Question about Inverter/Charging batteries

Inverters are not magic sources of 120vac power, they draw power from batteries just to operate themselves and will run house batteries down quickly when high wattage appliances such as heaters and microwave ovens are plugged into them. They are useful for charging laptops and other low wattage devices.

"Which doesnt seem like an extreme amount to cause a low voltage on the inverter, with 2 brand new batteries."

New batteries, old batteries...that is a big load. Electric heating with batteries isn't practical.

Drawing 125 amps from a 200AH battery bank will get you that voltage drop for sure and knock out the inverter for low voltage. Needs more AH in the bank. Also the wiring from inverter to bank should be short and fat to reduce voltage drop just from the wiring.

You can use the inverter and shore power (or generator) the same time. Say you only have a 15a shore power connection. You can run the high amp things on inverter, but plug your charger into the 15a shore power so it is not on inverter making that loop, but does support the battery bank. Depends on the charger's amp size if it will cover all the draw, but it helps. it keeps charging between high amp events, so the battery will catch up over time.

Not clear about your inside and outside outlets/receptacles, but don't run the charger off the inverter to the same battery bank the inverter is using. That is the loop that drains the battery because the charger pulls more amps than it puts in.

Hope this makes sense!

Makes no sense to me. :h :?



https://community.fmca.com/topic/6161-inverter-turn-off-while-on-shore-power/

If you were plugged into a 120v power source then you would not have a problem. You would run the heater directly off the shore power bypassing the inverter.

Seems like you are not hooked up to a power source , like 120v shore power and running your electric 120v heater is draining your two 12v batteries, because the heater is running off the inverter, draining the batteries. Is that what is happening ?

Are you attempting to LOOP your power from an outlet feeding from your inverter, then attempting to LOOP that 120v inverter power back into an inside power outlet as an "INPUT' power source to charge your batteries , so you can replenish what your heater is extracting from them ? If that's what you are trying to do, then NO, you can't do that.

Since you have shore power, why are you running the heater on the inverter?

12.5 amps out of the inverter = 125 amps out of the battery. You really should have 6+ batteries to drive that inverter anywhere close to full load. Honestly electric resistance heating from battery is a fools errand. Use the propane fired furnace.

I do hope the "exterior outlet" is actually an inlet so that you are not using a dead man's cord with a male plug at both ends.

PartyOf Five wrote:
Those heaters draw a lot don't they? How many amps is it

Hey great question! Looking online it has a draw of 12.5amps on 1500w (high) and 6.25amps on 750w (low)

Which doesnt seem like an extreme amount to cause a low voltage on the inverter, with 2 brand new batteries. I also had lights on 2x 18" fluorescence and 4x LED bulbs which I cant see drawing a lot of power.

Those heaters draw a lot don't they? How many amps is it