I have a WAECO battery
manager which measures Amps charging
and discharging from the service battery
and computes/displays the state of discharge of said batteriy in Ampxhours.
To this effect net Amps are measured from a shunt on the - pole of the battery bank.
Unfortunately, the battery manager either underestimates the charging current
or over estimates the discarging current
: After a week it displays say 300 Amp x h discharge when the battery is actually fully charged and the MPTT in float mode.
I then reset the battery manager to zero discharge.... and a week later it displays again 300 Amp x h discharge when the battery is fully charged.
Could someone advise?