Using a B2B with a BatteryMaster

[DBK]

I've just fitted a Stirling battery to battery charger, model BB1260. I'll post a thread about the installation when it is all completed but for the moment I have a question about using it with a BatteryMaster. I would ask Sterling but they seem to have gone home for the weekend.

In disconnecting the split charge system, which the B2B replaces, I have also inadvertently disconnected the BatteryMaster. This is because the positive feed from the battery to the split charge relay also powers the BatteryMaster. By removing the fuse in this cable to disable the split charge system I've thus left the BatteryMaster powerless. It is easy enough to re-wire things so the BatteryMaster is back on line but I am wondering about the consequences.

At the moment the B2B is operating in its default mode when it turns itself on automatically if it detects an input voltage above 13.6 volts, which is what happens when I start the engine.

If I reconnect the BatteryMaster and the sun comes out it will try and charge the vehicle battery from the solar power which I think is very likely to cause the B2B to start up when it senses the increase in voltage at the vehicle battery terminals.

To get around this I can change the B2B operating mode by connecting a wire from it to an ignition feed so it only comes on when the engine is running.

But what about the BatteryMaster? I can see a situation when the engine is running and the B2B is charging the leisure batteries with say 14.4 volts. Because there is no split charge system now the voltage at the vehicle battery is likely to be less than this, possibly at the float voltage of 13.6 or even less if the B2B is drawing a lot of current. The BatteryMaster will sense the difference and could try charging the vehicle battery.

Is this a problem?

I think it won't be as the BatteryMaster limits how much current it puts out but I would be grateful for any comments from the technical experts.

 

[hilldweller]

Looks like the DBK version of the hadron collider.

 

[Nirvanauk]

Leave well alone I say.

 

[Deneb]

I wouldn't have thought it a problem. As you say, the current is small. I have no experience with the Battery Master, my kit is all Votronic. My solar controller diverts up to 1.0A to the vehicle battery whenever it is generating sufficient current, so that happens at the same time as my B2B might be charging or virtually any other time that the sun is shining on the panels. All the Votronic kit states it is designed to work seamlessly with multiple charging sources and consumers in operation.

Wouldn't you be better with the B2B triggered by the D+ signal though? If you don't have a take off on your Elektroblock or similar, it's easy enough to switch from a relay on the conversion socket.

https://www.motorhomefun.co.uk/forum/threads/ducato-x290-wiring.188788/#post-3132736

 

[Robert Clark]

We set up our B2B charger with the D+ trigger for this very reason
Works a treat with our battery master
The only thing I’ve found is that the 60a output from from the B2B charger soon drops after starting the engine.
Wondering if this is because the B2B charger sees the voltage from our solar panels

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[DBK]

I wouldn't have thought it a problem. As you say, the current is small. I have no experience with the Battery Master, my kit is all Votronic. My solar controller diverts up to 1.0A to the vehicle battery whenever it is generating sufficient current, so that happens at the same time as my B2B might be charging or virtually any other time that the sun is shining on the panels. All the Votronic kit states it is designed to work seamlessly with multiple charging sources and consumers in operation.

Wouldn't you be better with the B2B triggered by the D+ signal though? If you don't have a take off on your Elektroblock or similar, it's easy enough to switch from a relay on the conversion socket.

https://www.motorhomefun.co.uk/forum/threads/ducato-x290-wiring.188788/#post-3132736

Thank you, that makes sense. My system doesn't use an Elektroblock but I have found an ignition feed very handily placed - it is the wire going to the split charge relay which causes it to operate when the engine is running.

 

[DBK]

Looks like the DBK version of the hadron collider.

By a curious coincidence I discovered this week why the Large Hadron Collider is called "Large". It isn't because of its physical size (half the size of Switzerland) but because it collides large hadrons - derived from lead atoms.

Once I find out what a hadron is I will know everything.

 

[DBK]

We set up our B2B charger with the D+ trigger for this very reason
Works a treat with our battery master
The only thing I’ve found is that the 60a output from from the B2B charger soon drops after starting the engine.
Wondering if this is because the B2B charger sees the voltage from our solar panels

That's interesting. It sounds as if I need to do some trials although I wouldn't have thought the BatteryMaster would generate enough power to significantly alter the voltages.

 

[Deneb]

Once I find out what a hadron is I will know everything.

I think it's the name of the particle before it has collided. i.e. "We hadron but now it's gone".

Mrs D is always telling me she doesn't think I'm funny either!

 

[Robert Clark]

That's interesting. It sounds as if I need to do some trials although I wouldn't have thought the BatteryMaster would generate enough power to significantly alter the voltages.

I don’t think the battery master has any effect
It’s the solar output I think is effecting things

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[Robert Clark]

I could test this by turning off the solar output

 

[DBK]

I don’t think the battery master has any effect
It’s the solar output I think is effecting things

Given my luck with weather on trips this may not be a problem.