Solar Panel Starter & LB charging.

[windywatson]

Hi,

I would like to pass this idea by those members that may have auto electrical expertise. I have a solar panel on my Bongo that I use to keep the LB topped up whilst the van is not in use + helps extend battery life whilst on CL sites without electric hook up.
Is there any reason why I shouldn't wire the feed from the solar panel to feed in of the split charginging system? My reasoning is this, it would be acting like the altinator providing power to charge my starter battery for me & when that battery was topped up the splitcharger would then switch over to charge the LB in the same way as if the engine was running.
I can then have both batteries kept in good condition whilst the vehicle is not in use.

Cheers.

[Dodgey]

There is no reason you can't do this though do bear these things in mind:

a) When the relay links the batteries, you will indeed be charging both - but, and it's a huge but - you will also be draining both! (with your electrics that were previously just draining the LB!) - i.e the relay will make the two batteries become one larger one. It'll last ages, but if you flatten it, you can't start your van.

b) I have seen instances where solar charging the starter battery sets off the alarm.

If you are doing this when the vehicle is not in use then it's a much safer bet - but I'd recommend instead running a small wire from the SB live to the LB live so the solar charger is charging both as one battery. This way the relay isn't going to be clicking on and off all the time as clouds pass over - wearing out your relay

[Jaws]

I have just such a set-up with the solar panel linked to the leisure battery. BUT it needs a dual sensing relay. So if the LB is fully charged and the voltage rises it links to the SB and charges that too. Alternatively if the SB is fully charged and the voltage rises there then it links to the LB. With no input from alternator or solar panel the relay is open and the batteries are independent.

It works well but make sure you have a dual sensing relay set at the right voltage to avoid draining the SB inadvertently

[g8dhe]

Just noticed this news item on the BBC this morning 47% tax on Chinese PV panels starting 6th June to December to start with ....
http://www.bbc.co.uk/news/business-22684663

[Dodgey]

....tell me about it.... my 80W supplier is dry due to this, and my new 100W panels - I'm having a nightmare getting them at the moment.