Q
Do I need to disconnect my BM1/BM2 when I leave the boat
for long periods?
A
No. The BM1/BM2 is designed to be permanently connected to the
battery. It is independently fused, and draws only 1.5mA from the
battery. At such a low current, it would take several years to
discharge a typical fully-charged marine service battery.
Q
Why does my battery seem to have less capacity than it says
on its label?
A
The value on the manufacturer's label is seldom the value achieved
in service, because of the deterioration of the cells' plates and
many other factors. If it seems to have much lower than its
expected capacity, it may need replacement, or you may feel that
changing the nominal capacity from the Engineering mode will
suffice to let you know well enough the percentage charge
remaining.
Q
Why does my BM1/BM2 show a large net charge after a day's
cruising?
A
You have put more charge into the battery than you have used.
The amount should not exceed the total battery capacity. If it does,
it may be wise to check that the charging system is working
correctly and is not over-charging the battery.
Q
When on heavy load, the time to run is lower than I expect. Is
this correct?
A
YES. When heavily loaded, a lead-acid battery delivers less energy
than expected owing to electrolyte exhaustion and stagnation.
When the battery is delivering heavy currents the BM1/BM2 uses
Peukert's equation to allow for these effects and so show a better
estimate for the time to run.
Q
Why is my BM1 showing incorrect readings?
A
Check the connections in the terminal block are correct and that
the clamps in the block are fastened on the copper of the wires
and not the plastic insulation of the wires .
