Leisure battery wiring advice

[hammy747]

Hi folks,

I have recently bought a T25 and new to the whole VW world and in the process of adding some mods to improve my first bus.

I'm after advice about wiring in a new leisure battery under drivers seat.

1. Is it ok to wire leisure battery direct to alternator rather than to starter battery in parallel? The reason I ask I'm sort in length on split charging kit I bought online and the wire reaches alternator ok rather than battery.
2. Is it ok to wire the split charging relay direct into starter solenoid control wire from ignition, rather that direct into ignition barrel as mentioned in instructions?

Folks in advance many thanks for your help

[California Dreamin]

I'm guessing yours must be a Diesel? with the starter battery in the engine bay...

Using the starter solenoid wire will switch the split charge relay whilst cranking so you run the risk of the starter drawing a high current via the leisure battery and 'PUNY' slit charge relay (remember the starter on a Diesel can draw up to 190amps on a cold morning)
Taking the 'trigger' from the exciter circuit (blue wire on the back of the alternator) will ensure the split charge relay does not operate until the engine has started....no risk of burning out the split charge relay circuit.
I know it's not what you want to hear.
Martin

[hammy747]

Hi Martin,

Yes I have a 1.6td jetta engine fitted to the bus.

Thanks for the advice I will look into wiring through the exciter wire as you mention.

Is it ok to wire the leisure battery direct to alternator rather than paralleled to the starter battery? A bit unsure with electrics.

Many thanks for your help

James

[aisha]

If you look at this diagram, that's how Westfalia wired them.
Charging relay switched by blue wire from alternator and earthed through starter exciter wire - meaning charging relay is only activated after engine is running, and won't drain the main battery during cranking (as relay sees 12v at both sides of the switch and doesn't activate...)

Not sure about wiring it directly to alternator. I'm surprised that it's closer than the battery? Mine's a diesel too, and they're only 30cm away from each other, but the battery is still "closer" (as the wires run clockwise around the engine compartment)