Victron Orion B2B discharging leisure battery when driving

[BigDean]

I have a 12v Multiplus/Cerbo/SmartSolar/Orion setup in my Adria motorhome. Everything works fine except when driving.​

I have a Thetford 3 way fridge which is supposed to use the alternator when driving (connected to the D+ signal).

What is happening is that the leisure battery (lithium) discharges when driving to power the fridge!

Looking in VRM I can see a draw of 20A when the fridge is on 12v. If I turn the fridge off, this stops.

The Orion has D+ connected to H, so only kicks in when the engine is running, and has Engine shutdown detection turned off. (I tried it turned on and it makes no difference).

The input voltage lockouts are set to 12.2 and 12.5. What happens (if I watch the Orion in VictronConnect), is that the input on the vehicle battery starts at around 12.8v. When I start the engine, it starts outputting at around 14v into the leisure battery. BUT this causes a drop in voltage on the vehicle battery to around 11.8v, so the Orion stops. Because it stops, the vehicle battery then goes back up to over 12.5v so starts again. It is stuck in this cycle.

If I turn the fridge off, I still get this constant cycling.

I am presuming there is a link to the fridge problem and the Orion, but who knows!

Any help very much appreciated.
Thanks
BigDean

 

[cmcardle75]

I have a 12v Multiplus/Cerbo/SmartSolar/Orion setup in my Adria motorhome. Everything works fine except when driving.​

I have a Thetford 3 way fridge which is supposed to use the alternator when driving (connected to the D+ signal).

What is happening is that the leisure battery (lithium) discharges when driving to power the fridge!

Looking in VRM I can see a draw of 20A when the fridge is on 12v. If I turn the fridge off, this stops.

The Orion has D+ connected to H, so only kicks in when the engine is running, and has Engine shutdown detection turned off. (I tried it turned on and it makes no difference).

The input voltage lockouts are set to 12.2 and 12.5. What happens (if I watch the Orion in VictronConnect), is that the input on the vehicle battery starts at around 12.8v. When I start the engine, it starts outputting at around 14v into the leisure battery. BUT this causes a drop in voltage on the vehicle battery to around 11.8v, so the Orion stops. Because it stops, the vehicle battery then goes back up to over 12.5v so starts again. It is stuck in this cycle.

If I turn the fridge off, I still get this constant cycling.

I am presuming there is a link to the fridge problem and the Orion, but who knows!

Any help very much appreciated.
Thanks
BigDean

Sounds like the wiring between alternator and Orion is too small/not firmly clamped. Either that or the alternator is worn out/under specced. The Orion is dropping out because the undervoltage protection. It might also be related to a smart alternator not producing enough voltage as it thinks the vehicle battery is full, although 11.8V is probably too low for float.

 

[BigDean]

Sounds like the wiring between alternator and Orion is too small/not firmly clamped. Either that or the alternator is worn out/under specced. The Orion is dropping out because the undervoltage protection. It might also be related to a smart alternator not producing enough voltage as it thinks the vehicle battery is full, although 11.8V is probably too low for float.

Thanks for that.

Only a year old, so would hope alternator is in good shape, but who knows?

I am away for another few days, so will have to wait until I get home before disconnecting everything to get into where the Orion is. I wish motorhome manufacturers would make larger service bays for the electrics.

Will just have to ensure hook up between journeys to top back up. Don't normally bother with EHU.

 

[Two on Tour]

My understanding is that the alternator only supplies the D+ signal that the engine is running to switch the 12v supply from the cab battery which in turn is charged from the alternator and the alternator having no direct connection to the fridge, which is how it is wired on our van.

 

[cmcardle75]

Thanks for that.

Only a year old, so would hope alternator is in good shape, but who knows?

I am away for another few days, so will have to wait until I get home before disconnecting everything to get into where the Orion is. I wish motorhome manufacturers would make larger service bays for the electrics.

Will just have to ensure hook up between journeys to top back up. Don't normally bother with EHU.

So it is probably a smart alternator. It will have dropped voltage as it moving the cab battery to float. Then, inadequete cabling to the Orion is causing more voltage drop and causing the Orion to drop out, despite having an active D+.

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[cmcardle75]

So it is probably a smart alternator. It will have dropped voltage as it moving the cab battery to float. Then, inadequete cabling to the Orion is causing more voltage drop and causing the Orion to drop out, despite having an active D+.

Oh and check the earthing to the Orion. That needs to be beefy, too.

 

[BigDean]

My understanding is that the alternator only supplies the D+ signal that the engine is running to switch the 12v supply from the cab battery which in turn is charged from the alternator and the alternator having no direct connection to the fridge, which is how it is wired on our van.

Thats my understanding, so thanks for the clarification.

 

[eddie]

The B2B is only rated at 25 amp so not really big enough

 

[BigDean]

So it is probably a smart alternator. It will have dropped voltage as it moving the cab battery to float. Then, inadequete cabling to the Orion is causing more voltage drop and causing the Orion to drop out, despite having an active D+.

Looks like I am going to have to disassemble everything and get some new cables run in.....

Thanks

 

[BigDean]

The B2B is only rated at 25 amp so not really big enough

Is it not 30a? But whether 25A or 30A, wouldn't seem like the cause of the problem?

Thanks

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[BigDean]

I think the fridge is a mis-nomer. I now seem to have the problem with the fridge on gas!

So that narrows it down the load of 20A when the engine is running. Guessing a cable issue somewhere.

 

[eddie]

I think the fridge is a mis-nomer. I now seem to have the problem with the fridge on gas!

So that narrows it down the load of 20A when the engine is running. Guessing a cable issue somewhere.

The plot thickens! And yes your right the Orion is 30amp! Getting old lol

 

[BigDean]

Thanks all. Just going to remove the existing cables and and rewire directly to the cab battery and to the busbar for the leisure battery. I will feel more comfortable then

Thanks again.

 

[autorouter]

It sounds like you are getting a big voltage drop somewhere, when the alternator is trying to supply current. I would definitely check the earth straps, the voltage drop could be along the earth return path.

One easy check is to clamp a jump lead between the alternator metalwork and a metallic point on the main bodywork. If the problem goes away, then it's an earth strap problem.

 

[BigDean]

It sounds like you are getting a big voltage drop somewhere, when the alternator is trying to supply current. I would definitely check the earth straps, the voltage drop could be along the earth return path.

One easy check is to clamp a jump lead between the alternator metalwork and a metallic point on the main bodywork. If the problem goes away, then it's an earth strap problem.

Thanks for that, will do.

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[BigDean]

Just an update on this for anyone interested. The problem seems to have been the input voltage lockouts. By disabling these and letting the smart alternator "do its thing", then all is good. Power flows from the alternator to the leisure battery. The cab battery, after 300 miles yesterday, is full and so is the leisure battery. The down side is that the Orion was very hot at the end of the day..... I dont know if there is a way around that.

I have now realised the 12v side of the fridge is wired through the Nordelettronica NE350 (which controls the factory fitted electronics in the motorhome). The fridge takes its power from the NE350 (signalled by the D+), which, if the Orion is not outputting only has the leisure battery for power. A bit peculiar, but I think it makes sense.....

 

[Tombola]

they can get hot.
some folk fit a larger pice of steel behind to act a a larger heat sync, and dont forget to mount it the correct way so heat dissipates quicker

 

[BigDean]

they can get hot.
some folk fit a larger pice of steel behind to act a a larger heat sync, and dont forget to mount it the correct way so heat dissipates quicker

Thanks for that.

 

[Guigsy]

The Victron Orion is pretty inefficient. It gets hot very quickly. Some people have bolted it to a big metal plate as a heat sink. Others run a fan to force air through the fins. If it gets too warm, it quickly drops its power output to prevent overheating. Some people have discovered this means it won't even keep up with a 3-way fridge in battery mode.

My solution... I got a Voltronic B2B instead.

 

[cmcardle75]

Just an update on this for anyone interested. The problem seems to have been the input voltage lockouts. By disabling these and letting the smart alternator "do its thing", then all is good. Power flows from the alternator to the leisure battery. The cab battery, after 300 miles yesterday, is full and so is the leisure battery. The down side is that the Orion was very hot at the end of the day..... I dont know if there is a way around that.

I have now realised the 12v side of the fridge is wired through the Nordelettronica NE350 (which controls the factory fitted electronics in the motorhome). The fridge takes its power from the NE350 (signalled by the D+), which, if the Orion is not outputting only has the leisure battery for power. A bit peculiar, but I think it makes sense.....

That might be worth rewiring, as is will be taking a good 10A of the Orion's output to run the fridge, and it could easily run directly off the cab battery instead, using a D+ controlled relay.

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[BigDean]

That might be worth rewiring, as is will be taking a good 10A of the Orion's output to run the fridge, and it could easily run directly off the cab battery instead, using a D+ controlled relay.

Thanks for the input.

Why do manufacturers not think about efficiency???? Grr.

 

[Tombola]

what about the sterling one ? 60 amp .... recommended by anyone

BB1260 Sterling Power 60amp Automatic 12V DC to 12V DC Battery to Battery Charger

BB1260 Sterling Power 60amp Automatic 12V DC to 12V DC Battery to Battery Charger Sterling s range of Battery to Battery Chargers B2Bs has grown

simply12volt.co.uk

 

[cmcardle75]

Thanks for the input.

Why do manufacturers not think about efficiency???? Grr.

To be fair, before the Orion was installed, it was probably just sharing the split charge relay with the battery charging, which was a completely reasonable thing to do, if the cables were thick enough.

 

[Two on Tour]

what about the sterling one ? 60 amp .... recommended by anyone

BB1260 Sterling Power 60amp Automatic 12V DC to 12V DC Battery to Battery Charger

BB1260 Sterling Power 60amp Automatic 12V DC to 12V DC Battery to Battery Charger Sterling s range of Battery to Battery Chargers B2Bs has grown

simply12volt.co.uk

I been running one faultlessly for the past four and a half years. No app on your phone to set it up, but once setup it just does its thing and needs no altering.

 

[AgeingAndrew]

Just an update on this for anyone interested. The problem seems to have been the input voltage lockouts. By disabling these and letting the smart alternator "do its thing", then all is good. Power flows from the alternator to the leisure battery. The cab battery, after 300 miles yesterday, is full and so is the leisure battery. The down side is that the Orion was very hot at the end of the day..... I dont know if there is a way around that.

I have now realised the 12v side of the fridge is wired through the Nordelettronica NE350 (which controls the factory fitted electronics in the motorhome). The fridge takes its power from the NE350 (signalled by the D+), which, if the Orion is not outputting only has the leisure battery for power. A bit peculiar, but I think it makes sense.....

How does the system work?

Presumably the B2B supplies all charge to the battery via the NE350 when the engine is running.
As the leisure battery charges, the B2B reduces its current delivery to go through its bulk, absorption and float stages, so maintaining health of the battery.
Only in your system it cannot, as you are powering your fridge from the B2B while the engine is running, constantly drawing around 10A. This would keep the B2B running on bulk or absorption mode as long as the engine is running.

This is probably the reason the B2B was very hot after driving 300 miles.

I would definitely rewire the hab electrics so that the B2B does not power the fridge while the engine is running.

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[BigDean]

How does the system work?

Presumably the B2B supplies all charge to the battery via the NE350 when the engine is running.
As the leisure battery charges, the B2B reduces its current delivery to go through its bulk, absorption and float stages, so maintaining health of the battery.
Only in your system it cannot, as you are powering your fridge from the B2B while the engine is running, constantly drawing around 10A. This would keep the B2B running on bulk or absorption mode as long as the engine is running.

This is probably the reason the B2B was very hot after driving 300 miles.

I would definitely rewire the hab electrics so that the B2B does not power the fridge while the engine is running.

Maybe....

I "think" the battery charge does not go through the NE350 as there is a DIP switch to tell it there is a B2B which disables its internal relay for charging.

I am going to the Adria factory next month, so with a bit of luck I will be able to ask someone.....

Also reading the Victron community forum, it appears the Orion does run hot! I have ordered a steel plate and will attach it to that and orientate differently as per the suggestions there.

Looks like re-wiring of the fridge is a must! So just to confirm. Running the 12v side of the fridge directly from the cab battery, when the d+ is high is the way to do it?

Thanks
BigDean.

 

[autorouter]

The fridge normally has two separate 12V supplies, usually called the Low Current (LC) and High Current (HC). The LC supply comes from the leisure battery/NE350 via a small fuse and thin wires. It powers the fridge control board, switching, gas ignition and the display if there is one.

The HC supply powers the fridge 12V heater element only, and has its own supply, fuse and thick wiring, from the NE350. The fuse is usually 15A or 20A.

If you are rewiring the fridge power, the usual way is to wire the HC supply via a relay from the starter battery/alternator, triggered by the D+ (engine running) signal. The LC supply can be left as it is, the current is very small.

I "think" the battery charge does not go through the NE350 as there is a DIP switch to tell it there is a B2B which disables its internal relay for charging.

I think the Orion output goes to the NE350 and charges the leisure battery. Disabling the internal relay simply stops the internal relay trying to connect the leisure battery directly to the starter battery, which would cause problems with the Orion B2B.

 

[cmcardle75]

Looks like re-wiring of the fridge is a must! So just to confirm. Running the 12v side of the fridge directly from the cab battery, when the d+ is high is the way to do it?

Yes. This will remove the 10A fridge current path from going through the Orion unnecessarily, whilst ensuring it doesn't run without the engine running.

 

[cmcardle75]

Yes. This will remove the 10A fridge current path from going through the Orion unnecessarily, whilst ensuring it doesn't run without the engine running.

BTW, this applies to absorbtion fridges only. Compressor fridges should always be wired to the leisure battery.

 

[BigDean]

Well folks, to wrap this one up….

Victron Orion OUT. Far too hot in use for less than an hour. Very disappointed.

Original 40A NE325 b2b reinstalled (built in fan). Liked the Bluetooth control on the Victron but no good when it could burn your hand!

Can now categorically say that the fridge is running through the NE350 central controller so if b2b doesn’t produce power, it WILL use leisure battery. It also means you are losing a lot of power from the b2b as it is directing the first 15a or so to the fridge, so only the balance to the leisure battery.

After next trip will be rewiring direct from cab battery.

If I get a chance, will discuss this with Adria when we are at the factory next month.

Thanks for all your input.

BigDean.

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