Split Charger for leisure battery

[MidLifeCrisis]

Ok - that sounds fair enough; and I assume that you connected pin 85 to a ground?
And you said that your relay only had 4 pins right?
I would disconnect the wire going from the relay to the leisure battery at the leisure battery end and measure the voltage on that wire as you start/stop the engine? (This will eliminate any confusion about whether you are reading the starter battery voltage or the leisure battery voltage)
Try that and report back what you get?
Then disconnect the wire going to your pin 86 (the one from the charge light) and measure the voltage on that as you start/stop the engine - and report back on that?
(Also pictures could really help or a sketch of the circuit that you have created?)

[TONYT25T25]

Hi, thanks for response, before coming on line I did the first check you mentioned, I disconnected the lead from the pos terminal on the leisure battery and measured the voltage on the lead, this is where I got the same reading as the main battery therefore isolating any confusion from the leisure battery, I will check the second part you mentioned ref the link to the the charge light via pin 86. May not be able to get back tonight but will update u when I can. Further to my last, is it ok to connect 85 the earth direct to the main battery or does this cause problems?? Rgds

[MidLifeCrisis]

Nope - you should be ok connecting 85 to battery - but obviously must be the negative terminal!! But also ok to ground to a bit of clean metal on the van if that is easier.

[MidLifeCrisis]

Another test .....
Connect everything back up as you had it; turn the ignition on but don't start the engine; now disconnect the wire to pin 86 and the relay should NOT click (try repeatedly connecting/disconnecting to be sure there is no click); now start the engine and do the same test - you should get a clicking sound from the relay each time you connect/disconnect the wire to the relay??

[TONYT25T25]

Tks, used this connection on battery as could hear the relay clicking more clearly, leaning towards the connection to the alternator light as a possible problem, I am also using a four point relay valued at 30 amps, It came with a car alarm which is my next project. just read your last post will do that test also.

[TONYT25T25]

Update on Split Charger issue.

I would disconnect the wire going from the relay to the leisure battery at the leisure battery end and measure the voltage on that wire as you start/stop the engine? (This will eliminate any confusion about whether you are reading the starter battery voltage or the leisure battery voltage)
Try that and report back what you get?

DID THIS NO VOLTAGE SEEN.


Then disconnect the wire going to your pin 86 (the one from the charge light) and measure the voltage on that as you start/stop the engine - and report back on that?

ABOVE 14V SEEN WHEN ENGINE RUNNING

Another test .....
Connect everything back up as you had it; turn the ignition on but don't start the engine; now disconnect the wire to pin 86 and the relay should NOT click (try repeatedly connecting/disconnecting to be sure there is no click);

TESTED AND NO CLICK HEARD.

now start the engine and do the same test - you should get a clicking sound from the relay each time you connect/disconnect the wire to the relay??

DID THE ABOVE AND THE RELAY CLICKED

[CJH]

Only the result of the first test is odd. It sounds like your trigger wire is ok, and the relay is opening and closing correctly. So it sounds like a fault with your supply wire from the starter battery or the feed wire to the leisure battery. Or perhaps a faulty relay. So a couple more tests to pinpoint it:

1) Make sure the supply from the starter battery always has the starter battery voltage on it (I know you've said this is the case, but best to check nothing has changed), and make sure it is connected to pin 30 of the relay.

2) Remove the leisure battery feed wire from pin 87 and then use your multimeter to check the voltage on pin 87 both with and without the engine running.

3) To check that the relay is working (if the above two tests don't pinpoint the problem), remove the wires from pins 30 and 87, set your multimeter to 'Ohms' or 'continuity', and check that those two pins are joined when the engine is running and that they're separated when the engine's off.

[TONYT25T25]

Tks again, will do the above checks and get back with results on Monday.Rgds

[TONYT25T25]

Managed to get some time to resolve issues, it looks as if along with two U/S in line fuses and a faulty relay may have been the cause of my problems, both fuses had blow or were no good when I installed them, after doing a bit of continuity checks all now appears ok. Tks for assistance given above, hopefully the issues I had will assist other users. Rgds

[California Dreamin]

I intend to use 15 amp cable with 10amp fuses and a 30 amp relay

I haven't read every reply word for word so forgive me if I am repeating what others have said.

Looking at your original post I am surprised that knowone (unless I've missed something) has pointed out the serious shortcomings in the hardware setup you have installed.

Taking a simple leisure battery/starter battery split charge relay setup, where the starter battery is around 60ah and leisure 80 - 100ah that the initial amps flowing between the two with a discharged leisure can easily peak in the mid 30's amps, quickly dropping to low 20's.

So...lets have a look at the hardware you are proposing/have fitted.

30 amp relay (under rated...needs to be a minimum of 40 if not higher)
15 amp wire...totally inadequate.
10 amp fuse...again vastly under rated BUT the only thing preventing the wire from melting.

Serious 'MINIMUM specification' should be:

40 amp relay (you might get away with 30 but the contacts will have a tenancy to stick/burn given the load is so close to the relays maximum handling capacity.
35 amp wire (battery to battery) the switch wires can be much lighter gauge (blue switch & opposite earth)
30 amp fuse (even this may blow on the rare occasion)

No wonder you are having problems.....how many 10 amp fuses have you already used?

Martin

[Eloise]

Sorry to jump on the thread but it saves me starting a similar one. My van only has the one battery wired in, I want to wire in a second to run the 12v when camping. The van currently has a working fridge with the usual 12v when engine running facility, hook up or gas at site. Am I right in thinking that there must be a split charge type circuit or relay there from manufacture to enable the fridge to work on 12v?

If this is the case, can I splice into the trigger for this relay, for the trigger for the new split charge relay, instead of splicing behind the dash? I think this relay maybe close to the original battery or in a cupboard near the fridge? If anyone knows the usual location of it, can you offer advice please.

Cheers neil

[MidLifeCrisis]

If this is the case, can I splice into the trigger for this relay, for the trigger for the new split charge relay, instead of splicing behind the dash? I think this relay maybe close to the original battery or in a cupboard near the fridge? If anyone knows the usual location of it, can you offer advice please.

No idea where your relay is but yes you should be able to splice into the trigger for that relay to trigger the split charge relay.

[Eloise]

Thanks for that.

[TONYT25T25]

Hi all, thought this thread had ended hence no reply to valuable information give above ref values of fuses when using a split charger, have not had any more issues and both batteries appear to be keeping their charge, although I have not depleted the leisure battery enough to warrant the above issues yet so will keep an eye on any fuse blowing etc. Tks again.

[TONYT25T25]

Ref split charger for fridge, my fridge does not work on electric either 240 or 12v and have not used the gas option, but when investigating I found a relay behind the fuse panel which houses the water pump, 12v supply etc and other fuses found towards the internal rear of the vehicle, this appears to be the relay that only allows the fridge to run only when the vehicle is being fed from the alternator. Still trying to work out why my fridge does not work on electric even the 240v option so any tips welcomed.