Club 80-90 Forums

I'm sure this has been covered before but I had a bit of a search and couldn't find a thread. In a nutshell, can I plug a battery charger into the plug socket in the van while on hookup and charge the starter battery with it? So it would be kind of charging itself.

Yes. If you have any concerns just disconnect one terminal so it is isolated but there should be no need to.

I have a battery charger permanently plugged into my van mains circuit and wired to my leisure battery. So when I am on hook up my leisure battery is permanently on float.
This is handy as I can hook up to mains at home to top up my leisure battery. If I should let my leisure battery get completely flat the thirty Amp fuse in the charge line will sometimes blow when I start the engine as the alternator is spec'd at 90Amp. That is my suspicion anyway.
Note: The alternator is not connected to the leisure battery unless the engine is running as the relay is not activated, not that I think there would be a problem as the Mains transformer in the charger should be double isolated by today's standard.

CS

Citizen Smith wrote:I have a battery charger permanently plugged into my van mains circuit and wired to my leisure battery. So when I am on hook up my leisure battery is permanently on float.
This is handy as I can hook up to mains at home to top up my leisure battery. If I should let my leisure battery get completely flat the thirty Amp fuse in the charge line will sometimes blow when I start the engine as the alternator is spec'd at 90Amp. That is my suspicion anyway.
Note: The alternator is not connected to the leisure battery unless the engine is running as the relay is not activated, not that I think there would be a problem as the Mains transformer in the charger should be double isolated by today's standard.

CS

A lot of chargers do not have mains transformers now!!!

My resident van charger has an input transformer so I didn't give it a thought however:
While being au fait with PWM circuitry the question of isolation just never occurred to me. I just assumed that the design standards covering these products would preclude use of circuitry which would not meet the double isolation standards. The idea that an open circuit in the zero volt line could result in the output positive rail going high does not sit well with me. I guess you could have a point there though considering the apparent Laissez-faire attitudes applied to today's marketing standards... Something to look into when that round-to-it turns up
CS

Thanks for the replies. The charger I'm planning on using was a cheapo one from somewhere like Aldi, I used to take the main battery out and charge it in the house overnight when needed but it's a bit of a faff.

The tiny solar panel I've been using for trickle charging just about replaces the voltage used by the radio but in this overcast weather it's falling a bit short. I'll hopefully only be using the mains charger in the van for topping up every now and then

If you have a multi meter you can check if it's OK to use.
Plug the battery charger into the mains and check the output to earth with the meter. Check both POS and neg but obviously not at the same time.
As long as the output is not linked to the earth you should be ok

nicq wrote:If you have a multi meter you can check if it's OK to use.
Plug the battery charger into the mains and check the output to earth with the meter. Check both POS and neg but obviously not at the same time.
As long as the output is not linked to the earth you should be ok

Thank for that, I'll give it a go