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

[ched999uk]

I went back to beginning of thread just to check things.

What does your relay look like?

This https://www.ebay.co.uk/itm/Heavy-Duty-Split-Charge-Relay-Kit-Leisure-Battery-200-Amp-x-2M-Power-Cable/324236634282?hash=item4b7e0268aa:g:TywAAOSwVapfFxHf or https://www.ebay.co.uk/itm/0-727-33-DURITE-SPLIT-CHARGE-RELAY-12V-140A-140-AMP-VOLTAGE-SENSITIVE-CAMPERS/191899198454?epid=24032159398&hash=item2cae1563f6:g:-OMAAOSw-GNb5CQd

Can you show a picture of relay? or at least make and model number?

I assume you are testing voltage drop when engine is running?

If you just switch ignition on (no engine running) can you hear the relay click?

 

[Davy G]

I can't recommend a relay from personal experience but the 0-727-33 DURITE SPLIT CHARGE RELAY 12V 140A seem to be used by quite a few. 

It doesn't need an ignition control connection as it senses van batt voltage and then only connects leisure batt when van is charged. So it works a little different to your one. 

It is so difficult to remotely diagnose things and I wouldn't want to cost you unnecessary money. Do you have any mates that are into electronics or can use a multimeter? 

I would have said if there is a voltage drop then relay faulty but you tried a new one and exactly same issue. 

Might be a stupid question but is current system causing an issue? 

That's the relay I use very successfully. I never mains charge. I checked the voltage on the two linked 120 AH leisure batteries this afternoon. The reading was 12.5 volts and the van hasn't been started since we finished our week's work on Wednesday afternoon. A short week which tied in with a week we had off a while back. Our 6 weekly scheduling makes it easy for us to manage the round.

I'm happy with that voltage as a cruising/standing reading.  I don't strive for fully charged all the time. I don't think it's good for the batteries.

 

[Quickwindowclean]

I went back to beginning of thread just to check things.

What does your relay look like?

This https://www.ebay.co.uk/itm/Heavy-Duty-Split-Charge-Relay-Kit-Leisure-Battery-200-Amp-x-2M-Power-Cable/324236634282?hash=item4b7e0268aa:g:TywAAOSwVapfFxHf or https://www.ebay.co.uk/itm/0-727-33-DURITE-SPLIT-CHARGE-RELAY-12V-140A-140-AMP-VOLTAGE-SENSITIVE-CAMPERS/191899198454?epid=24032159398&hash=item2cae1563f6:g:-OMAAOSw-GNb5CQd

Can you show a picture of relay? or at least make and model number?

I assume you are testing voltage drop when engine is running?

If you just switch ignition on (no engine running) can you hear the relay click?

Hi one sec I'll try find the relay 

None of those. I'll be able to confirm the one-click tomorrow as the battery is currently taking a heavy bench charge last 5 hours... 

The relay is definitely clicking but I'll confirm exactly you're saying ignition on on no engine running.

Back in a sec and I'll try and find a relay thank you very much for your help

 

[Quickwindowclean]

Wait a minute there is one thing did you say the fusing has to be near the split relay as in in any fuse because there's plenty of fuses nearer to the auxiliary battery is that an issue?

 

[Quickwindowclean]

This is the split relay exactly this one.

https://www.ebay.co.uk/itm/30-AMP-SELF-SWITCHING-DUAL-SPLIT-CHARGE-RELAY-CARAVAN-FRIDGE-MAYPOLE-MP2883-/283943633323?_trksid=p2349624.m46890.l49292

Its cheap 

 

[ched999uk]

Wait a minute there is one thing did you say the fusing has to be near the split relay as in in any fuse because there's plenty of fuses nearer to the auxiliary battery is that an issue?

+12v on Van battery - Fuse - cable to Split charge relay - cable - Fuse - leisure battery.

There should also be fuses from the leisure battery to your pumps and reels.

 

[Quickwindowclean]

+12v on Van battery - Fuse - cable to Split charge relay - cable - Fuse - leisure battery.

There should also be fuses from the leisure battery to your pumps and reels.

I tell you what I'll inbox you some pictures so we dont flood this post too much later if we do managed to resolve it we can share the winning solution.

Perhaps you will see something regarding fuses etc

How about tomorrow 

 

[Davy G]

I look forward to hearing the results when you and Ched solve it.

 

[ched999uk]

This is the split relay exactly this one.

https://www.ebay.co.uk/itm/30-AMP-SELF-SWITCHING-DUAL-SPLIT-CHARGE-RELAY-CARAVAN-FRIDGE-MAYPOLE-MP2883-/283943633323?_trksid=p2349624.m46890.l49292

Its cheap 

OK so found out a bit more about this.

You should have the van battery connected to either or both of the pins labelled as 12v. The pin labelled as 0V should be connected to ground (Van chassis). It appears that the pin labelled Pin 2 should then go to your leisure battery. That should be all that's required. 

Here is the connections if you were using it for it's intended purpose which is for a caravan. The pin numbers refer to connecting to the car side of a 12S caravan connector which does the bits other than the vehicle lighting:

MAYPOLE MP2883
12v = van battery
12v = van battery
Pin 6 12S = Fridge
Pin 4 12S = Battery
Pin 2 12S = Ignition +ve (Battery Charging) THIS ONE connects to leisure battery
0V      = Van Chassis

So check which pin no is connected to your leisure battery. Let us know. I will carry on looking.

 

[ched999uk]

This looks like the instructions:

 

[ched999uk]

There is also a very small rotary control on relay front top left corner. This appears to adjust when it switches as it is a voltage sensing relay. Which means that it will only start charging leisure battery once van battery has reached a certain voltage. So in theory this control can be rotated to adjust the switch voltage. ie. you could adjust it so it connects the leisure battery to van battery at say 13v then it would start charging the leisure battery sooner but your van might not get fully charged. I wouldn't start tweaking yet as we don't know if there is anything not quite right yet.

This device doesn't seem to be ignition controlled so I don't know why there is an additional wire going under your dash? 

You should just have 3 wires on it. 1 from van battery, 1 to leisure battery and an earth. No others are necessary as far as I can see.

 

[ched999uk]

Bit more info:

The relay is set at default to switch on at 13.5 volts and off at 13.2 volts and features heavy duty screw terminal blocks for cable up to 4mm²

So that means that when the the van battery reaches 13.5v the leisure battery should start to be charged. When the van battery drops to 13.2v i.e. engine off alternator not charging then the leisure battery is disconnected.

 

[Quickwindowclean]

OK so found out a bit more about this.

You should have the van battery connected to either or both of the pins labelled as 12v. The pin labelled as 0V should be connected to ground (Van chassis). It appears that the pin labelled Pin 2 should then go to your leisure battery. That should be all that's required. 

Here is the connections if you were using it for it's intended purpose which is for a caravan. The pin numbers refer to connecting to the car side of a 12S caravan connector which does the bits other than the vehicle lighting:

MAYPOLE MP2883
12v = van battery
12v = van battery
Pin 6 12S = Fridge
Pin 4 12S = Battery
Pin 2 12S = Ignition +ve (Battery Charging) THIS ONE connects to leisure battery
0V      = Van Chassis

So check which pin no is connected to your leisure battery. Let us know. I will carry on looking.

Wow . Looks like you're really on top of this thx alot. So I'm going to check tomorrow as a van is parked a few mins away but I have 12v in from main in pin 6 is the earth and pin 3 for the auxiliary battery. You're saying it should be pin 2?

There is also a very small rotary control on relay front top left corner. This appears to adjust when it switches as it is a voltage sensing relay. Which means that it will only start charging leisure battery once van battery has reached a certain voltage. So in theory this control can be rotated to adjust the switch voltage. ie. you could adjust it so it connects the leisure battery to van battery at say 13v then it would start charging the leisure battery sooner but your van might not get fully charged. I wouldn't start tweaking yet as we don't know if there is anything not quite right yet.

This device doesn't seem to be ignition controlled so I don't know why there is an additional wire going under your dash? 

You should just have 3 wires on it. 1 from van battery, 1 to leisure battery and an earth. No others are necessary as far as I can see.

The auto guy pointed this out but I did not want him to play with it.

The live feed into the exilory battery is coming from under the dashboard rather than through the engine area as its firewalled off there's no difference though regarding the voltage drop as I have also run a wire directly from the battery so in other words I'm getting the live feed from a wire within the dashboard leading into the back of the van where the Leisure battery is.

Bit more info:

The relay is set at default to switch on at 13.5 volts and off at 13.2 volts and features heavy duty screw terminal blocks for cable up to 4mm²

So that means that when the the van battery reaches 13.5v the leisure battery should start to be charged. When the van battery drops to 13.2v i.e. engine off alternator not charging then the leisure battery is disconnected.

I think you're onto something here because

That's the maximum voltage into the battery meanwell my Leisure battery has been taken a heavy charge for the last 6 hours still on 2.0 2.1 wasn't fully depleted but definitely wasn't it enough for the usage I need and I feel the lack of voltage is struggling to keep the battery fully charged.

What I'll do is I'll get some pictures of the fuses did you say the fuses need to be near the leisure battery or near the relay because there's plenty of your fuses near the leisure battery if I remember correctly.

 

[ched999uk]

Wow . Looks like you're really on top of this thx alot. So I'm going to check tomorrow as a van is parked a few mins away but I have 12v in from main in pin 6 is the earth and pin 3 for the auxiliary battery. You're saying it should be pin 2?

OK so to clarify the MAYPOLE MP2883 images I have seen the connections are labelled I am not counting the connections from left to right I am using the numbers on the sticker!

The connection to the leisure battery should be the one next to the 0v/earth.

So first 2 are from +12v feed (under dash might not be able to provide 30Amps) I realise there is a firewall (Bulkhead) between passenger compartment and engine bay but there are not many if any cables under the dash that are capable of providing what they were designed to do plus an additional 30Amps to charge your leisure battery!!! It's not a good idea to try and tap into wires under that dash to pull significant current as the cable and fuse protecting it are not designed to do that!!!!

Bulkheads/firewalls will have rubber grommets that allow wires to pass through. It's normally possible to push through extra wires through the rubber grommets to get from van battery through towards back of van. Any such cable should have a new fuse added next to the van battery, the closer to the battery connection the fuse is the better.

This is a car stereo connection but you get the idea how close a fuse holder should be to battery:

It's a very posh fuse and a bit over the top especially for a windy van ? 

 

[ched999uk]

That's the maximum voltage into the battery meanwell my Leisure battery has been taken a heavy charge for the last 6 hours still on 2.0 2.1 wasn't fully depleted but definitely wasn't it enough for the usage I need and I feel the lack of voltage is struggling to keep the battery fully charged.

What I'll do is I'll get some pictures of the fuses did you say the fuses need to be near the leisure battery or near the relay because there's plenty of your fuses near the leisure battery if I remember correctly.

I do wonder how much charge the MAYPOLE MP2883 is currently actually giving to your leisure battery. Hopefully the battery will recover but it might have suffered damage and reduced it's capacity.

The fuses near the leisure battery are probably just for your pumps and reels so shouldn't be important to the issue.

If it's wired into dash and not doing a good job I would be inclined to buy a kit like this https://amzn.to/2VFdl4b It's not cheap and will require a big crimp tool or soldering but then you could connect directly to van battery with supplied fuse, through bulkhead then to split charge relay to fuse to leisure battery. All connectors are included and 5m of thick cable. You would need someone who can solder thick connectors on and can use heat shrink sleeving etc. If you need a professional to fit it I would look up local motorhome service people as they should know about split charge systems and ask them about split charge systems before you buy a new one.

Anyway take the picks tomorrow and let us know as I would like to get to the bottom of what is happening. 

 

[Quickwindowclean]

I do wonder how much charge the MAYPOLE MP2883 is currently actually giving to your leisure battery. Hopefully the battery will recover but it might have suffered damage and reduced it's capacity.

The fuses near the leisure battery are probably just for your pumps and reels so shouldn't be important to the issue.

If it's wired into dash and not doing a good job I would be inclined to buy a kit like this https://amzn.to/2VFdl4b It's not cheap and will require a big crimp tool or soldering but then you could connect directly to van battery with supplied fuse, through bulkhead then to split charge relay to fuse to leisure battery. All connectors are included and 5m of thick cable. You would need someone who can solder thick connectors on and can use heat shrink sleeving etc. If you need a professional to fit it I would look up local motorhome service people as they should know about split charge systems and ask them about split charge systems before you buy a new one.

Anyway take the picks tomorrow and let us know as I would like to get to the bottom of what is happening. 

Hi.

I will do I'll get in touch tomorrow thank you very much it looks like you are going to crack the case.

 

[spruce]

There is also a very small rotary control on relay front top left corner. This appears to adjust when it switches as it is a voltage sensing relay. Which means that it will only start charging leisure battery once van battery has reached a certain voltage. So in theory this control can be rotated to adjust the switch voltage. ie. you could adjust it so it connects the leisure battery to van battery at say 13v then it would start charging the leisure battery sooner but your van might not get fully charged. I wouldn't start tweaking yet as we don't know if there is anything not quite right yet.

This device doesn't seem to be ignition controlled so I don't know why there is an additional wire going under your dash? 

You should just have 3 wires on it. 1 from van battery, 1 to leisure battery and an earth. No others are necessary as far as I can see.

That unit isn't ignition controlled so he won't hear a clicking noise when he switched the ignition on.

Where is he taking power from to this vsr? (It's not technically a split charge relay, rather a voltage sensing relay.)

On the first model Transit Connects the wiring harness was the same harness used in the people carrier. The people carrier had an auxiliary power take off point in the boot. They omitted this accessory from the van but later added it with later builds. However you could tap into it. There was an empty fuse slot in the fuse box. I can't remember if the relay activating this accessory was included. I think it was as it supplied other electrics.

That accessory needed a 15 amp fuse.

Personally, he needs to remove his current system totally and fit one of those 140amp vsr's with 16mm battery cable running from his van battery to the relay and then from the relay to the leisure battery with correct fuse positioning.

I had one of those relays op has on my first van and it failed. Hence the Mpower unit I replaced it with.

 

[Quickwindowclean]

I do wonder how much charge the MAYPOLE MP2883 is currently actually giving to your leisure battery. Hopefully the battery will recover but it might have suffered damage and reduced it's capacity.

The fuses near the leisure battery are probably just for your pumps and reels so shouldn't be important to the issue.

If it's wired into dash and not doing a good job I would be inclined to buy a kit like this https://amzn.to/2VFdl4b It's not cheap and will require a big crimp tool or soldering but then you could connect directly to van battery with supplied fuse, through bulkhead then to split charge relay to fuse to leisure battery. All connectors are included and 5m of thick cable. You would need someone who can solder thick connectors on and can use heat shrink sleeving etc. If you need a professional to fit it I would look up local motorhome service people as they should know about split charge systems and ask them about split charge systems before you buy a new one.

Anyway take the picks tomorrow and let us know as I would like to get to the bottom of what is happening. 

 

[Quickwindowclean]

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[Quickwindowclean]

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I've put out pictures of the split relay connectors as per the picture and I've also put out pictures of the fusing near the battery there is one fuse from the live under the dashboard but when we remove that fuse with the auto electrician we also had the same issue.

The battery has taken a hellacious charge about a good 14 hours so far yet it was showing 12.65 on the voltmeter before.

There's one thing which I haven't done as it felt it was too simple and that was could my battery have a very low resistance and caused this voltage drop at all across the system?

It might sound a bit silly not sure but I might swap this battery with the other battery in the other van and see if I get the same 13.3 mind you the battery is about to be fully charged so I may be able to see.

Please let me know your thoughts on the earthing etc and I think what's spruce says is a good idea to rewire with appropriate size cables and the better relay.

 

[Davy G]

I think at this stage it probably is a good idea to change the SCR for a Durite. I have two, one in the workvan that was professionally fitted at Hall's Electrical, Swindon (They do a lot of work on emergency vehicles so know their stuff), and one in my campervan that I fitted myself, after. Taking great care and checking and double checking as I went on. I got a 5 metre complete kit online. I worked from the leisure battery back to the starter battery and did a final check before I fitted the fuses and made it live.

Ps, if you go this route, make sure you get a kit that is suitable for your vehicle.