AIMS 4000W 12V Pure Sine Inverter Charger w/ Transfer Switch 120V ETL

Last year, with no experience in this field, I purchased a Power Bright 3,500 watt modified sine inverter for my motorhome conversion from generator to battery bank with solar. The Power Bright was a good unit for the price but the output voltage varied with battery voltage all the way down to 88 volts. The Power Bright unit also didn't play well with my microwave. I came to the conclusion that I needed a pure sine inverter.I found that there are two types of pure sine inverters. The cheaper smaller ones are high frequency. The AIMS PICOGLF20W12V120VR is a low frequency inverter. Low frequency inverters have tremendous starting power. This unit is rated to hold 6,000 watts of starting power for 20 seconds. The high frequency inverters are usually only rated to hold twice their power for less than a second. This unit easily starts my rooftop air conditioner which takes about 4,500 watts to start but settles back to 1,200 watts in operation. The difference is that this unit is very heavy. It's heavy because it has a large copper wound transformer in it - you get what you pay for.Why was I willing to go from a 3,500 watt inverter to 2,000 watt? I learned that you can only draw so much current from a 12 volt system without generating tremendous heat. Under a constant 2,500 watt load, my heavy 2/0 welding cables and connectors would get very hot. I would say that it's impractical and perhaps dangerous to draw constant loads over 2,500 watts from a 12 volt battery system (Update: I used 2/0 welding cable throughout, marine quality bus bars and switches, and fused both sets of batteries (200 amp) as well as the inverter (300 amp). Also all of my 120 volt appliances are under 2,000 watts continuous. The microwave is 1,200 watts. Coffee maker and toaster about the same.My other issue was voltage. Whereas the modified sine inverter's output voltage declined with battery voltage, the Aims unit holds a nice 121 volts AC at 60 cps down to battery voltage cutout.Overall I believe this AIMS unit is an extremely well built, high quality unit. It has large connector posts for your 12 volt cables. The connectors for wiring 120 volt input and output are also high quality. The indicator lights on top of the unit are nice but for my application I purchased the REMOTELF remote display. There is also a little rheostat type dial on top which you can use to adjust how much of your 120 VAC input goes to charge and how much gets passed through (Update: This is a very important feature if you have a smaller generator My 2000 watt inverter generator (1,600) continuous will trip the breaker at the full 70amp charger draw. I can adjust this to load the generator at about 75% for a two hour charge). The transfer switch is very fast and doesn't drop loads when switching from house power to inverter or inverter to house power. The fan is quiet and only runs when there is a significant load or is charging at a high rate.The unit does draw substantial idle power. It does have a power saver mode but this works by cycling power into the system every second or so. Problem with this is that my refrigerator doesn't see the power when deciding to use electric or gas so goes to gas. My other problem with it is that my microwave seems to have some type of relay in it that clicks every time the power cycles. The power saver was impractical for me to use so I just turn the inverter on from the remote when I need 120 VAC.This unit has 1 more dip switch than shown in the manual. Also has a couple of green wires hanging out the back that look like they could be connected together or to external wires. I had no idea what they were for except some type of ground. I called AIMS and there customer service was very responsive. They told me that I should connect them for a motor home application but I still don't understand why. (Update: I've since learned a bit more about electrical and these two wires are connected to bond your 120 volt AC neutral to ground) It wouldn't hurt them to put out an addendum to the manual with the changes to the unit since the manual was printed and some explanations such as what the functions of these green wires are and when they should be connected or not and why. The manual could be much better.Just took my 4 dogs out overnight in my Class C with the new solar installation and AIMS inverter. Found a nice isolated meadow on the eastern slope of the Washington Cascades about 40 miles from home. Turned on the AIMS inverter and popped some microwave popcorn (not good for you). Woke up at 5AM, let the dog's out, turned on the AIMS and made some coffee. Happiness in my old age.

Now, I have only had this inverter for about a week now, but so far I am extremely impressed. I normally wait a few months to write reviews, but I really wanted to share my opinions. Let me also say, I have never really been a fan of inverters in general, because they always seem to fail, or fault out on constant alarms. Let me also state that ANY inverter is only as good as the battery bank you have hooked it up to. There is no way you will get the rated output if the batteries can't handle itMy setup is as follows in my mobile service truck- 9 group 31 batteries (each is 950 cold cranking amps, not positive of the amp hour rating though) hooked up to my service truck's charging system... so essentially, the batteries are being charged whenever the truck is on. From there, I have 4/0 battery cable going from the batteries to the inverter, and from the inverter, I have 12awg wiring feeding my a/c grid in the truck. Now, this inverter has been able to run the following, not all at the same time of course, but none the less:- Air compressor- Vacuum pump- 3/4 hp oil pump- 4 Fluorescent light fixtures (256 watt total)- Microwave- Electric tank band heater (draws 1500 watts)- Electric heat gun (1000 watt)- Electric grinder- Recovery Machine-.... on and on...The air compressor was my biggest concern, as it takes a huge surge to start it up. The air compressor spikes at 152 amps (18,240 watts) only for split second upon startup, then comes right down to about 13 amps (1560 watts). I am surprised this inverter can handle that. I have not had one issue as of yet.Basically, this inverter can run everything in my truck. Very very impressed. Now, you can have everything on at once, nor do I need to, but this inverter can certainly pull it's weight and it useful per it's rated output. I also think that because this is a pure sine wave inverter, everthing runs quieter and smoother. With a modified sine wave inverter, I would notice some humming coming from the electrical devices, to the point where I was concerned about damaging the devices.Also, this inverter has a built in "standby mode". Which means that the inverter will have very minimal draw (25w) until an electrical load is detected, which then "wakes up" the inverter and it starts putting out power. After you turn all loads off, it goes back into standby. Very impressed with that feature too. At the beginning of the day, I'll switch on the lights (takes a couple seconds for the inverter to recognize the load), then the inverter starts up and runs no problem. At the end of the day, I turn the lights off, and the inverter shuts off. Perfect.I have not checked out the charger aspect of this inverter yet. Like I mentioned, this setup is on my truck, so the batteries are always being charged. Sounds like a good idea though.Overall, if you have a good battery bank and good size cabling, you should not have any problems with this unit. Again, I have only had this a week, but it has blown me away with how well it performs. If anything should change, I'll be sure to update this review. Hope this was helpful.

I have had this .... doorstop ... for about two years, and I cannot in any way recommend it.We live off-grid, in a low-footprint model. This device was intended to serve our power needs, but also charge our batteries with a generator, if the sun vanished for a few days - which, living in the sticks of the East Coast of Canada, it does.I have developed the same issues as other AIMS models (I thought I had done my research, but alas): it overheats, and cannot generate any notable power without shutting down.The first issue came about a year ago, when the fan simply died. Fortunately, I had access to a spare computer, and was able to install a new fan. Then in August of this year, I tried out an induction element, which draws a max of 1,200 watts. At the time, the fan came on, and stayed on all the time - which, given that we live in 500 square feet makes for a bit of noise.Last week, the inverter overheated and shut down, while in the generator mode. The negative terminal now grows incredibly toasty at the slightest application of power, either charging or discharging.Today, it overheated and shut down twice: it now can't even handle a 250 watt crockpot.DO NOT BUY. I spent $800 CDN on a piece of junk that gives out about as much power now as an old 300w Morningstar. Should have gone with an Outback or Xantrex. My old Prosine could power the woodsplitter without issues, this thing shuts down instantly.As a guy with a fair bit of electrical savvy, I have replaced the fan myself (again). However, I expect it to last about a year or so, before it bakes again.Oh, and a further update:: the plastic bridge that allows hard-wiring has melted, and the customer service department has ignored any queries. Again.