Leisure Battery charging problem

[thechubbsdub]

Not sure how this can happen. Any advise on how to solve the problem would be very welcome. My leisure battery does not seem to be charging from the split charger. I suspect the problem is with the split charger as the following happened this morning. I took voltage readings before driving approx 20 miles. They were main battery 12.45v, leisure battery 11.19v I then took readings again and they were main 12.96v and leisure 7.48v
The zig unit is a CP400 and was not turned on at any point. I have also replaced the leisure battery within the past month.
I first noticed the problem a few weeks back when the green light on the zig was changing to red very soon after a long run.
Being of very limited technical ability, I don't even know what a split charger looks like, never mind what to with it if I found it.
So my questions are - does this sound like a split charger problem or something worse such as alternator? Where am I likely to find the split charger? What sould I do to it if I do find it?

Thanks

Adrian

[AngeloEvs]

Compare the voltage across the leisure battery (and starter battery) with engine off and then engine on. The voltage across the leisure battery should be higher with the engine running even when idling and virtually identical to the starter battery (which should also read higher) with engine on. No change across either battery indicates a problem with the alternator. If the starter battery voltage increases but not the leisure battery then you have a fault in the split charge relay circuit, a fuse ruptured, etc. Relays for the charging circuit (and fridge), fuses,etc, are often placed close to the starter or leisure battery but this can vary according to who fitted the split charge wiring. Some conversions require you to select the 'Touring' position and don't always include a spit charge relay. There should be no drain on the leisure battery if everything is switched off so something strange there have to say.

[Oldiebut goodie]

Your Zig unit is not a charger one - it is only a distribution panel.
You will have to look for a relay split charge as per AngeloEvs post above.
Relay should look something like these.

Untitled 1.jpg

[Red Westie]

I think you have already part answered your own question.....Quote: I took voltage readings before driving approx 20 miles. They were main battery 12.45v, leisure battery 11.19v I then took readings again and they were main 12.96v and leisure 7.48v
It is clear that your main starter battery has been recieving charge but the leisure has not.
So you need to look for a positive wire that connects the two batteries together...somewhere along this wire there should be the split charge relay and fuse (usually close to the starter battery) check the fuse first as it could be that simple (not alowing charge across to the leisure)
If the wiring/relay are in anyway damaged (melted, evidence of heat, bad corrosion) you may be just as well advised to remove the defective wiring and fit a new smart split charge relay and appropriate wiring (40amps plus) for peace of mind (wiring/relay/terminals that can handle at least 40 amps continuos) 50 amps preferable. That should be fine for a single standard 75 amp leisure battery.These new charge sensing relays are very simple to install as they don't have the added complication of switch sensor wiring so everything is done inside the van between the two batteries.
If you have to terminate old wiring remove what you can, and properly insulate wires that you don't remove.
Martin

[thechubbsdub]

Thanks for the replies and useful advice.
With your help, I have now established that the alternator is fine (charging starter battery) and there is no movement on the leisure battery voltage with the engine running. I have also checked the wiring from positive to positive on the batteries and found two relays near the starter battery. My next question is how do I check these to see if they are working?

Adrian

[AngeloEvs]

you will hear them click or 'feel' them click when someone else starts the engine but I would be looking for the in-line fuse and checking this first, should be close to the relays if wired correctly but may be elsewhere. Also try to establish which relay is for the fridge and which is for the split charge if possible just in case the fuses are OK ans you need more help.

[thechubbsdub]

I have checked both inline fuses but not listened for a click from the relays. Is the fridge one to power the fridge from the starter battery while driving?

[AngeloEvs]

yep, one for 12V operation of the fridge, listening for the click can be tricky but placing something solid from relay to lug hole can help. Could be that the feed that drives the relays from the ignition/alternator is faulty but if one works and t'other doesn't then its the relay or an in-line fuse,etc. The relays will have heavier gauge cables for the source - feed and are connected using spade connectors. The relays will/should have a diagram (usually moulded or printed) on the relay body with some sort of indication of which terminal does what. The feed terminals that operate the relay is a square with the other symbols being the switch contacts. If you aren't sure, sketch the relative positions of the cables and remove the relay, take a piccy, post it and loads of help will flood in from all quarters of this club.

[thechubbsdub]

Thanks again. I will try that then get the daughters boyfriend to have a look at it over the weekend. He had a T25 himself and is pretty handy with leccy.

Adrian