Originally Posted by kiwi_bloke

Hi Guys,

A week ago I had an issue with my 280E (M104) which involved the battery going flat repeadidly. Each time I would recharge, and after a couple of days it would end up flat in the morning. One morning I jump started it but after a 20 Minute trip it hadnt taken any charge.

Battery voltage = 12.03 Volts
Voltage at battery poles when engine running = 14 Volts
Current draw at rest = 200 to 300 MA - Probably 400 MA with alarm on

Does this mean my alternator is charging sufficiently?

I replaced the battery on this occasion, and havent had any problems for a week now.

However the thing I have trouble with - is the battery is sitting in our project car (XJ6 Jag). After an initial charge is has been able to crank it and start it each day for a week without even sounding flat.

Can any one give a logical explanation for this?