Car battery flat, again!

Good morning all. The battery died a few weeks ago and we called the breakdown service provided by our insurance (MMA) and monsieur duly arrived 30 minutes later, connected it to his portable charger et voila, all sorted. Took car to town (20kms) did shopping and came back. All seemed to be ok. Went out this morning, and battery dead again. The mechanic said if we don't drive the car that often (usually no more than once or twice a fortnight) we should start it up and let it run for a few minutes. I have since spoken to a neighbour who says he has the same problem. So is it a faulty battery? Should we be driving the car every 3 or 4 days for say, 15-2- minutes?

And final question - when we were in Ireland, if you called out the AA, they had the right to charge if you called them out again for the same problem if you hadn't taken steps to rectify it. Don't know if it's the same here, so I didn't call the breakdown people. Have borrowed a battery charger.

Thanks everyone for your replies. Last time the breakdown lad came out he said he was happy with the alternator, but nevertheless I'll lask the garage to check it when I book the service. It has been damp and cold here, and humidity is much higher than normal - normal is around 50-55% and today, for example, it is 77%. However, our neighbour drove us to our appointment and other neighbour dropped over the battery charger yesterday. It is Heineken Cup weekend with our team playing tonight, so I'll worry about the battery on Monday! :-)

Thanks again, all.

a fully charged battery should have a reading of 12.5volts, when charging when engine running this will climb to 14.4 volts, the output of the alternator,

if the car has been left for a while the battery will discharge due to items in your car using small amounts of energy. ie radio, clock, alarm, immobilisers, engine management system and braking system. so after about 10days the battery will be discharged.

the starter motor when starting the engine draws about 90 amps, depending on size of engine. this will flatten a poorly charged battery after a few attempts to start.

a battery when new should last about four to five years with no problems. as long as it is regularly used ie car run twice or thrice a week.

another problem that occurs with older cars is that the electrical system gets damp and this can slowly discharge a battery especially in wet and damp conditions.

best bet is to buy a small multi meter for about 15euros and also a set of jump leads and a battery charger.

regularly test the state of your battery by going across the terminals, when engine is off and when engine is running, see above for readings.

if you are not using your car for long periods charge the battery a few days before you are going to use it.

and always carry set of good jump leads for those emergencies.

if you have a spare battery keep it charged and either in your car or easily accessible for those emergency times.

We had this problem and changed the battery but then a year later the same thing started happening to the new battery and it was the alternator which had then as I understand it...killed the new battery so had to buy another new battery.

We repeatedly called out the Green Flag who thankfully didn't charge us but it was ridiculous at one point it was like every time we used the car (weekends only) we needed to wait an hour for Green Flag to come out and bump start us. In the end we bought one of these and that worked a treat. It takes 24 hours to reload it so it has enough juice to start our car :( but it works really well. We did replace the alternator in the end as it wasn't charging the battery properly. One of the problems we found though was if the car was left for a few weeks it wasn't just not starting it was completely dead and the locks wouldn't open and the whole car computer system shut down and went into German again! ![](upload://irrNxW8YrpifJYnaYREy6AwyWD6.jpg)This has been great though and we keep it in the boot charged up now in case we ever have an airport issue which touchwood since we replaced both battery and alternator it's been fine and sits for up to 3-4 weeks without a problem.

Have them take a look at the alternator as well it may not be charging up the battery.

Hi Angela and thanks. Well, the car is probably due a service anyway, so I'll get them to take a look at the battery. Hope all is well with you.

This message is more by way of sympathy, Sheila, as we had the same problem for the last 2 months or so; the car started first thing in the morning but then after the 3rd or 4th 'restart' during the day, no life, so I often ended up calling out my husband (rather than the AA!) to come with the cables... we took it to the garage & they measured the battery charge as Vic says, but they said it seemed to be ok. It wasn't. In the end I decided the stress levels of being stranded were worth the price of a new battery - even if it did come to 183 euros( with the fitting included)!! And now things are fine.

Thanks Vic. Neighbour brought round his charger, other neighbour driving us to our appointment in town, Henry has made me a fresh cappuccino, will ring garage on Monday and make appointment (and relax...)

No idea how old the battery is - we bought the car second-hand in May 2011 (with said battery) and have had no problems with the battery up to recently, so suspect a duff cell may be it.

How old is the battery? they don't last forever! Check & top up the electrolyte levels,get it well charged up & take it to a garage who can do a discharge test which involves putting a tong type thing across the battery terminals to measure what current it can discharge quickly. This will normally tell if it's OK or if it has a duff cell.