dealing with various vendors, issues with wiring and building codes, etc, etc, etc.

For those of you who find this kind of thing eye wateringly boring, well, you have my sympathy. So posts about the solar system will be prominently labeled with a GSSB tag in the title so you can skip those parts and just drop in to look at photos or read the other nonsense I babble about here.

Questions. And Some Answers. Maybe

I was going to wrap up this whole Bluetti/solar generator discussion last time but some additional stuff came in email ( and other sources, so let’s get on with this.

Battery Safety

A couple of people have apparently been spending way too much time on YouTube watching people deliberately blowing up lithium battery packs and expressed the opinion that having a lithium battery in your home is the equivalent of having a rather large bomb waiting to go off at any moment. I won’t bother to point out that there are literally hundreds of millions of lithium batteries out here in the real world that somehow have managed to not blow up or suffer from “runaway thermal events” as they call it. Instead I’ll just mention that the batteries in the Bluetti and in many of these systems use LiFePo battery chemistry which is not only much safer, it also gives the batteries a much longer lifespan. I’ve seen LiFePo batteries being beaten with hammers and rocks, drilled through multiple times, stabbed with fishing spear, had nails driven through them, etc. and none of them exploded or turned into unquenchable blowtorches. They will get hot, they will vent gasses that I would very much want to avoid breathing, but none of them got explody or anything like that. If treated reasonably well LiFePo batteries could potentially continue to work well for years.


I got questions from a couple of people who have a power station or are thinking of getting one and don’t want to have to run extension cords all over the house in order to keep things running during a blackout. Why can’t you just use your house’s existing wiring system? Well you can, sort of. If you look at that photo of the AC200Max over there you’ll see a very large 3 prong socket on the far right. That’s a TT-30 plug, a high amperage connector. Well, sort of high amperage. If I remember right it’s only good for about 20 Amps because of the limitations of the AC200Max’s inverter. It’s intended to feed power to the electrical system of an RV but there’s no reason you can’t use that to supply larger amounts of power to a transfer switch system to feed selected circuits in your home without having to run extension cords everywhere.

So that takes care of… Uh? What’s a transfer switch? Ah I suppose I’m going to have to explain that now.

Okay, here’s the deal. You can’t just pump power from an external generator into your house’s electrical system. If you try most of your power is going to backfeed into the grid, overloading your generator and quite possibly killing some poor lineman working on a pole somewhere trying to restore power during a blackout. And you are not permitted to just shut off the main breaker on your electrical panel, either. In a lot of jurisdictions it is flat out illegal to hook any kind of alternative power source to your house’s wiring without the installation of some kind of transfer switch system.

And here’s an example of one.

This kit may seem expensive at $300 but it includes pretty much everything necessary to install one of these things. No, I don’t get paid by Reliance. I bought this thing with my own money. I don’t get kickbacks or free stuff or cash or anything like that. And I am seriously disappointed by this. Other bloggers get companies throwing stuff at them all the time: hugely expensive batteries, inverters, charging systems, solar panels, hardware, tools… Me? Zilch. Nada. I mean if, oh, Power Queen wanted to send me four of their 48V server rack batteries I’d be more than happy to test them out for five, six years. Or GroWatt. What’s up with you guys? Why haven’t you sent me one of your 8KW inverters, or that neat split phase unit? Hmm? I’m not above a bit of bribery now and then….
The Big Ass Plug (BAP). Well that’s what I call it. Oh, the orange thing in the bottom right isn’t part of the kit, that’s my Klein circuit tracer thingie.

That is a Reliance transfer switch kit that I picked up at a local home improvement store for about $300. These things are designed to allow you to take up to 6 individual circuits in your home and let you switch them to work with an external power supply like a generator or something like the Bluetti. A BAC (Big Ass Cable) plugs into the big socket on your generator, and the other end plugs into a BAP (Big Ass Plug) wired into the transfer switch. When you flip the switches on the box up there, you switch that circuit from the LINE, which is your connection to the grid, to the GEN input, which is fed by your generator.

And no, I’m not going to give you instructions on how to install one because I don’t want to be responsible for you electrocuting yourself or starting your house on fire or something like that. These things aren’t hard to put in. There are numerous videos out there showing you exactly how to do it. But I am going to put in the usual disclaimer that you shouldn’t go fiddling around in your circuit breaker box because you can kill yourself or someone else, burn down your house or damage equipment if you don’t know what you’re doing. In a lot of jurisdictions it’s technically illegal for you to do so. Legally you may need to get a permit, hire an actual real electrician to do the work, have it inspected, etc. before you can use one of these. So I’ll leave it at that.

Money Stuff luxurious headquarters

During the weekly staff meeting here at the palatial offices of someone brought up the topic of maybe looking into some tax credits or something if we did a solar power system, so we’re looking into that to help offset the cost of putting in a 10 – 15 KWh battery system with something like a 8 KW or larger inverter fed with 48V batteries. We’re currently in the planning phase of that. With our electric bill running $300/month here, a decent tax credit and other factors it’s beginning to look as if it might make sense economically to install such a system to take at least part of the house’s needs off the grid.

Gardening Stuff

We already have most of our garden planning done, all the seeds bought already, and are just waiting for the weather to get better so we can get out there and start puttering around in the dirt again. We have a lot of plans, but whether or not any of it will actually get done is something else again. Some of the plans are on the expensive side and if we go ahead with the solar project that might eat up a lot of our discretionary budget for the year. So we’ll see.

And that’s about it for now.

New Email, Solar Panels, Last Bluetti Article

My AC200Max with a B300, 3,000Wh expansion battery

I want to do one last article about the Bluetti AC200Max before I move on to other things. I’ve been doing a lot of research into solar power systems, have my own solar power system up now, well, sort of, and I wanted to talk about trying to use one of these in an off-grid situation.

First, though, has a new email address. It is If you have questions or comments about any of the stuff you see here or even suggestions for future articles you can reach me at that address.

Now let’s get on with what I hope will be the last Bluetti article for a while. I’ve tested this thing with one B300 3KWh expansion battery (you can add two of them) and it’s handled everything I’ve thrown at it. It is working exactly as advertised and I’m very pleased with it. With the extra cost B300 ($2,300) battery it now has 5KWh of power. Preliminary testing indicates that it could keep the furnace going for at least 24 hours, maybe as long as 36 hours. And it will keep our sump pumps going for 2 – 4 hours in heavy spring rains depending on weather conditions.

But one thing I didn’t talk about much was recharging this beast. 5 KWh is a hell of a lot of energy to pump into a battery pack and eventually this thing has to be recharged. That’s where I start to run into what could be potential bottlenecks for some people, especially someone trying to use this as their primary power supply in an off-grid situation.

It comes standard with a big AC charging brick that will put 450W into this unit to recharge it. That’s a lot, but this is also a massive battery which means it’s going to take a considerable amount of time to fill it up from empty. With my system it would take the AC charger alone more than 11 hours to fully recharge it. If I had the 2nd battery pack for a total of 8KWh it would take almost 18 hours to do a full charge. Frankly I think that’s woefully inadequate.

Now I could fudge and fiddle around. The B300 battery has its own AC charging port.I could get a second AC charger and dump another 450W into the battery independently of the AC200Max to get a total 0f 900W AC charging. That would bring the charge time for my 5KWh system down to about five and a half hours.

But they call these things “solar generators”. Where the hell is the solar part of all of this?

Well you generally don’t get the part that actually makes it a solar generator, the solar panels. Those are an extra cost option. Companies like Jackery and Bluetti will gladly sell you their own branded portable folding solar panels. For a price. A really, really big price. Generally two or three times what it would cost you to get the same wattage in generic panels you bought off Amazon or somewhere. Here’s an example.

Bluetti will sell you this:

That’s the PV350. It’s a folding panel intended for temporary use. It folds up into a nice neat package, gives you up to 350 watts of power to dump into your Bluetti, and from all the reviews I’ve seen of it, it is very, very nice.

But dear lord, that price!!! $850 for only 350 watts of power? Seriously? And I’d need two of these things because with just one of them it would take 15 hours to recharge my system. It’s winter here in Wisconsin. The days are short, the sun is low in the sky. We often have clouds. With just one of these panels it would take something like three days to fully charge my system in the winter. And that’s if I wasn’t using the system to power something. Even with two of these panels it would take me more than a day to recharge because I only get about 5-6 hours of usable sunlight a day this time of year.

So I did some shopping around and a great deal of research and finally came up with these:

That’s a set of 4, 100W panels from a company called HQST. So I could get two four panel sets for a total of 800 watts for $550, or I could get two PV350 for a total of 700W for $1,700.

Guess what I bought? Damn right. I may be crazy but I’m not stupid.

Yes, I know that’s only six. There’s a reason why I could only hook up six at first. Read on to find out what I ran into.

And the panels themselves are actually really nice. They’re well made, sturdy, small enough and light enough to be easy to handle. And best of all, they work pretty much exactly as the company claims they do. And I now have all 8 of them outside leaning up against the south side of my garage all hooked up and feeding power into the basement.

Hooking up solar panels is about as easy as it gets. Most of them come equipped with MP4 connectors that just snap together. It’s pretty much impossible to wire them wrong. They just daisy chain together in series, plug in the cable to go to the basement. The AC200Max comes with a pigtail that has MP4 connectors on one end to go to the solar panels, and a T90 connector on the other that plugs into the AC2ooMax. And that’s all there was to it. It took me less than half an hour to set up six panels, hook them together, run a cable into the basement, plug it into the Bluetti and start sucking up all that yummy free solar power.

Well, sort of. I ran into some limitations which kept me from using all 8 panels, but let me tell you about the realities of solar power first of all.

The first thing I learned is that I will almost never get the maximum rated power out of those solar panels. Oh, they don’t lie when they give you those numbers. But you need to remember that those ratings are done in a laboratory under ideal conditions. Conditions that you will almost never see out in the real world. Especially not in Wisconsin. In February. I had 600W of panels out there but the maximum I was getting out of them was about 400W, and that was only for a couple of hours around midday.

Still, the system was working. I tried running my office/radio shack/mad scientist’s lab in the basement off the Bluetti and feeding it power from the solar panels and it worked quite well. By about 9:30 in the morning those six panels were producing enough power to run my little office, about 240W, that would gradually go up during the day, peaking at midday around 400+ watts in perfect weather, then dwindle until about 3 when power production shrank to under 100W. I was running my office entirely off those panels alone for about 3 or four hours in good weather.

Why Only Six Panels

Okay, let’s deal with that situation. The AC200Max has a built in solar charge controller. It is rated at up to 900W, 145V, 15A. Those are the maximum numbers it can handle. If you exceed those inputs by more than a small amount either the system just won’t use the extra or, even worse, the charger will just shut down to protect itself.

So now we need to do some math. Don’t worry. It won’t hurt. Much.

My panels were hooked in series, like in this diagram below.

It’s quick, it’s simple, and it works well. But as you can see from the diagram when panels are hooked together in series the voltage of each panel you add to the string is added to the voltage previous panels, and eventually you get to a voltage that the charge controller can’t handle.

My HQST panels have an open circuit voltage of 21.6. Six panels in series gives me a voltage of 129.6. The AC200max can handle 145V so that’s just fine. But if I add a seventh panel? 129.6+21.6=151.2. And 151V is over the 145V limit. So I can’t have more than 6 of these panels in series without going over the limit.

So how can I stuff more watts into this beastie without going over that limit? This is where parallel wiring comes along. Here’s another diagram for you to look at.

When connected in parallel, the amperage of each panel adds up, while the voltage stays the same. My panels have an amp rating of 5.5. So I could put two panels in parallel and remain under the 15A max rating of the Bluetti. In effect I’d have a single 200W panel producing just 21.6V at 11A, well within the Bluetti’s limitations.

So I started doodling and came up with this.

I’d create 4 banks of two panels each connected in parallel. Each bank would have 21.6V and 11A. Then I’d connect all 4 banks in series. That would give me all 800 watts they could produce, I’d have a voltage of 86.4, and my amperage would be 11. Of course I didn’t have the right connectors to do that and I’d need some extra cable so it was off to Amazon and a few more bucks and a couple of days later that stuff arrived and I spent a half hour or so switching from series wiring to my parallel/series sketch, hooked everything up this morning.

Then the moment of truth came. I crossed my fingers, held my breath and plugged it into the Bluetti and… And it worked? Wait, it actually worked???

Yeah. It worked. I was getting about 80V, the amperage looked good and the watts coming in… Well okay I was only getting 80W but it was 7:30 in the morning and the panels were still mostly in shadow. By 9:30 they were making 300W and by noon I was getting between 650 – 700 watts! Damn, it works!

As I said before my conditions here for solar are far from ideal, so seeing those 800W of panels peaking at 700 watts at midday was very satisfying.

And on the charging side of things? If I were drawing no power at all from the Bluetti and could get a consistent 700W solar input I could charge my 5Kwh system in a bit over 7 hours, which isn’t … Well I was going to say it isn’t bad, and I suppose it isn’t absolutely horrible but I only get useable sunlight here for about 5 – 6 hours a day this time of year, so it would take me more than a day to recharge this thing.

The Problems With Going Off Grid

Now let’s talk about going off grid. If you start scrounging around on YouTube and places like that you’ll run into videos from people who claim you can use the AC200Max like mine to go off-grid, using it as your primary source of power to run a small house or cabin or whatever, and replenishing the power you use entirely with solar. I have the Bluetti with 5KWh of power stored in it. I have all those solar panels. Why not try to run part of the house off grid and see what happens? So I’ve been experimenting with running my office/radio shack/mad scientist’s lab off the AC200Max and keeping it charged with just solar. And I’ll tell you right up front that it ain’t gonna work. I’m sorry, but it isn’t. At least not in the real world. Not without having to resort to some kind of additional power inputs from either the traditional grid or a backup generator of some sort. The numbers just don’t work. I knew that even before I started the experiment but I decided to try it anyway just to get some real world experience with the system.

My office uses about 270W of power as long as I’m not using my laser engraver or other energy hog piece of equipment. Just to keep things simple let’s round that up to 300W. That means that if I run my office for 10 hours I’d use 3,000Wh, with 2,000Wh remaining in the Bluetti.

So it’s the morning of the next day. I need to recover that 3KWh of energy I used the previous day. I have 800W of solar power but that only peaks at about 700W. But that’s not too bad. 7ooW of solar going into the system would recover that 3KWh in a bit over 4 hours. Great.

Well, no, not so great. First of all I only get those 700 watts for an hour or maybe two, during midday. The rest of the time I’m getting much less than that.

Second, I’m still running my office off that system. I’m not going to shut down for 4 hours to recharge the batteries. So even as I’m trying to recharge it, I’m drawing 270W. Even if I were getting 700W of power out of the panels, I only have a net gain of 430W. Recovering 3,000Wh with an input of only 430W gives a time of about 7 hours.

And I only get about 5 hours of usable sunlight a day this time of year.

And that’s with a load of only 270W. If you’re trying to use this system as your primary source of power running a furnace, refrigerator, some lights, etc. you’re going to be drawing considerably more than that.

So as I said, the numbers just don’t add up. This time of year, with the conditions I have here, with the amount of daylight I have here, I am never, ever, going to be able to get ahead with the amount of energy my solar system puts out. Even if I could max out my solar and put together a system that would pump the 900W maximum into the Bluetti it wouldn’t work. That would give me a net gain of 630W, and I’d get 3KWh out of the system in about 5 hours. But that’s assuming I’d get all 900W for that entire 5 hour period. And I won’t. Not even close. Not in Wisconsin, in February. With the standard solar charging system in the Bluetti I simply cannot dump enough power into it, fast enough, to get ahead.

Is there a way I can fudge things? Well, yeah. Sort of. The B300 expansion battery has its own solar charger built into it. Granted it is a pathetically wimpy one, only able to handle 200W. Trying to charge a 3KWh battery with 20oW is sort of like trying to fill a bathtub with a teacup, but it’s better than nothing. And if I’d add that into the 900W theoretical max I could dump into the AC200Max: 900 + 200 = 1,100W. 1,100 – 270 = 830. I’d now have a net gain of 830W. That gets us down to a bit less than 4 hours to recharge my system.

Now I’m finally seeing some numbers that almost make sense. Well, in July. In February I only have 5 hours of usable sun and I’m not going to get anywhere near peak production so I’m still going to be running at a net loss most of the day.

Bluetti will sell you a gadget they call a DC charge enhancer for $200. That would let me dump up to another 500W of solar into the AC200Max through its AC charging port. I build myself a third solar panel system, this one with 500W. I plug that into the charge enhancer, and that plugs into the AC charging port of the AC200Max giving me another 500W. 900 into the AC200 +200 going into the B300 battery +500 going into the charge enhancer = 1,600. 1600 minus my power consumption, 270W gives me a net gain of 1,330W. Now I’m looking at recovering those 3,000W in about two and a half hours.

Now, finally, I’m seeing numbers that would let me get ahead of the game. Peak solar production is only for around 2 hours at midday. But that, together with producing a bit more solar than I’m consuming the rest of the 5-6 hours of useable daylight I have, might get me to the break even point or even a bit better.

But only at the cost of building two additional solar panel systems, that $200 DC charge enhancer, cables, connectors, etc. But it should work.

Well until you get a day like today where we have solid cloud cover and my 800 watts of solar panels are putting out a whopping 80 watts of power.

So could you go off grid with the AC200Max and a couple of the expansion batteries? Uh, well, maybe? If your total power consumption was less than about 5KWh or so per day, and if you max out solar production by building extra solar arrays and adding in the DC charge enhancer and if you had perfect weather conditions to max out solar production.

But out here in the real world? No. Not without having to resort to some kind of alternative power source like a gas generator to help along in bad weather or help to cover unexpected power demands.

This particular system is great at what it is intended for, which is being a relatively short term power replacement during grid failures or to provide power for an RV or camper. It is not intended for use as an off grid system, long term, primary power system.

One more bit about solar power systems before I shut down this discussion and get back to more important things like fiddling around with gardens and photography and plants or wood and stuff.

Bluetti, Ecoflow and a few other companies make absolutely massive power systems that are intended to provide power for almost an entire home for lengthy periods of time. Some of them offer up to 18KWh. Eighteen thousand watt hours of power. If you really want to go off grid should you consider one of those?

Frankly, no. Those massive beasts look tempting, even will give you true 240V split phase systems. But the prices are just as massive as the battery packs. We’re getting up into price ranges and amounts of power where you should be seriously considering contacting a professional solar system contractor. A fully loaded AC500 system from Bluetti is going to be pushing $15,000, and that’s without a solar system to keep it fed.

And here’s another thing to consider. There’s no reason why you couldn’t save yourself a lot of money and build your own. LiFePo batteries have really come down in price. You can get a 2KWh or larger LiFePo battery for less than $700. You can get inverters that will handle a heck of a lot more than the 2,000W version in my AC200Max. You can get solar charge controllers to handle just about any configuration of solar panels and batteries you can build. And you can put it together with all off the shelf parts. And you can do it for a heck of a lot less than these plug ‘n play systems from Ecoflow, Bluetti and the others.

I’m seriously considering doing just that, covering the south facing garage roof with a couple of kilowatts of solar panels, putting a bank of LiFePo batteries in, getting a big inverter, and setting up a separate power panel in the basement to feed selected circuits in the house.

Well, maybe. I keep forgetting how lazy I am…

Bluetti AC200Max Update: This Time It’s All Good!

So, I have good news, and I have good news. Very good for a change.

First, regarding Bluetti customer service: Not only did I get a positive response from the company’s regular customer service department that was actually helpful, this morning I got an email from an actual engineer at the company to discuss specifics about the problems I encountered. As noted before the voltage fluctuation problem went away by itself but they’re concerned about that light flickering and wanted specific information about the brand, model and other details about that light so they could look into it. That’s not a big issue though because I believe the problem is related to that particular model light and that one only. All the others I tested had no problems. I suspect it is an issue with the design of that light fixture.

So that makes me feel a lot better when it comes to customer service.

My solar panels arrived! I ordered 4, 100W panels from a company called HQST mainly because they were very cheap. And it turns out that not only were they very cheap, they’re very good as well. It took me all of about 10 minutes to set them up leaning against the backside of the garage, one of them shaded by that stupid bush out there. And at the moment I’m getting almost 300 watts out of them (hooked in series) If I didn’t have that one panel being partly shaded and had them at the right angle relative to the sun I’d be getting close to the full 400 watts out of them. So I’m enormously pleased with that too.

Right now I’m getting between 250 – 300 watts out of ’em. We have some intermittent high, thin clouds that shade them out a bit which is why there is the fluctuation in output. I’m drawing 190W in the office at the moment running my laptop with 2 monitors, stereo speakers and a few other things, so the panels are making about 100W more than what I’m consuming here in the office.

I tried dual charging the AC200 as well, charging with the AC200Max’s AC charger and the solar panels and it was happily sucking down about 750 – 800 watts from both sources at the same time.

So I am enormously pleased. (Squeals like small child)

Bluetti Review Update

So far so good, but there have been some curious issues so I thought I’d throw this out there quick.

I was looking at the thing sitting there the other day and I said to myself, Self, it’s kind of silly having that $2,000 box sitting there doing nothing possibly for months waiting for a power failure. You should do something with it.

So I did. I took my entire radioshack/office/mad scientist lab off-grid with it. Well, sort of off-grid. My solar panels haven’t arrived yet so I still have to charge the AC200MAX off the grid but I wanted to see if it would work, and yes, it did. Quite well, with a couple of glitches.

Making the switch over was simple because all of my sensitive electronics are all plugged into UPS systems that include meters that tell me many things about the power coming into them, brown out protection, surge protection, etc. (I very strongly urge people to always, always keep their electronic equipment plugged into one of these instead of plugging directly into the mains. I lost a very expensive gaming computer due to multiple brownouts/power surges during a storm a couple of years ago. These things aren’t cheap but they can keep you from losing thousands of dollars of equipment.)

So I unplugged the UPSs from the wall and plugged them into the Bluetti and, well, everything just worked just fine.

Then I noticed that the meter on one of the UPSs was showing the voltage coming out of the Bluetti was shifting +- 2 volts, about 118 VAC to 120VAC. That was curious.

Something odd going on with the inverter in the AC200? Bad plug on it maybe?

I switched the flickering UPS to a different plug on the Bluetti. Did the same thing. I plugged it into the wall outlet. It showed a stead 119V.


I got out my meters and started checking things. My Fluke definitely showed that the AC coming out of the Bluetti was shifting +- 2 volts.

Now I should point out that a volt or two fluctuation in the current coming into my house from the grid happens rather often. In fact the electrical service coming into the house can go from a high 0f 122V to a low of 110V during the day.

That bothered me, though. I put the scope on the Bluetti and it showed the AC coming out was at a virtually perfect 60 Hertz sine wave, so that was okay.

I shut everything down. I started up the Bluetti again and the voltage fluctuation was still there. I did a ‘restore to factory defaults’ on the device and restarted it and tried it again. The fluctuation was still there.

And then later it just went away. I ran my entire office/lab/radioshack off it for two days, and the power fluctuations just went away. Why? No idea. Did it just need to, oh, stabilize somehow, to ‘burn in’? No idea. All I know is that all day yesterday the voltage coming out of the Buetti was an almost perfect 119V.

Then there was the light issue. I replaced the overhead fluorescent lights in there with LED versions a year or two ago. They give better light and use a fraction of the energy. I plugged one of those into the Bluetti and it flickered rapidly. Sigh…

I got out the meter again and expected to see the voltage fluctuation had gotten worse, but the meters were showing a solid 119V. I put the scope on it again. A perfect sine wave. Okay, now what was going on?

I plugged in a different LED light. That one worked perfectly. I scrounged up several more LED lights. All of them worked fine. Only my overhead tube lights flickered. As far as I can tell the problem is only with that specific light and no others.


Now let’s talk about radio. I’m an amateur radio operator as you probably know if you’ve been reading this blog for a while. Solar power systems and these battery inverters can be troublesome when it comes to causing RFI (radio frequency interference). So I was anticipating some problems, and I found them. This is what the scope on my Kenwood TS-990 shows when I’m running it off the Bluetti.

See those vertical lines? Those are not supposed to be there. They represent spikes of radio interference that appear at regular intervals throughout almost the entire HF range.

Now if you’re an amateur radio operator and that image up there just sent you into a panic, it isn’t as bad as it looks. At least not in my particular case. Yes, those spikes are nasty, but with my particular AP200Max none of those spikes appear in any of the amateur radio bands. Whether that will be the case with other units I don’t know. But in my case the situation is tolerable.

There is some more or less generic RFI coming off the thing that seems, in my case anyway, to be concentrated on 40 meters. 30M was completely clear, no RFI at all. 20M was decent, 17, 15, 12, 10 meters were all good. On 40 there was some significant RFI but not enough to prevent me from operating. And engaging the noise blanker on the transceiver knocked a lot of that out.

What the RFI situation will be like once I hook in the solar panels, well, we’ll just have to wait and see. But if necessary I could run my whole radioshack off the Bluetti with very few problems.

I did send a complaint in to Bluetti describing the issues I had with the light flickering, the voltage fluctuations and the RFI issues, including that photo up there showing the RFI problem. I got a canned response back that they would respond within 48 hours, so we’ll see.

Overall the test running my office/radioshack was successful. I discovered that I actually use surprisingly little energy in there. Typically less than 300W, which rather surprised me because that’s including a gaming laptop, two monitors, the Kenwood TS-990, big stereo speakers and a few other goodies. I didn’t try running larger loads like my soldering equipment, the 3D printer or the laser engraver. And, of course, when actually transmitting with the TS-990 the wattage went up considerably.

Coming Up

I have 4, 100W solar panels coming that should be here by the end of the month. I picked the cheapest ones I could find and I’m not expecting much out of them, but it should be enough to be able to test charging the Bluetti off solar. Well, if we ever get sunlight, that is. My eventual goal is to get semi-permanent solar panels up on the garage roof, as much of it as I can afford and fit up there. The roof faces straight south and it is already at nearly the perfect angle, and that location should provide me with solar through almost the entire day now that the trees around the garage are gone. I’d like to get at least 800 – 1,200 watts of solar up there this year.

The other thing I did was buy one of the expansion batteries for the AC200Max, the 3,000Wh one. That should be here by the end of the month as well That will push the capacity of the system to up over 5,000 watt hours. So watch for a review of that in the near future.

Comments and questions are always welcome!

A Look At The Bluetti AC200MAX Portable Power Station

I want to talk about how to keep the lights on when the grid fails, something a lot of people were thinking about when that major winter storm rolled over much of the United States during the holidays and then when another hammered California and the southern part of the country, leaving millions of people without power, and sometimes even trapped in their homes.

This is going to be a two part series. I’m going to talk about the AC200MAX first because there are several people waiting for the review of this device. The second part is going to talk about these portable power systems in general, why you might want one, and most importantly how to determine how to properly size it to suit your needs without wasting money and, even worse, getting mislead by the advertising.

These things are often mislabeled “solar generators”, but they are neither solar nor generators. If you buy the almost always optional solar panels to recharge these devices you could make the argument they’re solar generators I suppose. But these devices by themselves are really energy storage devices. Basically they’re a big box of batteries.

Bluetti has been around for a few years now and its PPSs (portable power stations) are generally rated well in reviews and so far my experience with the one in the photo above has been completely positive.

The model I picked, the AC200MAX has a capacity of 2048 watt hours, and it can handle a maximum sustained load of 2,000 watts, and can handle brief surges in demand of up to 4,000 watts. It has a built in inverter that converts the batteries DC power to 120VAC. There are four standard 120 VAC plugs on the front. It also has a 30 Amp 120V NEMA TT-30 connector typically seen in RVs that would let it power an entire RV.

If you have a device that needs power, AC or DC, the Bluetti has enough plug ins of various types to handle just about anything you might need.

It also has a variety of DC power ports including USB-A 5V 3A, two USB A 18W ports, a 100W USB-C port, a DC 12V 10A cigarette lighter type plug in port, a DC 12V 30 Amp port, and as if that wasn’t enough, there are two wireless 15W charging pads for cellphones on the top of the box.

Basically this thing has just about every kind of power plug I’ve ever heard of. All of the outputs have overload and short circuit protection. And no, I did not test that. I’m not about to deliberately short circuit a device that cost me almost two grand just to see if the protection actually works.

The two top connector are for the optional additional battery packs that can be added to give the unit a capacity of up to about 8,500 Wh. The blue cap covers the plug for optional solar panels. The lower right is the connector for the 500 watt AC charger that comes with the unit.

On the lower left side of the unit are there are two connectors to hook up optional external battery packs. Up to two optional battery modules, either a 2048Wh ($1,300) or 3072Wh ($2,200) battery packs can be added to the unit to that can give it a total capacity of more than 8,000 Wh. And that, folks, is a hell of a lot of energy to be packed into that small of a space.

Also on the left side of the unit are the charging ports. You have several options here too for charging. The unit can be charged by, well, just about anything. It comes with a 500 watt charger for topping off the AC200 from the grid and it will charge up the unit reasonably quickly. The single AC charger will replenish the AC200MAX in about 5 – 6 hours.

There is also a DC input port intended for use with an optional solar charging system. There is a solar charge controller built into the AC200. That port can also be used to recharge the unit from a car with an optional cable (I’m not sure how long that would take but at least it’s an available option).

If that’s not enough options for you and you need to recharge the AC200 even faster, you can pick up a second 500 watt charger and with an optional cable charge the unit with two chargers at once, one plugged into the solar charging port. Or you can charge it at the same time from a solar panel system and the AC charger.

If you plan on getting solar panels for recharging the device it can handle up to 145V and 15.2 Amps maximum without the need for an external charge controller.

The manual claims you can recharge this thing by plugging a cable into a car’s cigarette lighter. Considering those things only put out about 120 watts, be prepared to wait a while to do a recharge. But still it’s an interesting feature that might be useful.

Physically, this thing is a beast. It is as large and heavy as my Yamaha 2KW gasoline powered inverter. It weighs in at about 60lbs, and the physical dimensions are around 17″ X 11″ X 15″. At 60 pounds you aren’t going to be casually carrying this thing around. If you end up getting the optional expansion battery packs this thing is going to be seriously heavy. But the weight and size is typical for portable power stations with this capacity.

Oh, and I should talk about the batteries. This unit uses LiFePO4 batteries. The manufacturer claims that after 3,500 charge cycles the batteries should still retain about 80% of their original capacity. That means you could recharge this thing every day for 10 years and still have 80% capacity left.

The touch screen is easy to read. In the “home” screen it shows the basic status of the unit. Here you can see that the AC outlets are turned on and that something is drawing 368 watts of energy, and it has 99% capacity left in the battery. It was running the house’s natural gas furnace when this photo was taken.

Now we come to the control systems. Just left of the screen is a big ON button. Push that and after a moment it will boot up and the color touch screen turns on. The screen not only displays all of the information you need, it is the primary control system for the unit.

Before you can use it you have to specifically turn on the DC and/or AC power systems to make the plugs “live”. But once you do that it’s ready to go and all you need to do is plug in whatever devices or appliances you need to power.

Other information is also available on various screens including load statistics, the ability to switch the system to handle European or Japanese electrical devices which use a different power system, and a few other goodies.

And there is a free app you can get for your phone that allows you to monitor what the Bluetti is doing. It is Bluetooth only, the device has no WiFi capabilities, so the range is limited. I was able to keep in touch with the Bluetti with my phone anywhere I was in the house, garage and even much of my backyard.

How well does it work?

If you thought all of the above was boring, you’re going to find the actual in-use evaluation of the Bluetti even more dull. It just works exactly as specified by the manufacturer. No drama, no problems, no issues, nothing. It just did everything it was supposed to do without any problems at all.

The primary use for mine is to provide backup power for two essential systems in the house, our gas furnace and our sump pumps. So that’s what I’ve been testing it on.

A gas furnace doesn’t use a lot of electricity, just enough to keep the thermostat system operating, which is minimal, and, of course, the blower fans. The actual heating is done by the combustion of natural gas. A natural gas furnace doesn’t use a great deal of electricity, generally in the 350 – 700 watt range. The electronic igniter that actually lights the gas uses some electricity of course. Rather a lot, in fact, but it works for such a short period of time that it isn’t that important.

My furnace was already set up to be used with our backup generator so I didn’t have to do any additional electrical work to make it possible to power the furnace alone. All I have to do was turn off the furnace, plug in a single electrical cable to switch from grid power to the Bluetti, and turn the furnace back on again.

Sidenote: I am going to give the usual disclaimer here. Consult with a licensed electrician before trying to make any modifications to your house’s electrical systems. Yes, I know house wiring isn’t that difficult to deal with, but unless you know what you’re doing you can end up in serious trouble or even dead if you screw something up. Then there is the legal issues to consider. A lot of jurisdictions require a licensed electrician to make any significant changes to a home’s electrical systems. There are also issues when it comes to your home owner’s insurance. If there is a fire in your home and subsequent investigation reveals that the home had electrical modifications that did not meet building codes or that were not performed by a licensed electrician the insurance company may refuse to cover the damage.

So, how did the Bluetti work while powering the furnace? Exactly as I expected it would. It handled the furnace easily with no issues at all. As my research indicated, the furnace required about 350 – 550 watts during operation. The wide range there is because this model furnace has a variable speed blower fan.

After 3 hours running the furnace the Bluetti still had 78% capacity left.

Once you know how much power a device draws, figuring out how long a battery system will run that device is pretty simple. The Bluetti has a bit more than 2,000 watt hour capacity so it should be able to run a device that needs, on average, about 400 watts, for about 5 hours. But that’s assuming that the device will be running all the time, and the furnace isn’t running constantly. The fans only run when the furnace’s burner is actually in use. On the day I did this test after 3 hours of operating the furnace the Bluetti still had 78% capacity, far better than I had anticipated.

So in actual testing, with those particular weather conditions, with the thermostat set at 67F degrees, the Bluetti should have been able to keep the furnace operating for around 12 hours.

Those numbers are under a specific set of conditions that could change quickly, of course. The weather was relatively mild with outdoor temperatures about 30F and very little wind. During colder weather and higher winds the furnace would run more often and for longer periods of time in order to maintain the temperature in the house. That, of course, would deplete the Bluetti more quickly.

The other intended use for the Bluetti is to keep the sump pumps going. We had part of the basement flood because of a sump pump failure here some years ago and we do not want to go through that again. I now have a backup pump on the shelf along with all of the tools and plumbing parts I need, and I changed the whole system so I can swap out a pump in just a few minutes. But in case of a power failure that isn’t going to do me any good. And since power failures often happen during storms when we’re getting heavy rain, they can happen at the worst possible time when we need the pumps the most.

Sump pumps require considerably more power than the furnace. The pumps I have require about 700 watts to run, but they run only intermittently. In addition to that load, there is a significant surge current when the pump first starts up, with can hit 1,300 watts for a few seconds.

I picked the capacity of the Bluetti specifically so it could, hopefully, handle both sump pumps at the same time. It can handle a current demand of up to 2,000 watts, sustained and the pumps together would take about 1,400. The PPS can handle a surge demand of over 4,000 watts. In a worst case scenario the two pumps might start at exactly the same time so there would be a momentary surge demand of about 2,600 watts. So it should be able to handle both pumps, at the same time, even if both pumps start at the same time.

I did test the Bluetti running the pumps. I already knew that because of the surge load and increased power requirements I would get much less actual runtime on the pumps than I would with the furnace. And I was a bit anxious about it being to able to run both pumps at the same time, especially if both started at exactly the same time. I’m pleased to report that it was able to handle both pumps with no problems. The Bluetti’s internal cooling fans did come on while running the pumps, but that was expected and normal.

During an actual rainstorm situation the Bluetti wouldn’t be able to keep both pumps running for more than an hour or so I estimate, but that’s all I need from it. I want it to give me some breathing room, carry the load for a while until I have a chance to get one of the gasoline generators running. My big Generac is cranky and hard to start sometimes, and even my little 2KW Yamaha inverter takes a while to get set up in a good location outside and run a cable down to the basement.

Could it run both of the pumps and the furnace at the same time? Well, maybe? That would be pushing the Bluetti to its full capacity, though. Theoretically it could. Total sustained demand running all three at the same time would be about 1,900 watts, maybe a bit more, really close to it’s top limit of 2,000 watts sustained load, and in a worst case scenario where both pumps and the furnace would start up at exactly the same time the surge load would be pushing the theoretical limits of the device’s maximum surge capacity.

Hopefully that won’t be necessary to deal with. Usually during the heating season the pumps don’t run at all. They’re generally only needed in the spring, summer and fall, and then only when we have a significant rain event.

Now, what about recharging this thing? At the moment I’m using the grid powered 500 watt charger that came with the unit. Bluetti will sell you solar panels that are capable of recharging this unit in a reasonable amount of time, but there are problems with that system. First it’s expensive, Buetti’s system will cost you $800+ for enough capacity. And even worse, these are portable, non-weather proof and not intended to be left outside. They can’t be left up in rain or snow. That’s not what I’m looking for. I want to set up a solar charging system that will be more or less a permanent installation that I don’t need to worry about. I’m still looking into that. I’ll probably set something up this spring when I can get outside to work.

So let’s sum everything up. The Bluetti AC200MAX is a very well made piece of equipment, it works exactly as advertised. I’ve encountered no problems at all with it during testing. It has met and even exceeded my expectations all the way around and I am very pleased with it. Yes, it’s heavy and awkward to lug around but so is any PPS with this capacity. It just plain works, and works well.


This thing ain’t cheap, and this may be a deal breaker for a lot of people. The Bluetti model I’ve been talking about cost me, including taxes, $2,000. That’s a heck of a lot of money, especially when you can get a gasoline powered generator with the same capacity or even more for a quarter of that price. So before you buy one of these you need to consider all of your options and what your needs are.

In our case here, we feel it was worth the money even though we have gasoline powered generators. The Bluetti takes some of the panic out of the situation. If necessary it could keep the essentials, the furnace and pumps, running long enough to give me a chance to get one of the gas generators set up and running. And I was also thinking of MrsGF if I didn’t happen to be home when there was a power failure. There’s no way she could get the big Generac set up and running by herself and there’s a good chance she couldn’t get the little 2KW Yamaha running either. With the Bluetti all she has to do is turn it on and plug in some electrical cords and she has some time to figure out what to do. And she would have some, oh, buffer time, let’s call it, to possibly get out the little Yamaha generator and get it running to take over if the outage lasts more than a couple of hours.

Long Term Plans

I’m looking into a solar panel system to keep it charged but at this point I don’t know what that is going to be. I want something that can be semi-permanently mounted on the roof of the garage where it is out of the way and I don’t need to worry about it. I’m looking for a system that would give me a minimum of 800 – 1,000 watts and that would be easily expandable because I’m seriously considering trying to make at least some of the household independent of the grid, not for any particular reason but just because I want to.

I’m considering getting another PPS, not necessarily another Bluetti, and using that as the primary power source to run my entire combined office, radio shack, electronics work area, charged by solar panels on the roof and/or on the south facing wall of the garage. How far that project will go depends on how ambitious I get and what my budget looks like.

Comments and questions are always welcome.