Dead cell in the battery or something is on pulling power from the battery. Light or relay.
how Can you charge multiple 12 volt batteries with a car?
they are continually recharge by an alternator on the car engine.
yes
charge batteries with caps in place.most U.S.A batteries are made with flame.
No they lose some of its power over time. it depends on the type of the battery. rechargeable lose more of there charge that normal battery's.
The batteries are probably bad.
Depends on the quality of the batteries and the care that you charge them with.
small battery can lose charge fast,and big batteries can loose charge at large time
Take it to a place that check and charge batteries like the auto zone or kragens.
No, you will ruin your batteries and charger.
We know that AA batteries (or any others) lose charge because energy is taken out of them with use. The chemical reactions that generate the voltage occur, and this "uses up" the energy in the cell. This is the long and short of why batteries lose charge, and you can see it if you think it through. We can also see a situation where a cell loses charge when stored. No materials are perfect insulators. And lengthy storage, or storage under improper or poor circumstances will set up conditions under which leakage current could discharge a cell. Plain and simple.
Between 12V-14.2V is recommended, however standard charging units will optimize their charge to your batteries needs.