question

Greetings,

I recently set up three Victron smart controllers to harvest PV power from three solar arrays on my sailboat (each controller takes the input from two panels connected in parallel). I also installed a Battery Sense to send battery voltage and temperature data to the network.

My house battery bank consists of four Lifeline GPL-4CT 6v batteries connected in series and parallel to form one 440 amp hour 12-volt battery. The starter battery is fed current from a Xantrex Digital Echo Charge and is not connected to the solar chargers.

All is well and the solar controllers are networked, working together and showing normal PV as well as battery voltage and watts into the battery bank when appropriate.

I'm a bit stumped as to initial voltage settings for the batteries. Lifeline publishes a very temperature-specific chart of absorption and float charge values. For example, they list the respective values for 77 degrees Fahrenheit (25 Centigrade) as 14.30 and 13.30, and these are the values they print on the batteries themselves, so I've used these voltages in my user-defined setup, but the battery temperature is nowhere 77 degrees yet where I live. I entered the temperature coefficient (0.013V/degree F) as listed in the same manual. Are the controllers supposed to automatically adjust for the temperature? Or should I set the user-defined value for the voltage recommended for the actual temperature of the batteries at the time I set the values? For example, today the battery temperature was 56 degrees Fahrenheit. Should I have set the voltage limits according to the Lifeline values for that temperature? But then what about when it gets warmer as summer comes on? Surely we're not meant to keep chasing the settings every day as ambient temperatures go up and down. It's rather confusing, and I thank everyone in advance for clarification.

Carter