Forum Discussion

Kd7vea's avatar
Kd7vea
Explorer
Apr 14, 2020

What solar panels, and what charge controller do I need?

I’m hoping you can help me with this, or at lest point me in the right direction. I have a motorhome that I’m going to add solar panels to. I have 12 100ah gel cell batteries. These are alpha cell 195 gxl batteries, I got them for free, so that is why I am using them. I know that you want to put a Slower charge on gel cell batteries, so the question is do I want to go with a 40 amp charge controller and 600-900 watts of solar, but will I not be able to utilize all of that charging/wattage coming from the solar panels? The controller I have been planning on is the Tracer 4215BN, but I’m just starting to wonder if that is more than I will need.
  • Kd7vea's avatar
    Kd7vea
    Explorer
    Apr 14, 2020
    Okay, so the Controller works with Gel Cells. I was wondering if having 600-900 watts of solar would excessive if the charging could never utilize that much power, but thinking of it now, that should help as the sun is rising or setting and each panel is barely coming into operation right? if I have 1 100 watt panel in low light, I would be getting a few watts out of it, but if I have 9 panels with low light, I may get closer to 100 watts out of them altogether. Is my logic correct here?
  • ppine's avatar
    ppine
    Explorer II
    Apr 14, 2020
    You will need a larger MPPT controller for 600-900 watts, around 60-90 amps.
  • RJsfishin's avatar
    RJsfishin
    Explorer
    Apr 14, 2020
    1st of all, do you know the difference tween gell and AGM ?
    1st thing to do is make sure you are dealing w/ gell and not AGM
  • pianotuna's avatar
    pianotuna
    Nomad III
    Apr 14, 2020
    Check to see if that charge controller has a setting for Gel batteries.

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