Alternator charging via EBL 119

[SeanF1]

Evening all,

My MH is a 2017 Sunlight T60, Fiat Ducato 2.3 with an Schaudt Elektroblock EBL119 power system.

The EBL manual goes into great detail on the charging curve when connected to EHU but re charging whilst driving it only says "Simultaneous charging of the starter battery and the living area battery via the alternator, parallel connection of the batteries via a cut off relay"
I do not have a battery monitor fitted yet, but using a plug in USB with voltmeter into a 12v socket, I can see that when the engine is running the leisure battery is reading 14.4v.
Does anyone know what amps the leisure battery is likely to be receiving from the alternator whilst driving? I ask because I am about to fit a Renogy DC TO DC charger capable of delivering maximum 50 amps whilst driving. I am connecting it up directly to the batteries (ie not through the EBL) and I am now wondering if this will in fact give me any charging benefit over plain old alternator charging? It will also be working alongside the alternator charging through the EBL, and I am wondering if this will give me any benefits or indeed issues?

Any comments gratefully received.

Many thanks all,

Sean

 

[Lenny HB]

Charging via the EBL is just via a split charge relay inside the EBL and charge current will be dependant on the cable size used but unlikely to be above 15 amps after the first 10 mins of engine starting.

Only fit a 50amp B2B if you are sure you have an uprated alternator otherwise I would only fit a 30 amp one.

 

[SeanF1]

Many thanks Lenny. Any idea how I tell if the alternator is an uprated one? 2017 Fiat Ducato 2.3 Maxjet. As far as I know no alterations since new.
Thanks again

 

[autorouter]

A split charge relay is a direct metal-to-metal connection between the batteries, with no fancy electronics to get in the way. That means the voltage of the starter and leisure batteries will be equal, apart from a bit of voltage drop. If you wire in a B2B, the relay will effectively connect the input and output of the B2B together, so the B2B will do nothing. To allow the B2B to work, you need to disable the split charge relay.

On an EBL, it's easy.There will be a wire from the starter battery to the EBL, with a 50A fuse. Remove this fuse and you disconnect the starter battery input to the split charge relay, disabling it.

On the EBL you don't have to worry about the supply to the fridge while driving - it's a separate wire, it's the one with the 20A fuse. That wire is also used by the EBL to measure the starter battery voltage, and also to trickle-charge the starter battery while on EHU.

 

[SeanF1]

A split charge relay is a direct metal-to-metal connection between the batteries, with no fancy electronics to get in the way. That means the voltage of the starter and leisure batteries will be equal, apart from a bit of voltage drop. If you wire in a B2B, the relay will effectively connect the input and output of the B2B together, so the B2B will do nothing. To allow the B2B to work, you need to disable the split charge relay.

On an EBL, it's easy.There will be a wire from the starter battery to the EBL, with a 50A fuse. Remove this fuse and you disconnect the starter battery input to the split charge relay, disabling it.

On the EBL you don't have to worry about the supply to the fridge while driving - it's a separate wire, it's the one with the 20A fuse. That wire is also used by the EBL to measure the starter battery voltage, and also to trickle-charge the starter battery while on EHU.

Thanks for this Autorouter. Do you mean the 50 amp blade fuse? There are also two 50 amp mini fuses. Not sure what these are for.
Many thanks again
Sean

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[SeanF1]

Hi Autorouter,
I've just looked in the manual for the van and it says that the blue 15a blade fuse in the above photo controls the relay. Is this the fuse to remove?
Thanks

 

[autorouter]

Do you mean the 50 amp blade fuse? There are also two 50 amp mini fuses. Not sure what these are for.

Yes I'm pretty sure that 50A blade fuse is the one. Don't get confused by fuse terminology. The big blade fuses like that 50A are Maxi fuses, the 15A is a Standard blade fuse, and there are smaller blade fuses called Mini fuses. On the battery terminal post, there are three Midi fuses and one brown Mega fuse.

I've just looked in the manual for the van and it says that the blue 15a blade fuse in the above photo controls the relay. Is this the fuse to remove?

No, that is the control signal that tells the EBL that the alternator is powered up, ie the engine is running. It's used inside the EBL for several things in addition to the split charge relay, such as the fridge relay. Removing it will disable the split charge relay, and also all the other circuits. Actually if you remove the 50A fuse, the split charge relay will still operate, but since it has no input it will have no output, so it will do nothing.

 

[SeanF1]

Yes I'm pretty sure that 50A blade fuse is the one. Don't get confused by fuse terminology. The big blade fuses like that 50A are Maxi fuses, the 15A is a Standard blade fuse, and there are smaller blade fuses called Mini fuses. On the battery terminal post, there are three Midi fuses and one brown Mega fuse.

No, that is the control signal that tells the EBL that the alternator is powered up, ie the engine is running. It's used inside the EBL for several things in addition to the split charge relay, such as the fridge relay. Removing it will disable the split charge relay, and also all the other circuits. Actually if you remove the 50A fuse, the split charge relay will still operate, but since it has no input it will have no output, so it will do nothing.

Thank you for this. I will try this tomorrow

 

[SeanF1]

Yes I'm pretty sure that 50A blade fuse is the one. Don't get confused by fuse terminology. The big blade fuses like that 50A are Maxi fuses, the 15A is a Standard blade fuse, and there are smaller blade fuses called Mini fuses. On the battery terminal post, there are three Midi fuses and one brown Mega fuse.

Hi Autorouter. This proved to be perfectly correct advice.

Many thanks for your help.

Sean

 

[VXman]

I do not have a battery monitor fitted yet, but using a plug in USB with voltmeter into a 12v socket, I can see that when the engine is running the leisure battery is reading 14.4v.

Sorry to resurrect this thread but it addresses something I have been wondering about.

As a result of my lesiure battery/fridge problems discussed in another thread I have been monitoring my lesiure battery charging via my Victron Solar app. I too noticed that when driving the lesiure battery is reading 14.4volts even when the Victron app says the battery is in float i.e. fully charged. I assume this is because this is what the alternator is giving out. So even though the battery is full it still sends 14.4v. Is this what is happening? Is this not bad for the leisure batteries?

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[LithiumConvert]

I assume this is because this is what the alternator is giving out.

Yes, unless you have one of the new fangled not-so-smart alternators, from which the voltage varies depending on .....

 

[autorouter]

As a result of my lesiure battery/fridge problems discussed in another thread I have been monitoring my lesiure battery charging via my Victron Solar app. I too noticed that when driving the lesiure battery is reading 14.4volts even when the Victron app says the battery is in float i.e. fully charged. I assume this is because this is what the alternator is giving out. So even though the battery is full it still sends 14.4v. Is this what is happening? Is this not bad for the leisure batteries?

This is one of the downsides of charging directly from the alternator. The leisure battery gets whatever the alternator thinks the starter battery wants. However it's not as bad as you might think. Gel and AGM batteries usually have an extended absorption time at 14.4V, often for several hours. And presumably you won't be driving much more than 8 hours per day anyway.

Some people are concerned that for AGM batteries for example, they are supposed to be taken to about 14.7V in absorption, so they don't get to 100% on just the alternator charging. If it really is causing a problem, the answer is to fit a B2B charger that will monitor the leisure battery, supply the correct voltage and switch to float when it's 100% full.