Dead Battery Question - Alistair
I left my lights on (for a few days - oops! - I'm student scum) which resulted in a call out to RAC. They reckoned my 7 mile drive would be enough to charge battery up again, but it wasn't, and I needed a jump start at the other end.

On my way back I stopped halfway, cut the engine (on a downhill in case bumpstart needed) and it restarted fine. Today, the battery is almost completely dead.

Have I killed the battery, or does it just take a very long drive to charge up when completely dead?


Re: Dead Battery Question - David Woollard

It is far easier to completely kill a battery than folk realise. If it is already a few years old or suffered previous abuse you could well have finished it.

Having said that I wouldn't say you've done nearly enough to prove that yet. 7 miles isn't far. You need it to go on a proper mains charger overnight really.

I have an electronic type the manages the charging process. In a case like yours it may cycle on and off for 12 - 24 hrs before the fully charged light comes on. This charger does seem to have the ability to recover a battery like yours better than any of the old fixed rate chargers.

Of course a new battery may be cheaper than a battery charger and less trouble.

Don't find students scum, mostly penniless with mums required for bill paying episodes!

Re: Dead Battery Question - John Slaughter

David's right - a few miles won't charge a flat battery. Witness my neighbour. W plate A3, and I've seen the RAC start his dead car at least 6 times this year. He usually disappears for about 20 minutes after each episode, and last time left it idling on the drive for 20 minutes. What the battery needs is 12hours at least on a charger, and he won't be calling them out. He's just moved to Scotland, I believe, so I wouldn't be surprised if it's fixed when he gets there after an all day drive.


Re: Dead Battery Question - andy bairsto
Talking about batteries my uncle used to repair them when they were totally clapped.He used to take the top off lift the plates out take out the acid clean the bottom of all sediment (this is what causes the battery to die it shorts the plates out)put the plates back and refill with new acid and bobs your auntie they used to last another year
Re: Dead Battery Question - andy bairsto
Charge the battery up and take it for a discharge test ,try and find out how old it is if it is over four years old it is probably duff.Also make sure the ignition light is not glowing when you are driving as this will indicate a diode failure in the alternator
Re: Dead Battery Question - bogush
Heard that that is how they "make" different types of batteries.

You want a 3 yr guarantee battery: you make the gap at the botom deep enough to take three years worth of deteriorated plate.

One year? Make it a third the depth (I'm assuming it's a constant steady process) :-(

Want a new market beating battery: make the gap bigger and give a longer guarantee.
Re: Dead Battery Question - Alistair
Thanks for top advice, guys. Battery is at least 4 years old, and says Halfords on it too - neither look auspicious. Halfords want £37.99 for a new one, or more for something fancy.

After a push start I'm off down Euro Car Parts for a Hella battery for sixteen quid. I hope they don't mind me changing it in their car park.

I'd better tell you all I'll then take the old one to the tip. You seem a very responsible lot - until someone mentions Sp**d Ca**ras!


Re: Dead Battery Question - Andrew Moorey (Tune-Up Ltd.)
The battery may not be beyond help. Check fluid levels, top up if req'd. On some types of "maintenance free" you will have to prise the top covers off carefully. Put the battery on charge for 12 hours then rest it for a couple of hours then charge again for 12 hours. Leave it for an hour or so before fitting it to the vehicle ensuring terminals are tight and clean. If alls well then alls well, if not get a new battery. Delco batteries from Vauxhall dealers are about the best about IMHO
Re: Dead Battery Question - Michael
ditto the delco battery view, Andrew. I can't remember the details but they are made from different materials to other makes (cadmium or something similar). Either way it improves performance and they last longer (given reasonable usage and no abuse!). Halfords currently sell two type of batteries, the usual, with 3 yr warranty and a high performance unit with 4 yr warranty. The high perf ones are built along the same lines of the delco batteries, imho.
Re: Dead Battery Question - Ash Phillips
If you get a cheapo battery charger dont always trust what it tells you - mine lights the full led when its just about half full - which can be too little for a cold crank on a damp winter morning. Some gel maintenance free batteries can require 2 or 3 days when on a trickle charger to get up to full. You need to get a DMM on one when its rested to really tell what state it's in.

Battery Materials - John Slaughter
I saw a while back that Ford havive been fitting a cadmium-silver (I think - lost the article!) battery as standard fit for the last 3 years.

Presumably these are very different to a lead acid, and get round the battery life, memeory effect and low temperature performance problems that plague the othe alternatives to lead acids. Looks like delco may be using it too.


Re: Battery Materials - Michael
I think so, John, although in delco's defence they have been using it for a lot longer than 3 years. Didn't know that lead acid batteries suffered from the memory effect, thought this was a ni-cad problem. The current lead acid battery that has been in use for the last 20 years or so (early 80's) is not the same construction as earlier batteries. First thing you notice is the current ones are lighter, second thing is that old, worn out batteries could be recharged and would hold a charge for a short time, generally enough to get you started. I remember recharging an old battery every night for a month while saving to buy a new one. Current lead acid batteries rarely do this. Once a cell has failed it is rare to be able to recharge it. Last weekend my Dad's battery failed. It measured 10v across the terminals. We charged it for 24 hours and it still measured 10v across the terminals. Final test was to try and start the car while watching the 6 cells. Sure enough, the failed cell bubbled and gassed like alka seltzer in a glass of warm water. I guess we could have tried to remove the lid, clean the plates, etc, but to be honest, it did not look possible. Having said that, current batteries seem to work better, when in good condition, than older ones did. But then engines are much easier to turn and start nowadays with thin oil, fuel injection and electonic ignition.
Re: Battery Materials - John Slaughter

Yes, you're right. I was refering to an earlier topic where the question as to why the lead acid battery had been maintained in automobile use when alternatives appeared to be available. Issues of memory effect, temperature sensitivity etc apply to NiCad particularly, not lead acid and are the key reasons why they are not suitable for the vehicle starting/high charge duty.

I've noticed too that modern batteries seem to fail rapidly. In the past you got some warning, and could survive for a while on overnight charges, but not these days.

Interesting that delco have been using this new technology for a while longer than Ford. I wonder why it's not been advertised. The article I saw was in Ford News, and even they seemed to be publicising it 3 years after introduction. Trying it out on the public first perhaps?

It seems to me that OE batteries these days are pretty good quality. My Vectra was on its original delco battery after 80k miles, and our Corsa is now 5 years old and on the original. I'd certainly agree about the quality of these. I must check if there's any indication about the battery technolgy being used. Have the cadmium sulphur units been around since 1996?


Re: Battery Materials - Michael
John, I think so, my first delco battery was on an 82 cavalier (still on the car when sold at 120k) followed by an 85 cavalier, lasted 8 years and 130k miles. Now you have raised the question, I'll do some more research and find out more about delco batteries.
Re: Battery Materials - Michael
John, I found the information I was looking for on


It is the construction technique that appears to make the difference, particularly the lead calcium (not cadmium-sorry) grid between the plates.
Re: Battery Materials - John Slaughter

Thanks - I'll check the links.



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