I'm Charging my Battery

Hi All,

i have a lead acid battery 12 Volt 7AH.....i have bought since 2 months and i was use it very rarely. now i found it empty with volt of 11.8

so i'm chargig it using a normal computer power supply 12 volt , it's being charging now for about 2 hours but the volt doesn't exceed 11.9 .....what does it mean

why it stopped charging

You need a charger, NOT a power supply - in order for current to flow into the battery the charger feeding it has to be higher than the battery voltage. You can't charge a 12V battery (nominally 13.8V) off a 12V supply.

See the battery label shows what voltage & current use to charge. A 12V supply is not enough to charge a 12V battery.

For a float charge it needs 13.6V -14.0V
For fast charges it will be more around 14.7-15V

the label says.

normal charge 14.4 - 15.0 volt 2.1 A
standby/trickle 13.5-13.8 Volt 2.1 A

i think i have to build a charger .... i used the powersupply because i thougth it would be enough

The right way to do it is a charger of course.

But I have found cheap 12VDC wallwarts that are 14-15 and used them for a trickle charge. It will take a while based on the current it can provide. But a though until you do build/buy one.