Mastervolt BTM battery monitor

[BlueStringPudding]

Hello,

 

I have a Masterolt BTM battery monitor that I want to check is correctly wired up. The fact that one of the wires isnt attached to anything and that the monitor isn't brilliantly accurate at measuring charge going in, is making me think its not! I have downloaded the instruction manual for it but it doesn't clearly describe the many little coloured wires and where they are supposed to connect. Instead they are just numbered. Needless to say my wires don't have numbers written on them!

 

Does anyone have one of these monitors installed and if so please can you list what battery terminal each coloured wire is supposed to attach to?

 

Thanks

Edited June 29, 2012 by BlueStringPudding

[bottle]

Just a guess, as I do not know the instrument, do the terminals have numbers?

 

If they do.............................. it is just a matter of reading numbers, looking at the colour of the cable in the terminal and tracing where the cable should go.

[BlueStringPudding]

I've not been able to find anything with numbers on it hence assuming the colours of the wires might have some relevance.

[bottle]

If no numbers, then the colours will be relevant, sorry cannot help any further, someone will be along that has one.

[bottle]

Had a look at the manual for a BTM-1

 

Go to page 29 (PDF download) ,diagram of internals, look at the back of your monitor and make sure it is the looks the same, if so, the terminals are numbered 1 to 8 left to right.

 

The table below tell you where they should go.

 

1 and 2 power the unit.

 

3 and 4 go the shunt

 

5 and 6 to the domestic batteries

 

7 to the start battery

 

8 probably the one not going anywhere is a signal wire that could be wired to an alarm

[BlueStringPudding]

Ok. I'll have another snoop around for numbers tonight. Thanks.

[smileypete]

Mastervolt BTM-1 manual:

 

ftp://scally.dyndns.org/Downloads/NauticalLibrary/Equipment/Mastervolt%20Manual%20BTM-1.pdf

 

cheers, Pete.

~smpt~

[bottle]

I think she has that but it may be a help to others.

 

I have downloaded the instruction manual for it but it doesn't clearly describe the many little coloured wires and where they are supposed to connect. Instead they are just numbered. Needless to say my wires don't have numbers written on them!

 

I admit I did not read it all, so may have missed where it states colours.

[BlueStringPudding]

And anyone know what "service battery voltage sence" means?

 

Hang on, edited to say I can, of course, use Bottle's very helpful summary of what each pair of numbers refers to, to cross reference from the instruction manual..thanks Bottle. It seems that it is Mastervolt's way of describing the domestic bank in as un-user friendly terms as possible!

Edited June 29, 2012 by BlueStringPudding

[BlueStringPudding]

Having now spent an hour following un-numbered cables, I really am none the wiser about the reading my battery monitor is giving me. The wiring appears to be correct but judging that is somewhat arbitrary in the absence of numbers. Perhaps there used to be a sticker with the numbers on, who knows? The terminal for the meter has no numbers anywhere in it. Following a logical sequence, what I assume to be wires 1-4 are situated underneath the terminal and go to either side of the shunt, the + power and the - power. Meaning the more accessible ones on top of the terminal having to be wires 5-8 namely the + domestic, - domestic, + starter and the wire for the non existent low battery alarm. That last wire has been rigged to the earth for reasons best known to the previous owner of the boat. Is that wise? (to quote John Le Mesurier)

 

I'm about to start another thread on the readings from the battery monitor as they're related to my solar panels, but it's obviously connected, although indirectly to this thread.

[BlueStringPudding]

Okay peeps. Having rejiggered my wiring this past week as per my other thread, I have now completely and utterly baffled my battery monitor worse than it was before! I didn't change the connections of any of the battery monitor cables when tidying up the wiring and all my electrics are working fine. However the shifting of some cables around the shunt and the moving of the starter negative must have scrambled which bits the battery monitor thinks its reading. And chances are it wasn't perfectly wired in before either.

 

So today I have followed each coloured battery monitor cable and drawn a diagram of what is connecting to where. Firstly here is a simplified diagram of the battery wiring (picture 1) with numbered points on the batteries/shunt which relate to the battery monitor diagram (picture 2). This really is just a simplified reference diagram so please let's not go off topic trying to draw all the details in, that's for another thread on another day. The purpose of this diagram is to show the numbering of key areas that might falter to the battery monitor's connections / performance.

 

 

And here is what the battery monitor is connected to (remember my wires aren't numbered, but I have made a note in blue of what the cables should connect to, if they were numbered. My iPad drawing app has limited colours hence the labels.

 

 

What this tells me, (I think, all constructive opinions and advice welcome) is that had the cables been numbered then...

 

1 is the Thick Red cable and that is correctly connected to D4+

2 is the Thick Black cable and I assume that is correctly connected to shunt point C (earth)?

3 is either the Brown or Beige 2 cable... Not sure if it's connected to the correct part of the shunt?

4 is either the Brown of Beige 2 cable... Again not sure if it's connected to the correct part of the shunt?

5 is the Thin Red and is correctly connected to D4+

6 is probably the Army Green cable but that connected to a shunt negative not battery negative. So not sure that's right

7 is the Beige 1 cable and if so, is correctly connected to the ST+

8 is, for reasons best known to itself, connected to D2- despite, assuming the numerical order runs right to left on the monitor terminal, it being the alarm cable which isn't required for my set up.

 

So my question to you guys is, where do I begin sorting this lot out!? At the moment the battery monitor is reading even less accurately than before, completely contradicting the dials on my iginition panels (they tell me the batteries are at a healthy 12-13v... The battery monitor thinks they're at 10ish volts and it also can't read charging current properly, although it does recognise an increase in volts and Amps when the engine is running, just not the correct increases.

Edited July 8, 2012 by BlueStringPudding

[smileypete]

So my question to you guys is, where do I begin sorting this lot out!? At the moment the battery monitor is reading even less accurately than before, completely contradicting the dials on my iginition panels (they tell me the batteries are at a healthy 12-13v... The battery monitor thinks they're at 10ish volts and it also can't read charging current properly, although it does recognise an increase in volts and Amps when the engine is running, just not the correct increases.

Nice diagrams

 

Have a look at the PDF linked to further up.

 

Looks like connections 3 and 4 are best twisted together then 3 goes to point B (hull earth/load side of shunt) and 4 to point A (battery side of shunt)

 

Connection 6 should go to point C (hull earth) and I expect connection 8 can be left unconnected.

 

Maybe take a piccy of the unit where the wires come out and post it up. Is there a removable terminal cover on the unit?

 

cheers, Pete.

~smpt~

[BlueStringPudding]

Thanks Smiley. I've been working from the pdf as i have it already. It doesnt describe the colours of the cables, so i think they're arbitrary. So i Hve to assume the numbers. It's all highly inaccessible so a photo would show very little. The four top wires can be seen exiting the monitor terminal, the lower ones can't. It's all squished in between the batteries, alternator controller, diode and other cabling. The terminal cover isn't removable for the same reasons.

 

What you've described above sounds pretty much what the set up is already. Perhaps the Beige 2 and Brown cables are the wrong way round on the shunt though. And it sounds like the final cable which is currently connected to the domestic negative batteries needs disconnecting altogether. I wonder whether that's enough to sort out the battery monitor's ability to read what it's supposed to.

[smileypete]

Thanks Smiley. I've been working from the pdf as i have it already. It doesnt describe the colours of the cables, so i think they're arbitrary. So i Hve to assume the numbers. It's all highly inaccessible so a photo would show very little. The four top wires can be seen exiting the monitor terminal, the lower ones can't. It's all squished in between the batteries, alternator controller, diode and other cabling. The terminal cover isn't removable for the same reasons.

 

What you've described above sounds pretty much what the set up is already. Perhaps the Beige 2 and Brown cables are the wrong way round on the shunt though. And it sounds like the final cable which is currently connected to the domestic negative batteries needs disconnecting altogether. I wonder whether that's enough to sort out the battery monitor's ability to read what it's supposed to.

The other way you could try is a process of elimination, bit by bit.

 

If you connect connection 5 (service battery +ve sense) to hull earth, the service battery reading should drop to zero volts. Similarly for connection 7 (start battery +ve sense).

 

If shunt connections 3 and 4 are connected to the same side of the shunt, the current reading should drop to zero.

 

After doing that, the PDF shows the unit's power supply +ve linked to service batt +ve at the unit, and similarly for the unit's power supply -ve, maybe that would make things less error prone.

 

If the unit has never worked properly it's possible it's just kaput, maybe water/condensation got inside it somehow

 

cheers, Pete.

~smpt~

[BlueStringPudding]

Good plan. I can certainly check the reading of the volts as you've suggested. So I'll try that. Unfortunately the amps are at zero on the monitor screen at the moment anyway!

 

The monitor, although not perfectly precise at working out the difference between the starter battery and domestic battery voltage, was always able to show incoming and outgoing amps, and general voltage info which went up when it was supposed to and down when it was supposed to. So I haven't written the monitor off as being water damaged or kaput in any other way, as it's only gone completely gaga since the battery/shunt rewire. I reckon it's repairable if I can just workout what is supposed to be where.

 

Thanks for your advice.

Edited July 8, 2012 by BlueStringPudding

[BlueStringPudding]

 

 

 

.

 

Right, I have made a few discoveries ater a few evenings of tinkering after work.

 

1. The monitor has no power to it unless domestic negative cable (cable 6) is attached to the battery negative terminal. It doesn't work even when attached to the hull earth (point C). I wonder if that's an indicator of something going on with its other negative cable (cable 2) I ought to look out for?

 

2. The last cable does indeed appear to do nothing at all to the reading, whether it's plugged in or not meaning I have probably correctly guessed the numbering of the wires, assuming its in consecutive order, of course.

 

3. I have checked the routes to every cable to the best of my ability and it appears to all be correctly connected. The power in negative (cable 2) is not fixed to the same place as cable 6. I interpreted the wiring diagram in the Mastervolt manual as showing them as connected to the same point, which I thought was point C, the hull side of the shunt. However the monitor has no power when those two cables are in that position.

 

And so the reading is still wrong. It stil says about 11v despite the dial on the ignition panel telling me the batteries are at about 12.4v this evening. I am convinced this is something to do with the negatives not being quite right becaus it was much more accurate before I changed the earth cables and put the isolator switches in the positive instead of negative cables. I feel it in my waters!

 

Could a possible place for the problem be the MPPT negative cable which as you can see from my original diagram above, goes via the busbar to the hull earth (point c). Could that be perplexing the monitor, because its on the other side of the shunt to the batteries? I reckon an option could be to try the MPPT negative cable connected directly to the negative on the domestic batteries instead... I feel like I'm clutching at straws here.

 

I could well be mistaken but it's one of the only things I haven't tried. What do you guys reckon?

Edited July 26, 2012 by BlueStringPudding

[Smelly]

What do you guys reckon?

 

Can I suggest pantaloonies and beer?

[BlueStringPudding]

Ah... It was that good a suggestion eh?

 

 

It is then....

[smileypete]

I could well be mistaken but it's one of the only things I haven't tried. What do you guys reckon?

 

Ayayay!

 

Maybe find a spare 12V battery, and carefully remove the monitor, labelling the wires and test it separately. Find which two wires to connect to the batt to power the monitor up.

 

Then find which wire to connect to the batt to give the correct reading on the start batt display, then which wires to connect to the batt to give the same reading on the service batt display. The shunt wires should be two of the ones left over.

 

I suspect one of the batt sense connections is not connected as it should be, or broken somewhere, even inside the unit itself. Doing a separate test will help show where any faults or mis connections lie.

 

cheers, Pete.

~smpt~

[BlueStringPudding]

Thanks, smiley. I'll try that

[Richard10002]

Just a guess, as I do not know the instrument, do the terminals have numbers?

 

If they do.............................. it is just a matter of reading numbers, looking at the colour of the cable in the terminal and tracing where the cable should go.

 

What do Mastervolt say? Given the time that's gone by, it must be worth a call to their technical help line... Whatever they might call it.

[BlueStringPudding]

I give up. I can't access 50% of the wiring for the monitor without taking out the starter and two domestic batteries, which I physically cannot lift. Quite frankly I wish I'd left the battery cabling as it was with the negative isolator switch because at least it worked then.

 

The eight tiny wires are attached to one of these at the battery end which is why there is no numbering to follow:

 

Fuse holder

 

And it's nestled among the battery cables so half of it cannot be reached.

 

All the fuses are intact at least. Shame I can't get to half the wiring to trace the full length of where it goes. Something logically is not making sense. The Mastervolt manual definitely shows the negative wires going to the earth, not to the domestic battery negative. But when I do that there is no power to the monitor. It doesn't make sense.

 

I don't give up easily. But I've had enough now.

Edited July 27, 2012 by BlueStringPudding

[matty40s]

I give up. I can't access 50% of the wiring for the monitor without taking out the starter and two domestic batteries, which I physically cannot lift. Quite frankly I wish I'd left the battery cabling as it was with the negative isolator switch because at least it worked then.

 

I will send this bloke round to solve your issues.....

 

 

[BlueStringPudding]

That is the exact tool I need to finish the damn thing off once and for all.

[smileypete]

That is the exact tool I need to finish the damn thing off once and for all.

LOL, p*xy Mastervolt!

 

How about just get a cheap digital voltmeter off Ebay, bung in plastic box, add fuse by battery positive, job done!

 

http://www.ebay.co.uk/itm/150849871532

 

 

When it's working and you're happy with it, think about an ammeter too.

 

cheers, Pete.

~smpt~