Fridge on 12v (and b2b + mains charger questions)

[DuncT]

Evening all.

Nearly there with my lithium battery & chargers but just had a few last questions for those in the know.

I've fitted the Victron Orion 50a b2b between the starter battery and the leisure battery with 16mm2 cable which is about 1.2m long.
I've just started the van and at tickover it's only producing around 21a into the b2b. Is this normal and will it increase once being driven?

Next question ... How do I keep my 3 way dometic fridge on 12v power? It's not got an auto option but when I choose 12v, it does the normal beeping to warn the engine's not running. Can I force this to run on 12v (I know it will pull around 10a). Is there something I can do at the EBL end so it stops complaining and just works?

Lastly, I'm going to install the Victron 30a mains charger tomorrow. I know I need to pull the fuse from the front on the EBL to disable the existing mains charging but can I just connect the pos/neg to the back of the EBL which goes to the leisure battery?

Cheers all for advice/help

 

[AdrianChen]

Evening all.

Nearly there with my lithium battery & chargers but just had a few last questions for those in the know.

I've fitted the Victron Orion 50a b2b between the starter battery and the leisure battery with 16mm2 cable which is about 1.2m long.
I've just started the van and at tickover it's only producing around 21a into the b2b. Is this normal and will it increase once being driven?

Next question ... How do I keep my 3 way dometic fridge on 12v power? It's not got an auto option but when I choose 12v, it does the normal beeping to warn the engine's not running. Can I force this to run on 12v (I know it will pull around 10a). Is there something I can do at the EBL end so it stops complaining and just works?

Lastly, I'm going to install the Victron 30a mains charger tomorrow. I know I need to pull the fuse from the front on the EBL to disable the existing mains charging but can I just connect the pos/neg to the back of the EBL which goes to the leisure battery?

Cheers all for advice/help

Did you replace an existing B2B or split charge relay system which may need bypassing?

There are folk who have addressed the 12v requirement - I have as well but through our Victron Cerbo - so will leave that for someone who's done it.

 

[DuncT]

Did you replace an existing B2B or split charge relay system which may need bypassing?

It was just the standard split charge relay in th EBL. I removed the 50a fuse at the starter battery which I think is all that's needed. Then wired the new Victron b2b straight from the starter battery -> leisure and use the existing d+ power to start it charging. This all works as expected but as I said, only pulls about 20a from the starter battery. No other electrics/loads are on.

 

[LithiumConvert]

I've just started the van and at tickover it's only producing around 21a into the b2b. Is this normal and will it increase once being driven?

The battery will only take what it needs.
And, if half charged, this could be enough.

How are yoou measuring 21A into the B2B?

How do I keep my 3 way dometic fridge on 12v power? It's not got an auto option but when I choose 12v, it does the normal beeping to warn the engine's not running.

What happens if you start the engine?

Can I force this to run on 12v? [when not driving]

Many motorhomes are configured such that the default answer to this is "No"

can I just connect the pos/neg to the back of the EBL which goes to the leisure battery?

Yes, but check the battery fuse is the correct value for a 50amp charger. (and the existing wiring)
If not, you may need to set the B2B to give a lower output.

 

[LithiumConvert]

This [now] all works as expected but as I said, only pulls about 20a from the starter battery

It was pulling 21A at the time of your original post - which may well mean the battery is part charged and now even more charged than before.

19A tomorrow (and 18A the day after) would be good.

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[DuncT]

How are yoou measuring 21A into the B2B?

Just through the Bluetooth app on the Victron. It showed the 21a in from the starter battery. The leisure battery was at around 50% state of charge. It's a 285a lithium jobbie.

What happens if you start the engine?

If the engine is started, all is good. The beeping stops and the fridge works on 12v. I've just been reading a bit more and think the power for the fridge is pulled from the starter battery so even if I could force the fridge to start on, it would bugger my starter battery. I assume I'd need to run a wire across to the 20a fuse near the starter battery from the leisure battery?

 

[LithiumConvert]

I removed the 50a fuse at the starter battery

Depending on which EBL it is and how it was wired, that may stop the EBL charging the engine battery.
Worth checking.

 

[LithiumConvert]

I would leave the fridge how it is - only working when the engine is running.
Which battery is not really an issue then - as the alternator is doing the real work.

 

[DuncT]

Depending on which EBL it is and how it was wired, that may stop the EBL charging the engine battery.
Worth checking.

I will check but there's another 20a fuse with this that I think is for that purpose. There's no way the trickle charge -> starter battery from the EBL when on mains hook up would need a 50a fuse.

 

[LithiumConvert]

I will check but there's another 20a fuse with this that I think is for that purpose. There's no way the trickle charge -> starter battery from the EBL when on mains hook up would need a 50a fuse.

That sounds normal, but is worth a check.

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[LithiumConvert]

It sounds like you well on the way to a finished job.

As for running the fridge on the leisure battery without the engine running; it is also fiddlly because you need to by-pass the fridge wiring which is set such that the fridge will only run when it has the D+ signal, no matter which battery it is connected to.

 

[Lenny HB]

As for running the fridge on the leisure battery without the engine running; it is also fiddlly because you need to by-pass the fridge wiring which is set such that the fridge will only run when it has the D+ signal, no matter which battery it is connected to.

Depends on how the van is wired it's common with German vans for the fridge to be able to run from the leisure battery.
With Hymers just a case of fitting the AES fuse on the EBL if not already fitted.
Maybe the same on a Knaus.

 

[LithiumConvert]

With Hymers just a case of fitting the AES fuse on the EBL if not already fitted.

Every day is a school day.

 

[autorouter]

Which EBL number is it? As @Lenny_HB says, running the fridge from the leisure battery while the engine is not running is usually possible with nearly all EBLs. Try inserting a 20A fuse in the AES slot, and switch the fridge manually to 12V. That usually works.

If it doesn't, you may need to swap a wire in one of the connectors. The details depend of exactly which EBL number and how it is wired, but it's fairly easy to do.

Some EBLs have two fridge relays, and the installer chooses to use the one that does or doesn't allow the fridge to run from the leisure battery when parked up. It's quite easy to change over.

 

[autorouter]

I will check but there's another 20a fuse with this that I think is for that purpose. There's no way the trickle charge -> starter battery from the EBL when on mains hook up would need a 50a fuse.

The wire with the 20A fuse from the starter battery is a second supply to the EBL, that powers the fridge 12V when driving, and trickle-charges the starter battery from the EBL mains charger when parked up. It also is the wire used by the control panel to measure the starter battery voltage.

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[DuncT]

As always, amazing info/help.

Mine's the EBL 252 (manual attached). The fridge hasn't got an auto setting but I just wanted to be able to stick it on 12v, it beeps for a bit and then stops but then can have it running from my new lithium leisure battery.

I know it'll pull 10a, but at least during the day that'll be fine with my solar.

Cheers again guys

 

[DuncT]

Additional functions
This relay supplies the AES/compressor refrigerator with power from the starter battery
when the vehicle engine is running and the D+ connection is live. An AES refrigerator is also
powered by the leisure battery when the vehicle engine is not running.
CAUTION!
The ”AES / Compressor refrigerator” fuse (see Fig. 2, Pos. 11) may only be used when the
refrigerator installed in the vehicle is a compressor refrigerator. If it is deployed when using
an absorber refrigerator, the leisure battery is discharged within a short period.

This sounds like the kiddie!!!!
So do I just need to stick a 20a fuse in the AES slot and I'm laughing??

 

[autorouter]

So do I just need to stick a 20a fuse in the AES slot and I'm laughing??

Yes, the EBL252 only has one fridge relay, unlike some other EBL numbers. So that should do it. It's not very popular to do this, because the fridge power can easily flatten a standard leisure battery in a few hours. With a big battery and lots of solar on a sunny day it's a reasonable option. However it is really very easy to forget, and wake up to a flat battery.

Some solar controllers have an 'S+' output when the batteries are charged but it's still sunny. It switches the fridge to 12V in half-hour intervals, and back to gas/mains when the sun goes away.

 

[DuncT]

autorouter works like a charm... thanks again for this help. Stuck the fuse in and the fridge is pulling about 10a from the leisure battery. Start the engine and it takes this from the starter battery/alternator.

Don't suppose you've got any idea why the Victron 50a b2b is only pulling 20a ish from the starter battery? The battery was at around 50% SOC and the fridge wasn't switch on. Does it really throttle back that much as the battery charges?

Cheers

 

[AdrianChen]

autorouter works like a charm... thanks again for this help. Stuck the fuse in and the fridge is pulling about 10a from the leisure battery. Start the engine and it takes this from the starter battery/alternator.

Don't suppose you've got any idea why the Victron 50a b2b is only pulling 20a ish from the starter battery? The battery was at around 50% SOC and the fridge wasn't switch on. Does it really throttle back that much as the battery charges?

Cheers

What type of leisure battery is it? Does it put any more through at higher revs?

Post up the settings/battery settings if there's anything in those that can be tweaked, I'm sure somebody will help.....

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[autorouter]

Don't suppose you've got any idea why the Victron 50a b2b is only pulling 20a ish from the starter battery? The battery was at around 50% SOC and the fridge wasn't switch on. Does it really throttle back that much as the battery charges?

It should keep outputting 50A until the battery voltage rises to the absorption voltage, whatever that is. Can you measure the voltage at the B2B output terminals, to see if it's less than the absorption voltage? I suppose a bit of resistance in the wires or the connections could increase the voltage seen by the B2B, and make it switch to absorption mode prematurely.

That's assuming the settings are correct. It is quite possible on the Victron XS to set the output to anything from 1A to 50A in 1A steps, so maybe double-check that's not happened.

 

[DuncT]

Thanks. It's definitely set at 50a in & out. I'll have another good look later and maybe even go for a drive. The problem I've got now is my leisure battery is at 100% from the bloody solar .
On another note, I'm just fitting the Victron mains charger (30a one) and the terminals on the back of the EBL are not big enough to get the extra neutral in as there's already 2 ferrules in there. Does the neutral for the mains charger need to be the same guage as the positive?

Or... Can I connect this neutral to an existing about an inch from the back of the EBL? If that makes sense.

Sorry for all the questions.

 

[DuncT]

This is what I've got. The red wire is actually the new neutral going to the Victron mains charger. I'll wrap it in a black sleeve once I know all's good. But I can't fit the 3 wires into the central connector

 

[DuncT]

That'll do the trick

 

[Raul]

The one on the brown wire is a pin not a ferule. You can buy pins, put all 3 in the same pin and crimp them.

As in regards to the b2b XS, it should pull 50A with ease at idle even from 90% SOC down. Mine pulls full current till about 95-98% SOC, then tappers down.
You have to check voltages under load and see where you have voltage drop, intake side, and voltage bloating on output side, this could push it into absorb prematurely. Check all connections for good contact
Are the XS settings for lifepo4?
If yes, try to change the absorb to 14v and see if amps increase, if it does you have weak output circuit and voltage drop.

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[Raul]

That'll do the trick



View attachment 1037272

That is for solid core or coarse stranded, if you use that for fine strands, you will need pins or at least ferules.

 

[DuncT]

That is for solid core or coarse stranded, if you use that for fine strands, you will need pins or at least ferules.

I was going to use ferrules but instead have ran the cable right through using two screws per cable. And I've then used a 50mm piece of 35mm2 to connect to the EBL (again using two screws on the connector block.
It's no different to the connections on the back of the EBL tbh.

 

[Miggs]

Don't suppose you've got any idea why the Victron 50a b2b is only pulling 20a ish from the starter battery?

Cheers

It may be the solar is affecting the amount you get from the B2B.
Try switching off the solar if you have a breaker and recheck the B2B output.