Charging van battery in situ

Had a quick read of past posts but couldn't see what I was looking for. 

I just charged my van battery in situ and then went to charge the leisure battery but found it had a high voltage already. 

Am I correct in assuming it was charged via the split relay and is there any issue with this happening? 

DrGonzoSnr said:

Had a quick read of past posts but couldn't see what I was looking for. 

I just charged my van battery in situ and then went to charge the leisure battery but found it had a high voltage already. 

Am I correct in assuming it was charged via the split relay and is there any issue with this happening? 

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What split charge relay have you got?

If you have a standard one then no as it needs a trigger wire from either the alternator or ignition switch. If you have an intelligent one then yes as its activated or triggered by voltage.

If you have a Durite 140 amp or one of the cones of this relay, ie M Power for example, then its bi-directional. This means if you put the charger leads on the leisure battery it would also charge the starter battery.

Yes it is triggered by voltage. 

Is it OK to let this happen or do I need to disconnect the batteries in future?

I've just bought a replacement starter battery and I intend to look after this one 

DrGonzoSnr said:

Yes it is triggered by voltage. 

Is it OK to let this happen or do I need to disconnect the batteries in future?

I've just bought a replacement starter battery and I intend to look after this one 

Click to expand...

Just do as you have done. The starter battery will usually be well charged with a non smart alternator so your charger will be topping it off as well as fully charging the leisure battery.

On my current van I has a Sterling Battery to Battery charger which is voltage activated. I have a permanent connector on the starter battery side of the B2B charger. This means the van battery and the leisure battery are both charged by the charger as is yours.

My 10amp Numax charger is rated for a battery of 165amps or less. In Daz's case he has 2 x 115 amp leisure batteries. Grippa supplied him a 20 amp charger. As he charges both batteries every night he could have got away with a 10 amp charger. But Grippa have covered all bases and correctly supplied a 20amp. If Daz only recharged the batteries when they were flat, then a 10 amp charger would be too 'small.'