Battery Charging

[spud350]

I don't use my van regularly so the SB and LB lose a bit of charge. I have a willinton kit on, so if I put a trickle charger on the SB, once it's fully charged up will it switch over and start charging the LB, bearing in mind there isn't any ignition on. What do you think?

[dave_aber]

Yes it will. The Willinton will see the higher SB voltage and act as if the alternator is running and link the batteries.

[spud350]

That's good then. I'll just attach it to the SB and charge them both.

[tcflinty]

Hi New Member ......Please excuse my ignorance but what is a Willington kit? I have a small white junction box under the bonnet where my electrics from the Control Management System come in to . In the box is a relay and on the outside of the box there is TWO 40amp fuses and One 5amp fuse,the problem I have is the 5amp keeps blowing .I think this is the reason my L/B is not charging ,is the 5amp fuse to low ?
Would appreciate any help.

Flinty

[g8dhe]

That doesn't sound like a Willinton kit (name of the chap who sells Split Charge relays/wiring loom/battery tray on Ebay) without knowing what the 5 Amp fuse is doing then its difficult to say if its been replaced previously with two low a rating or if there is a fault which the fuse is correctly blowing for!

In any split charge system there should be TWO fuses, close to the batteries, which protect the cables running to the split charge relay, there should also be a fuse to protect the cable that supplies the power from the L/B to the additional circuits again close to the battery. 40 Amps sounds about right for the first two, 5 Amp sounds too low for most additional circuits, the fuse protects the wiring remember - not the devices, normally you would expect at least 15 Amp for that circuit at least, possibly higher, if the wiring is suitably rated.

[tcflinty]

Thanks for that Geoff ,sorry but I made a mistake they are two 25amp fuses not 40amp . I will try a 10amp in first to see if that stops blowing and the L/Batt starts charging.

Flinty

[g8dhe]

OK that sounds fine for the two fuses @ 25 Amps, which should be protecting the charging cable itself.

Incidentally if one should ever blow, ALWAYS replace BOTH as they will have both have got very hot and one will have failed just milliseconds prior to the other, hence its very common to replace one and then find that the other blows very shortly afterwards because it has been damaged by the heating.