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.

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.