Installing Victron B2B charger

[burtonwisher]

I have a couple of questions about the installation of a Victron Orion DC-2-DC / B2B charger into my motorhome.

The motorhome is a Ducato based 2010 Autotrail Apache, with a Sargent EC225 control unit and EM50 interface unit.

The reason for this is that I am installing LiFePO4 batteries. I already have a Victron MPPT solar controller and a Victron mains charger, so those charging profiles are OK for lithium, and I want to make sure that the alternator charging is also optimised for Lithium and doesn't cause any problems.

My problem though is that it seems there is no way to disconnect the existing charge to the leisure batteries from the alternator, without also disconnecting other critical connections. I spoke to Sargent who told me this. They say that the only way to disconnect their split charge relay to stop the alternator charging the leisure battery would also stop the 3-way fridge running on 12v when the engine is running, stop the step retracting, and cut off the EMC relay.

So my 2 questions are:

1) Does anybody have any knowledge or experience in disconnecting the existing alternator-leisure battery charge in this setup, without any detriment elsewhere?

2) If I install the Orion B2B but left the existing setup in place, would that cause a problem or prevent the Orion B2B from working properly?

Many thanks

 

[Hoovie]

Ah - so you are disconnecting the Leisure Battery from the EC rather than the Starter Battery (mixed up my Brown/Blue with my Brown/Green )
I think personally I would have dropped the Starter Battery connection (if the Relay fails and locks to NO or goes OC totally, you loose all your leisure electrics. If it fails and is on the Starter Circuit, very little consequence), but either way would work.

 

[Revolvor]

Ah - so you are disconnecting the Leisure Battery from the EC rather than the Starter Battery (mixed up my Brown/Blue with my Brown/Green )
I think personally I would have dropped the Starter Battery connection (if the Relay fails and locks to NO or goes OC totally, you loose all your leisure electrics. If it fails and is on the Starter Circuit, very little consequence), but either way would work.

You are right. The cable to the leisure battery was easier to access, which is why I did that. The relay is very accessible, so if it does fail, I will just remove it and connect the two wires until I can replace it.

burtonwisher has pointed out to me that just removing the fuse for the vehicle battery, in the EC225 has the same effect, but with loss of some functionality - no voltage display on the panel, and also unable to charge from the EC charger.

 

[burtonwisher]

Here's an update on where I'm up to with this and what I know so far, although the work isn't completed yet so I'll update after the weekend when it's done and fully tested....

In regards to my original second question, it became clear that I did need to disconnect the existing split charge relay to avoid having any problems when installing the Victron B2B.

As Broken Link Removed said, after a conversation with Sargent and some trial & error, I found that in my setup, removing the 20A Vehicle battery fuse from the EC225 control box cuts the split charge function. The split charge relay is located inside the EC225, and it closes the vehicle and leisure battery connections together when the D+ engine running signal is detected.
Removing the vehicle battery fuse therefore prevents the connection being made.
With this fuse out, the fridge still works fine in all scenarios, and the step still works fine too. These were my initial concerns but they turned out not to be problems. These things are all managed by the EM50 unit, so removing the fuse from the EC225 has no impact on them.
There are some issues with this setup though, which aren't problems for me but could be for others:
- The control panel won't show the vehicle battery level, but as I have an external monitor for this, it's not a problem
- There is no longer the ability to direct mains charge to the vehicle battery by manually selecting it on the control panel, but I've installed a seperate Victron mains charger anyway so I don't use the one in the EC225, so also not a problem for me
- If you do select the vehicle battery on the control panel, you get a low battery warning buzzer. However for the above 2 reasons I don't ever press this button, and it always defaults to leisure battery first when powered up.
If I ever do need to use these functions I can just stick the fuse back in.

So I'm now planning to install my Victron B2B this weekend and will update again when it's done.

I do think that the solution Broken Link Removed has implemented is a neater and more permanent solution, which I intend to do myself at some point. Thanks to Broken Link Removed for sharing the details of this. It essentially does the same thing but without any of the issues I listed above, so I'd recommend it to anyone wanting to do the job properly.
But for now at least, pulling the vehicle battery fuse from the EC225 does the job with no negative impact for me.

I've also learned through this that even when the same equipment is in place (EC225 and EM50) in other vehicles, the connections aren't always the same, so I guess an element of testing and trial & error will always be needed to be sure in each case.

 

[Motorhomer14]

This is a great thread and very informative for anyone with the Sargent system. Its not the easiest of systems to play with as I have found in the past. Lucky for me I have a better system which is much easier. I just wanted to add a couple points after reading all the replies.

burtonwisher What you have done is what I have posted else where. It should remove the charging supply which can be tested by taking a voltage reading of the leisure battery which should not increase when engine is started. I would expect this not to interfere with fridge supply as this should be on a separate fused supply. The main issue as you have said is loosing the mains changing of the starter battery.

Revolvor solution is much nicer. It essentially removes the leisure battery from the circuit. Only thing that would be nice is to have a warning or fail safe if this was to fail. A buzzer on the N/C circuit from the D+ supply if the relay was not to come in the buzzer would sound. The reason I say this, if the relay failed to come in you would essentially have the B2B and Sargent charging in parallel which is not good.

Hoovie has already said what I was going to point out, where people say they drop the lithium in and it works and see a charge through the B2B with the Sargent connected in parallel. Yes they are correct you will see a charge but this will be split between the B2B and the Sargent system. One issue Hoovie has stated that the charge algorithms will be all off, the B2B will be trying to charge a lithium and the Sargent will be charging an AGM. Even if the Sargent was on Lithium they are not communication with each other so will be setting different parameters. This is not good, it will work for some time but eventually it will kill your lithium battery and for the cost of them its a waist of money.

The other issue you have, the B2B is being fitted to give a good charge profile but also to limit charge current. So a 30 amps B2B will limit at 30 amps. If you are bypassing the B2B by leaving the Sargent system in then anything above 30 amps will run through the Sargent system. Essentially bypassing the 30 amp limiting which is why you are fitting it. So in the end over time again you may end up burning out your alternator.

Out of all this i think unless you can find the correct fuse to pull Revolvor has the perfect solution and nicely thought out

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[Captain Birdseye]

I have a couple of questions about the installation of a Victron Orion DC-2-DC / B2B charger into my motorhome.

The motorhome is a Ducato based 2010 Autotrail Apache, with a Sargent EC225 control unit and EM50 interface unit.

The reason for this is that I am installing LiFePO4 batteries. I already have a Victron MPPT solar controller and a Victron mains charger, so those charging profiles are OK for lithium, and I want to make sure that the alternator charging is also optimised for Lithium and doesn't cause any problems.

My problem though is that it seems there is no way to disconnect the existing charge to the leisure batteries from the alternator, without also disconnecting other critical connections. I spoke to Sargent who told me this. They say that the only way to disconnect their split charge relay to stop the alternator charging the leisure battery would also stop the 3-way fridge running on 12v when the engine is running, stop the step retracting, and cut off the EMC relay.

So my 2 questions are:

1) Does anybody have any knowledge or experience in disconnecting the existing alternator-leisure battery charge in this setup, without any detriment elsewhere?

2) If I install the Orion B2B but left the existing setup in place, would that cause a problem or prevent the Orion B2B from working properly?

Many thanks

Sorry can't help, other than to say that both mains and solar charging on my Polite go through the standard Scheiber unit which has a lithium profile that can be selected via the tablet.
I believe that the b2b connection is separate as is the modification that enables the latest Euro 6 alternator to provide charges even when the engine batteries do not need it.

 

[Beast]

I have just had this exact work done on my Hymer B578 Fiat 2.3 Ducato by Jackson Leisure Wakefield Yorks. Last week.
2x 100 li lithium batteries.
Apparently according to them and Victron there’s no need for any major adjusting,,, if your E Block has a switch over to gel that’s all that’s needed re alternator,, plus no need to alter your solar controller as the voltage is almost the same.
So no need to fit a b2b controller,,, or buy a dongle to alter solar,,
If lithium battery sellers should supply a lithium charger, as in my photo,,,so that needs a connection to your mains supply so it can be charged via hook up.
My whole charge was just for labour £200,, saving on a £55 dongle and £290 b2b unit.
ps there’s no comparison to battery usage and recharges within hours, plus 75%less weight, ok 3 times the cost but heh ho, living the dream.

Hope that helps

 

[HectorsHoose]

Here's an update on where I'm up to with this and what I know so far, although the work isn't completed yet so I'll update after the weekend when it's done and fully tested....

In regards to my original second question, it became clear that I did need to disconnect the existing split charge relay to avoid having any problems when installing the Victron B2B.

As Broken Link Removed said, after a conversation with Sargent and some trial & error, I found that in my setup, removing the 20A Vehicle battery fuse from the EC225 control box cuts the split charge function. The split charge relay is located inside the EC225, and it closes the vehicle and leisure battery connections together when the D+ engine running signal is detected.
Removing the vehicle battery fuse therefore prevents the connection being made.
With this fuse out, the fridge still works fine in all scenarios, and the step still works fine too. These were my initial concerns but they turned out not to be problems. These things are all managed by the EM50 unit, so removing the fuse from the EC225 has no impact on them.
There are some issues with this setup though, which aren't problems for me but could be for others:
- The control panel won't show the vehicle battery level, but as I have an external monitor for this, it's not a problem
- There is no longer the ability to direct mains charge to the vehicle battery by manually selecting it on the control panel, but I've installed a seperate Victron mains charger anyway so I don't use the one in the EC225, so also not a problem for me
- If you do select the vehicle battery on the control panel, you get a low battery warning buzzer. However for the above 2 reasons I don't ever press this button, and it always defaults to leisure battery first when powered up.
If I ever do need to use these functions I can just stick the fuse back in.

So I'm now planning to install my Victron B2B this weekend and will update again when it's done.

I do think that the solution Broken Link Removed has implemented is a neater and more permanent solution, which I intend to do myself at some point. Thanks to Broken Link Removed for sharing the details of this. It essentially does the same thing but without any of the issues I listed above, so I'd recommend it to anyone wanting to do the job properly.
But for now at least, pulling the vehicle battery fuse from the EC225 does the job with no negative impact for me.

I've also learned through this that even when the same equipment is in place (EC225 and EM50) in other vehicles, the connections aren't always the same, so I guess an element of testing and trial & error will always be needed to be sure in each case.

So helpful! As we are hoping with our new set up never to use EHU pulling the fuse (which we’ve already located) is a perfect solution. We might just put a switch inline instead for simplicity. We already have an external suitcase solar panel which we can use to charge vehicle battery if it’s ever needed & we’ll put a cigarette lighter socket plug in battery monitor to monitor vehicle battery voltage….sorted! Hopefully

 

[Tombola]

So helpful! As we are hoping with our new set up never to use EHU pulling the fuse (which we’ve already located) is a perfect solution. We might just put a switch inline instead for simplicity. We already have an external suitcase solar panel which we can use to charge vehicle battery if it’s ever needed & we’ll put a cigarette lighter socket plug in battery monitor to monitor vehicle battery voltage….sorted! Hopefully

stick a eddievanbitz battery master on, that will sort your cab battery out from your leisure and solar. fit and forget

Battery Master install like this

I have 2 16mm cables feeding a b2b charger coming from the cab battery into the leisure/charging area, about 1 metre away. I have ordered a battery master from eddievanbitz (funster code didnt work but hey ho) Am I ok to install the battery master like the pic below? behind the B2B

www.motorhomefun.co.uk

 

[HectorsHoose]

I seriously don’t think we’ll need that. We ‘tour’ & the longest we’ve ever been in one place was 6 days & that was unusual! So our vehicle battery will get charged by the alternator everytime we drive anywhere. If the vehicle battery started failing we would see it as we’ll be monitoring it so we can charge with our external panel (which we use if hiding in shade when very hot) in order to go & purchase a new battery. Over winter we can restore the EHU charging that we do at home by switching back on the relay to the EC500/EM40. We also intend to put an isolator switch from solar to B2B so that lithium battery can be stored at the recommended 55% for maximum lifespan. Plus considering buying a ‘jump starter power bank’ for emergencies so we can quickly get back on the road & not get held up potentially waiting hours for solar recharge or breakdown vehicle. I think we’ve catered for every scenario…we like to be prepared!

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[cmcardle75]

I seriously don’t think we’ll need that. We ‘tour’ & the longest we’ve ever been in one place was 6 days & that was unusual! So our vehicle battery will get charged by the alternator everytime we drive anywhere. If the vehicle battery started failing we would see it as we’ll be monitoring it so we can charge with our external panel (which we use if hiding in shade when very hot) in order to go & purchase a new battery. Over winter we can restore the EHU charging that we do at home by switching back on the relay to the EC500/EM40. We also intend to put an isolator switch from solar to B2B so that lithium battery can be stored at the recommended 55% for maximum lifespan. Plus considering buying a ‘jump starter power bank’ for emergencies so we can quickly get back on the road & not get held up potentially waiting hours for solar recharge or breakdown vehicle. I think we’ve catered for every scenario…we like to be prepared!

I've just got an manual handwheel isolator on the battery negative. Stops dead any load or charging. Ideal for winter. It's still running the BMS, but my calculations show that it would go many years on that load alone.

 

[Motorhomer14]

I have just had this exact work done on my Hymer B578 Fiat 2.3 Ducato by Jackson Leisure Wakefield Yorks. Last week.
2x 100 li lithium batteries.
Apparently according to them and Victron there’s no need for any major adjusting,,, if your E Block has a switch over to gel that’s all that’s needed re alternator,, plus no need to alter your solar controller as the voltage is almost the same.
So no need to fit a b2b controller,,, or buy a dongle to alter solar,,
If lithium battery sellers should supply a lithium charger, as in my photo,,,so that needs a connection to your mains supply so it can be charged via hook up.
My whole charge was just for labour £200,, saving on a £55 dongle and £290 b2b unit.
ps there’s no comparison to battery usage and recharges within hours, plus 75%less weight, ok 3 times the cost but heh ho, living the dream.

Hope that helps

If you say victron advised not to fit a B2B then why have you paid to have one fitted. I'm not clued up on the E block. Putting any charger into GEL for EHU charging is advised as it increases the charge voltage. The main issue here is charging on float. This will damage lithium over time if you leave your van on EHU in storage. As for the B2B I can only assume the E block has some current limiter fitted for them to advise you not to fit a B2B. I would question this with them myself they are very good at answering quickly. In end you have opted to fit the B2B and I assume they fitted this inline with the E block to add protection. It's entirely up to the individual what they want to do. It's your money and your van you want to protect

 

[autorouter]

Apparently according to them and Victron there’s no need for any major adjusting,,, if your E Block has a switch over to gel that’s all that’s needed re alternator,,

The gel switch on the EBL is only on the mains charger, and has no effect on the alternator circuit via the split charge relay.

The main issue here is charging on float. This will damage lithium over time if you leave your van on EHU in storage.

Float charging is when the charger applies a voltage just a bit higher than the resting voltage, so that a small current flows in to compensate for any self-discharge.

A fully charged LiFePO4 battery has a resting voltage of about 14.4V. Applying anything above that will be float charging it, which is not good. Applying anything below that will simply result in either no current flowing in, or even a small current flowing out until the resting voltage adjusts. This is not a problem, especially considering that it's best not to fully 100% charge a LiFePO4 battery anyway.

 

[cmcardle75]

The gel switch on the EBL is only on the mains charger, and has no effect on the alternator circuit via the split charge relay.

Float charging is when the charger applies a voltage just a bit higher than the resting voltage, so that a small current flows in to compensate for any self-discharge.

A fully charged LiFePO4 battery has a resting voltage of about 14.4V. Applying anything above that will be float charging it, which is not good. Applying anything below that will simply result in either no current flowing in, or even a small current flowing out until the resting voltage adjusts. This is not a problem, especially considering that it's best not to fully 100% charge a LiFePO4 battery anyway.

Ideally, your "float" voltage for LiFePO4 would be 13.5V or below. 14.4V is far too high, more like an absorbtion voltage.

 

[Motorhomer14]

The gel switch on the EBL is only on the mains charger, and has no effect on the alternator circuit via the split charge relay.

Float charging is when the charger applies a voltage just a bit higher than the resting voltage, so that a small current flows in to compensate for any self-discharge.

A fully charged LiFePO4 battery has a resting voltage of about 14.4V. Applying anything above that will be float charging it, which is not good. Applying anything below that will simply result in either no current flowing in, or even a small current flowing out until the resting voltage adjusts. This is not a problem, especially considering that it's best not to fully 100% charge a LiFePO4 battery anyway.

I agree with you the gel setting is only for EHU so nothing to do with the B2B which is why I said I don't understand why they would mention this. As for float charging lithium look it up it's not good to do this over a long period of time. The main question was why would victron say not to put in a B2B unless the eblock has something in it I don't see. Which is very unlikely as it does not have lithium settings. I would question victron about installing lithium on this E block without a B2B I expect they will not guarantee this

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[autorouter]

Let's be clear - what we're talking about is how to bodge a Lead-Acid 3-stage charger so it is tolerable for a Lithium battery.

Gel settings have an absorption voltage of about 14.7 to 14.8V, which is OK for active charging but not OK for long-term supply, ie 'float'. Gel profiles often have a timed stage of several hours at 14.8V. This serves a useful purpose in recombinant lead-acid batteries like gel or AGM. However it is not ideal for LiFePO4 if the timed stage extends past the fully charged point.

Standard Lead-acid settings have an absorption voltage of 14.4V, and it is not timed. So it finishes when the charging current reduces below a predefined threshold. If it was my battery, I think I'd be happier with that.

 

[Motorhomer14]

Let's be clear - what we're talking about is how to bodge a Lead-Acid 3-stage charger so it is tolerable for a Lithium battery.

Gel settings have an absorption voltage of about 14.7 to 14.8V, which is OK for active charging but not OK for long-term supply, ie 'float'. Gel profiles often have a timed stage of several hours at 14.8V. This serves a useful purpose in recombinant lead-acid batteries like gel or AGM. However it is not ideal for LiFePO4 if the timed stage extends past the fully charged point.

Standard Lead-acid settings have an absorption voltage of 14.4V, and it is not timed. So it finishes when the charging current reduces below a predefined threshold. If it was my battery, I think I'd be happier with that.

Same here. My battery was £800 so not going to float charge that on none lithium profile.

 

[BillyKontiki]

My understanding is that if you have a good BMS. on your lithium battery it will look after the battery.
ie from overcharging on float, it will simply reject any incoming charge.

 

[eddie]

My understanding is that if you have a good BMS. on your lithium battery it will look after the battery.
ie from overcharging on float, it will simply reject any incoming charge.

No that’s not the case

 

[BillyKontiki]

No that’s not the case

Can you elaborate please.
As I changed to lithium a couple of years ago and checked with the battery manufacturer who confirmed what I said as the Bms would protect my batteries, and Sargent also supported their charger would also turn off.

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[Motorhomer14]

Can you elaborate please.
As I changed to lithium a couple of years ago and checked with the battery manufacturer who confirmed what I said as the Bms would protect my batteries, and Sargent also supported their charger would also turn off.

It all depends on the BMS and if you can change the settings. Also if the GEL setting on the Sargent system has a low float voltage. Check out wills link below explaining how you can get low time with correct charge profile. A couple of years is nothing for lithium I would want 10s of years

Also this video from battle born says about float charging at a low level

But if you are charging on low float level for long periods of time you will reduce battery life.
What you can do is charge till full charge then switch charger off
But this is nothing to do with B2B which is the original question. B2b if for vehicle charging and protects against charge voltage and over current on your alternator. No BMS will protect your vehicle.
In end it's your choice. You could get several years charging on a charger that was not designed for lithium. But it's not that expensive to fit a lithium charger and then you will probably never have to buy a battery again. They are not cheap but if you get 10s of yours out of them then they are cheap

 

[eddie]

Can you elaborate please.
As I changed to lithium a couple of years ago and checked with the battery manufacturer who confirmed what I said as the Bms would protect my batteries, and Sargent also supported their charger would also turn off.

The BMS is there to protect the cells from over voltage and under voltage and to balance them, taking from one to top up the other

This is its prime function, it isn't to regulate the charge on a daily basis

This is why Victron as an example, produce a mains charger with a Lithium profile, Solar regulators with a Lithium profile, and a DC 2 DC charger with a Lithium profile for their Lithium batteries range, some having "Built in" BMS and some needing the external Victron BMS

 

[autorouter]

A lithium battery needs some electronics that measures the voltage of individual cells within the battery, and shunts charge from higher voltage cells to lower voltage cells to balance the battery. Obviously that needs wires to each individual cell, so it can't be provided by a device that just connects to the main positive and negative terminals. Once you have electronics inside the battery, you might as well have a simple over-voltage and undervoltage shutoff, and even a temperature sensor and a bit of logic to stop charging when too hot or cold. That's basically what a BMS is.

Of course there's no reason why you couldn't build a full-blown charger into each battery, so that it will charge perfectly whatever voltage is thrown at it. But that would be expensive, and the charger would be scrapped with the battery at the end of its life.

 

[BillyKontiki]

The BMS is there to protect the cells from over voltage and under voltage and to balance them, taking from one to top up the other

This is its prime function, it isn't to regulate the charge on a daily basis

This is why Victron as an example, produce a mains charger with a Lithium profile, Solar regulators with a Lithium profile, and a DC 2 DC charger with a Lithium profile for their Lithium batteries range, some having "Built in" BMS and some needing the external Victron BMS

Thanks for your reply.
I will check with Sargent as there charger is the pc 300 which although it hasn’t got a lithium profile Sargent have confirmed there’s no need to change it.
The only other charger is a victron 30 amp BTB.

 

[BillyKontiki]

It all depends on the BMS and if you can change the settings. Also if the GEL setting on the Sargent system has a low float voltage. Check out wills link below explaining how you can get low time with correct charge profile. A couple of years is nothing for lithium I would want 10s of years

Also this video from battle born says about float charging at a low level

But if you are charging on low float level for long periods of time you will reduce battery life.
What you can do is charge till full charge then switch charger off
But this is nothing to do with B2B which is the original question. B2b if for vehicle charging and protects against charge voltage and over current on your alternator. No BMS will protect your vehicle.
In end it's your choice. You could get several years charging on a charger that was not designed for lithium. But it's not that expensive to fit a lithium charger and then you will probably never have to buy a battery again. They are not cheap but if you get 10s of yours out of them then they are cheap

Thanks for your reply and vlogs which I watched I’m afraid he lost me not long after he introduced himself
I must try to learn more.

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[Motorhomer14]

Thanks for your reply and vlogs which I watched I’m afraid he lost me not long after he introduced himself
I must try to learn more.

What do you mean I lost you I thought I did it as simple as I could in end be a little carful taking advice from Sargent if they do not make lithium chargers/settings/b2b they may not be the best person for advice. There is a tun of info on YouTube. Try watching some of sterling vlog seeing as they are professional in this market

 

[Beast]

If you say victron advised not to fit a B2B then why have you paid to have one fitted. I'm not clued up on the E block. Putting any charger into GEL for EHU charging is advised as it increases the charge voltage. The main issue here is charging on float. This will damage lithium over time if you leave your van on EHU in storage. As for the B2B I can only assume the E block has some current limiter fitted for them to advise you not to fit a B2B. I would question this with them myself they are very good at answering quickly. In end you have opted to fit the B2B and I assume they fitted this inline with the E block to add protection. It's entirely up to the individual what they want to do. It's your money and your van you want to protect

Hi l said l saved money by NOT installing b2b as not needed so you misread the note but thanks.
I read somewhere on a forum that installing lithium although professionally can damage your step electrics which l found bizarre until within 2 weeks later my habitation step circuit board burnt out ,, replaced at great expense, now my drivers step has refused to work, coincidence maybe, or too much power to the circuits, who knows.
Thanks again.

 

[Googlebot]

Hi l said l saved money by NOT installing b2b as not needed so you misread the note but thanks.
I read somewhere on a forum that installing lithium although professionally can damage your step electrics which l found bizarre until within 2 weeks later my habitation step circuit board burnt out ,, replaced at great expense, now my drivers step has refused to work, coincidence maybe, or too much power to the circuits, who knows.
Thanks again.

Can’t see how the lithium has damaged your step. It’s just a voltage, though a bit higher that lead acid, it’s still within the design parameters.

 

[Diabalo]

burtonwisher Do you have an update date on you final solution and how it's going please?