Car Battery Life

[arun1uk]

Afternoon,

How long is a car battery supposed to last before it's deemed "dead"? How long has yours lasted?

The reason I ask is that, apparently, I have to get my battery replaced....
My car is almost 3yrs old and regularly serviced, driven in a range of motorway and city environments and generally well looked after. I parked at Heathrow for the week and it started first time when I got back (Friday), not a problem.

On Sunday I went to do some maintenance and pump the tyres up. I started the car and used a compressor to pump the tyres up (connected to the cigarette lighter). I was using it for less than 5 mins before I had to pop back in the house. When I out, I went to start the car but the engine didnt even turn over. The battery completely died....How does that happen when it worked just a few minutes before?

Anyway, I called out the recovery service and the guy stated that sometimes it just happens, batteries just die without warning. On the contrary, I've had the same battery for 8 years in my other car!

What are your experiences? Any recommendations on brands for a new one?

[anonymous-user]

Mine died after the recent bad weather, managed to eek some life out of it with a charge but it was screwed, it had been in the car for 3 years, bought from Halfords originally

I went to Halfords to use their 4 year guarantee expecting a technicality but no, straight swap, job done brand new battery for nowt

[jshell]

My old merc ML has had same battery since new - 7 years now and tested 'strong' recently...

[anonymous-user]

doogz said:

You started the car, turned on the compressor, and went inside.

When you came back out, the car wouldn't start?

I think something's missing there.

Did you leave the compressor running for a while with the engine off?

I wouldn't imagine so

Start car using slightly knackered battery

Run car for 5 mins, not giving alternator chance to charge, whilst pulling a load on said alternator/battery

Ergo battery that was fked, is more fked

[Bluebarge]

In a modern car, with aircon and lots of other bells and whistles, I would look at anything over 4-5 years as a bonus. I would also use a foot pump.

[anonymous-user]

anonymous said:

[redacted]

He said he was using it for 5 mins then had to pop inside, I assumed he stopped the car as only an idiot would leave an open car running whilst they weren't in attendance

OP I have assumed you aren't an idiot, please tell me this is so

[Ean218]

arun1uk said:

On Sunday I went to do some maintenance and pump the tyres up. I started the car and used a compressor to pump the tyres up (connected to the cigarette lighter). I was using it for less than 5 mins before I had to pop back in the house. When I out, I went to start the car but the engine didnt even turn over. The battery completely died....How does that happen when it worked just a few minutes before?

At tick over the car's alternator will not be providing anywhere near enough amps to cover the drain from your compressor. Therefore the next time you needed a lot of power to start the car the battery was too far drained to do it.

However I do not think your battery is now shagged, just flat. If you can get hold of a "smart" charger like an Optimate or a Cetek you will probably be able to get it working properly again.

I had a similar issue about 4 years ago with an alarm problem continually flattening the battery on my 7 series. Once the alarm was sorted a session on an Optimate got the battery as good as new. That battery is now about 8 years old and still works fine.

[anonymous-user]

doogz said:

Fair enough, i regularly leave my car sitting outside warming up or running while i nip inside to stick the kettle on if i'm working on it or whatever.

Makes sense though.

Sorry I didn't mean to call you an idiot by association just something I wouldn't ever do myself, my mate nipped into a shop once, left it running could only have been 2 mins or as long as it takes to say "10 B&H please" and chuck £3 at the guy.

Came out to see his merc moving away from him at a rate of knots, he gave chase on foot knowing they would get caught at the lights, they mounted the pavement to get away and took out a barrier and most of the front end of the car, no insurance payout as keys were present

[r11co]

Ean218 said:

However I do not think your battery is now shagged, just flat. If you can get hold of a "smart" charger like an Optimate or a Cetek you will probably be able to get it working properly again.

You might want to take a look at this thread.

[arun1uk]

anonymous said:

[redacted]

Thanks for the assumption, no, i'm not an idiot!! Yes, car turned off when I went inside, came back out to start and it wouldnt. The thing is that I only had the car running for < 5mins. I wouldnt have thought it would make that much of a difference, however, can see the point about the alternator not having a chance to charge the battery.

The AA man ran a test on the battery and his little tester thing actually printed "replace battery"! It wont start on it's own now, but will when jumped. Trying a trickle charger tonight otherwise, it's new battery time.

[Willy Nilly]

Car registered at the beginning of August 1998. Battery original. Aircon never been switched off. Rock music always on the radio. Short journeys. Lights on a lot. Car used 3 or 4 times a week at most. Never failed to start.

[arun1uk]

can anyone recommend a decent replacement battery? Could go with a Unipart type thing, or something a bit more substantial

[hairyben]

Depends largely on the car- on a mercedes, if you don't drive it "properly" the battery will fail after 2 years

(whether you've been driving it "properly" can be ascertained from the odometer... 12k in 2 years is improper, according to a merc main service center in w london.