In the Bleeding Edge source code on Github, we’ve implemented a battery charging prediction model. It is accessible through the Experimental section. Here’s what it does.

When you start charging the battery, CanZE fetches the State of Charge, battery temperature, chargepoint power and  the range estimate from the car. The first three are fed into a mathematical model of the battery. The model is then run for 100 minutes. Each 10 minutes the State of Charge is displayed, along with a range prediction. This will allow you to estimate how much time you have before the required range to get to your destination is reached.

The model is of course not perfect, and by it’s nature, errors accumulate. Feedback is appreciated. We intent to put it in the next release.

Edit: The screen shows always 10 lines. It’s silly to pretend accuracy is better than that. Depending on the possible charging power detected, the number of minutes between two lines varies between 10 and 50 minutes. We’ve ironed out a couple of nasty bugs, but it’s ready for the next release now.

Sometimes chargepoints are wrongly commissioned, i.e. set for 63 amps, but fused for 40, which works mighty fine for all EVs, until a 43 kW capable Zoe comes along and trips the breaker.

In another case a driver in Belgium owning a new R240 and who has a single phase 32 amps chargepoint installed, the car consistently reports 20 amps max. He called the installer who insisted all was A-OK. So, the driver blamed the car. Renault couldn’t tell him if 32 A single phase is supported on the R240. However, they were nice enough to lend him a Q210 to try (and the Q210 supports the 32 A single phase configuration). Whoops, again 20 amps only.

CanZE of course reports this all, but to exclude any issue in the car, I build a little “amp checker” which reports the maximum current per lead the chargepoint communicates to the car. It’s a tiny, tiny little bugger. If you’re into some electronics fiddling and not afraid to try, here’s the instructable.

SAE J1772 EV charger checker