First the positive observations. Leaving the disappointment for last.

Upon arrival of inverter/charger unit, I decided to get my partially charged 460AH LiFePO4 battery fully charged. First tests were with unit connected to grid power - so AC pass through mode. Had to do the awkward pre-charge procedure. Good news though is that charge current into the battery looks right.

Moved on to test inverter mode with grid disconnected. Auto-switchover worked fine and 110VAC shows up on output as expected. Added a substantial AC load and watched the inverter drive that fine without voltage droop.

So what's the problem? In a nutshell, power efficiency. The specs look quite reasonable but when one actually looks at the measured power output-to-input ratio, the numbers are rather disappointing. Am pretty sure that gaming of the specs is happening - suspiciously if idle (overhead) power gets subtracted before computing the power ratio, the results come close to spec. Maybe something other manufacturers do too but I still think it is dodgy.

Finally, battery charging power efficiency is even worse. Yes, the correct 60A charge current does get produced - but with a 400W overhead penalty! That is a substantial amount of heat being dissipated from the inverter. Not a good thing in warm weather scenarios if mounted inside an RV. Plan B - the battery charger can be disabled with a configuration switch. Then use an efficient external battery charger.

I sent an inquiry to customer support asking about the disturbing power issues. Two weeks later and no response. Am guessing their way of avoiding the possibility of dealing with return/refund issues. Though their pay your own return shipping and hefty restoking fee policy pretty much makes that a non-starter. For me, I will put the unit to good use. Just another get what you pay for thing with a seemingly attractive price. Pretty much I got what I paid for rather than what I had hoped for.

So far so good, only have used it for a week. It draws 9 amps on idle, nothing connected to it. Be aware.

It works well. Only humming sound is from the fan when it needs to cool the unit. After that, it's totally quiet.

I was really bummed-out with DC-to-AC power inverters with so-called "Modified-Sine-Wave (MSW) outputs. Either the attached loads (mostly inductive or motorized equipment) would hum loudly and become excessively hot during operation, as well as struggle to even run at full, rated output simply due to the higher-order harmonics present in such inverters' outputs, not to mention having occasionally caused actual equipment damage with MSW output power.

But thanks to my new ExpertPower AC-to-DC power inverter with its truly honest-to-goodness low-frequency (NOT high-frequency) Pure-Sine-Wave output, even my most demanding loads, such as a 10,000 BTU window unit A/C, run like a champ despite large inrush currents while the A/C compressor is starting-up. Just try and pull that stunt with an "el-cheapo" MSW inverter with its high-frequency "pretend sine-wave" output and it's literally hello 'snap, crackle and POP!'

But wait, it gets even better yet. When my ExpertPower equipment arrived, I discovered that its Display Remote Controller panel was totally DEAD. While certainly a little disappointing for me, I was definitely most pleased with the fact that Customer Service shipped a new controller to me; they had my inverter up-and-running just 2 days later because they shipped a new controller unit to me via 2-Day air at NO additional charge whatsoever! I know just who to turn to for all of my future power conversion needs. Kudos for a first-class job-Keep up the good work and team-effort!

Shipping was fast and everything arrived in good condition. Installation was straight forward, I replaced a 10 year old modified sinewave Tripplite inverter charger in our RV so I could run a new residential refrigerator.