How to operate the GP-MPPT Solar Controller 20-85
Battery Charging Profile Chart
NOTE: Values before and after the slash correspond to 12 and 24 V systems respectively.
When GP-MPPT-85/20 is connected to the battery bank, the controller will start a power up mode which takes several seconds to complete.
The green LED may flash for a few minutes after startup even if no PV is detected. This delay is to avoid erratic day/night transitions.
Switching Between Battery Banks
In some applications, two battery banks with different nominal voltages need charged from the same solar array. An external switch or relay can be used to select which battery bank is charged by the controller.
GP-MPPT-85/20 automatically determines nominal system voltage at startup. If there is a large jump in battery voltage (i.e. switching from one battery bank to another with a different nominal voltage), then the controller will detect the new nominal system voltage and reset.
WARNING: Switching must be done with an external device. Each battery bank must have a fuse or breaker. The switching circuit must not allow the battery banks to be connected/shorted.