Two 6 volt batteries or two 12 volt batteries ??
Two 6 volt bats in series (12v) or two 12 volt batteries in parallel. Generally, which is a better way to go.amp hrs ??? Comments and experiences appreciated.
Forum Discussion
Yes, your solar charging will offset voltage drop and current draw but only to the shared amount of battery charging that is taking place. I like to think of this relationship as the solar charging being a continuous stream of water into a container and any current drawn as taking the water out of the container (although, technically, it isn't that simple).
FWIW, I maintained a fleet of golf carts at one time, over 300 6V's. Said fleet was influenced by cart jockeys that ran carts down to inoperable (even caught one doofus trying to make his record jump into a sand trap). I have a lot of respect for the Trojan 6V. Similar respect is growing for the Sam's Club 6V. I think we are into year 6 with the Sam's Club batteries.
I'd suggest that you try a pair of 6V's. It is less than a $200 experiment and some of that is recoverable, should you later decide to go back to 12V jars. With constant solar charging and a good charge controller, the 6V batteries will last a long time, probably +10 years. If you run a hybrid 12V set down very low more than a few times, at the least, you'll have a loss of capacity. At the worst, you'll have inoperable batteries.
Your inverter mfg should have pertinent info on cable size and distances. I use a 1000W inverter and use 4 AWG, distance to nearest bus box--18". When my 120V fridge is running, the TV screen is being used, my 120V stereo receiver is on, and am powering a laptop, voltage drop is very, very rarely even close to the inverter shutdown point. I typically see voltage drop to 11.75V-> 12V, depending on SOC at the time everything is powered. If I disconnect the 120V devices, battery voltage immediately rebounds above 12.2V -> 12.5V.
Voltage drop happens no matter what type of battery you have. As long as there is available current above acceptable voltages, you're good to go.
FWIW, I maintained a fleet of golf carts at one time, over 300 6V's. Said fleet was influenced by cart jockeys that ran carts down to inoperable (even caught one doofus trying to make his record jump into a sand trap). I have a lot of respect for the Trojan 6V. Similar respect is growing for the Sam's Club 6V. I think we are into year 6 with the Sam's Club batteries.
I'd suggest that you try a pair of 6V's. It is less than a $200 experiment and some of that is recoverable, should you later decide to go back to 12V jars. With constant solar charging and a good charge controller, the 6V batteries will last a long time, probably +10 years. If you run a hybrid 12V set down very low more than a few times, at the least, you'll have a loss of capacity. At the worst, you'll have inoperable batteries.
Your inverter mfg should have pertinent info on cable size and distances. I use a 1000W inverter and use 4 AWG, distance to nearest bus box--18". When my 120V fridge is running, the TV screen is being used, my 120V stereo receiver is on, and am powering a laptop, voltage drop is very, very rarely even close to the inverter shutdown point. I typically see voltage drop to 11.75V-> 12V, depending on SOC at the time everything is powered. If I disconnect the 120V devices, battery voltage immediately rebounds above 12.2V -> 12.5V.
Voltage drop happens no matter what type of battery you have. As long as there is available current above acceptable voltages, you're good to go.
