Fitting an ammeter is a much debated subject, from our perspective we see the following;
- Can be interesting to see what you are using.
- Can indicate mechanical faults.
- Needs a shunt [adds losses], or hall effect sensor [expensive].
- What exactly is it measuring? [battery and motor current are usually different].
- Most meters are not calibrated for measuring square wave PWM currents.
A battery voltmeter is more useful – we would even say essential since, as the battery discharges, its voltage drops, so this will tell you the charge state of the battery. Also, under heavy load, the battery voltage dips. If the voltage dips too far then either the load has increased or the battery is getting old.
The built-in approach
Our new Pro-160 controller has been designed with a built in low loss hall effect current sensor. This allows us to display both the battery and motor current as well as battery voltage and controller temperature. Additionally the built-in approach lets us set accurate limits to the drive and regen currents, and also to implement more advanced battery protection measures.