Last time I did this it was around 20 to 25°C weather and I’m still convinced that higher ambient temperature won’t help with the battery heat. So now that the temperature dropped another 10°C I did the same test over again at 15°C. And yes once it dropped another 10°C I will do this test at aroun 0 to 5°C. If we reach -10°C here in Belgium this winter I’ll do that test again.
15°C ambient temperature but rather sunny so I first had some fun on local roads riding up to the highway where the actual test could start. Below is the route collected using the GPS on my phone. Since I’m using Bluetooth for OBDII data I have no BLE connection to the Energica dashboard itself.
On the highway I passed the ionity site first with really fast chargers. I have a card for it but since I had just started riding here (Doornik on the map) it didn’t make sense to charge. So instead I continued on the highway at 110 kph indicated (so 100 kph actual) for around an hour to reach Roeselare where they have 4x 50 kW fastNed chargers. Not the fastest around but plenty for us Energica owners.
I started charging at 60A, well no I did at 75A but then noticed my mistake and corrected for it. From highway riding the battery temperature was already gone up from 20°C garage temp to 25°C. The good news is that I could charge for the full 20 minutes at the 60A speed I selected. The temperature did go up to 35°C.
If someone is interested I can always provide better graphs, these are just screenshots from the phone I was using. The resolution isn’t that great. But good enough to see that the temp (red) went up and the charge speed (blue) was steady.
Next I continued riding hoping for better cooling during that ride since the ambient temperature drop. However I didn’t notice any difference from my previous test runs. Battery temperature dropped at a rate of approx. 2°C an hour.
My next charge stop was near Gent, not even a full hour ride from Roeselare so I reached it with 34°C battery temp. But in the time required to get the charger going it dropped to 33°C. I knew I would get in the 40°C at this point if I didn’t lower charge speed but I was also not planning on doing more charges than these 2 so I did it anyway.
And indeed the temperature was at 40°C at the end of this 20 min charge and at around 60% SOC the charge speed dropped slightly. The graph here doesn’t show it that good but the speed started at 60A and ended at 50A. Not a big issue for this charge but for sure an issue for the 3rd charge of the day (if that would’ve been needed).
So a bit disappointed now that a difference in ambient temperature doesn’t help much while riding. I did however notice a few times already that the battery temp would drop a degree while setting up a charge. So that makes me wonder if the best way to cool it is to not use it for a few minutes.
Plus at what rate it would then drop in order to evaulate if it would gain time overall if I had just let it cool for a few minutes before starting high current charges. In order to explore that I’ll have to update the app with a time based temperature graph. For now you can already somewhat see the effect in the below graph where I was charging at home at 3 kW later that day.