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Voltage drop when split relay connected to 13.3 down from.14.4

WCF

Help Support WCF:

So Question regarding this earthing 

So the starter battery is earthed to the chassis the leisure battery is being charged when you run the engine does that mean that the leisure & starter batteries are effectively in parallel whilst the engine is running? and that could mean that the negatives of each battery as well as the positives via a relay are connected together.

I'm just trying to figure it all out its defo more fun then cleaning windows but if the above is true if that is the case can this mean the leisure battery is already connected to the chassis.?

Hope my question makes sense.
We have only seen a photo of the relay. It will be easy enough to see if your leisure battery has a cable to earth.

https://www.ebay.co.uk/itm/New-Cable-30-76Cm-Car-Earth-Strap-Battery-Lead-Cable-Post-Negative/353083182353?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20201210111314%26meid%3D034b55294b4742db9c2d430f139360d0%26pid%3D101195%26rk%3D2%26rkt%3D12%26mehot%3Dpf%26sd%3D353083183835%26itm%3D353083182353%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseUnbiasedWeb%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851

You will have other wires coming off your leisure battery; those for the pump controller and the electric hose reel. These wiring diagrams are only to do with the charging side.

Here is a longer video of the same clip you put up earlier.




 
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Little update. Purchased a new Excide 115amp ER550 as I'm sure they were mentioned here along with Numax to purchase. These are good battery's right @spruce? And also purchased the split relay charge Pack with 16m sq cables. These tables are so much thicker than the ones I have.

I have an appointment booked on Saturday too to wire it all up for a reasonable cost.

Everything is going to be earthed this time!

I saw a lot of people Mount the split relay on the starter battery area and it gets earthed there also does anyone recommend this also and if not please let me know.

Thanks!

 
Little update. Purchased a new Excide 115amp ER550 as I'm sure they were mentioned here along with Numax to purchase. These are good battery's right @spruce? And also purchased the split relay charge Pack with 16m sq cables. These tables are so much thicker than the ones I have.

I have an appointment booked on Saturday too to wire it all up for a reasonable cost.

Everything is going to be earthed this time!

I saw a lot of people Mount the split relay on the starter battery area and it gets earthed there also does anyone recommend this also and if not please let me know.

Thanks!
We mounted the Durite SCR on the back (cargo side) of the bulkhead as it has a light that comes on when charging so we can monitor it and change it easily in the unlikely event. We can also monitor it by sound as it clicks as well, which is just audible from the cab. I'd do the same again. It's easy to run an earth. Having stuff easy to monitor and maintain is very important to me. My van battery is under the double passenger seat. I rarely need to see it.

 
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Little update. Purchased a new Excide 115amp ER550 as I'm sure they were mentioned here along with Numax to purchase. These are good battery's right @spruce? And also purchased the split relay charge Pack with 16m sq cables. These tables are so much thicker than the ones I have.

I have an appointment booked on Saturday too to wire it all up for a reasonable cost.

Everything is going to be earthed this time!

I saw a lot of people Mount the split relay on the starter battery area and it gets earthed there also does anyone recommend this also and if not please let me know.

Thanks!
Personally I would prefer to fit it inside the van rather than the engine department.

We bought my son's van from a window cleaner who wanted to upgrade to a bigger van. The split charge relay came with the van, and it is situated in the engine compartment with no issues. But if I was doing the job I would fit it inside where it is dry.

@P4dstarhas an Exide battery and it's fine according to his last report. No battery will last forever. Experience has show that these combo batteries are working in 'no man's land.'

Its just imperative that the battery is fully charged. I do mine every night. Adding a diesel heater and/or an electric hose reel does zap the battery's energy.

 
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Personally I would prefer to fit it inside the van rather than the engine department.

We bought my son's van from a window cleaner who wanted to upgrade to a bigger van. The split charge relay came with the van, and it is situated in the engine compartment with no issues. But if I was doing the job I would fit it inside where it is dry.
Cheers and what do you think of the battery?

I recall you mentioned exide 

 
I have the ER550 in both vans. With a discount code (there's loads online) you'll get it for circa £130. Best part was when I had an issue (On a previous battery) my local ECP just took the battery and changed it, never questioned what it was used for. It is B rated by the caravan club. 

https://www.eurocarparts.com/p/exide-leisure-er550-battery-115ah-444776790

Worth investing in the B2B charger instead of a split charge too. I haven't had to bench charge my battery since fitting one of these. Worth mentioning I do more miles than the average windy, going between villages round here.

 
I have the ER550 in both vans. With a discount code (there's loads online) you'll get it for circa £130. Best part was when I had an issue (On a previous battery) my local ECP just took the battery and changed it, never questioned what it was used for. It is B rated by the caravan club. 

https://www.eurocarparts.com/p/exide-leisure-er550-battery-115ah-444776790

Worth investing in the B2B charger instead of a split charge too. I haven't had to bench charge my battery since fitting one of these. Worth mentioning I do more miles than the average windy, going between villages round here.
Looks like I got a good battery then I paid about 115 for this one brand new

 
I'll just like to update this has finally been resolved.

Voltage is now finally showing 14.4-14.5 at the leisure battery.

Purchased the split relay pack with 8m of 16m2 red 2m of 16m2 black. Durite relay heat shirks good quality eyes 100amp fuses etc.

One of my old mechanics basically done me a favour for mates rates we both worked on it actually took I don't know how but took 6 hours! Now Totally understand why a professional would charge a decent amount of money for his time.

It's just very fiddly the longest time was finding the clear path from the the starter battery to the glove compartment. We had to dismantle some of the van and there is a clear path but you need to have a long rod to aim it. Anyhow 

Everything is guided in everything is perfect with conduit protected. 

The relay is mounted in van with a solid earth.

The leisure battery is now earthed solidly with the thick cable directly down into the the seat area which indeed provides a very solid Earth!

What I will say is the battery was actually Earthed already but with a thin black cable so before we placed the new earth I tested the voltage with current earth and it was good 13.9, 14.00 much better than 13.2 to what I was getting with the thin live if you remember the 1v drop but once we connected the thick earth it jumped up to 14.4 14.5! Which is exactly what the alternator provides.

So the conclusion

As anticipated given the previous good performance of my other van it's all in the thicker cable.

make sure you have the appropriate thickness of cable 16m2 that's all the way so starter to relay relay to Leisure and the earth. Make sure all your Earth connections are solid we used an angle grinder to scrape away paint. So if you ever experience a voltage drop which is definitely more likely to happen with thinner cable just check all connections and double check your Earthig thoroughly. With the right cable thickness both your batteries when engine is running should show 14.3-14.5v. And once these relays detect a voltage of 12.65 or less it will cut off the light will then turn off!.

Anyhow as you can all see I've learnt quite a lot from everyone on this forum I'm pretty knowledgeable now about the whole thing largely thanks everyone on the forum thanks to everyone for thier input on this topic ?

 
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Great stuff! I think you'll find the Durite SCR and decent leisure battery to be a fit and forget solution. You may or may not need to mains charge sometimes to top up. That will unfold over a few weeks.

Well done. ?

 
I'll just like to update this has finally been resolved.

Voltage is now finally showing 14.4-14.5 at the leisure battery.

Purchased the split relay pack with 8m of 16m2 red 2m of 16m2 black. Durite relay heat shirks good quality eyes 100amp fuses etc.

One of my old mechanics basically done me a favour for mates rates we both worked on it actually took I don't know how but took 6 hours! Now Totally understand why a professional would charge a decent amount of money for his time.

It's just very fiddly the longest time was finding the clear path from the the starter battery to the glove compartment. We had to dismantle some of the van and there is a clear path but you need to have a long rod to aim it. Anyhow 

Everything is guided in everything is perfect with conduit protected. 

The relay is mounted in van with a solid earth.

The leisure battery is now earthed solidly with the thick cable directly down into the the seat area which indeed provides a very solid Earth!

What I will say is the battery was actually Earthed already but with a thin black cable so before we placed the new earth I tested the voltage with current earth and it was good 13.9, 14.00 much better than 13.2 to what I was getting with the thin live if you remember the 1v drop but once we connected the thick earth it jumped up to 14.4 14.5! Which is exactly what the alternator provides.

So the conclusion

As anticipated given the previous good performance of my other van it's all in the thicker cable.

make sure you have the appropriate thickness of cable 16m2 that's all the way so starter to relay relay to Leisure and the earth. Make sure all your Earth connections are solid we used an angle grinder to scrape away paint. So if you ever experience a voltage drop which is definitely more likely to happen with thinner cable just check all connections and double check your Earthig thoroughly. With the right cable thickness both your batteries when engine is running should show 14.3-14.5v. And once these relays detect a voltage of 12.65 or less it will cut off the light will then turn off!.

Anyhow as you can all see I've learnt quite a lot from everyone on this forum I'm pretty knowledgeable now about the whole thing largely thanks everyone on the forum thanks to everyone for thier input on this topic ?
6 hours - that sounds like the time it would take me. ?

Seriously, thank you for the update. The leisure battery earth cable is something I never thought to ask about as we generally take it for granted it would be a standard earth strap.

It's like when I was trying to talk my mother-in-law through signing onto her iPad recently. I was trying to get her to press the home button at the bottom of the iPad to get to back to her front screen. She didn't have a button. I didn't realize she had her iPad upside down.

 
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