Tools R Us said:Kalawang
Lead acid battery technology maybe different where you are, but US spec batteries are considered full capacity charged at 12.7 V and discharged, having no usable capacity at about 11.7 V. The voltage test is only an indicator of charge and bad cells, should be used with load and hydrometer test results to determine battery condition. Car batterys have six 2.1V cells, so if one is bad the reading will be about 10.5 with a full charge.
A battery with a 12 V reading has about 25% of full charge capacity, if it wont recover to over 12.4 V after charging I would replace it for reliable operation.
Tools,
Not different, just older technology. Back when the U.S. Bases were here, car afficionados used to haunt the tiny shops outside the base to snap up things like batteries and other things that the soldiers would sell secretly. ;p These days afficionados have to bring in their own stuff. But we're not that far off. You get a 5 year warranty. We get 2 years. I overspec my batteries so they last a little longer.
Kalawang