Hi,
If the wiring is properly balanced you can do more than 2. If you wish to understand the "why" surf here:
correctly interconnecting multiple twelve volt batteriesIt is true that the more cells there are, statistically there may be more chance of a failure. However, 4 of my house batteries are 9 years old, and 3 are 5 years old.
Recommended charge rate from Trojan is 14.8 volts.
500w/14.8v = 33.78 amps.
If it is a flat install that will be pie in the sky as far as amps go.
As far as having too much coming in from the panels, get a charge controller that allows for diversion loads--and use the excess power to run a water heater element. I do this manually myself--but I'm an energy pig so I rarely am in the position to not use every erg my panels are bringing in.
PNW_Steve wrote:
That does bring up another question:
What is the logic behind avoiding parallel battery setups?
I have been told "2 in parallel if you must but no more".
