battery removal with no loss of 12volts?

[FREDA MIND]

hi guys,
another job i need to do is remove the battery so i can clean and rust proof the battery tray(slight corrosion present)
i need to do this without losing 12v from the car as i have no code for the aftermarket stereo.i have a spare battery and jump leads but i recall if done incorrectly you double the voltage to 24V!!!!
can anyone help me?

[Muzorewa]

You need to connect in parallel, not series. Positive to positive, negative to negative

[dave_aber]

.... and insulate the red jump lead well........

[dandywarhol]

This is handy
http://www.halfords.com/webapp/wcs/stor ... yId_165557

[FREDA MIND]

wow thanks for swift responce fello bongo freaks!
perfect!!!

[Colin H F]

Am I correct in saying that once the engine is running you can dissconect the battery and the alternator will keep everthing ticking over the same? Colin

[g8dhe]

Its quite possible that the alternator will attempt to raise the voltage, higher than would be advisable, in an attempt to push a charging current through the battery. The alternator will have a cut-off voltage probably about 15 perhaps 16 volts - do you wish to try this out and report back to us all ?

[Scott]

Am I correct in saying that once the engine is running you can dissconect the battery and the alternator will keep everthing ticking over the same? Colin

I have done this a few times when I haven't had the code available (not on a bongo mind you) I then shoved a sock over the positive lead to insulate it (un-worn sock of course) and it has worked fine

But as said, haven't tried it on the bongo yet as have had no need... YET!

[Scott]

This is handy
http://www.halfords.com/webapp/wcs/stor ... yId_165557

this is a really clever idea tbh, but i'm not sure how it would be with split chargers, leisure batteries and re-wired fuse boxes

[dave_aber]

If your engine isn't running, then the split charge relay will be in the relaxed state - i.e. batteries are not connected together.

The Halfords dooberie will inject 12v into the cig socket, so that 12v will end up back-feeding the fuse box that the cig socket is supplied from, this will be either the main or the leisure battery but not both (depends how you have modified the wiring to take advantage of the leisure battery).

So, if the stereo and the cig socket are on the same battery, and thus on the same fuse set, then the halfords dooberie will keep 12v going to your stereo and keep the code.

remember that there are normally 2 supplies to a stereo, permanent 12v (for memory, security code, etc) and switched 12v to run it normally. If you have each feed off a different battery then you would need to be clear about what is going where first.

[FREDA MIND]

thanks guys , top stuff!!!!
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