Battery Problems

[pistonhead345]

Hi Guys,

The problem first started when about 6 months ago I got a random flat battery. Since then there every sort of two months the car will have a period of a few days where the battery will either be flat or takes a good few goes to start. The battery is less than 18 months old which got me thinking it’s unlikely to be the battery that’s causing the problem.

The other thing I’ve noticed is that when using the AC the car sort of whines when I accelerate. After googling the symptoms of this seems to be a bad drive belt. Could this also be the cause of battery battery problem I’m having?

I will be getting the car checked shortly but just wanted an opinion on what the problem could be?

Thanks

[QJumper]

Yes. If the alternator belt is slipping then the alternator will struggle to charge the battery.

[E-bmw]

If it is only whining when the AC is on, that is likely to be a bearing in the AC compressor, so no that is unlikely to be the issue.

If you battery went proper flat then that is more likely to be the issue as batteries rarely recover properly from being flattened.

[Oldandslow]

Can you adjust the belt tension?

[GreenV8S]

If the battery is going flat either you have a residual current drain, or the battery is failing, or the charging system isn't working properly, or you're making so many short trips that the battery simply doesn't have time to recharge after each start - or some combination of the above.

Flattening the battery is bad for it and doing it repeatedly can easily ruin it, so you probably need a new battery now. But unless you find and fix the cause of the original problem the new one will eventually gpo the same way.

To start with I suggest you find out whether the charging system is working correctly, and whether the residual current drain is excessive. That will tell you whether the battery is the problem, or just a victim of the problem.