NASA BM1 battery monitor

[bromleybysea]

my BM1 battery monitor seems to have developed a confusing fault. It always shows "charge" even when there is no charging taking place. It appears to show accurate voltage when being charged but then seems stuck at a resting voltage of 12.9 with the bar graph permanently showing 100%. I have recently fitted new batteries-160ah of AGM- and gone through the reset procedure as per the manual. Finally, when I turn on the illumination the amps display rapidly climbs and the volts display drops to 12.3. Any suggestions welcome!

 

[Sandy]

Give the lovely people at NASA a call on Monday. They know their stuff.

 

[CJ13]

Have you checked the connections to the shunt / batteries?
When my BM1 display was clearly wrong, a good clean of the conns sorted it.