Energy Matters Forums

[Tracker]

I could not find any MPPT charge controllers that would support independent dual battery setup, so was thinking of a way I could use something that is easily available...

But you are complicating it yet again by throwing in 36 and 48V

Well it took a bloody lot of words to get to the point/decision.. that it is NOT practical using the "Cheapest Available Device".
..
.

[karlajensen]

forget MPPT and buy a PL20, it will do everything you will ever need except MPPT, which another panel or will resolve simply and less expensively

It has a programmable output that is PWM controlled for a load of any description and another programmable output that can trigger a relay to operate something else.

For example it will run a dump load for a wind turbine and if then a pre-determined programmable max voltage is exceeded then it will turn on that relay. hysteresis etc is programmable.

I used one very successfully to run multiple dump loads with the "holy dooley" programmed so that if batt voltage was 60+ (if the grid failed and dump load 1 or the PWM function failed) it would click the relay and throw in 3000W of dump load, dropping the battery voltage in big chunks.

You would need a suitable charger for the Lifepo4's and my suggestion there would be an inverter from the batts and normal LifePO4 charger that will charge the bike.

Did i mention the PL20 is bulletproof? you can even trick it to run an almost unlimited sized array by using those dumpload control functions to control the batt voltage...

EG connect 8 panels in 4 strings of 2 to the Solar input side
direct connect another 8 panels in 4 strings panels to the batteries and use the 20A PWM load control
direct connect another 16 panels in 4 strings to the batteries and use the relay load to fire up a 3000W inverter and charge the car!