Split Charge Relay Help

Right, I've got a Spring controller with charging facility in it. I've just bought a 110 amp leisure battery. I'm finding that I'm having to charge the battery when I get home from work. I usually drive about 50 miles home. The charge in the battery shows around 12.4 - 12.6 when I get home. I would have thought the battery would be fully charged by the time I got home? @spruce, didn't you say that some newer vans have a problem  with charging a leisure battery? I'm thinking of buying a split charge relay to see if this makes any difference. My charging point is a cigar lighter socket in the back of the van near the rear light. What have you guys got and what wires etc will I need to buy? This is the one I was looking to buy https://www.ebay.co.uk/itm/Automatic-Caravan-Battery-Charging-Relay-30-Amp-with-Voltage-Sensor/162074143107?_trkparms=aid%3D333200%26algo%3DCOMP.MBE%26ao%3D1%26asc%3D20180409081753%26meid%3D22a7c3395383472d930d690c56ecbb5b%26pid%3D100008%26rk%3D4%26rkt%3D12%26sd%3D282810258546%26itm%3D162074143107&_trksid=p2047675.c100008.

The reading sounds right. Not sure if different batteries show different to mine but im on a split relay, older type van and also shows between 12.4-12.6 when its fully charged. Im on 110ah numax.

When the van is running it will show just above 14.0 then when ignition switches off it will drop back to resting the reading you mentioned

I've got the same split charge relay and had it for 2 years and never got around to fitting it!

Reason is, none of the existing wiring is up to it so I'd have to put a dedicated cable from the battery and was having trouble routing it through under the dash. You might have a similar problem with your lighter socket not having a high enough rating. The current draw depends on how empty your leisure battery is when you're charging it but if it was very depleted it could draw a considerable current.

Cheers lads, I'm finding that it takes about 4 hours to get it back to fully charged when I hook it up to my charger when I get home. Fully charged with the ignition turned off shows 14.0

Does it still show 14.0 in the morning a few hours after it has been off charge with the van still turned off? 

If yours does then than must mean mine is on its way out

Tuffers said:

Cheers lads, I'm finding that it takes about 4 hours to get it back to fully charged when I hook it up to my charger when I get home. Fully charged with the ignition turned off shows 14.0

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I don't know if I'm just being thick. What do you mean by "Fully charged with the ignition turned off shows 14.0" I thought you hadn't set up the split relay yet?

If you mean charger instead of ignition then it's usual for the voltage to be higher just after charging but it should settle down to 12.8 - 13v

PureShine said:

Does it still show 14.0 in the morning a few hours after it has been off charge with the van still turned off? 

If yours does then than must mean mine is on its way out

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It shows 14 when I turn the pump on and select bat before I start the engine.

Skxawng said:

I don't know if I'm just being thick. What do you mean by "Fully charged with the ignition turned off shows 14.0" I thought you hadn't set up the split relay yet?

If you mean charger instead of ignition then it's usual for the voltage to be higher just after charging but it should settle down to 12.8 - 13v

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I have a charging facility inside my controller. I can see my van battery level and my leisure battery level on the controller.

A fully depleted 110ah leisure battery can take 12 hours to charge with a beefy 8a charger. Your lighter socket could supply anything from 5a to 15a so would still need several hours to charge completely.

You can't use a split charge relay in a new van with variable voltage charging, or whatever it's called, can't recall right now.

I had problem with my split charge when I changed my van to the new transit custom after along wait discovered it was because most new vans have a smart alternater which would not turn split charge on. Was told I would need a 12v to 12v charge fitted to van. This is the one I had fitted and never have charged my battery again 










 


12V – 12V BATTERY CHARGER 12AMP 


Charge 12V Leisure Battery from 12V Cranking Battery









 

Tuffers said:

Right, I've got a Spring controller with charging facility in it. I've just bought a 110 amp leisure battery. I'm finding that I'm having to charge the battery when I get home from work. I usually drive about 50 miles home. The charge in the battery shows around 12.4 - 12.6 when I get home. I would have thought the battery would be fully charged by the time I got home? @spruce, didn't you say that some newer vans have a problem  with charging a leisure battery? I'm thinking of buying a split charge relay to see if this makes any difference. My charging point is a cigar lighter socket in the back of the van near the rear light. What have you guys got and what wires etc will I need to buy? This is the one I was looking to buy https://www.ebay.co.uk/itm/Automatic-Caravan-Battery-Charging-Relay-30-Amp-with-Voltage-Sensor/162074143107?_trkparms=aid%3D333200%26algo%3DCOMP.MBE%26ao%3D1%26asc%3D20180409081753%26meid%3D22a7c3395383472d930d690c56ecbb5b%26pid%3D100008%26rk%3D4%26rkt%3D12%26sd%3D282810258546%26itm%3D162074143107&_trksid=p2047675.c100008.

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If you have a new van with regenerative braking then your current relay in the Spring controller will not work.

Neither will the relay you have linked to. If you have one of these vans then you need a battery to battery charger. Sterling do a BB1230 or a BB1260. Grippa also sell a version. They are more expensive.

I'm confused with your volt readings tbh. When you switch the ignition off you will only get a true reading from your leisure battery after the battery has stood at rest for 4 hours. A fully charged leisure battery will read 12.7v or higher. My battery shows fully charged at 12.8v.

On a standard split charge relay your alternator will charge your leisure battery at around 14.0v to 14.5v depending on the leisure battery's state of charge. When you switch the engine off the voltage will drop quickly to begin with and then more slowly back to 12.7/12.8v. (This takes 4 hours.)

A battery showing 12.4 volts is 50% charged and 12.5v is 75% charged and 12.7 or above is 100% charged. So 0.1 volts is the difference between 50% and 75% charged. This is how accurate your volt meter (Spring Controller) has to be.

As has been previously noted, an Australian RV forum once stated that it will take a trip of 750km for the vans alternator to fully charge a discharged 85amp leisure battery. Whilst 50 miles sounds like a long way, it could be less than an hour's drive on the motor way.

Our usual journey home after work takes 10 minutes most days. So 10 minutes to work, 10 minutes of the engine running and 10 minutes home means I have only put back 30 minutes of charge back into the leisure battery. If the battery was fully charged the previous night, then I have 20 minutes of charging. On my way home the alternator is charging the leisure battery by the tune of 7 or 8 amps. If I choose a 20 minute charge example I have only returned 2.7 amps back into the leisure battery. 

If we worked for 5 hours that day each then I estimate our actual pump running time would be around 2.5 hours for each operator. Our pumps draw 4.5 amps each so we have taken 22.5amps but only put back 2.7 amps. This leaves a deficit of 19.8 amps.

Our discharged battery will accept a faster charge than a nearly full one. You can't change this unless you go Lithium ion as they will accept a higher charge for longer. But their price is way out of reach for our application.

Numax also told me that for battery longevity, they only suggest that a battery is charged at around 10% of is capacity, So the maximum charge a 110 amp leisure battery should be charged at is 11 amps.

Johnwindow1987 said:

I had problem with my split charge when I changed my van to the new transit custom after along wait discovered it was because most new vans have a smart alternater which would not turn split charge on. Was told I would need a 12v to 12v charge fitted to van. This is the one I had fitted and never have charged my battery again 










 


12V – 12V BATTERY CHARGER 12AMP 


Charge 12V Leisure Battery from 12V Cranking Battery









 

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Have you got a link to that please?

I fitted a split charge last week. For the benefit of anyone reading this for advice I have the same van as @Tuffers (New Citroen dispatch). I have the battery housed under the passenger seat as it springs up. My readings each night have been between 12.75 and 12.95. The chap who helped me fit it is an electrical engineer, I mentioned how you have yours wired, he said something about why that wouldn't work and we fitted the full split charge the standard way directly to the battery in the engine.

What do you think of this?

Charges at 7a and will connect straight to your lighter socket in the back.

Skxawng said:

What do you think of this?

Charges at 7a and will connect straight to your lighter socket in the back.

View attachment 15828

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What's it supposed to do?

These things usually have a couple of batteries or capacitors inside just to give a car battery a little boost to start the engine. It was once calculated that a starter motor takes an initial draw current load of 200 amps to get a 2.0 diesel engine moving which rapidly drops off within the first second. If your starter motor takes just over 2 seconds to start the van, your battery is down by 4.5 amps - the same amount of current one of our Shurflo pumps draws in an hour.

So this little booster might work in an ideal situation but its not guaranteed. It certainly wouldn't run a WFP pump for long.

Tuffers said:

Right, I've got a Spring controller with charging facility in it. I've just bought a 110 amp leisure battery. I'm finding that I'm having to charge the battery when I get home from work. I usually drive about 50 miles home. The charge in the battery shows around 12.4 - 12.6 when I get home. I would have thought the battery would be fully charged by the time I got home? @spruce, didn't you say that some newer vans have a problem  with charging a leisure battery? I'm thinking of buying a split charge relay to see if this makes any difference. My charging point is a cigar lighter socket in the back of the van near the rear light. What have you guys got and what wires etc will I need to buy? This is the one I was looking to buy https://www.ebay.co.uk/itm/Automatic-Caravan-Battery-Charging-Relay-30-Amp-with-Voltage-Sensor/162074143107?_trkparms=aid%3D333200%26algo%3DCOMP.MBE%26ao%3D1%26asc%3D20180409081753%26meid%3D22a7c3395383472d930d690c56ecbb5b%26pid%3D100008%26rk%3D4%26rkt%3D12%26sd%3D282810258546%26itm%3D162074143107&_trksid=p2047675.c100008.

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Have a look at this tutorial I put up a few years back as there is a fair bit of info on that thread.

https://windowcleaningforums.co.uk/topic/22375-split-charge-relay/?tab=comments#comment-396866

Grippa tank also have a similar write up on their site (when I last looked) as to why a battery to battery charger is need with new vans with regenerative braking.

But you will still need to periodically bench charge your battery to fully charge it.

spruce said:

What's it supposed to do?

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It's not just a jump starter, it's a battery to battery charger that charges with a 7a output. The instructions say to have it connected for 45 mins to give another car enough charge to start.

It just seems pretty cheap for what it claims it can do. It's a good brand though so don't know what to think.

Skxawng said:

It's not just a jump starter, it's a battery to battery charger that charges with a 7a output. The instructions say to have it connected for 45 mins to give another car enough charge to start.

It just seems pretty cheap for what it claims it can do. It's a good brand though so don't know what to think.

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I don't either. We would use a set of jumper cables, but that would mean lifting the bonnet of both cars.

https://www.drapertools.com/products/manuals/46544ins.pdf

I’m reading this on my mobile and not taking all the info in ?. What I do know is that when I drive the van and then stop and turn the ignition off I can see chg flashing on the controller. I’m now confused as to whether it is charging as I drive or not.

Dunno if it’s any help but I bench charged mine last night. I’ve done 4 maintenance cleans, 2 first cleans and a 2 hour GFS, and 5 bed house and I’m reading 12.8. All jobs within a mile of my house... forgot to test it this morning for a reading but the charger showed fully charged. (Picture just incase I’m testing it wrong)

P4dstar said:

Dunno if it’s any help but I bench charged mine last night. I’ve done 4 maintenance cleans, 2 first cleans and a 2 hour GFS, and 5 bed house and I’m reading 12.8. All jobs within a mile of my house... forgot to test it this morning for a reading but the charger showed fully charged. (Picture just incase I’m testing it wrong)

View attachment 15829

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Where did you get the battery terminal clips from Paddy? Do you take off the leads going to your controller when you bench charge the battery? I have crocodile clips from the controller to the battery and unclip them when I charge.

Johnwindow1987 said:

I had problem with my split charge when I changed my van to the new transit custom after along wait discovered it was because most new vans have a smart alternater which would not turn split charge on. Was told I would need a 12v to 12v charge fitted to van. This is the one I had fitted and never have charged my battery again 










 


12V – 12V BATTERY CHARGER 12AMP 


Charge 12V Leisure Battery from 12V Cranking Battery









 

Click to expand...

Is there a link? 

Tuffers said:

Where did you get the battery terminal clips from Paddy? Do you take off the leads going to your controller when you bench charge the battery? I have crocodile clips from the controller to the battery and unclip them when I charge.

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The terminals came in the set with the split charge. I had some from Euro before but these seemed much stronger. I physically remove the battery from the van to charge it so I just unplug everything and take the battery inside. 

P4dstar said:

I fitted a split charge last week. For the benefit of anyone reading this for advice I have the same van as @Tuffers (New Citroen dispatch). I have the battery housed under the passenger seat as it springs up. My readings each night have been between 12.75 and 12.95. The chap who helped me fit it is an electrical engineer, I mentioned how you have yours wired, he said something about why that wouldn't work and we fitted the full split charge the standard way directly to the battery in the engine.

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How did you manage to get wires from inside the cab into the engine? I was going to wire directly to the van battery rather than the cigar lighter when I first started rigging the van out but I couldn't find a way of getting from cab to engine. What split charge relay have you got Paddy?