Paring different charge controllers…

Bunkysdad Registered Users Posts: 38 ✭✭
My original 300w solar system (4 panels) is tied to a MPPT single stage controller…A couple years later I added another 140w, lower voltage panels (2) but this time simply used the Truck campers OEM thru the rooftop #10AWG wiring (because of lack of MPPT controller headroom) and a 3 stage PWM (cheapo) controller…What I found was that the two different controllers tended to be fighting each other, resulting in little solar improvement….After this, I then switched out the cheapo PWM controller with a simple 12a single stage PWM (with an adjustable voltage pot), and it paired perfectly with the former MPPT controller…However, I’m now adding an additional 120w panel to the PWM system, so will need to upgrade the PWM controller with a higher amperage unit, again with adjustable pot…

Based on my previous remedy, I’m not anticipating a repeat of the aforementioned problem, but am a bit curious if others might have ran into this issue??



  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    No problem.  it just takes some fine tuning to get the voltages matched/tweaked between all the units
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,