Ampinvt 1200W Pure Sine Wave Inverter with AC Charger, DC 12V to AC 120V Output,UPS Backup Power Low Frequency Inverter for Lithium, Sealed,AGM, Gel,and Flooded Batteries

I purchased this to upgrade the modified sine wave inverter/charger in my RV. Its power output was a bit higher than my current system, it can be set for LiFePO4 batteries, and of course it provides a pure sine wave output (did you know that a "modified sine wave" will destroy the speed controller in a KitchenAid mixer? Well, now you do...). Unfortunately, it is not a good fit for this application, because the maximum battery charging current (the "converter function" in RV parlance) is only 15 amps. This means that after boondocking for a couple of days, or even while plugged in at an RV park, the house batteries will take a long time to fully recharge, and if there's much load in the coach, they'll never recharge and could likely discharge further. For this usage, the charger/converter really needs to be able to source well over 30 amps - 50 amps is way better. For a stationary UPS setup though, this unit is fine. The recharge rate is not so critical in this application, because the batteries aren't supplying the load while on city power. Also, the changeover from city to UPS power is extremely quick - less than a single cycle (17 msec). There's no drop-out at all during switch-over, just a bit of a glitch in the waveform. The fan does run at slow speed all the time, and it's not silent, but that's not a problem for me because it's installed in an equipment room with lots of other fans running too. I haven't run the unit at full load, so I don't know if complaints in some other reviews about not achieving full rated power are valid. It would be easily possible for some of those issues to be caused by drooping incoming 12-volt power (loose connections, too-small wire, or inadequate/discharged batteries). In my (new, re-purposed) application of an electronic equipment room backup, when paired with a 300 Ah LiFePO4 battery, it works great. A couple of other reasons the unit was able to hold onto its five-star rating: The display shows genuinely useful information - AC input voltage, battery voltage, load current. It also makes a guess about the battery state-of-charge, but it's usually wrong... It's also quite efficient. Its power draw in inverter mode when completely unloaded is well under an amp, which is certainly OK for sine wave inverters. (I have another one that draws 3 amps - 36 watts - continuously, even with no load.) Of that idle current draw, I bet at least half goes to keeping the fan running, which could have been optimized. The unit has another mode in which it powers up briefly every 10 seconds to see if there's an AC load, and if not, powers back down to very low draw. This could be useful in some applications where the load is constant when switched on, but may be off for prolonged periods (like a sump pump), and would wring a much longer life out of the backup battery bank. However, for more general ad-hoc applications, such as a cabin backup, the regular "AC-priority" mode, or possibly the "unattended mode", would be better. The "unattended mode" acts just like AC priority mode in that city grid power is used if available, or inverter power if not. In this mode, however, if the batteries get too low it goes to a very low power mode, then returns to inverter mode when the batteries are recharged some (via solar, for example). Just about perfect for a remote cabin with flakey city power and some solar panels. The unit appears to be conservatively designed and well built, and well laid out for convenient wall installation. There's an RS-485 port that should be useful, but I was unable to get any information about its communication protocol, so ... not so useful after all. All told, I'm quite happy with the unit in its UPS application, and I may end up moving it to a little cabin/pub I'm building in a remote corner of my property... ;-)

I bought the 1200W unit to use as an emergency power backup for when our house loses power in snowstorms. I primarily have it powering a blower on a gas fireplace and some LED lights, and one standby outlet in case we need to plug in a phone or something. In light of other reviews, the very first thing I did was wire it up and test the AC outlet on it to make sure it was wired properly. It was, so hopefully they've fixed the minor assembly error. While I was at it I tested the rest of the terminals and they all were correct too. As others have said, the unit itself is fairly heavy and the terminal screws are tough to get to when mounted, so best to connect the cables to it first and then mount it where you intend to put it. I made sure to attach it directly to studs, there's no way drywall anchors would safely hold this amount of weight. I paired it with a 100Ah LiFePO4, set the charging voltage to the recommended voltage for the battery, and run it in "AC Priority" mode and it works seamlessly. The display does incorrectly show the battery at "70%" when it switches to DC power, since the battery voltage is ~1V lower under load/rest than it is while charging. But I consider that to be par for the course for these types of things. I let it run my blower and lights for 3 hours and the charge hadn't dropped 1% yet, so it's working fine. The fan does indeed run all the time when the unit is on. I have it mounted in my heated garage with a bunch of other equipment so that's not an issue for me. I experimented with running it in "ECO Mode" but it wants a larger current draw than I'm providing at idle in order for the inverter to run. If you don't draw enough power in ECO Mode, then it cycles on and off in about 4 second intervals looking for a load. That struck me as suboptimal so I'm just going to use it in AC Priority mode like a typical UPS. The manual is a little unclear on this, but the setting for "Battery Charge Current" is settable in 20% intervals up to "100%", with no indication of what that current is. It seems 100% is 15A @ ~14VDC, so it adds about 2A to the 120VAC load it's drawing from the line circuit when it is charging the battery. Take that into account for your AC load capacity feeding the unit. Overall, exactly what I needed and I'm happy with it.

I replaced a APC UPS that did not do the job. The battery wore out in a bit over a year and even then I only had 10 minutes of backup from the first day. This AMPINVT 1200W is a huge upgrade for a total of $500. The machine appears to be very well made. Instructions are clear for installation. It took about 90 minutes to set the entire system up. I love it! I will add that the fan is quite loud as mentioned in other reviews. It is not as loud as my video makes it seem, but definitely needs to be in a different room. You’ll want it out of sight any way, so not an issue for me. I do wonder why it is so loud and why it has to run all the time since the default is a pass through AC current. I am running a router/modem, 2 PCs and a NAS, all with SSD storage, so not much demand on the system. Probably overkill. I could have saved $120 by using only one battery.

This power inverter is exactly what I was looking for. Maybe I could have used a 2k watts but Amazon didn’t have available at the time of my purchase for a reasonable price. Handles power very well as my regular usage loads this equipment within 10-17% of load. Something that brings my attention is that keeps running the fan since I connected and turned on, not sure if this is normal or is a defect so I took a star down due to that. Testing the device didn’t notice any interference on equipments used while power source output was on the inverter this translate into pure sine wave electricity which is what I wanted. I will update in the future I have or found any issue with this unit. Important detail is that I am running this with lithium batteries and the charge is enough for them.

Currently using to help offset some of the power usage of a cold plunge we have outside. We had some solar panels and 12v 280AH LiFePo4 and Victron solar controller for emergency power in case of power outage but they stayed unused most of the time. I was able to fit the battery, solar controller, breaker, and this inverter into a 50 gallon plastic deck box (with cut out vents). I'm using a 12 AWG extension with exposed wire for the grid connection. The cold plunge pulls around 660W with compressor and pump running and this handles it fine. I have it running in Battery priority mode, so once the battery is above the turn-on voltage (set in the inverter), it starts to use the battery. If the sun is out, that also means it uses the battery and solar charger output. It will run until it hits the cutoff voltage (set in the inverter). Then it starts over once the sun charges the battery back up enough. Some notes: - the battery voltage that the inverter reads (and therefore the voltage used for turn on/off) changes based on the load. If the pump is only on (roughly 120W), the voltage is pretty close. If the pump and compressor are on (660W), then the voltage is roughly 0.3V off. This is with 1/0 cable. It was 0.4V off with the included 6 AWG wiring. I haven't opened it up to see what wiring gauge is used from the input terminals so I wonder how much of the voltage difference can be attributed internal wiring. This ends up affecting the turn-on/off voltages. If I'm pulling 50 amps, then the inverter may end up switching the mains power sooner than expected. But if it's pulling 10A, then it gets to use more of the battery capacity. I ended up having the cutoff voltage as 12v and turn on voltage as 13.5V. - Anytime you go into the inverter mode setting, and change the voltages, it will set your charging current back to 0% Initially I wanted the battery to slowly charge from the grid so I could use it again, but then thought I'm basically losing some savings because no charger is 100%. So I ended up not minding the 0% charging reset. But it caught me off gauge the first time. - As of now, the cold plunge's integrated GFCI plug doesn't mind the switchover time between battery and mains (the plug resets if power is lost), so the switchover is fast enough, but not sure how fast the switch over is for other more sensitive electronics. I could definitely see this being useful as a UPS for more remote items as long as there is a battery and solar. Ik currently only using it at 50% capacity but it's been find for that, plus working as a power outage, if needed.

14 MARCH 2026 I am updating this review to report a major flaw in the charging logic of this unit that resulted in the destruction of my battery bank. The Problem: Constant High Voltage The "SLA" (Sealed Lead Acid) setting on this unit is incorrectly programmed for long-term maintenance. While the unit’s display reported a "97% Charge" and indicated a stable status, it was actually maintaining a constant 14.4V. It never dropped to a safe float voltage of 13.2V–13.8V. The Discovery: I discovered this by accident when the unit was unplugged and forced to run on battery power for a period of time. The unit alarmed at 10.5V. Up until that moment, the display had reported the bank was healthy. Because the unit indicated it was in a maintenance state, and the environment was climate-controlled, there was no reason to suspect the unit was actively overcharging the batteries. Physical Damage: Upon inspection, I found the roughly 20kWh bank (sixteen Interstate SRM31 batteries) had been "cooked" by the constant 14.4V charge over the last three years. Each battery required between 1.6 and 2.2 Liters of distilled water to refill. The electrolyte is murky with debris shed from the plates. The plates are physically compromised and the bank can no longer hold a charge reliably. Many had shorts already after the first test sequence. Owner Advisory: The hardware itself is durable, but the charging presets are a liability. If you use this for a lead-acid bank, do not use the SLA preset. You must use the AGM or Manual configuration to ensure the unit actually drops to a float voltage below 13.8V. Original Review: 2 Years of Continuous Use And Still Working! (1200 Watt Version.) I am using two 1200 watt versions. They have been hooked up continuously for two years now charging two separate 8-battery banks comprised of 12V deep cycle SLA 97 AH marine batteries that were all purchased at the same time. I did this setup to have backup power that could be charged and maintained via a/c power and act as a backup for key systems. It does so by immediately switching to battery power when wall power goes out. When there is power from the wall the unit output functions as a pass-through for that power while also keeping the batteries charged or recharging. It has worked so well that I am buying their solar chargers too. So, here is my setup and what you might want to know: 1. There is a setting in the instructions on how to set up for Standard Lead Acid Batteries. After doing some research I decided to pair 8 deep cycle 97 Amp Hour 12 Volt Marine batteries with each unit. You have to set the the charge current at 80% from what I recall but I cannot find the settings right now to verify. This setting matched the charging current to the battery bank size and type. You just hook them up in parallel. I also purchased short and thick gauge connectors from Interstate Battery. After that you hook the positive lead from the charger to one side of the bank on the positive terminal and the negative end to the other end of the bank on the negative terminal. This will keep all batterie in an even state of charge. 2. It costs around $8/month to keep the batteries topped off at around $0.14/kwh. 3. When the power goes out this thing does not miss a beat. You cannot even tell. No blips no nothing. I have security cameras, deep freezers and incubators plugged in and they just keep running as if nothing happened. 4. Two year old SLA Deep Cycle batteries are at 97% charge state according to the display. 5. The only bad part is the relatively loud fan. I have my banks in two parts of the house so hear them a lot. The good news is they run slower most of the time. There seems to be different speeds. After a while the noise drones in the background and is only noticed when the speed changes. 6. You will need to buy a three-pronged plug and wire to get power from the wall to the unit. I checked the configuration beforehand and found that it was fine and not reversed as some people reported with the 800W version. That was just not the case with the 1200W units.

Using this with a LiOn battery as a large capacity UPS. Fast switching when power fails and is adjustable for many different types of batteries.

Test of 1200 watt Ampinvt low frequency inverter supplied by Dumfume 100 AHr lifepo4 bubattery operating 8000 BTU Midea inverter window air conditioner. Inverter Load is 35%. Inverter is $165, battery is $150. AC uses 435 Watts at 107 volts. 4.8 amps. This is just a trial for an installation into a cabin bedroom. I have a 3 kw and 5 kw inverters of same brand which easily run the airconditioner. Just FYI if you want to set up a least expensive power option. 👍🏻

hay fallas incluso con poca carga es in inverter caro y de baja calidad