The better approach is to connect the two panels in parallel, and then to the controller, assuming that the controller you select is rated for the total amperage of the two panels. There is a good chance that the controller that you have for your 100 watt panel can handle the additional 40 watts... just check the controller's rated amperage (volts * amps approximately equals watts). Note that I said "in parallel", i.e. connect the positive wires of each panel together and the negative wires together, then connect these joined leads to the appropriate connector on the controller. This will give you exactly the same effect as having a single 140 watt panel, and will supply the correct voltage to the controller. Using separate controllers on each panel is not necessary unless the controller cannot handle the combined amperage, and in fact needlessly complicates the system. I run parallel-connected panels through a single controller myself, and it works well.
answered 10 months ago
- Yukon Territory, Canada
We would advise separating the two panels and placing both through their own controllers onto your batteries.
answered 11 months ago