Control unit current consumption - anyone measured?

[thehorse]

Hi,

I have -0.4A, sometimes -0.6A showing on the central control unit with nothing on + no plug in the inverter socket etc.

I have just measured the actual consumption which is much lower, as below....

CCU off = 25mA (0.025A)
CCU on = 68mA (0.068A)
CCU on with backlight = 114mA (0.11A)

Has anyone else made this measurement?

I still think the 25mA is highish if it is in sleep mode, and strangely when I put it on hookup I noticed the main engine battery voltage creeping up a little (a few 10's of millivolts), so am concerned there is some leakage current between the 2 systems.

Also tested with fridge on and CCU shows 4.4A, whereas actual is 4.0, so there is a 400mA offset.

Thanks!

 

[sidepod]

If you’re on hook up then I assume the engine is stopped and therefore the engine battery is isolated from everything else.

 

[WelshGas]

Hi,

I have -0.4A, sometimes -0.6A showing on the central control unit with nothing on + no plug in the inverter socket etc.

I have just measured the actual consumption which is much lower, as below....

CCU off = 25mA (0.025A)
CCU on = 68mA (0.068A)
CCU on with backlight = 114mA (0.11A)

Has anyone else made this measurement?

I still think the 25mA is highish if it is in sleep mode, and strangely when I put it on hookup I noticed the main engine battery voltage creeping up a little (a few 10's of millivolts), so am concerned there is some leakage current between the 2 systems.

Also tested with fridge on and CCU shows 4.4A, whereas actual is 4.0, so there is a 400mA offset.

Thanks!

On my 2014 SE, the Contro Panel shows -0.2 v with Backlight On.

You do realise that the Mains Charger will trickle charge the Engine Battery once the 2 Leisure Batteries reach a certain level. So I would expect the Engine Battery Voltage to rise.

 

[thehorse]

On my 2014 SE, the Contro Panel shows -0.2 v with Backlight On.

You do realise that the Mains Charger will trickle charge the Engine Battery once the 2 Leisure Batteries reach a certain level. So I would expect the Engine Battery Voltage to rise.

I didn't realise that, I thought it might be a fault with the split charge relay. Is this trickle charge of the engine battery documented anywhere?

 

[jts46]

Instruction manual?

 

[Loz]

I didn't realise that, I thought it might be a fault with the split charge relay. Is this trickle charge of the engine battery documented anywhere?

Shown on the wiring diagram.

 

[thehorse]

Shown on the wiring diagram.

On the one I've seen it is connected via the split charge relay, so only connected when the engine is on and the alternator operating.

Also checked the manual and it says the 230V hookup charges the 2 leisure batteries and the engine (alternator) charges the 2x leisure and the engine battery.

 

[sidepod]

Engine battery charging.

 

[sidepod]

Horse,

You seem pretty handy with a multi meter and a current flow diagram.
Start pulling leisure load fuses and re-test until you find the source of your load?

Laborious but strangely satisfying

 

[thehorse]

Thanks Sidepod for the diagram. The problem with automotive diagrams is they aren't proper circuit diagrams so difficult to work out what is going on. It isn't clear from the one above how/if it is supposed to be connected. It would make sense through a diode in parallel with the isolation relay but this isn't shown. The diagram I have explicitly states the starter battery is disconnected from the charging circuit as below...

 

[sidepod]

Automotive diagrams are proper circuit diagrams! Perfectly logical and easy to read. + rail across the top, - along the bottom. Easy column to and from numbers along the bottom.

The diagram you’ve attached is simply a basic leisure load scheme.

The point you are missing is that the starter battery is charged from a secondary output from the charge unit and as such, isn’t shown on the leisure load scheme you attached.

In other words, if you remove the charger unit from below the fridge you will see two distinct outputs, one for the leisure circuit and one for the starter battery.

This secondary output is unaffected by the split charge relay.

The current flow diagram you describe as “not proper” clearly shows this.

 

[Loz]

Just to add.. @thehorse your diagram is from the self study guide and not a proper circuit diagram its provided to show the concept only and its out of date as the currently supplied on board supply unit does not include an inverter.

 

[thehorse]

Yes, both are just basic diagrams, sidepod's is a wiring diagram but to know exactly what is going on would need a full circuit schematic.

@sidepod - Are you saying the red/orange wire coming out of the charger, through the 5A fuse going to a red wire connects to the starter battery? It has a "1" label on the end of the red wire, but on the other diagram, the red wire has a "27" at the end, so how do you know they are connected?

 

[WelshGas]

Also the Mains Charger is located above the Rear Leisure Battery since at least 2014, if not a little earlier, and has not changed on the T6.

 

[sidepod]

Correct. The numbers shown in boxes (1 and 27) refer to the diagram column references, the numbers along the bottom of the diagram on each page.

In other words to trace the destination of 27 you go to line 1, here you’ll find a corresponding 27.
This is standard “relay logic” notation.

 

[Loz]

And the charger is connected to fuse SC31 which is on the Vehicle side.

 

[Loz]

Yes, both are just basic diagrams, sidepod's is a wiring diagram but to know exactly what is going on would need a full circuit schematic.

@sidepod - Are you saying the red/orange wire coming out of the charger, through the 5A fuse going to a red wire connects to the starter battery? It has a "1" label on the end of the red wire, but on the other diagram, the red wire has a "27" at the end, so how do you know they are connected?

 

[sidepod]

I’ve just discovered a cure for my insomnia

 

[Skewif]

Please does anyone know which wire from the under fridge charger is connected to the starter battery? Want to install a https://www.photonicuniverse.com/en...to-DC-battery-to-battery-trickle-charger.html. to charge starter from my solar via load connection on my Victron controller. And is said wire accessible through the small cover under the hob?

 

[sidepod]

Is this a trick question? Diagram above?
Yellow/Red wire out of the charger unit.

Splice into this with the positive feed from your charger and use any available earth, probably at a guess the earth shunt will have a big old stud to bolt to.

Make sure your solar unit won’t object to 14 and a bit volts feeding it with the engine running.

Access via hob? Don’t have a scooby doo?

 

[sidepod]

Or connect it here (+).
This is under the fridge.

 

[andyinluton]

The diagram I have explicitly states the starter battery is disconnected from the charging circuit as below...

View attachment 30156

That looks like the charging circuit from the T5 (i.e. before T5.1) cali. Back then the vehicle battery was never charged from the leisure charger.

 

[sidepod]

That looks like the charging circuit from the T5 (i.e. before T5.1) cali. Back then the vehicle battery was never charged from the leisure charger.

Page 2 will give you a argument.

 

[Loz]

Or connect it here (+).
This is under the fridge.

View attachment 30163

Under the passenger seat on the T6

 

[Skewif]

Is this a trick question? Diagram above?
Yellow/Red wire out of the charger unit.

Splice into this with the positive feed from your charger and use any available earth, probably at a guess the earth shunt will have a big old stud to bolt to.

Make sure your solar unit won’t object to 14 and a bit volts feeding it with the engine running.

Access via hob? Don’t have a scooby doo?

Thanks. Was more about accessibility. Can I get to said wire through the small circular access hole in the cupboard under the hob. Don’t need a ground / earth for charger and anyway would need to take out fridge to access shunt (I believe). Unit has a diode so one way only leasure to starter so no problem when engine running. By running through load out on solar controller I can choose to charge starter only once leasure on float and also see how much Amp-hour starter is needing each day.