Sterling Battery Monitor problem

[asj1]

I wonder if anyone can help....

I have an older style Sterling Battery Monitor ( don't know how old as I bought it 2nd hand from this forum). It measures volts from two batteries and amps from a shunt in the cabling to/from the domestic battery. The unit indicates that it can do the same from 4 batteries, but I don't need this. It isn't the sort that measures what % of battery remains.

When I arrive at the boat after a week with all electrics switched off and turn the unit and batteries on it works perfectly well.

However once I either use the engine or shorepower it ceases to be of any use and when I switch it on to volts it starts at a number between 9 and 30 and counts up - I usually get bored by the time it reaches 100 or so and switch it off. Similairly the amps figure seems to be wrong as it is unaffected by how amny lights etc I have switched on.

Has anyone had a similiar problem?
Any ideas for causes/repair?
Could it be static causing this odd behaviour.

If I ditch it I will need to replace it with something to cover up the hole I will be left with. NASA seem to do something similiar for circa £100.
- Can anyone report how relaible they are.
- I belive the NASA unit is for one battery, but presumably a simple 3 way switch would enable it to do the volts from two banks.

Regards

 

[ccscott49]

The sterling one I have, for four battery banks, works fine now, after I sent it back it didnt work when first installed.

 

[grimmy]

hi, I'm not familiar with the Sterling product, but are you certain you have this unit wired correctly. I would have thought that for any battery "monitor" to work it would need some basic information about your battery bank and would need to measure ALL current into and out of the battery bank. On the unit I have this is done by inserting the shunt on the negative terminal of the battery and making sure that all negative connections are downstream of the shunt. Obviously this can only work for one battery or bank unless the instrument is specifically designed for use with more than one battery bank. Therefore, having a single sensor with a switching sysyem would not work. Perhaps your charging sytem either from the engine or shorepower, or both, is somehow bypassing the shunt.

 

[asj1]

It is wired correctly, and does occasionally work correctly.

It measures volts from either battery bank by means of a switch on the unit. Each battery is seperately connected to the unit.

It only measures amps from/to the domestic battery by means of a shunt. (If I had more than one shunt it could measure amps at different points, agin byb means of a switch on the unit)

Regards