GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Question about plugging in a Portable Panel through existing MPPT

ArimaKisho | Posted in General Questions on

Hello all,

I am planning on installing two 120watt “24 volt” panels in parallel on my roof top. These panels are from NewPowa and are 120W 40.5Voc and 3.7Isc each.

I have a third identical panel that I would like to use as a portable panel occasionally. And when it is deployed, all 3 panels will be in parallel and all feeding into my MPPT charge controller. I want to be sure folks understand this is just a panel and not a solar suitcase with its own built-in controller.

My concern is with plugging in the portable panel. Even if the Circuit Breaker is open, so that the roof top panels are disconnected from the charge controller, there will still be ~40 volts on that connector junction. Will this arc when the portable panel is plugged in? Am I going to char up the connectors over time? Is there a better way to do this?


GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member
    Zephyr7 | | #1

    You won't have a big problem with arcing, but there will be some. You'll want to use a connector that is designed to tolerate this. Anderson Powerpoles are one such option. The design of such a connector has different areas for "first contact" and mated contact, so the arcing occurs on a part of the contact that isn't involved in carrying current once the connector is fully mated. This minimizes how much the arcing affects the resistance of the mated connector over time.

    You could also use a switch, so that the connector can be de-energized for mating, and then close the switch afterwards. This means any arcing is confined to the switch, which is designed for this. You'll just need to make sure that your switch is rated for DC at the current levels involved with your panel (around 5 amps), which shouldn't be too difficult to find.


  2. Expert Member
    Akos | | #2

    Any of these NewPowa posts are spam to get a random brand out onto forums.

    Spam is getting much better to get through filters.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |