38.9v on First Charge w/ New Batteries

[yurtle]

Sounds like you're fine.

44 - 46 is the voltage when the charger turns off. I don't know how fast the 45 +/- drops, and it may not be linear. 12 hour measurements are meaningful. As JohnnyB said, newer batteries may be a little higher. Once they're broken in, you should see 6.37 volts per battery or 38.2 for the pack.

[JohnnieB]

The rate the voltage drops after the charger shuts off is more or less exponential. Drops fast at first and tappers off quickly.

The same thing happens, but in the opposite direction, after a discharge is stopped, and it doesn't take as long to reach the At-Rest voltage.

[cooose]

Thanks so much guys, I really appreciate your inputs.

@ Johnnie B = Any chance you have a SOC chart for the GC2-RD-UTL battery...I know my AH are ~ 7%less than standard but was the best I could afford with some other things going on at the moment. I want to make sure I'm following Scotty B's recommendations on the battery breakin process and staying above 75% for the first 20 charges or so.

[JohnnieB]

The SoC charts are the same for all AH capacities for deep-cycle batteries from the same manufacturer.
The voltage at 100% SoC for deep-cycle batteries from some manufacturers is higher than others, but all the charts are about the same from 90% SoC on down.

Interstate uses the same chart as Trojan, which is the chart usually posted.