Digital 12v ammeter for solar charger.

[Rjt]

I’m going in circles and need some help.
I have a Sunsaver SS-MPPT-15L running my 2 x 150w fixed solar panels.

My problem is I’m trying to install a 12v digital ammeter/volt meter to check where my power is coming from. (I have wind and another set of solar on a hybrid controller)

Meter is the same as this one : https://www.ebay.com.au/itm/DC-Digit...YAAOSwh-1W2vO4

I installed it between the panels and controller, and it worked. So, moved it between the controller and batteries and can’t get it to work.
This is the wiring diagram I’m working on.


Now I’m seeing 25.7v and 0.00 A. Battery monitor’s showing 12.6v. [emoji31]

Im treating the controller as the source, and the batteries as the load.

There’s many posters on CF who understand this way better than me.
I’m hoping the excellent collective knowledge on here can help me out.

[HankOnthewater]

Hi RJT
In principle there are 3 sets of 2 wires: one for power to the unit, one set for voltage sensing (ideally directly to the battery terminals), and one set for measuring the current and connected to the shunt (however in fact it is measuring the very small voltage that the current is causing). Very often and and in this case, the first and second sets are combined into one set, leaving the unit with 2 sets of 2 wires: 4 wires in total. In your case it looks like the thick black wire is used for both the amps measurement and the negative power supply.... only 3 wires by the looks of it.

I think that in your last sentence you highlighted your mistake: "treated battery as the load"

Most of these kind of panelmeters measure the current via the shunt in the negative wire. Sofar so good with the diagram supplied, however the black wire that goes from the panelmeter to the shunt is NOT the negative anymore, it will slightly higher than the negative.
Not sure how you then measure the 25.7 Volt though.

I would experiment first with a 9 volt battery as powersupply, connected to the thin red and black wire, yellow wire to go to the positive battery terminal, and the thick black wire to the negative (battery side) of the shunt, and the thick red one to the other side of the shunt. See how you go then.

Note: connecting these panel meters the wrong way around will lead often to damage of the units, as I believe most of them have no wrong polarity protection.... I found. And if they have that kind of protection I was able to circumvent that kind protection in a very effective way