Is this noraml for a battery?

path1 wrote:
I charge house battery up to around 12.75 Has a battery disconnect switch (installed on neg side) in about two weeks later, I test with same volt meter and reading is 12.18 volts.

Is this normal or is something sucking juice out of it very slowly?

Thanks

Are you testing the voltage right after taking the battery off the charger? If so, there is going to be a difference. To get a true measurement of voltage, you should test a bettery at least 4 hours AFTER taking it off the charger. That will tell you the true voltage. A place for great information is 12volt side of life. Google it.