Battery conundrum

[bigwow]

Last year I renewed the batteries and rewired using VSR’s to do away with the manual switches. At the same time I fitted a BEP Matrix battery monitor. All has been fine since; however this week-end after not having been near the boat for 4 weeks, the monitor for the house bank was showing 0 for amps and battery %. Everything had been switched off, and there are no take offs direct from the house bank, 480amp. I switched on the battery charger and after approx 3 hours the bank was showing 70%, it’s only a 20amp charger. Is there a chance the monitor has zeroed itself and might need recalibrating or have I got a more serious problem?

 

[ghostlymoron]

The monitor itself would only have consumed 30ahr in 4 weeks assuming it is permanently displaying. Has the bilge pump been running? I notice that the matrix battery monitor can monitor bilge pump operation.

 

[bigwow]

The monitor itself would only have consumed 30ahr in 4 weeks assuming it is permanently displaying. Has the bilge pump been running? I notice that the matrix battery monitor can monitor bilge pump operation.

The monitor is connected to 3 battery banks, 2 starter and 1 house. Nothing else connected.

 

[noelex]

The most likely explanation is that you have a power draw that you do not know about. I would double check there is no draw in the configuration you left the boat. The easiest way to trace these problems is with a clamp on multimeter, but if the meter counted down to zero it must have been measuring the discharge so it should show on the meter.

 

[Richard10002]

Did you measure the voltage at the batteries with a multimeter, or even check it at the monitor?

If it was around 12 volts, (11.9-12.8), there may be an issue with the monitor. If it was less than say, 11.7 volts, then something is draining the batteries when you think everything is switched off.

If the latter, but the monitor shows zero amps when you think everything is switched off, the culprit is connected directly to the batteries, or at least between the batteries and the monitor shunt.

On Rogue, I used to have an unknown 0.5A draw when everything was off - turned out it was the Navtex, which doesn't have an off switch/function, and must have been connected between the battery isolator and the shunt.

 

[bigwow]

To be honest I didn't do much in depth checking, I saw the monitor, thought "Oh S***" and switched the battery charger on. The sun was shinning we had some nice wine and it was good to be back on the boat. I will be going back down this week to have a closer look. I know there is nothing between the battery and the monitor as I rewired last year, it also seemed to charge up very quickly from a 20amp charger.

 

[ghostlymoron]

It doesn't take much to draw down even your large battery bank in four weeks - I calculate 0.7amps - so it could be an electronic device.

 

[halcyon]

I switched on the battery charger and after approx 3 hours the bank was showing 70%, it’s only a 20amp charger. Is there a chance the monitor has zeroed itself and might need recalibrating or have I got a more serious problem?

Does it have a sleep mode, shuts down to save power ?

But need to check more voltages first, to see if it's batteries or gauge. Always make a note of battery volts when you arrive at boat, if there lower each time visit, a good indication of a growing problem.


Brian

 

[bigwow]

Does it have a sleep mode, shuts down to save power ?

But need to check more voltages first, to see if it's batteries or gauge. Always make a note of battery volts when you arrive at boat, if there lower each time visit, a good indication of a growing problem.


Brian

Everytime I've gone to the boat, even after a few weeks, the gauge has shown 99% or there abouts on the house bank up untill this week-end.