Car battery

Merlin5

Merlin5

Merlin5

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Finchley, London
I disconnected my battery for 10 minutes to reset dashboard ECU, then reconnected. I sat in my car for about 45 minutes with ignition on but stupidly not the engine and ran the battery down. I was fiddling around with the radio and other things. RAC started me, did a diagnostic and his computer said replace battery. He was going to charge £139 for a new battery with 5 year guarantee. Do I need to spend that much? How about any of these? Although I'm a bit wary of a Bosch and Varta being so cheap.

 
Varta are fairly decent batteries and no you don't need to spend £139 unless you drive something that needs a hefty crank.

Varta Silver are well worth the money IMO but more money than you absolutely need to spend if on a budget.

EDIT: Dunno specifics but a lot of these batteries are made in the same place with a slightly different cosmetic/label anyhow.

EDIT2: Make sure you take into account any stop/start requirements if appropriate when choosing a battery.
 
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Rroff said:
Varta are fairly decent batteries and no you don't need to spend £139 unless you drive something that needs a hefty crank.

Varta Silver are well worth the money IMO but more money than you absolutely need to spend if on a budget.

EDIT: Dunno specifics but a lot of these batteries are made in the same place with a slightly different cosmetic/label anyhow.

EDI2: Make sure you take into account any stop/start requirements if appropriate when choosing a battery.
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How do you mean stop/start requirements?
My screenshot is rubbish btw, it's not showing text properly. But there's a couple of Varta Silver batteries for £73. I assume they're too cheap and possibly fake?
 
If you have a vehicle with certain features like automatic stop/start you might need a battery that supports it, etc.

If you are looking for ~60ah, ~500CCA shouldn't need to spend more than £70 to get something decent.
 
You've just run the battery flat, of course it's going to say replace battery as the diagnostic will be reading low voltage. Just charge up the battery and you'll be fine unless your battery has been seriously discharged (unlikely) or is 5+ years old.
 
Rroff said:
If you have a vehicle with certain features like automatic stop/start you might need a battery that supports it, etc.

If you are looking for ~60ah, ~500CCA shouldn't need to spend more than £70 to get something decent.
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Oh no, my car didn't have that stop start feature. £70 sounds good to me.
 
Scythe said:
You've just run the battery flat, of course it's going to say replace battery as the diagnostic will be reading low voltage. Just charge up the battery and you'll be fine unless your battery has been seriously discharged (unlikely) or is 5+ years old.
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I like what you have to say! That makes good sense. RAC bloke probably knew that but wanted a sale. I guess I won't worry about the battery for now then.

Edit: however, is 45 to 50 minutes with no engine running about the right amount of time to flatten a battery which might otherwise be in good shape? I'm sure I've done similar on my peugeot without flattening the battery.
 
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Merlin5 said:
I like what you have to say! That makes good sense. RAC bloke probably knew that but wanted a sale. I guess I won't worry about the battery for now then.
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They are known for up-selling batteries,I thought they had agreed not to do it any more but it appears not.
 
Merlin5 said:
I like what you have to say! That makes good sense. RAC bloke probably knew that but wanted a sale. I guess I won't worry about the battery for now then.

Edit: however, is 45 to 50 minutes with no engine running about the right amount of time to flatten a battery which might otherwise be in good shape? I'm sure I've done similar on my peugeot without flattening the battery.
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I wouldn't expect a battery to die in that time, but I guess all cars power consumption will vary.
 
Clarkey said:
I wouldn't expect a battery to die in that time, but I guess all cars power consumption will vary.
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My feeling is that the battery is at the end of its life. Surely I should be able to sit in the car without the engine running for less than an hour, tune radio stations and mess around with a few other things, and the battery shouldn't go flat for a few hours, right?
 
Probably not a few hours if you have the ignition on, you have to remember all of the engine control systems are online, all of the ECUs/modules, all of the associated sensors, solenoids, fans, ignition coils, heated o2 sensors etc.., the engine is supposed to be running. If you want to tart with the radio then you should use the accessory mode, ACC on your ignition barrel, or the first press if keyless. This only powers the accessory circuit, things like the radio, and you will drain the battery far less rapidly.
 
What Clarkey said.

It also depends if the battery was fully charged to start with. If you do regular short journeys this will exacerbate it as the battery doesn’t get fully charged in time after starting the car.

what car is it? As clarkey suggests, modern cars have much more electronics.
 
Yeah, good points. I bought it about a week ago, toyota auris. I've only driven it once so far, a 5 mile journey. The dealer drove it to me and it probably had been sitting at his place for a while. So yes, it may well be that it needs some more driving to fully charge it up.
 
How old is the car? batteries are funny things... they can last years and years or they can last a few years and be knackered...

I flattened mine last weekend to the point where the ignition would be turned on and zero electrics... Charged it for 2 days approximately and it's now sitting fine, car still reports 80% charge. Will be giving it a run in a few days to ensure all is well.
 
Merlin5 said:
Yeah, good points. I bought it about a week ago, toyota auris. I've only driven it once so far, a 5 mile journey. The dealer drove it to me and it probably had been sitting at his place for a while. So yes, it may well be that it needs some more driving to fully charge it up.
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It'll definitely need a good charge. Cars sit on forecourts for ages and the batteries run flat, it wouldn't surprise me if the dealer give it a jump start to deliver it.

I'd call the dealer if you've only just bought it, they should take it back and charge it. Alternatively, invest in a charger and charge it overnight and it should be fine.
 
Scythe said:
It'll definitely need a good charge. Cars sit on forecourts for ages and the batteries run flat, it wouldn't surprise me if the dealer give it a jump start to deliver it.

I'd call the dealer if you've only just bought it, they should take it back and charge it. Alternatively, invest in a charger and charge it overnight and it should be fine.
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Well it's starting now. Won't just driving it more allow the alternator to charge it up?
 
Scythe said:
Cars sit on forecourts for ages and the batteries run flat, it wouldn't surprise me if the dealer give it a jump start to deliver it.
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Yeah that's very common. I always charge the battery up and do a test on it. If any doubt we just replace it.
 
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