Clipper BM-1 battery monitor

[Billows]

Why would it be reading 104% charge?
Wiring is ok as per manual and has been reset as per manual.
It is the compact model type

 

[Richard10002]

The simple answer is “because it does!”

Which doesn’t help, but is a fact.

I’ve had a BM2 for several years, and have ignored the 104% reading without coming to any harm.

In fact, shortly after starting to use it, I recognised that the State of Charge percentage reading is useless, and probably correct less times than a stopped watch, (which is twice a day ).

So you can happily ignore anything to do with state of charge, and base your decisions on rested voltage, and tail charge.

 

[Graham376]

When setting up the BM1, the batteries should be rested so it will indicate 100%. When on charge and almost full, the voltage will be higher than when rested. Off charge, the display will soon return to 100%.

 

[[70521]]

The explanation is in the manual, they correctly state that it is almost impossible to work out the state of charge of a battery +/- 5% is pretty good assuming that you are fully charged. You could spend a huge amount of cash to get a more accurate figure.

 

[Richard10002]

You could spend £125 or so buying a Smartgauge, like I did, only to find it isn't accurate when charging, nor when it is discharging if it reads over 80%.

Together, I actually find them quite informative, but the ability to see the charging tail current on the NASA is the most useful of all the features of the two gizmos.