Guys chill out i solved the problem.
I bought 2 225 amp hour batteries and will be running the lights off one of them at a time just so i have an emergency backup.

I decided i WILL NOT run in 24 V because afraid I will stay out to long and drain the batteries wayyyy to far down and ruin them quicker that way.

 

Heck, I stay chilled. And yes your total run time will be longer with both those batteries hooked together-in parallel or series.

 

Depends if the low battery is low because it simply was not charged fully, or could be the cell has deteriorated as to limit the possible high voltage which will bring the other down to its level, if the previous, the voltage will find middle ground between the voltage difference, which in turn forces the load to draw more amps, and therefore lower capacity since the watt load is unchanged so either way their is a loss, heck any time any amperage flows, their are losses.
Also charging 12v batts in parallel can confuse smart charges delivering its charge unevenly further amplifying the first issue.

czachary, I too have 225 amp hour batts, but by choosing to run them one at a time (12v) you have now brought that chart of peukerts law into effect and your run time will be quite a bit less than using both 24v. Just fyi.
Hands down the best thing one can do to a deep cycle is never discharge below 50%

 

Total 240 watts divided by 12 volts = 20 amps
Total 240 watts divided by 24 volts = 10 amps
10 amps ( 120 watts ) from each battery .... 12 volts or 24 volts

Big advantage to 24 volts is smaller wire from battery bank to load ( lights or troller )

Note
Disadvantage to 24 volts if you run batteries way down ( with led’s they will work 100 % from 10 volts to 30 volts ) if each battery dropped to 6 volts each, 12 volts out to lights they would still work but the amperage would now be 20 amps and your wire and any switches may melt.( This is also true with your troller, when they start to slow down the amperage is going way up) This also happens with 12 volt setup. Running batteries this low is not good for the battery and will shorten its life. Always put a fuse or breaker of right size to protect your wires and switches.

 

View attachment 18541
Total 240 watts divided by 12 volts = 20 amps
Total 240 watts divided by 24 volts = 10 amps
10 amps ( 120 watts ) from each battery .... 12 volts or 24 volts

Big advantage to 24 volts is smaller wire from battery bank to load ( lights or troller )

I think you just summed up what I've been saying since the subject was first brought up umpteen led threads ago.

 

Awe heck, what was that famous Robert Duvall line in Apocalypse Now , " I love the smell of smouldering insulation in the morning"...or something like that...

Does anyone wire in a little battery indicator to their lighting system? Probably wasn't a big deal off a genny but with these LED setups it looks like it will be a good idea. I suppose I should have done the research on this before just askin....but is it possible.... how.... and what?

 

http://www.ebay.com/itm/Waterproof-...ter-4-5-30V-for-12V-24V-/150782568207?pt=LH_DefaultDomain_0&hash=item231b57670f

 

Dayum !! I'm tard after readin all that !! Now ........ which is it ...........................parallel, sreies, 12,24......... he!! with it I'm just gonna use a spot lite.

 

I will say i ran 13 27W LEDs off one of my 225 amp hour battery Saturday night to 5.5 hours without a glitch. It was a "hot" right off the charger battery registering 12.9 V, when tested it at end of night it was down to 11.4 V

 

So 13 x27w= 351 watts total [assuming each actually is 27w?] 351 / 12 v= 29.25 amps for 5.5 hrs= 161 amps total from a 225A rated battery and it pulled it down 1.5v
Good baseline comparison, thanks for that. The Tech at US battery told me don't go below 10.5 v

 

i think im gonna take up dancing after reading all this.