Installing a B2B charger in Euramobil 810 C class based on a 2005 Fiat Ducato

[nigelivy]

Hi Folks

I currently have two 90ah AGM leisure batteries in my Euramobil 810 C class (based on a 2005 Fiat Ducato), which I believe are on their way out. I've been wanting to make the jump to a set of LiFeYPO4 batteries, which I realise I'll need to make extensive changes to the entire charging system (EHU, engine & solar).

I'm currently considering <Broken link removed>, which is quite pricey, but the write-ups seem very good and feels like it'll be easier to install than separate chargers, plus I like the idea of the charger being able to manage where the charge comes from (e.g. charging from solar at the same time as engine).

I've got my head around what is needed to change the EHU & solar chargers, but the thing that I'm still trying to get my head around is the built-in split charge system from the engine. Does anyone have any pointers on what needs to be disconnected/changed for that?
I know that I need to run substantial cables as per the manufacturer's specs for the B2B charger that I choose, but what changes do I need to make to the existing split charge system?

Many thanks,

Nigel

 

[Kannon Fodda]

I haven’t read all the specs but it looks like the B2B function from alternator is only 20A? That’s small probably barely better than any present relay. You need to know it is compatible with the lithium.

 

[ManTheVan]

Hi and welcome. You won’t regret a move to LiFePO4, but you already realise that it will involve quite a bit of kit upgrading.

There are many threads here about this, but check out the excellent one by Pausim, which describes almost exactly what you ask. It involves installing a normally-closed relay to bypass the built-in split charge, which is the advice I followed.

I‘d also suggest checking out the Sterling Power website. They have a selection of refurbished and/or end of line units at a good discount. As the previous poster said, the 20A supplied by the votronic won’t really cut the mustard. Sterling do a 30A model and others of greater capacity. They all have built-in LiFePO4 profiles.

I highly recommend the Victron Smartsolar controller. They do various sizes, but have a useful Bluetooth function which works with a dedicated app to give you real-time information.

I bought my LiFePO4 battery from Batterymasters and have been delighted with it. https://www.batterymasters.co.uk/li...cle-life-lighter-weight-charger-included.html

It all takes some thinking through, but definitely worth doing if you can. We have not used EHU at all since upgrading.

 

[nigelivy]

I haven’t read all the specs but it looks like the B2B function from alternator is only 20A? That’s small probably barely better than any present relay. You need to know it is compatible with the lithium.

Thank-you! Tbh, I'm not hung up on which gear to install. I have no problem with installing multiple separate devices (B2B, Solar, etc..). The main reason I was looking at that particular one was that I thought it might be better to have it all in one so the device decides where the charge comes from at a given point. So thank-you for the input. I'll definitely look at higher amperage.

 

[nigelivy]

Hi and welcome. You won’t regret a move to LiFePO4, but you already realise that it will involve quite a bit of kit upgrading.

There are many threads here about this, but check out the excellent one by Pausim, which describes almost exactly what you ask. It involves installing a normally-closed relay to bypass the built-in split charge, which is the advice I followed.

I‘d also suggest checking out the Sterling Power website. They have a selection of refurbished and/or end of line units at a good discount. As the previous poster said, the 20A supplied by the votronic won’t really cut the mustard. Sterling do a 30A model and others of greater capacity. They all have built-in LiFePO4 profiles.

I highly recommend the Victron Smartsolar controller. They do various sizes, but have a useful Bluetooth function which works with a dedicated app to give you real-time information.

I bought my LiFePO4 battery from Batterymasters and have been delighted with it. https://www.batterymasters.co.uk/li...cle-life-lighter-weight-charger-included.html

It all takes some thinking through, but definitely worth doing if you can. We have not used EHU at all since upgrading.

Thank-you! Really appreciate the advice. I've heard good things about the Voltronic gear. Do you have separate Voltronic gear for your set up (e.g. charge controller, B2B, etc..) and is it smart enough to know what to do when you're running the engine and also receiving solar charge? Does this cause any problems for LiFePO4 cells?

^{_{Subscribers  do not see these advertisements}}

 

[Lenny HB]

Votronic gear is good and made in Germany. The Road Pro spec for the 3242 is incorrect, it is 20 amp mains charger and 30 amp B2B also the solar is only 250 watt.
You would be better with the 3246, 40 amp mains charger, 60 amp B2B & 430 watts solar.

I'm not a great fan of all in one units as if one section fails and you need to get it repaired you are stuffed, separate units may be a bit more expensive but give more flexibility.

I don't know what your system is but you could simply disconnect the existing split charge relay.

 

[nigelivy]

Votronic gear is good and made in Germany. The Road Pro spec for the 3242 is incorrect, it is 20 amp mains charger and 30 amp B2B also the solar is only 250 watt.
You would be better with the 3246, 40 amp mains charger, 60 amp B2B & 430 watts solar.

I'm not a great fan of all in one units as if one section fails and you need to get it repaired you are stuffed, separate units may be a bit more expensive but give more flexibility.

I don't know what your system is but you could simply disconnect the existing split charge relay.

Thanks for the input, Lenny. Much appreciated!

I'm not hung up on what I install, so open to suggestions on that. My initial thoughts on having an all in one system is that it might be better as it can decide where the charge comes from, but I suppose most of the "good" brands of chargers (be it solar, B2B or 240v) will be smart enough to work together and I might be advised to stick to a single make in order to ensure that?
I agree that the risk of having all in one is that if it dies, we're stuffed, so from a redundancy point of view, separating them out is advisable.

Do you happen to know how best to locate the split charge relay or where I can get some sort of wiring diagram/documentation on this?
I have searched through this forum, but not found any threads on doing this on a Euramobil of similar configuration to mine (yet) and my experience of dealing with Euramobil has been nothing short of painful, so haven't even bothered contacting them directly to ask for help.

 

[Lenny HB]

If going for seperate units Votronic do seperate mains, solar & B2B chargers they would be my choice, another good brand is Victron.

I don't know how you use your van but we very rarely use EHU and rely on solar and engine charging. If I wanted to save a bit I might go for a cheaper mains charger.

 

[nigelivy]

If going for seperate units Votronic do seperate mains, solar & B2B chargers they would be my choice, another good brand is Victron.

I don't know how you use your van but we very rarely use EHU and rely on solar and engine charging. If I wanted to save a bit I might go for a cheaper mains charger.

We VERY rarely use EHU. On the current set up, we pretty much only connect EHU when the van is parked on our driveway to keep the batteries topped up. We use the van often (and intend to continue using it often), probably at least once a month, sometimes more. We mostly wild camp and if we do stay in proper sites, we rarely connect up. The most important for me is the B2B and solar system. I currently have two 100w solar panels on the roof, but might add another one or two if need be once I see how the current panels cope with the new Lithium batteries.

Tbh, the EHU charging system is an easy change anyway and something I'm very comfortable with as I've already figured out what goes where, what needs to be changed, etc.. to install a new charger. The B2B part of the set up is what I'm trying to figure out now, particularly to ensure that I don't cause any problems with the existing split charge system and if possible, I'd like to see if I can keep the ability to run the fridge off 12v (when the engine is running) in the new set up.

I like what I've read on both Voltronic and Victron and would be open to using either.

 

[denisejoe]

I think there is a b2b fitted to your euramobile there is on mine

^{_{Subscribers  do not see these advertisements}}

 

[nigelivy]

I think there is a b2b fitted to your euramobile there is on mine

Do you know where it's located on your van?

 

[denisejoe]

Its by the internal batteries solar also shows charging the engine battery when leisure batteries are full

 

[Al-Di]

yes B2B fitted to 800 series, our is on the main panel in front of batteries,

 

[Lenny HB]

I'd like to see if I can keep the ability to run the fridge off 12v (when the engine is running) in the new set up.

Shouldn't be a problem there should be one relay for the split charge and one for the fridge.

Also the Votronic Solar regulators have an AES output that switches the fridge to 12v when the batteries are charged & there is plenty of solar. It does it in half hour blocks so as not to flatten the batteries. You will need to fit a switch or relay in line with the feed so it doesn't switch to 12v when on EHU.

With the age of your van the fridge won't have the connection for solar, I think you just need to fit a diode in series and connect to the D+ on the fridge.
I think funflair has done this on his last van.

 

[funflair]

Shouldn't be a problem there should be one relay for the split charge and one for the fridge.

Also the Votronic Solar regulators have an AES output that switches the fridge to 12v when the batteries are charged & there is plenty of solar. It does it in half hour blocks so as not to flatten the batteries. You will need to fit a switch or relay in line with the feed so it doesn't switch to 12v when on EHU.

With the age of your van the fridge won't have the connection for solar, I think you just need to fit a diode in series and connect to the D+ on the fridge.
I think funflair has done this on his last van.

Lenny is correct that I fitted the solar AES on our last van, but he might not be correct about stopping the 12v switching when on EHU as our 7 series never did that as it had the correct priority sequence later fridges seemed to get it wrong.

Back to the Votronic with AES out, yes this will switch a normal D+ fridge but the diode is required on the end of the run signal cable from the alternator to stop the AES signal going to ground via the alternator windings.
.
.

^{_{Subscribers  do not see these advertisements}}

 

[nigelivy]

Hi Folks!

Many thanks to everyone for your input and advise. I thought I'd share some photos of the system that my van has, in case that is helpful and incase anyone has any pointers.

There are two 100w solar panels, that each have their own charge controller. I'm not sure why they have separate charge controllers, but they do. I'll be looking at replacing these with a single modern charge controller that can charge the LiFeYPO4 batteries that I intend to get.

This is the existing charge that's wired to the EHU. Obviously this will need to be replaced.

This is the 240v trip switch where the EHU comes in, goes to the charger, goes to the plugs, etc..

This is some sort of regulator/monitor that obviously connects to the display unit. The 12v coming from the EHU charger & engine come into here and then out to the batteries.

This is the 12v circuitry with fuse board. I can see here that the cables coming from the engine come in here, onto the board and then out again to the batteries. It looks like there is a relay on the board, but I'm not 100% of that. There is also a relay in the wiring, but I haven't yet traced where that goes. It's quite a crows nest of wires!
I still haven't found a B2B charger on my van, but I assume there isn't one and that the split charge is built into this board?
Does anyone have any idea where (if possible) I would be able to get a wiring diagram for this unit?

 

[Lenny HB]

That looks like fun.
Try emailing CBE they should be able to give you a basic block diagram that will give you all the connections.

 

[RogerIvy]

That looks like fun.
Try emailing CBE they should be able to give you a basic block diagram that will give you all the connections.

We've emailed CBE, waiting for a reply.
We've also emailed Votronic just to see what they say.
We've also emailed Euramobil, they simply state that this is not something they can help with as it's a change they have never had to make. Kinda shocking really.

 

[Lenny HB]

It's unbelievable the lack of support by manufacturers of electrical systems. They fit fairly complicated systems, yet refuse to issue wiring diagrams even to their dealers.
Schaudt appear to be the most helpful of all the companies but not much use if you have a CBE system.

 

[RogerIvy]

It's unbelievable the lack of support by manufacturers of electrical systems. They fit fairly complicated systems, yet refuse to issue wiring diagrams even to their dealers.
Schaudt appear to be the most helpful of all the companies but not much use if you have a CBE system.

Schaudt were very helpful about ten years ago when I needed them.

^{_{Subscribers  do not see these advertisements}}

 

[Terry and Angie]

I have just seen that the Ultramax 100 amp lithium batter is now just over £400 now I think that is affordable for me, they say on there site it is a drop in replacement is this not right,I have a 2016 bailey with a NDS 100w solar panel and controller which lithium setting on it , now I’m thinking that the van will not charge the lithium battery fully is that right, or do I need to replace loads of other stuff...

 

[RogerIvy]

After reading up for days on end my take on it is that older chargers will bring the batteries to 90 or 95% but never 100%. I read one article (can't find it now) where the writer explains how older chargers can damage LiPO4 batteries but have read many more that say it won't happen.

So for me there were two questions:
1) Will my current charging system keep my Li batteries safe (answer I believe = Yes)
2) Will my current charging system charge Li batteries reasonably fast (answer I believe = No ... given that Li batteries can be changed much faster than lead)

I can assume therefore that I should upgrade my main charging system (B2B) and possible change cables etc.
My solar controller is quite old ( installed 2011) but I'd consider leaving it as my panels are also old and not that effective. Good MPPT controllers that handle 2+ panels are expensive.
When on EHU even a smaller charger is fine because one assumes you've arrived with reasonably full batteries from your B2B and as you're on EHU you're not draining much from your batteries. Therefore may as well change it to an inexpensive charger. But ... many have stated that Li enables you to go completely off grid anyway so why use EHU at all? Maybe just because you've paid for it?

Nigel is installing his new Li batteries this week and I'm keen to see how it works before I spend money.
wfdTamar mentioned Lead carbon in this post and I'm keen to follow this option too with the only real downside being no weight reduction (and slightly less capacity than Li).

 

[RogerIvy]

... now I’m thinking that the van will not charge the lithium battery fully is that right, or do I need to replace loads of other stuff...

One way of looking at it (and it's just my theory) is that by using normal lead charging stuff your Li batteries will last much longer as you'll operate within the 20%-95% band which makes them very happy.

 

[denisejoe]

I just connected solar to the leisure battery’s shows on main panel when charging engine battery by showing 2 batteries connected

 

[denisejoe]

When on solar does any charge go to the engine battery Check engine battery at night and then at midday

^{_{Subscribers  do not see these advertisements}}

 

[autorouter]

This is some sort of regulator/monitor that obviously connects to the display unit. The 12v coming from the EHU charger & engine come into here and then out to the batteries.

That blue cylinder thing is a current sensor. All the DC current comes in on the left terminal, through the fuse, then along that wire bridge that goes through the cylinder, and out through the two right terminals. The circuitry measures the current, and transmits the information along those thin wires.

This kind of current measuring device is called a Hall Effect Sensor, and works on a different principle to the usual Resistive Shunt type of sensor.

 

[nigelivy]

That blue cylinder thing is a current sensor. All the DC current comes in on the left terminal, through the fuse, then along that wire bridge that goes through the cylinder, and out through the two right terminals. The circuitry measures the current, and transmits the information along those thin wires.

This kind of current measuring device is called a Hall Effect Sensor, and works on a different principle to the usual Resistive Shunt type of sensor.

Thanks for the info! That makes sense!

 

[autorouter]

After reading up for days on end my take on it is that older chargers will bring the batteries to 90 or 95% but never 100%.

This desire to top up and keep the batteries at 100% is a feature of lead-acid and its variants (flooded, gel, AGM, lead-carbon etc). Lead-acid batteries degrade if left below 100% for long periods of time. Lead sulphate forms inside the battery as a normal part of the discharge process. It starts off as a soft gooey paste, which can change back into other chemicals during charging. If left for long periods it hardens into crystals which are impossible to change back again. So the battery loses a bit of capacity.

Lithium batteries don't suffer from that problem. In fact it's recommended to charge them to about 50% for long-term storage. They degrade if they are overcharged or float-charged. Best to keep them between 10% and 90%, avoiding extremes.

Lithium battery chargers don't have a float-charging mode like lead-acid types. The ones intended for charging an isolated battery on a bench simply cut off when fully charged. Some lithium chargers, especially in motorhomes, have a final state where the voltage is a bit below the 100% level, to avoid overcharging but able to supply power to loads without discharging the battery. People call it a float-charging state, but it isn't really.

As luck would have it, most lead-acid chargers have a 'float voltage' that is OK for most lithium batteries, but it's best to check.