I am just getting my feet wet, so I have one 100 watt panel and a 12v marine battery. I plan on running a small water pump to circulate water in a black hose to see if I can heat some water.

The manual talks about grounding. Do I really need to ground this simple system of 1 panel, one battery and a charge controller?

Victron Energy SmartSolar MPPT 100/50

3.2 Grounding ● Battery grounding: the charger can be installed in a positive or negative grounded system. Note: apply a single ground connection (preferably close to the battery) to prevent malfunctioning of the system. ● Chassis grounding: A separate earth path for the chassis ground is permitted because it is isolated from the positive and negative terminal. ● The USA National Electrical Code (NEC) requires the use of an external ground fault protection device (GFPD). These MPPT chargers do not have internal ground fault protection. The system electrical negative should be bonded through a GFPD to earth ground at one (and only one) location. ● The charger must not be connected with grounded PV arrays (one ground connection only)

Thank you for you help.

  • A floating 12v won't hurt anything, but if you tie your system to the grid it's not optional at all. You might want to ground positive on a floating system to help reduce corrosion on any exposed positive terminal/conductors.
    – dandavis
    Commented Jan 27, 2021 at 18:06
  • Thank you @dandavis If I were to ground the battery, just attach wire to + terminal then to some copper pole in the ground? I am not going to buy and hammer an 8' grounding pole. Ideas on something a bit easier?
    – Terrence
    Commented Jan 27, 2021 at 22:20
  • @Terrence -- what are you using for circuit protection and disconnection here? Commented Jan 28, 2021 at 0:11
  • to reduce corrosion, anything metal will work as a stake, even a stripped back wire, long nail, tent stake, bbq fork, etc, and it doesn't have to be deep.
    – dandavis
    Commented Jan 28, 2021 at 4:11
  • @ThreePhaseEel for this simple panel, charge controller, pump I had not thought of adding one, but to be safe I guess I should.
    – Terrence
    Commented Jan 28, 2021 at 21:46

1 Answer 1


Only if you want your installation to be code compliant and to minimize the risk of fire and electric shock. What are the odds that you'll "forget" to install the ground later when you expand the system to 10 or 20 panels, and add another 20 or 30 batteries? What if there is a fire? There will be an investigation, and if the insurance company can prove that the installation wasn't to code, they may not pay your claim. If, of course, you're alive to collect on it.

  • Good habits start early and last a lifetime.
  • Bad habits start early and last a lifetime. They also tend to shorten your lifetime.
  • Thank you @FreeMan. this is a weekend project which will be broken down and put up until another idea comes to mind. Totally temporary out in the back yard. I do like your advice on starting right from the beginning.
    – Terrence
    Commented Jan 27, 2021 at 22:18

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