Solar Current Meters

by Adrian on January 19, 2014

Once I’d fitted our new solar panels, it seemed obvious to want to know how much current they were producing individually.

Solar Charge Meters

I have fitted simple digital current meters across each of our 3 solar panel to accurately measure and show the current flowing into the battery from each charge controller.

(Interestingly, with full batteries and the main solar panels pumping current into the system, the two smaller charge controllers detect the full state and back off and don’t contribute anything – hence the near-zero input figures here. The negative values in this picture are as close to zero as I can get them after calibrating to show accurate current and voltage readings whilst charging. )

These charge meters were bought online via ebay (search for “20V 50A DC Amp Volt Meter shunt”)

They come straight from China and are cheap, simple and do the job nicely. They work out about £10 each. I bought a couple of spares in case of failure at any point.

Installation required cutting a simple rectangle in a panel and wiring the shunt into the charge cable connecting the charge controller to the battery’s positive bus bar. The meter also requires 12v +ve and -ve supply for the electronics and display. All simple stuff.

Installation instructions.

The power makers:

  • 2 x 10A Tracer MPPT charge controllers for the two 65W port and starboard coachroof panels
  • 1 x Victron 40A BlueSolar MPPT charge controller for the 270W arch panel
  • 1 x Marlec MPPT charge controller for the 914i wind generator (10A @ 20knts wind speed. Max 20A)
  • 1 x Studer Xtender XTM-2000-12 Inverter / Charger

Charge Controllers

{ 2 comments… read them below or add one }

Paul Ormerod January 21, 2014 at 07:47

So, is that 16w. Nearly enough to charge your iPhone!
2600w mine peak at, on the three sunny days of the year!


Adrian January 26, 2014 at 09:59

16 Amps @ 12v charge current = 192 watts (from 1 of the panels)

Thats a lot on a sailing yacht, and over 4 or 5 hours will supply enough charge to replenish the power drawn by the fridge and freezer each day!


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