A voltage/amp meter combo is my next project. Reading the voltage is no big deal, providing a fair indication of the capacity of your battery. But better still, is to be able to see the amount of current flowing in the system. To do this the circuit must be broken and a current measuring device put in circuit, in series.
I have combined breaking the circuit and inserting the meters in one small box. Two Anderson connectors and the meter mounted on a small box. Inside is a shunt that permits the current to be read. It's done using Ohms Law, in that, the shunt is a know resistance, in my case 0.5 ohms. The meter reads the voltage across the shunt and displays that voltage as a current value. The meter has duel displays.
The alloy cast box from Jaycar was the most expensive bit. So yeah no big outlay.
Interesting: Found that the Dometic PLB-40 that I'm using has a very stable control over the rate of charge by controlling the current it accepts regardless of the voltage applied. Hence, when charging, you can plug it into the car cig lighter or straight into a solar panel without any other voltage control device. This is part of the reason I went with PLB-40 rather than mucking with a controller and separate batteries. I suppose the only downfall, as far as it and me are concerned, is that I like knowing more of what's going on. Hence my new box.
 |
| The gizzards. |
 |
| 12.9 volts and 3.5 amps. |
