Two 6 volt batteries or two 12 volt batteries ??

lawrosa wrote:

ktmrfs wrote:

lawrosa wrote:

SoundGuy wrote:

skipro3 wrote:
The reason I bought 6 volt batteries is because each plate is much thicker than the 12 volt batteries.

Which is why their internal resistance is significantly higher than those in 12 volt jugs, which in turn results in greater voltage drop under heavy load from an inverter. 12 volt AGMs in particular offer significantly lower internal resistance and for those running an inverter can be the "best" choice. ;)

I never read anywhere about this voltage drop... How much are we talking about? I run an 1100 watt inverter. I have 3 24 group batts @ 75 ah..

I run 800 watt toater oven and coffee maker.

I ran #2 wire 5 feet maybe..

How much worse will the voltage drop be with 6 volts?

I been meaning to go 6 volt but now this threw a wrench in the works...

I have 2/0 cable of 2 ft from my two GC to the inverter. with a pair of GC, anything below 80% SOC or so will kick out the inverter with a 800W load on the inverter. For your application I'd say stay with 12V.

12V has two big advantages for you. One, significantly lower internal resistance on each battery. Two, you are sharing the load between two parallel batteries so each battery is supplying roughly 1/3 the total current draw. 12V wins' hands down.

you would need at least 4 GC to run what you want on the inverter at reasonable DOD on the batteries.

OK.. So I am able to run say my toaster oven now. Even @ 12.5 volts the drop dont go much below 12v..

So your saying if I went 6 volt and had the batts @ 12.5 and put a 800 watt load on the voltage would drop below my 11.5 inverter cut off?

If so thats is good info..

my experience and also BFL, going through similar use, if the pair of GC drops below about 75-80% SOC, you can hit the inverter shutoff limit pretty easy with loads of 800-1000 W. Some may depend on the specific inverter and what it's lower limit is.

Now if the batteriesa are above 80% or so, you in good shape. but that means keeping them near full charge when you want the inverter. So.... run the furnace at night then get up and turn on the toaster.... likely be a nope! low temps= higher internal resistance, lower capacity, coupled with partial discharge.

IMHO if your happy with your current 12V setup, don't mess with it. Or, get GC for most of the stuff and run the inverter off 1 or 2 12V AGM's or similar.