All these threads on batteries....

[MaxyMan]

My battery died other week had a good story to go with it if you read it it, anyway.. my new/ second hand land rover battery died on me today. Sat with just ignition on (2.5 n/a) for around 30/40mins with radio&subwoofer and interior light on went to start her back up and just about had enough to make a noise but nothing to start the engine. luckily parked on top of hill and bump started it. I know its my fault sat there with radio and subwoofer on but question is does it only take that little time to drain the battery?
Was parked with 2 other defenders both same batterys as I had in and both had subwoofers and radio/lights but running started up first turn of key no trouble.
My alternator is charging correctly. Why's mine dieing and theirs aint! As I've said thaught a battery could cope better than that. Any suggestions or maybe a new alternator even though its fine?

 

[Jongould]

Yes it only takes that little amount of time, an amp will draw maybe 30-40 amps, a stereo probably about 10 amps, a standard battery may do about 45AH from new, take into account the age and also the temperature and yeah, 1 flat battery.

A pure starting battery is designed for alot of power very quickly, a leisure battery is the opposite, a little power for a long time. You can get dual purpose batteries like the Numax which gives the best of both worlds although they still dont have the AH rating of a decent leisure battery (most big ones will do 110-150AH)

Oh yeah, AH means Amp Hours, basically they can supply 1 amp for XX hours, a 50AH battery will supply 1 amp for 50 hours e.t.c.

 

[BearDy89]

or 50amps for 1 hour