batterys

[hot66]

If a battery has not been used for 6 months, then brought back into service, is there a possibilty of it suddenly refuseing to hold charge?

All of a sudden my batteries have lost their charge ( won't turn the engine over) . They did seem to be OK for the past month, then all of a sudden ( after coming back from suspension work) don't hold any charge

I am a bit inept when it comes to electical stuff but I gather this could be due to a bad earth, a short or that the batteries are shagged?

[hmy7k]

Have you checked the voltage across the battery?

It may be a connection rather than the battery itself.

Batteries should be stored and kept fully charged or they will degrade especially when its cold. I keep mine on a trickle charger to prevent this.

[hot66]

each battery is at 11.58 volts (voltmeter across + - ) .

[Barry]

On the face of it, that sounds more or less O.K. James (would be nice to see a bit closer to the full 12v though): a good test is to see what happens to the volts as you crank the engine. A usual voltage when cranking would be 9-10, if it stays higher with no cranking, then you've got a poor connection somewhere.

On the other hand, if the battery volts dip to 5 or 6, and especially if the batteries have been badly discharged at any point in their lives, and you have tried to charge them, then they've probably had it.

Usually a very quick test to see whether it's the starter motor/solenoid, is simply to turn the headlights on before cranking. If they stay bright, but the engine barely turns, there's a problem with ignition switch, starter motor connection, the motor itself, or the solonoid. If the headlights go dim, it's battery main positive (top of battery and main cable into loom), battery earth, or the actual batteries themselves.

Anyway, my money is going to be on the batteries, esp if they won't take a charge and they've been run down at some point. I believe that sulphates build up on the plates of a badly discharged battery: as I understand it, these sulphates compromise the battery's performance plus can fall off the plates, and lie between them: leading to shorting of the individual cells. This assumes my limited understanding of poorly batteries is correct .

[hot66]

just nipped out to check.

Turned lights on, tried to turn the engine over and the lights go out.


Out of interest, the lights are on full beam, and I flick them to dipped the 'transition' is quite slow. Probabally not related

[impmad2000]

Batteries don't like to be left discharged. If they have been left flat for a period, then it is quite likely that they will refuse to accept a charge. If you want to check out the theory before buying new ones, I have a pair sat around here that I am concerned will go the same way if not used.... you can certainly try them out. Cheers
Tim

[hot66]

just borrowed the battery tester .... the digital display said ' battery F**ked, buy some new ones '

According to my local garage man, this is quite common on modern batteries for them to just die without warning

Anyone got any preference for battery makes? Lucus?

I'm need 2 off 063's

[Lightweight_911]

You can get Bosch replacements for a good price at Eurocar parts.

[hot66]

thanks Andy

I have 2 bosch silvers being delivered today Just hoping the problem is just the batteries & not anything else.

[Barry]

Can highly recommend the Optimiser battery charger/maintainer. Designed to keep the batteries topped right up, even when not being used.

There are plenty of similar products out there: I usually hard wire a couple of connectors into each car/bike, and just swap the Optimiser around every other week or so. Yet to have to fit a battery to any car (other than 'new' arrivals).

[hot66]

Ironically I have 2 trickle chargers , A stand alone one & my Carcoon one .

I am going to fit the new batteries tomorrow night & hope they keep charge until after LeMans