Battery charging problem?

[nimrod1230]

Well here goes. Cristec CPS2 60amp charger fitted as OEM. Worked well with both shore power and suitcase input. Yesterday, after running the generator for 4 hours the domestic battery voltage was lower than before I started. While pottering I had the heating on full blast. Before charging the batteries registered 12.6v. On charging the input showed 14.4v. I didn't check for a while and later the input voltage had dropped to 13.4v. Curious, I switched the charger off and on where the input was back to 14,4v for a few seconds and then down to 13.4v, I assumed ( wrongly as it turns out ) that the batteries were charged and the charger had reverted to float charge as in the past. Now, I am pretty useless with electics so any guidance as to possible causes and a starting point appreciated.

 

[Plevier]

Those all look sensible.

What's the battery voltage now open circuit having been off load and off charge for a while?

 

[nigelmercier]

Sounds normal to me.

 

[mariner62]

Well here goes. Cristec CPS2 60amp charger fitted as OEM. Worked well with both shore power and suitcase input. Yesterday, after running the generator for 4 hours the domestic battery voltage was lower than before I started. While pottering I had the heating on full blast. Before charging the batteries registered 12.6v. On charging the input showed 14.4v. I didn't check for a while and later the input voltage had dropped to 13.4v. Curious, I switched the charger off and on where the input was back to 14,4v for a few seconds and then down to 13.4v, I assumed ( wrongly as it turns out ) that the batteries were charged and the charger had reverted to float charge as in the past. Now, I am pretty useless with electics so any guidance as to possible causes and a starting point appreciated.

Long shot ... Is your heating taking more power than the charger can provide, and so some of the power to run your heater has come out the batteries?

 

[nimrod1230]

Never had a problem running onboard systems and charger before. Don't know the rested figure but within minutes of generator/heating off voltage showed 12.3v. After 4 hours I would have expected 13+volts at this stage.

 

[Plevier]

13+V should decay very quickly.
Should settle at around 12.6-12.8V at normal temperatures.
12.3V is low but are they very cold? If so that reduces both OCV and charge acceptance.