There has been discussion in the past about the "light codes" on MinnKota battery chargers. Hope this helps.
MK110, MK210, MK315, MK220, and MK330
A GREEN power light is lit to indicate AC power is applied.
A YELLOW light is lit for each bank to indicate the battery is charging.
A GREEN light is lit for each bank to indicate the battery is fully charged and in maintenance mode.
A RED light for each bank is lit if any of the following apply:
A) No battery is connected to an output lead. This may also indicate a blown fuse in the fuse holder.
B) The battery voltage is below 8.0 volts.
C) The battery is connected reverse polarity.
RED and GREEN lights are lit simultaneously for each bank if any of the following apply:
A) The battery voltage is below 8.0 volts.
B) A damaged temperature sensor on the output lead. The bank will not operate if this occurs.
MK230, MK345, MK460, MK440
A GREEN power light is lit to indicate AC power is applied.
A YELLOW light is lit for each bank to indicate the battery is charging.
A GREEN light is lit for each bank to indicate the battery is fully charged and in maintenance mode.
A RED light for each bank is lit if any of the following apply:
A) No battery is connected to an output lead. This may also indicate a blown fuse in the fuse holder.
B) The battery is connected reverse polarity.
RED and GREEN lights are lit simultaneously for each bank if any of the following apply:
A) A short circuit.
B) The battery voltage is below 8.0 volts.
C) A damaged temperature sensor on the output lead. The bank will stay in maintenance mode if this
occurs.
MK "D" Chargers
On the "D" chargers:
Plugging in all lights come on monetarily while "reading" the batteries
Yellow: Bulk charge mode til battery reaches 75% of charge
Flashing Yellow: Absorption Mode, charging current tapers holding battery to 14.4V apx
Flashing Green : Maintenance mode, voltage goes to 13.4V
Green: Charger turns itself off after 24hrs and monitors battery
When battery voltage drops below 12.6V, charger will turn back on