Main battery wont hold a charge...

[ianpaull]

Hi all, I wonder if anyone can help/advise? I have the mrs taking the van on a long trip this weekend and she's scared about it not starting...
Everything was fine recently until my dopey stepson managed to try and drive his scooter off with the hook up cable inexplicably caught around it. He managed to pull the hook up at the back of the van out of its housing a little and blew the two 20amp fuses on the leisure battery. Once I'd been made aware (of course it wasnt his fault) I replaced leisure battery fuses and all seemed fine again...However I now have issues with the main "car" battery. It discharged fully at about the same time so I jumped it from another vehicle but after 2-3 days its almost flat again and I keep having to Jump it (haven't done it from the leisure battery yet and would rather not given the choice) I wondered if this issue has been caused by a knock-on effect of the original "incident" or is just an unrelated battery problem? any thoughts or recommendations on how to fix or a replacement unit available in Halfords or the like? Thanks as ever, Ian

[g8dhe]

No obvious reason why the problem should have affected the SB itself, but have you checked that Charge lamp goes out when running the engine, it might be that the alternator has failed ?

[ianpaull]

thanks for your reply g8dhe, once the engine is running it all appears normal. battery is apparently charging as after a long run on Monday eve it still started again on Tuesday morning but having left it sitting since then and trying it this morning it now again hasnt enough charge to start the vehicle. there's still enough there to light the dash (including glow plug light) but when this goes out there's not enough to turn the engine over. I keep thinking is there something left on thats draining the battery but i've checked lights etc and no joy...

[ianpaull]

Sorry, Geoff is better than g8dhe...Just noticed your signature...still getting the hang of this!

[g8dhe]

I respond to most mixtures (g8dhe is my amateur radio callsign)!
It does sound in that case very much like an unexpected load on the battery. Might be worth checking that both battery terminals and the chassis connection on the -ve are all good clean and as expected.
If you have a meter, might be worth putting it on a High current range and then removing each of the 4 main fuses on the +ve battery terminal arm and seeing if there is any unexpected high current thru any of them, with everything off and a LB in place you wouldn't expect anything higher than a 100mA to be drawn.

[ianpaull]

Ok, thanks Geoff

[ianpaull]

Worst case I guess its a new battery...Do I need to look for something specific for this type of vehicle? normally I would go into Halfords and check on their chart but of course they don't have Mazda Bongo or Ford Freda listed!

[g8dhe]

See here http://www.igmaynard.co.uk/bongo/forum/ ... 71#p616871

[ginger colin]

Check the rear (tail) door is fully closed, if not the ignition key hole green light wont go out. The light is on a timer so be patient. Its only a tiny draw but an easy slip up.

When running check voltage at leisure battery and at main battery. Usually over 13.5v should be OK.
Halfords will test your battery, the RAC did mine, its not done with a big 2 pronged load resistor any more (too dangerous)
The find the mah (milli amp hour) rating of the battery, load it up with a "safe" box and see what comes out.

[jimmo62]

There are 2 likely problems - something draining the battery or a dead battery. You could fully charge it then disconnect it from the car (remove the earth cable) and connect a headlamp bulb across the terminals. A 55W bulb will draw about 5 amps so your battery should easily power it at full brightness for 10+ hours. If the battery is dead it will only last a couple of hours. Just be careful as the bulb will get very hot!

If the battery is OK you will need to work out where the drain is going to by taking out fuses one at a time as Geoff suggested.

[ianpaull]

Thanks for all your comments and suggestions. I've disconnected the battery and I'm giving it a proper full charge. Also disconnected the earth strap and gave it a good clean up...fingers crossed that will sort it. Failing that perhaps a new battery from car parts (thanks for the 7.5% discount tip, worked in couple of hours!)

[Bob]

Bear in mind a battery is normaly good for about 5/6 years, and even a new one if 75% discharged will be FUBARed.

[ianpaull]

mornin' all...right battery has been on charge for 15 hours or so and is only showing 50% charged on the dial (albeit its an old, basic charger) I'm beginning to think its had it now (the Mrs has left the lights on too many times!) So will order a new one from carparts4less...thanks for all your help

[francophile1947]

mornin' all...right battery has been on charge for 15 hours or so and is only showing 50% charged on the dial (albeit its an old, basic charger) I'm beginning to think its had it now (the Mrs has left the lights on too many times!) So will order a new one from carparts4less...thanks for all your help

It depends on the power of your charger - a 2Amp charger for 15 hours won't do much i.e. 30A/h If it is such a low power charger, it will probably take a couple of days.