battery keep draining

[haza]

Hi, looking for a bit advice,i have bought 3 new batterys in the last 3 weeks only lasting about 5/6 days and then totally dead,had AA out everytime and after a few checks said alternator etc was fine and says it was batterys,so i took batterys back and gave them a AA inspection sheet saying batterys were b******d,now i havent a clue what to do, any ideas????

 

[big-all]

disconnect the battery when you leave the car and reconnect when you use and see what happens

or wait for an answer as to what is draining the battery when you leave the car

 

[Peter.N.]

If the battery stays charged when disconnected, connect an amp meter in series with one of the leads and the battery and check the current being drawn with everything switched off, it should be less than 100ma, if more you have an electrical fault.

You can check if the battery is charging OK by connecting a voltmeter across it with the engine running, it should read about 14 volts if charging OK.

It might help if we knew what the car was.

Peter

 

[gregers]

check for any interior lights being kept on etc,or have you got anything on charge?

 

[spraggo]

Hi, looking for a bit advice,i have bought 3 new batterys in the last 3 weeks only lasting about 5/6 days and then totally dead,had AA out everytime and after a few checks said alternator etc was fine and says it was batterys,so i took batterys back and gave them a AA inspection sheet saying batterys were b*****r,now i havent a clue what to do, any ideas????

I fail to understand why you have bought 3 batteries, surely when the first battery went dead all you had to do was recharge it?.

 

[mfarrow]

Boot lights are usually a favourite - you can't see them!

 

[JohnD]

in this cold weather, have you perhaps been driving the car with HRW on, fan on full, lamps on full, wipers on full? This is liable to use more current than the alternator provdes, especially on short or slow journeys, so will run down the battery.

Have you got any aftermarket electrical accessories, such as lamps, that do not switch off in the usual way?

 

[Spark123]

Have seen u/s alternators drain batteries when the engine is switched off yet charge the battery OK when running.
An ammeter is the best bet, however don't try starting the engine with a normal multimeter type ammeter connected in series with the battery (and don't connect an ammeter across the battery terminals as you will probably see a big bang and a flaming ammeter!)