As Martin confirmed the MPPT-2420-LC hw and fw are capable to work in buck or boost modes.
I found interesting to modify the hw and fw in such a way that the device should be capable to charge a battery in buck mode during day time, than in dark condition it should operate in boost mode to supply a high power LED light so energy stored in the battery will be used for lighting.
I opened this topic to share this project with anyone who might be interested in this feature.
I’m sharing my first draft schematics and some thoughts.
The Q2, R2 and D1 are unnecessary and should not be placed for this modification, I’m just planning to leave it there in case the boost feature is not needed or if someone wish to keep the current protection circuit.
For boost mode Q2 S-D should be connected to allow current flow.
To detect day/night conditions I need a way to measure the PV voltage continuously. I thought not to interrupt the SOLAR-, so I’m planning to use the reverse protection from MPPT_Charger_12A.
PV_Voltage output can be used for monitoring purpose.
I added LOAD(LED) output which can be turned on with DCDC_LOAD(LED)_OUT.
I’m planning to use relatively high voltages
Any comments / ideas are welcome!