inverter vs charger why u no work?

I got an inverter (1200w pure sine ampeak) to charge my stuff off my car at AVS.

I run my prototipo charger, and my lipo charger at about 1000w combined and things are fine.

My lonestar charger (10A 12s yewy ) on it’s own does about 550w and it will randomly trigger the inverter to declare “short circuit”. and shutoff.

i was originally trying to do the lonestar charger first, adding the lipo charger at low load (~150w) and it would seem to trigger things so I thought i twas load spikes. but it turns out just leaving the lonestar charger alone it will trigger short circuit within a few mins. (550w)

is my lonestar charger bad in some way?

It sounds like it may just be the massive current inrush of the chargers capacitors filling up. This unfortunately isn’t a new issue. @jack.luis had something similar I think?

Smaller charger would be the fix to that.

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Yup, @fessyfoo why do you think I hung around you guys so much at maryhill? Because you guys had the generator, my 3000 watt inverter didn’t do shit for my board :frowning:

/s love ya

I will have the @hoytskate Mobile, which will be able to do tons of charging for the low low price of 1 foot massage per 500Wh


It seems like the more time you spend esk8ing the more you turn into @BillGordon


it trips after running for a while tho… I would think the inrush would be at power on / plug in?

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How about I bring my inverter also, with some wiring tools and soldering irons, and we try to find a way to bypass this overcurrent limit haha


I’m assuming it’s some kind of momentary load spike the charger is causing.
the wattage display on the inverter doesn’t show a rise, so I assume it’s a quick spike.

wondering if a different inverter would handle it better? … or if the charger is doing things it shouldn’t. (since the others can drive twice as much load and not trip it. )

annoying. :smiley:

it was good there was a reason. :slight_smile:

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What charger was it? How did it fail?

20s charger adjustable from 2-10A, would fault immediately after plugged in no matter what amp setting it had


I’ve heard of similar issues with people trying to charge power tool batteries through an inverter. I believe it has something to do with what type of wave the inverter uses.

But I am totally speaking out of my arse, i have no experience with it.

I bet if you look up ‘charging 18v batteries with an inverter’ on the google machine, you might be able to find something useful

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Right. That one does sound like inrush to capacitors.

yeah that’s all i’ve found so far,

something like things that used switch mode power supplies (like our chargers) aren’t happy with modified sine wave inverters. This inverter is supposedly a “pure sine wave inverter” though. so supposedly shouldn’t have that issue.

wonder if there’s a cheap way i can check out the wave form. never used or known anyone with an oscilloscope. nor have any idea how to apply that to a HV AC signal.

not sure that would explain the “short circuit” condition from the inverter in any event.

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@fessyfoo I have a xantrex prowatt 2000 and it works perfectly with my lacroix 12s 10amp charger.

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appreciate that data point.

wondering if 2kw is just enough more than my 1.2kw to handle whatever load spike is happening. or this inverter is just outright better. hmm.

I think the xantrex has a peak rating of 3000 watts. Wish I could be more helpful. It’s definitely cheaper to buy a lower amperage 12s charger than to upgrade the inverter.


Honestly. Get a bunch of 12s 1.5a chargers on amazon (which are fanless and have very little capacitance) and send em in parallel.

my 3kw one wouldn’t work, also claims pure sine

I think your problem is different than mine tho. yours happens at startup. mine charges for a bit then flakes out.

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The only thing i can think of is that your lead acid battery and alternator can’t supply enough amps for very long. Alternators overheat and don’t like to put out a lot of amps at idle anyway. My 130a alternator in my van is only happy putting out 20amps at 12v. I tried a b2b 40a charger once and my van did not like that.

My battery bank is a battleborn lifepo4 100ah and that thing is a tank. It can put out 100a at 12v continuous until it’s empty.

I’m not being super clear, but my thought is there is a chance your issue isnt the inverter - but rather the upstream battery/alternator not putting out enough amps at 12v to keep the inverter happy.

From your original post it sounds like you can charge other chargers continuously at 1000w total - is that right? If you can draw 1000w continuous for an hour with other chargers, it kind of nukes my theory.

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yeah. that’s right. that’s why i think it’s something momentary in the charge cycle that that particular lonestar charger is doing.

fwiw, I did experience something similar to what you describe. I tried to drive the load closer to the 1200w rating… as i got to 1100w the input voltage dropped to below 10v. and the inverter shut itself off.

The setup is actually an EV with a built in 3000w dc/dc converter to charge the 12v system. I connected via 20ft 4GA jumper cables to the inverter. (it was easiest to connect). I suspect the voltage drop at ~90A is mostly due to this connection. the cable I think would be about 5.964mΩ so only .5v drop… but probably the alligator clamps? … or the internal DC/DC isn’t really 3000w. :smiley:

but… i digress.

not sure any of those things are related to my original problem, which is the one lonestar charger at 550w runs for a few minutes then causes “short circuit”. and the other two can run for at least 20min at 1000w. (didn’t test longer, they weren’t the things i wanted charged. )