Help Help Help Battery Not Holding Its Charge

[lex 85]

hi i have recently put a new Battery on my is200 but now it is totally flat and have to jump start it but there is no Battery warning light on the dash, could it still be the ultinator or something else flattening the Battery?? ive checked if any lights were left on but nothing and after jump starting it and running it for a bit if i turn it off its flat again please can any1 help

[doog442]

Did the previous Battery suddenly die ? Your Battery may be a dud, exchange it and see what happens.

[rigga955]

Disconnect your earth and place a multimeter in series measuring amps, this will give you an ideas if anyything is draining your Battery .... if there is a drain you can isolate it by removing fuses one at a time to see what circuits are the issue.

To see if your alternator is working run the engine with lights air con heated rear window all on and at idle with a multimeter should get a voltage reading of 13 to 14 volts any less and it won't charge the Battery any more and the rectifier is toast and its cooking the cells in the Battery.