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MG MGF Technical - Battery charging

Due to lack of use a few days ago my 96 MGF battery was flat so I jump started the car and it started fine. I went for a short run in it but I cannot have gone far enough because yesterday the battery again didn't have enough charge to start the car. So yesterday I put the battery on a charger for an hour foolishly without disconnecting it! Today the battery still didn't have enough charge to start the car so I tried jump starting it again. Although it turned over fine it wouldn't start. I am now worried that I've damaged something yesterday by charging it without disconnecting the battery. Any suggestions/ideas regarding what the problem might be? It usually starts fine but I've always had a problem with battery discharge if I don't use it regularly. Thanks.
DW Staniforth

More likely damp/condensation in the ignition - are your plug leads/distributor cap/rotor arm/coil in good order?
I've often had to put a fan heater blowing up the car's jacksie for an hour to get it to fire, but if the above-mentioned are up to scratch there should be no problem.
Mike Cunningham

OK but it started fine on the jump leads earlier in the week. Ive not had any problems with the leads/distributor cap/rotor arm/coil so I'll try jump starting it again before investigating them. Thanks for the advice, so are people of the opinion that the charging will not have damaged anything?
DW Staniforth

had the same problem with mine noticed the poor quality of the clamps earth strap not fully tight turning on battery post had new clamps tonight will do weekend
rj hardwick

Hi DW,
If you can... get a lend of a good charged up battery from someone and give it a go to see if it will start your car. Then you'll know if good battery starts your car you havn't damaged the electricals when you tried to charge the old bad battery when still connected.
Sue
Sue Wilson

Is the car garaged or parked outside? Mine will survive for about a week, in cold weather, parked outside (and locked!). When garaged I always leave it unlocked and the reduced current drain will allow it to be left for perhaps five or six weeks. (Yes, yes, I know the battery needs replacing!).

I have never (yet, touch wood) had a problem charging the battery in situ, but I always make sure the -ve terminal is attached to a good earth point and not the battery itself.

Sue's suggestion above is a good starting point.
Mike Hall

Trying a good battery is the way to go.
Sometimes a low battery will suffer a cell failure therefore a good Multimeter to check the voltage is useful
The EEC has a drop off voltage which I recollect is something like 11.4 Volts.
I always consider a good battery is as important as having petrol so the MG gets a Varta D21 and luckily the other two cars take the same battery so get hand me downs.
Geoff F.
Geoff Farthing

Update,

I had the battery tested at 2 garages and one concluded it needed changing whereas one said it was fine! I changed the battery 2 weeks ago and it has been ok since then in terms of holding charge and starting. The old battery was only fitted last May! Yesterday I had the same starting problem as before, that is it turns over but shows no sign of starting. I'm going to get the RAC out to look at the starting problem.
DW Staniforth

This thread was discussed between 31/12/2010 and 22/01/2011

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