Disable EBL308S Split charge

[dogster]

Hello All,
I'm in the process of installing a B2B charger, adding solar charging later. It currently has a wet battery which I'll change to lithium later. The Adria Sunliving has an EBL308S electroblok. Looking at the circuit diagram I can't see an easy way of disabling the split charge function. I could disconnect the D+ input but then I'd lose the fridge cutover capability.
Has anyone either done this or have any suggestions how I might disable split charging?

Or - alternatively - will leaving the split charging in place damage the system when the 50A B2B kicks in?

Thanks for any tips!
Pete

 

[dogster]

Just to add... The B2B is directly between the starter and leisure battery so bypassing the EBL.
Attached is the 308 manual and the circuit schematic is on p11.

 

[fred_jb]

I am no expert on EBL units, others here have more experience, but I would have thought that so long as there is no connection to the main 30A starter battery input to the EBL, and that the B2B output goes directly to the leisure battery instead, then the split charge relay will have no effect. Its only function is to connect the starter battery to the leisure battery when the engine is running, and it can't do so if there is nothing on the main starter battery input. There is a separate input from the starter battery for the fridge via a 15A fuse and that will still get switched on when the D+ signal is live.

 

[fred_jb]

I should add that when its output is connected directly to the leisure battery the B2B effectively takes over the function previously provided by the split charge relay in that it indirectly connects the starter battery to the leisure battery when the engine is running. I say indirectly because the starter battery is no longer connected directly, but only via the B2B, the output of which provides a boosted version of the direct starter battery feed which now only goes to the B2B input.

 

[Pausim]

If you have connected the B2B directly to the leisure battery then the EBL split charge function must be disabled. If you do not disable it you will create a loop back to the engine battery and end up with the B2B output connected to its own input.

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[dogster]

Thanks Pausim and fred_jb.
So I will trace the 30A circuit and disconnect from either the starter or EBL end to remove the split charge problem.
I guess I'll lose the trickle charge of the starter battery as well, but once I install solar then I think that will provide the starter float (as long as the house battery is full).

Good job I asked! Thanks again. Will be wiring in the B2B at the weekend.
P.

 

[fred_jb]

If you have connected the B2B directly to the leisure battery then the EBL split charge function must be disabled. If you do not disable it you will create a loop back to the engine battery and end up with the B2B output connected to its own input.

Does this not depend on the model of EBL? One that Roger Ivy was discussing recently did have the potential for the issue you describe, but I don't think this is the case for most models of EBL. On mine and it appears that of the OP, the split charge relay does nothing if the starter battery is no longer connected to the normal input on the EBL. I am assuming the EBL internal relay labelled as battery cut off relay in the circuit diagrams for my and the OP's EBL is what we would call a split charge relay. If not and there is another relay with this function outside the EBL, then yes maybe that would have to be either disconnected or disabled.

From what he has said, the output of the OP's B2B no longer connects to this internal relay in the EBL, and this is also the case for my installation where I have not had to do anything further to disable the EBL's split charging. In this case all the relay will do is just connect an empty connection port to the leisure battery. Surely if you remove the starter battery input from the EBL that effectively disables the relay as it will still operate but will not connect anything.

 

[fred_jb]

Thanks Pausim and fred_jb.
So I will trace the 30A circuit and disconnect from either the starter or EBL end to remove the split charge problem.
I guess I'll lose the trickle charge of the starter battery as well, but once I install solar then I think that will provide the starter float (as long as the house battery is full).

Good job I asked! Thanks again. Will be wiring in the B2B at the weekend.
P.

I think the trickle charge should still work as I believe it takes a different path to the battery via pin6 on the connector labelled as Lumberg MFSQ.

 

[Pausim]

Does this not depend on the model of EBL? One that Roger Ivy was discussing recently did have the potential for the issue you describe, but I don't think this is the case for most models of EBL. On mine and it appears that of the OP, the split charge relay does nothing if the starter battery is no longer connected to the normal input on the EBL. I am assuming the EBL internal relay labelled as battery cut off relay in the circuit diagrams for my and the OP's EBL is what we would call a split charge relay. If not and there is another relay with this function outside the EBL, then yes maybe that would have to be either disconnected or disabled.

From what he has said, the output of the OP's B2B no longer connects to this internal relay in the EBL, and this is also the case for my installation where I have not had to do anything further to disable the EBL's split charging. In this case all the relay will do is just connect an empty connection port to the leisure battery. Surely if you remove the starter battery input from the EBL that effectively disables the relay as it will still operate but will not connect anything.

If the EBL is no longer connected to the engine battery then the split charge function will have been disabled. The OP originally made no mention of having done this. At #6 he says he will now investigate doing it.

 

[dogster]

Thanks Fred - I see what you mean about pin 6.

I'll work out which of the x2 30A fuses next to the EBL are on the +Starter line and pull it, which effectively should disconnect pins 3 & 4. Correct Pausim I've not yet done this but will do now before completing the B2B install!

There are another couple of relays next to the EBL which I've not yet worked out what they are for. I don't think they are for charging as the cables are fairly small, and think they probably are something to do with retracting the electric step and buzzing when the engine is turned on.

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[berni109]

Just put a 5 pin 40 amp relay in the wire to the habitation battery using the normally closed position.
Feed the coil in the relay with the D+ to disconnect the hab battery so not charging via EBL.
Engine running no feed to hab battery - engine off no D+ hab battery supplying EBL.

 

[fred_jb]

If the EBL is no longer connected to the engine battery then the split charge function will have been disabled. The OP originally made no mention of having done this. At #6 he says he will now investigate doing it.

You're right that this wasn't mentioned in the original post but to be fair to the OP, his second post did say that he would connect up the B2B directly between the starter battery and the leisure battery so as to bypass the EBL.

Thanks Fred - I see what you mean about pin 6.

I'll work out which of the x2 30A fuses next to the EBL are on the +Starter line and pull it, which effectively should disconnect pins 3 & 4. Correct Pausim I've not yet done this but will do now before completing the B2B install!

There are another couple of relays next to the EBL which I've not yet worked out what they are for. I don't think they are for charging as the cables are fairly small, and think they probably are something to do with retracting the electric step and buzzing when the engine is turned on.

If you take the starter battery connection cable out of the EBL and use it as the input to your B2B then you would want to leave a fuse in place, though will probably need to upgrade it to 60A to allow for the greater current draw of the B2B. you should find that the existing fuse is located close to the starter battery positive terminal. If you do intend to reuse the cable, then have a look at the cable size and check to ensure it is up to the greater current draw. I replaced my cable with a longer one but was able to use the existing fuseholder by removing the old cable from its terminal and putting mine in its place, but probably easier to just use a new fuseholder, putting it as close to the battery as possible.

If my vehicle is anything to go by (Hymer group Ducato van conversion) then one of the relays near the EBL will used for generating a positive D+ signal using the van's ignition on (12V Red) and engine running (0V Green) connections to activate the relay coil.

 

[Pausim]

You're right that this wasn't mentioned in the original post but to be fair to the OP, his second post did say that he would connect up the B2B directly between the starter battery and the leisure battery so as to bypass the EBL.

Connecting directly to the leisure battery and bypassing the EBL is exactly what causes the troublesome loop. He is now investigating breaking the loop by disconnecting the EBL from the engine battery but both actions are required and it is unsafe to assume that everyone knows this. I certainly didn’t when I installed my first B2B in 2016 on a Hymer with an EBL 29. My first attempt involved a direct connection from engine battery to B2B to leisure battery and I immediately detected a problem. I resolved it by feeding the B2B into the EBL which reached the leisure battery via the split charge relay as recommended by Votronic at the time. Knowing now a bit more about the workings of the EBL I would use a direct connection to the leisure battery and break the loop by removing the 50 A EBL connection to the starter battery.

My current van came with a Schaudt 121525 Booster (B2B) connected to an EBL262-4. I contacted Udo Lang at Schaudt about adding a 50A B2B to the system and he confirmed that with the 121525 Booster connected to the EBL it was safe to wire the 50A B2B directly to the 2 batteries. The Booster breaks the loop in the same way a relay would. I now have 75A available to charge my Lipo battery when driving.

 

[fred_jb]

Connecting directly to the leisure battery and bypassing the EBL is exactly what causes the troublesome loop. He is now investigating breaking the loop by disconnecting the EBL from the engine battery but both actions are required and it is unsafe to assume that everyone knows this. I certainly didn’t when I installed my first B2B in 2016 on a Hymer with an EBL 29. My first attempt involved a direct connection from engine battery to B2B to leisure battery and I immediately detected a problem. I resolved it by feeding the B2B into the EBL which reached the leisure battery via the split charge relay as recommended by Votronic at the time. Knowing now a bit more about the workings of the EBL I would use a direct connection to the leisure battery and break the loop by removing the 50 A EBL connection to the starter battery.

My current van came with a Schaudt 121525 Booster (B2B) connected to an EBL262-4. I contacted Udo Lang at Schaudt about adding a 50A B2B to the system and he confirmed that with the 121525 Booster connected to the EBL it was safe to wire the 50A B2B directly to the 2 batteries. The Booster breaks the loop in the same way a relay would. I now have 75A available to charge my Lipo battery when driving.

I think we getting hung up on semantics here. To my mind bypassing the EBL means not including it in the starter battery to leisure battery circuit which disconnecting its starter battery connection will achieve. As you and I have both said, the B2B then performs an analogous function to the split charge relay in that it only connects a boosted version of the starter battery to the leisure battery when the engine is running. The EBL no longer has a connection to the starter battery so its split charge relay does nothing.

 

[Pausim]

I think we getting hung up on semantics here. To my mind bypassing the EBL means not including it in the starter battery to leisure battery circuit which disconnecting its starter battery connection will achieve. As you and I have both said, the B2B then performs an analogous function to the split charge relay in that it only connects a boosted version of the starter battery to the leisure battery when the engine is running. The EBL no longer has a connection to the starter battery so its split charge relay does nothing.

I understand what you are saying but to me a bypass provides an alternative route without necessarily closing off the original one. A bit like a town bypass. The important thing is that the OP is now planning to include shutting off the original connection.