# Electrical Gurus - split charge relay, who/where he?



## NormanB (Sep 8, 2005)

I have just fitted new solar panels to our Laika Coachbuilt to charge 2 x 100ah leisure batteries and have noticed (having become an ampere watcher) that I have surplus amps which could be topping the vehicle battery.

I understand the Laika 230v battery charger tops up the vehicle battery as well as the leisure battery when on EHU but thats as far is that goes.

Reading as much as I can on the subject on MH Facts, from Gasperini EG10s to Battery Masters, I conclude that a Battery Master could keep the vehicle battery topped up. The BM fitting instructions show that only 3 connections are necessary (though I think I should fit isolating fuses at both ends as well?) - one to the positive terminal of the leisure batteries, one to the positive terminal of the vehicle battery and one to ground.

The +ve connection to ground and to the leisure batteries is easy, as the logical place to site the BM is beside the leisure batteries. The +ve connection to the vehicle battery is more troublesome for me. I don't want to drag another wire through the bulkhead into the engine bay to connect with the engine battery. 

The BM instruction leaflet recommends looking for a brown wire around the split charge relay to use to connect the positive BM wire to the vehicle battery. 

How would I locate and identify the Split Charge Relay when it's at home?
Any help from you ampere junkies would be helpful.


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## pieterv (Feb 3, 2009)

Hi Norman,

Glad you got your solar panels sorted.

Since you are not getting any replies I will give it a try, but as I don't know Laika might be all wrong.

If your van is anything like a Hymer it will have the charger integrated in a box with other electrical functions, like fuses, and also the split charge relay. So, if this is the case you will not have a separate split charge relay.

If you indeed have such an integrated box, see if you can get hold of a circuit diagram for it. That will show you where the 12V from the vehicle battery is coming in.

Pieter


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## vicdicdoc (May 14, 2005)

NormanB said:


> . . . The +ve connection to ground and to the leisure batteries is easy, as the logical place to site the BM is beside the leisure batteries. The +ve connection to the vehicle battery is more troublesome for me. I don't want to drag another wire through the bulkhead into the engine bay to connect with the engine battery.


I can't help - but I notice you say +ve connection to ground . . . 
is your vehicle Pos to ground ? I'd have thought that modern vehicles are all Neg to ground.
[sorry if I've got the wrong end of the stick so to speak :roll:


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## Pudsey_Bear (Sep 25, 2008)

I think it might just be a typo, he has very fat fingers has our Norman (not) hope it's a typo anyhoo.

Kev.


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## JockandRita (Jun 1, 2005)

Hi Norman,

I assumed, that our solar panel regulator was connected to the starter battery either directly, or via the Elektoblok. WRONG.

DABurgleigh put me onto CAK Tanks Battery Charger Manager BCM 12, on the bottom right of page 79.

Our starter battery now uses the excess amps that the 3 x leisures don't need, and when in storage with the alarm on and no hook up, the MH voltmeter shows a steady reading of 12.7 v and 13.5 for the leisures.

HTH,

Jock.


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## NormanB (Sep 8, 2005)

*Electrical Stuff*

Yes, finger trouble again on the connection polarity - Beam Me Down, Scotty.

Will look at the 230v battery charger under the drivers seat for any clues and try to get the manual translated from Italian to take the next step.

Thank you all who have helped.


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