Split Charge Relay

[Kleenwell]

Hi Guys,

Just looking for some help on adding a second leisure battery.

I already have a leisure battery installed which is connected to the split charge relay, but as I don't do a lot of miles over 2 weeks of the month due to the location of my work, I found that it wasn't lasting until I got back to my other work which is an hours drive away.

So I decided to buy another leisure battery for the lad that's with me, in the hope that it will last till we travel to the other work, what I don't know is, can I just connect the second battery to the split charge relay? or do I connect the batteries together, i.e. in parallel  + to + and - to - then connect the relay to the positive of one battery and the negative of the other battery? any information would be greatly appreciated. This is the relay I use.

View attachment 12173

Those relays have a permanent out and 2 “switched” outs.  Connect one battery to one output, and the other to the other out.  This way, draining one battery will not drain the second battery.    Assuming you have 2 pump controllers.   If not, fit a selector switch to change between batteries.    

The 2 terminals marked “12v”. Both go to your van battery.

0v to ground of van

From memory, 6 and 4 are switched

where as 2 is permanent 

 

[Stsss]

No it isn't I'm afraid.

Its the Durite ones that are.

https://www.ebay.co.uk/itm/0-727-33-12V-140A-140-AMP-DURITE-SPLIT-CHARGE-RELAY-VOLTAGE-SENSITIVE-CAMPERS/191899198454?epid=2224652821&hash=item2cae1563f6:g:sdUAAOSw-3FZDaT8

My Mpower unit is also bi directional

https://www.ebay.co.uk/itm/5mtr-Split-Charge-Relay-Kit-12V-140amp-M-Power-VSR-System-Ready-Made-Leads-T4-T5/262357392539?hash=item3d15b81c9b:g:42UAAOxylpNTPwrr

This is a Durite copy as well

https://www.ebay.co.uk/itm/5mtr-Professional-Split-Charge-Kit-12v-140amp-M-Power-Voltage-Sense-Relay/262893766265?hash=item3d35b08679:g:c34AAOSw5cNYWkF0

I know this is quite an old post, but will the mpower one work with my 110AH 12v leisure battery?

 

[ched999uk]

I know this is quite an old post, but will the mpower one work with my 110AH 12v leisure battery?

Yes as long as you don't have a Euro6 vehicle. Most Euro6 vehicles have what is called a 'smart' alternator that tries to charge when you brake. They also charge at a high voltage which your leisure battery won't like!!! Most Euro6 vehicles need a DC to DC charger!

 

[spruce]

I know this is quite an old post, but will the mpower one work with my 110AH 12v leisure battery?

It depends on your van. The problem starts when you have a smart alternator/charging system that is controlled by the van's ecu.

I had an MPower SCR on my Citroen Relay on an 04 plate. It was fine as I used a flooded leisure battery. This worked because my van's alternator wasn't a smart alternator and it charged at 14.6v. (14.6 volts is the recommended charging rate for a flooded starter battery. (Flooded means that you can unscrew caps on each cell and top them up with distilled water.)

The problem now comes when you have a maintenance free leisure battery and your alternator charges at 14.6v. A flooded leisure battery should only be charged at 14.2v. At 14.6v you are going to overcharge the leisure battery, but as you very really fully charge the battery on day-to-day mileage, it probably won't be the end of the proverbial world.

I replaced that Citroen Relay van with a 62 Plate Peugeot Boxer. I could have also used a MPower SCR on that as it also hasn't a smart alternator. However, the alternator only charges at 13.9v, so it's under the spec for charging a leisure battery. It will work but a leisure battery being charged by an alternator at 13.9v will never be fully charged.

On my Peugeot Boxer I opted for a Sterling Battery to Battery charger BB1260. It boosts my alternator charging rate to 14.2v for my maintenance free leisure battery. (I can set my charging output voltage on my Sterling unit.)

If your van is Euro 6 specced, then you will probably need a B2B charger. This Euro 6 standard was enforced from September 2015, but some vans sold and registered before that are Euro 6 specced. Any van with regenerative braking or an alternator that only charges the starter battery when it falls to 80% capacity will need a B2B charger.

 

[spruce]

Yes as long as you don't have a Euro6 vehicle. Most Euro6 vehicles have what is called a 'smart' alternator that tries to charge when you brake. They also charge at a high voltage which your leisure battery won't like!!! Most Euro6 vehicles need a DC to DC charger!

Agreed. According to George Sterling they have seen some Renault vans with smart alternators charging at 18 volts. 18 volts is far too high for a lead acid starter or leisure battery. The info at the beginning of this post is just as relevant today as it was 4 years ago, possibly even more so as we see more and more newer vans for sale.

 

[Deleted member 7446]

Just to add some more valuable information to the thread 

The two rules of thumb to determine whether your van has a smart alternator is as follows 

Does your van use AdBlue fuel additive 

Does your starter battery negative terminal have a black bulge or covered signal ECU probe on it within close proximity to the battery terminal and more than one cable coming from the the clamp 

If so your van is most likely a newer model with smart alternator 

 

[spruce]

Just to add some more valuable information to the thread 

The two rules of thumb to determine whether your van has a smart alternator is as follows 

Does your van use AdBlue fuel additive 

Does your starter battery negative terminal have a black bulge or covered signal ECU probe on it within close proximity to the battery terminal and more than one cable coming from the the clamp 

If so your van is most likely a newer model with smart alternator 

Another way is to buy one of those voltmeters that plug into the cigarette/auxiliary power socket and watch what happens when driving about.

If the volts read 12.9/13.0v when driving about and then jump up to 16 to 18v when decelerating, then that van is fitted with a smart alternator. You would need to cover a few miles and monitor the gauge for a while before drawing any conclusion. Those volt meter gauges aren't expensive.

 

[Deleted member 7446]

Another way is to buy one of those voltmeters that plug into the cigarette/auxiliary power socket and watch what happens when driving about.

If the volts read 12.9/13.0v when driving about and then jump up to 16 to 18v when decelerating, then that van is fitted with a smart alternator. You would need to cover a few miles and monitor the gauge for a while before drawing any conclusion. Those volt meter gauges aren't expensive.

I just use a traditional 12v accessory plug solderd onto some spare fluke meter leads, don't trust Chineseium 

 

[Stsss]

yeah, I really doubt my van will have smart anything ?, it's a 2008 VW Caddy

 

[Stsss]

Another way is to buy one of those voltmeters that plug into the cigarette/auxiliary power socket and watch what happens when driving about.

If the volts read 12.9/13.0v when driving about and then jump up to 16 to 18v when decelerating, then that van is fitted with a smart alternator. You would need to cover a few miles and monitor the gauge for a while before drawing any conclusion. Those volt meter gauges aren't expensive.

https://www.rydertowing.co.uk/products/caravan-relays/caravan-relays/tf1170-3?fbclid=IwAR05P-qMKBJ7PCsWPhuBwTMU8_32qX63MNoHShv8QhxBeO0oATUhsOkV_tE

This one seems pretty good.

 

[spruce]

https://www.rydertowing.co.uk/products/caravan-relays/caravan-relays/tf1170-3?fbclid=IwAR05P-qMKBJ7PCsWPhuBwTMU8_32qX63MNoHShv8QhxBeO0oATUhsOkV_tE

This one seems pretty good.

Sorry, but forget those. You need something more beefy such as a Durite 140amp or equivalent using 70amp cables at least.

https://www.ebay.co.uk/itm/252340115293?

I see this company are selling kits with 110 amp cable. The one I bought from them some 8 years or so ago had 70amp cables.

The other day after working on a large fascia and window clean I started my van up. The leisure battery drew 51amps of current for a few moments before it started to settle down. During the clean the pumps and diesel heater drew 27 amps from my 105 amp leisure battery.

This isn't the norm but amps such as these will kill that scr you linked to imho.

 

[Deleted member 7446]

https://www.rydertowing.co.uk/products/caravan-relays/caravan-relays/tf1170-3?fbclid=IwAR05P-qMKBJ7PCsWPhuBwTMU8_32qX63MNoHShv8QhxBeO0oATUhsOkV_tE

This one seems pretty good.

To small and flimsy. Better off with a tried and tested Durite 

 

[spruce]

Thank you for the answer..

another question I'm sure I read somewhere that if you use a b2b charger even on a older non stop/start van the charging is around 5x faster is this true?

I know this is an old question and I now have an answer.

I had to remove my Sterling BB1260 from the van a couple of months ago as it developed a fault. The cooling fan wouldn't switch off.

I replaced it with my MPower voltage sensing relay I used on my other van. I used the same cables as the BB1260 and the leisure battery was exactly the same one. I can advise that on my 62 plate Boxer Van there is only a slight improvement on the charge rate, which is hardly noticeable. I think the 5X faster is sales hyperbole. It might be true under very extreme comparison differences, though. If the right size cables are used with the right couplings, then there will be hardly any charge rate difference. The only difference was that my B2B charger was boosting my van's charging voltage from 13.9v to 14.2v. The higher the voltage charge, the faster the charge.

All in all, the B2B charger was out of the van for around 3 weeks before it was put back into service. So plenty of time to analyse the results.

With regard to the Sterling unit, it ended up to be a trapped cooling fan feed wire that was shorting out on the heat sink. It was a quick fix with Sterling's advice. The delay was ordering some liquid insulation 'tape' to repair the cable insulation from Ebay and then refitting it to the van.

 

[Den]

interesting info Spruce thanks for the update ?