Service battery being drained whilst switched off

[pvb]

I know. I know but that did not stop someone submitting a wiring diagram a few weeks back showing one incorrectly connected

Wiil look at the manuals again later .... gotta go for bloods now!

It could of course be a problem with the OP's Mastervolt charger....

Oh, and what if the shunt has been connected the wrong way round, and the 20A discharge is actually a 20A charge?

So many possibilities that it's not something which can be diagnosed remotely on a forum. It needs logical step-by-step examination.

 

[HissyFit]

Oh, and what if the shunt has been connected the wrong way round, and the 20A discharge is actually a 20A charge?

Just to be clear: we are talking of a shunt (a low value, high power resistor used for measuring current by calculation from the voltage drop across it) and not a shunt regulator (electronic device for dumping excess power to prevent over charging) ? Resistors do not have a polarity.

I was just checking Nigel Calder's book on the correct installation location for a shunt for current sensing. I couldn't find anything, and then I realised that he used the term "amperage" instead. Bl@@dy Americanisations! I still found next to nothing, only a couple of references about inserting "a meter [or shunt]" into the circuit. I was very surprised at this, as shunts are widely available and used devices.

 

[Boater Sam]

Just to be clear: we are talking of a shunt (a low value, high power resistor used for measuring current by calculation from the voltage drop across it) and not a shunt regulator (electronic device for dumping excess power to prevent over charging) ?
***Resistors do not have a polarity.***

No, but the connections do!

 

[VicS]

You cannot reliably establish anything if the meter is faulty.

If all the wiring ( except the power to the monitor) is disconnected from the positive terminal of the battery bank and the 20 amp reading remains it is pretty much proves that the monitor , or its installation, is at fault.
That would be half way to finding the cause of the problem

 

[Boater Sam]

What do I know?




If all the wiring ( except the power to the monitor) is disconnected from the positive terminal of the battery bank and the 20 amp reading remains it is pretty much proves that the monitor , or its installation, is at fault.
That would be half way to finding the cause of the problem



Sure I heard that before, Oh! I said it! But what do I know?

Its OK, I'm off for an early night now with my maid. Sam.

 

[VicS]

Just to be clear: we are talking of a shunt (a low value, high power resistor used for measuring current by calculation from the voltage drop across it) and not a shunt regulator (electronic device for dumping excess power to prevent over charging) ? Resistors do not have a polarity.

I was just checking Nigel Calder's book on the correct installation location for a shunt for current sensing. I couldn't find anything, and then I realised that he used the term "amperage" instead. Bl@@dy Americanisations! I still found next to nothing, only a couple of references about inserting "a meter [or shunt]" into the circuit. I was very surprised at this, as shunts are widely available and used devices.

I am quite sure pvb knows what the shunt is all about .......... and without reading Calders book

 

[JumbleDuck]

Oh, multimeters that read high DC current are hardly expensive, first random hit on Ebay:

UNI-T DIGITAL UT210E 100Amp 600V AC DC CLAMP METER Multimeter True RMS VFC diode | eBay

I have one of these, and it's very nice. I think it was VicS's recommendation which led me to it.

Not hard to explain how to use it, set to DC current, clamp over cable, read display.

Guaranteed to give a wrong reading, possibly a very wrong reading. What was that you said about "a user who isn't sure what he's doing"?

Hint: it's a Hall Effect sensor, not a current transformer ...

 

[pvb]

Just to be clear: we are talking of a shunt (a low value, high power resistor used for measuring current by calculation from the voltage drop across it) and not a shunt regulator (electronic device for dumping excess power to prevent over charging) ? Resistors do not have a polarity.

I was just checking Nigel Calder's book on the correct installation location for a shunt for current sensing. I couldn't find anything, and then I realised that he used the term "amperage" instead. Bl@@dy Americanisations! I still found next to nothing, only a couple of references about inserting "a meter [or shunt]" into the circuit. I was very surprised at this, as shunts are widely available and used devices.

Please note post 65....

 

[ste7ve]

Thanks for all the comments.
Just to be clear the monitor was working fine before I changed the batteries. It was a Nimbus factory install as was everything else on the boat electrics. This is a modern boat with largely industrial type wiring harnesses, factory made.
The new batteries last week were identical replacements to the old ones. Therefore absolutely no wiring changes.
The only thing I put in extra was the bluetooth dongle, which merely plugs into the monitor.

I will go to the boat tomorrow.
The things I'll do in order with battery isolator off are:
- measure resting voltage on battery bank
- disconnect shorepower and check stray amps
- disconnect charger feed to battery and check amps
- disconnect feed from alternator 'battery mate' to battery and check amps.
- disconnect other wires on battery and check amps

If stray amps are still there I'll reset monitor and then do new setup procedure.

It might even amaze you all that I have a degree in electronic engineering, a long time ago though!

 

[Jamie Dundee]

Its OK, I'm off for an early night now with my maid. Sam.

You have a maid called ‘Sam’?

 

[Hadenough]

Thanks for all the comments.
Just to be clear the monitor was working fine before I changed the batteries. It was a Nimbus factory install as was everything else on the boat electrics. This is a modern boat with largely industrial type wiring harnesses, factory made.
The new batteries last week were identical replacements to the old ones. Therefore absolutely no wiring changes.
The only thing I put in extra was the bluetooth dongle, which merely plugs into the monitor.

I will go to the boat tomorrow.
The things I'll do in order with battery isolator off are:
- measure resting voltage on battery bank
- disconnect shorepower and check stray amps
- disconnect charger feed to battery and check amps
- disconnect feed from alternator 'battery mate' to battery and check amps.
- disconnect other wires on battery and check amps

If stray amps are still there I'll reset monitor and then do new setup procedure.

It might even amaze you all that I have a degree in electronic engineering, a long time ago though!

Has your monitor unit got the latest Victron software? If it is out of date it will not be compatable with the latest Victron Connect app. I am having the same problem ATM, do not have a strong enough WiFi signal to update it and am getting spurious data from the monitor.

 

[ste7ve]

when you

Has your monitor unit got the latest Victron software? If it is out of date it will not be compatable with the latest Victron Connect app. I am having the same problem ATM, do not have a strong enough WiFi signal to update it and am getting spurious data from the monitor.

yes, when you setup the phone app it checks the monitor's software version. In my case it did a software update via the phone before the app would work.

 

[VicS]

You have a maid called ‘Sam’?

Those of a certain age will remember a Page 3 maid called Sam they would nor have minded an early night with.

Foxy!

 

[Jamie Dundee]

Those of a certain age will remember a Page 3 maid they would nor have minded an early night with.

Foxy!

Not quite so appealing now though, and I haven’t aged at all

 

[jamie N]

Munches carpets I believe?

 

[ste7ve]

Hi all

Here's the update.

It was the monitor after all.
With the battery at rest voltage I measured 0.3 mV across the shunt which clearly wasn't too accurate with a cheap multimeter on its 200mV setting. The monitor was showing 16 A going out at the time, whereas that should have given a 1.6mV reading. So seemed obvious the monitor was the problem.
So I just reset the monitor and did a new set up procedure, including a fully charged synchronisation.
I also disconnected the cables on the load side of the shunt meaning there was no possible current flow, and then did a zero amp calibration.
So now all is well.
How the monitor got so messed up I've no idea

Anyway thanks for those of you who eventually homed onto the monitor, because it really helped.


Steve

 

[VicS]

Hi all

Here's the update.

It was the monitor after all.

How the monitor got so messed up I've no idea

Anyway thanks for those of you who eventually homed onto the monitor, because it really helped.
Steve

Thanks for the update.
I wondered if there was a ( charge ) current, when it did the software update, which was zeroed out . Just a thought. Something upset it.

 

[JumbleDuck]

I wondered if there was a ( charge ) current, when it did the software update, which was zeroed out . Just a thought. Something upset it.

Sounds like a distinct possibility.

 

[PaulRainbow]

It could of course be a problem with the OP's Mastervolt charger....

Oh, and what if the shunt has been connected the wrong way round, and the 20A discharge is actually a 20A charge?

So many possibilities that it's not something which can be diagnosed remotely on a forum. It needs logical step-by-step examination.

Thanks for the update.
I wondered if there was a ( charge ) current, when it did the software update, which was zeroed out . Just a thought. Something upset it.

That should not happen, the updates don't change any settings as a rule. My monitor has been updated many times and almost always with a charge current of some sort.

I'd suspect someone has zeroed the monitor whilst under a 20a charge from the mains charger.

But, we'll never know for sure.

 

[179580]

If you're not happy here, you can always just not log in. If you stick around, you'll perhaps eventually realise that some posters offer sound advice.

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