Since I am not building my own controller or monitoring system, I have modified my plans with regard to what gets monitored.
First, I am going to use analog gauges to measure the traction pack voltage and current. These are going to be mounted in a gauge pod on top of the dash. I am going to wire things up to leave the option of adding motor current monitoring using the same gauges, as a future addition if I want. I don't want to have to tear open the dash again so I will leave this as an option.
Second, I am going to also use analog gauges to measure the voltage and current on the 12V system. These will be mounted somewhere in the console.
I think I like the idea of the analog gauges because you can get a much better feel for what is happening as the meter moves up and down, as opposed to staring at changing numbers on a digital display. Anyway, for better or worse, that is what I decided.
Now, for battery pack monitoring, I am going to use the mini-BMS system (see BMS page). This will cut off the charger if any cell voltage gets too high when charging. It will sound an alarm in the cab if any cell goes too low while driving, and will also provide an alert if a cell temperature is too high.
Also, for battery pack monitoring, I am going to use the EV Display (version 2 coming out soon at the time of this writing). The primary function is a coulomb counter to track the state of charge of the battery pack. But it will also monitor when charging and also provides a cutoff for the charger in case for some reason the charger does not cut off on its own. It also provides an output for the fuel gauge function which I will wire to the original fuel gauge in my dash.
Speaking of original functions of the dash, here are my plans:
- tachometer - show electric motor RPM
- fuel gauge - show the battery state of charge
- temperature gauge - TBD, will be used for some temperature display but I haven't decided yet
- engine light - electric motor temperature cutoff switch
- charge light - low battery state of charge - treated like a "low fuel" light
- unused at the moment - oil light, o/d light
The following is a list of items of which would be interesting to measure and display in raw or derived form.
An extended list can be found in the Monitoring Google doc
- 12V System
- Battery Pack
- Control Position