Is this a split charge relay system?

[Jungle_Jim]

Hi all, I bought a T25 a couple of weeks ago, having not driven it for about 5 days I went to it on Friday and both the engine and leisure battery were flat. Looking online I suspected that the split charge system was remaining open / on. Yesterday I picked up a battery charger and a multimeter, charged the engine battery and took out the leisure battery, with the van ignition off I was still seeing a voltage across the disconnected terminals of the leisure battery backing up my assumption. See below for a picture of the set-up below, I have looked online and now I'm not even sure this is a split charge relay system...:



Note I have disconnected the positive input to the accumulator charger which has stopped the current passing between the disconnected leisure battery terminals. See below for the technical spec of the accumulator charger, I am not sure this has anything volt-sensitive in so I don't know if a simple replacement would fix the issue of the batteries always being connected:

https://static.rapidonline.com/pdf/55-2467_v1.pdf

As you can see the set up is for two leisure batteries but currently the van only has one (I also probably won't get a second.

Engine and 'leisure' battery are both currently the same - Bosch S4 004. Both appear to be quite need and are giving good readings now charged once dormant and during / after start up.

In summary my headline questions for you are:
1. is this a split charge relay system or is the accumulator charger unit more designed to be connected to a solar panel or something (i.e. always open / on)
2. assuming it is not a split charge relay system what's the easiest solution given the set up above to get it to a volt sensitive split charge system (would be nice to have a light on the relay to know it was charging the leisure battery when the motor is on
3. are the batteries being used suitable for T25s in an engine or leisure capacity (I have a 1985 1.9 petrol)?

Many thanks in advance,

James

[937carrera]

Welcome to the world of T25's

That doesn't look like a traditional split charge system to me, in that it seems to merely split the charging current, so the answer is "sort of". Did you note the spec which says it carries 10A max, that's way below what an alternator may be delivering.

You have two options, VSD which you seem to know something about, and traditional split charge relay system. I prefer the traditional style, it's easier to test and be sure what is going on if there is a problem, relays are easily replaced.

On the battery front the starter battery should be capable of delivering high current for charging.Leisure batteries have a different design which means they can be discharged further / more often without causing damage.

I suspect you have two starter batteries. Many people do as leisure batteries are more expensive, so just be careful not to discharge the leisure battery too far. Some batteries are advertised as "dual use". I don't believe 'em

[Mocki]

That is not a Alternator triggered split charge , it just joins the two batteries together and slowly lets them equalise .

It’s a charge sharer if that was really a name !

It wouldn’t be the cause of two flat batteries, it may well be the cause of the second battery being flat after one of the failed or became drained by something else

[Jungle_Jim]

Thanks for the responses, after charging up the 'leisure' battery I reconnected that without the starter battery feeding into the charge sharer and I noticed the CD player made a noise trying to read a disc (I didn't know I had to take the fascia off to fully turn it off) so I suspect is what had drained both batteries. Both batteries are now holding their charge.

Am I right in thinking I could just replace that 10 amp volt sharer with a Durite Voltage Sensitive Relay (12 Volt 140 amp) and I should be good? The existing volt sharer is connected directly to the starter battery terminals and I'd rather not have to dig around and trail a wire to the alternator for a split charge relay if I can avoid it.

Many thanks

[steveo9007]

This is what i am putting in my van.



Got both these pics for reference

[Mocki]

check that the blue wire to the other automotive relay ( if you have a three way fridge it may well be for the 12v heater element ) already a trigger from the alternator ....
a basic 70amp automotive relay would be far more reliable, cheaper and better imho

[Buckaroo]

if it is so unknown, I would bin it and run my own wiring.
None of the cables look thick enough to run the 20 amps required to charge a battery..look up C20, its on your battery.
My system looks a lot like that which Steveo is going to install in his van.
....and please install a real leisure battery, a starting battery is just not the same, it will die.