Make sure to set the proper battery type on the Go Power MMPT Controller Dip Switches
Go Power’s MPPT 40 Charge controller has been discontinued.
Instead, try one from this selection of solar charge controllers
Time to add more panels or look for a more power controller capable of hanadling series and series parallel wiring? Go Power's MPPT controller might be the one for you. [Go Power MPPT 60](https://amzn.to/3VCMWAx)
This controller has been the workhorse of many RV solar arrays. For larger arrays it offers great power and fleability. With tons of input and output voltages and even bluetooth connectivity. Take a hard look at this particular controller for your RV.