Battery Separator - Intermittent

runner2011

Hi, hoping somebody can offer advice here before i start spending money on replacement parts. Developed an intermittent problem with the battery separator (I think) .. here's the problem . Start the Engine in the Camper and after about 4 seconds the CBE - PC200 panel should should show that the battery separator has kicked in , if the step is down the warning buzzer will sound and the fridge comes on if switched to Battery all with a slight audible click from a relay around the 12V distribution board (or inside it) which is a CBE DS300 but sometimes it doesn't and after a few switch off and on agains it does.. once it is on it stays on until i switch off the engine. I think it is the battery separator but hard to tell when it's intermittent. The main Engine battery is good , camper is only 3 years old (Euramobil , X250 based) , all connections are clean and tight. As far as i know the battery separator kicks in once it gets a higher than 13.3v feed from the alternator and if i measure at a feed off the Battery coming into the 12V distro board it reads 14V+ once the engine is started and around 12.8V when off. I am thinking that the DS 300 board is faulty but since they are STG£100 new i would really like to get some opinions first. I'm not sure if there is another "signal" box that tells the DS300 to engage the Separator ..i think its all self contained but again not sure. One thing i did do about a week ago was add a second 110A Leisure battery (now 2*110A same type and make) which is testing fine, was new and is holding charge just fine. I disconnected the second battery and the problem is still there.. not sure if that would have anything to do with it but thought id mention it. Any help or thoughts would be greatly appreciated.

Have you any electrical docs. manuals or a wiring diagram for your setup?

What is a battery separator? I'm guessing you don't mean the permeable membrane placed between a battery's anode and cathode.
What is it's function? Is it perhaps the relay that links the batteries to charge the leisure batteries off the alternator? If this is what you are describing then I think it's probably a faulty relay. €15 give or take depending on size. If you can remove it I'd bench test it first to confirm. Also check the relay terminal connections for 12v next time it doesn't work. You should have 2 lives, one ground and one dead if my hypothesis is correct.

Adding batteries in parallel is best done with similar aged batteries to prevent imbalances. It will have implications in the long term if they are significantly out of sync. I'd water and equalise the eldest if it's a flooded battery type to give it the best chance.

Parallel battery wiring to balance cells

Also batteries must be charged at a bulk rate of roughly 10% capacity (check for exact figures from manufacturer) this means a mains charger for a 220Ah bank should be 22Amp.
None of this however has any effect on you current predicament if your charger is too small it'll just take longer to charge and possibly undercharge but it will still work. Your alternator probably won't be concerned at all they're usually well over-spec-ed.

runner2011

Hi Sir Liamalot. Below is a link for the PC200 Kit and the "Wiring" Diagram...its not great. Firstly thanks for the reply and the info on the battery .. didn't think it would have much or anything to do with it but wanted to mention it. The Battery Separator is the relay that links the batteries to charge off the Alternator as you say. There is a bank of relays underneath the Distro Box and they are all identical types and ratings .. although i don't have the wiring diagram for the bank of relays i swapped them around and the intermittent problem was still there.
The Distro Box is supposed to house this so called Separator hence me thinking its that ... would this make sense that that device is built into this box? is there a typical location for this type of relay ..like near the Alternator? ..thanks a mil.

http://www.marcleleisure.co.uk/store/pdf/PC100_PC200_DS300_ENcircuits.pdf

runner2011

runner2011 wrote: »

i swapped them around and the intermittent problem was still there.

That suggests a wiring problem so. If you swapped the right relays.

runner2011 wrote: »

The Distro Box is supposed to house this so called Separator hence me thinking its that ... would this make sense that that device is built into this box? is there a typical location for this type of relay ..like near the Alternator? ..thanks a mil.

They should already be separated in essence that suggests it does nothing. Therefore I reckon it's working

It wouldn't be near the alternator on a coach build only cowboys do that. Too many belts and spiny things in that vicinity.

Usually the automotive and leisure electrics are separate. I've never been inside a coach build though so that's not saying a lot.
I'd imagine it's in the charger lemme have a gander at this doc.

[EDIT: Check socket on connector that links to...] pole 1 on connector 18 for 12volt [EDIT #2...when engine is running and battery light in the dash is off]. Use good chassis ground for negative meter probe.
Check fuse springs are strong (if you have any) & clean contacts on Fuse 10, 3A D+ (alternator signal live).

What ambient voltage does your alternator run at?

Here's a theory: your separator is designed not to overcharge your batteries, it achieves this by undercharging your batteries :rolleyes:.
The alternators I've worked with will overshoot 13.3v in jig-time. Mine usually runs at 14.0v - 15.0v. It could all be working as prescribed and it's just a dreadful design. Have you known the vehicle long and this is a new development?


Page 32 70A Relais, that's the suspect (Jaysus what a monster! ..that'll be a bit more than €15). Open up the distro and check the connections on that next time it doesn't work. If they're all good pull the relay and bench test it.
Can you verify that this is where the clicking noise comes from when you turn the ignition?

runner2011

I Checked all the connections and the Distro Box is getting the correct signal feeds.. Alt runs at 14.7V... Think you might have spotted it .. that 70A Relay .. its hot to touch and Smells , if you know what I mean, a bit burnt. Couldn't see that Relay originally as it's not with the bank of relays and hidden around the back of the Distro unit. I have ordered a new one €9.. from Flea bay ..genuine Tyco part..i'll let you know how i get on. Thanks a mil.

You may be better off to pull the relay first and bench testing it. Apart from the 3A fuse check the rest will need to be live circuits so it's up to yourself whether you are comfortable with that. Don't pull the relay out with the engine running, 70A @ 12volt is serious business (I really doubt it's running that high).

Ah the aulde hot and burnt piece of electronics chestnut...I know it well. Yeah it's a goner. Cool bananas. No worries, happy to help.

runner2011

Really appreciate the help .. great forum!

Sir Liamalot

Sir Liamalot wrote: »

Don't pull the relay out with the engine running, 70A @ 12volt is serious business (I really doubt it's running that high).

Actually second thought, turn everything off and disconnect both leisure batteries when removing/installing, even with the engine off your batteries have plenty-a bang in store.

runner2011

Received the Relay today and popped it in.. all sorted now. Again thanks for the help Sir Liamalot.

Glad it worked.

Um....before you sign off maybe check the new relay for heat?
Disconnect mains hook up.
Run the engine at warm idle with the alternator going for a while, 30mins or so with a everything on in the camper habitation.
Kill ignition and disconnect the leisure batteries after turning everything off.
Open the distro.
Feel the back of the new relay.
If it's getting hot to touch you have a problem elsewhere that may have caused the last relay to fail.
If it's modestly warm or not noticeable then all as is well.

runner2011

good idea... i ran the Camper for 30 mins with all the 12V gear on also ran the air con in the cab .. using an infrared thermometer the ambient air temp was 19c and the relay sat at 40.5c after 10 mins .. another relay that is on also is sitting at the same temp so im presuming thats normal. According to a data sheet i found from Hella the relays are bench tested at 50c and have a MAX full load temp of 80C ..so all seems good. Cheers!

Happy days.
Wouldn't worry about electronics under 50°-60°C it's fairly natural. My laptop will hit 80°C by times but that's another story.