I have a 48v system.
Originally I was going to have 4 200 watt solar panels for approximately 80v. Did not have room for the 4 panels and now have 3 panels at about 57v output. Unfortunately the SmartSolar MPPT 100/20 controller does not start charging until the batteries are down below 60%, because of the 5v difference required by the controller and then it only charges at 60w when the panels are generating 440w. Just need a 3-5 volt increase.
Bellow are the choices choices I can think of to fix this:
1. (It works, but should not have to do this and it doesn’t fix the issue.) I currently charge a power bank from the panels. It takes in the full 440w until full. Then turn around and charge the main batteries from it. Works but have to manually deal with it, has power loss from conversions, and I have to carry the power bank.
2. (Simplest option so far, but have not found a suitable(reliable and safe) device.) Add a Buck converter to increase the voltage from 57v to somewhere above 60v, but below the controllers 100v max. If this is the choice I unable find a quality converter that handle the 57v input with an output between 60-100v and would appreciate suggestions.
3. (If this is the answer I can do. Just a lot of hassle, cost, and reconfiguration work, and less power.) Replace the 3 200w(600w) solar panels with 5 100w(500w) panels that total 90v. Or find other higher voltage 200w panels.
Suggestion on how to proceed would be greatly appreciated.
Thanks for your help.