Cooling Down The Drive Battery

[episani]

Hi,

I'm new to this forum so I apologise if this has been asked before.

I'm wanting to use a Raspberry Pi with a Pican2 to control the temperature of the drive battery.

After reading some of the documentation I have learned there is a fan and a air conditioner in the battery.

So basically what I would like to do is to find the max temperature in the battery modules. If a certain temperature is reached start the fan and then after a higher temperature switch the aircon of the battery on.

I live in Australia and the battery of my MY14 seems to get quite hot. I would prefer keeping the battery cooler.

I believe a similar process takes place at the moment, but the temperatures that trigger these events seem to be quite high.

So the solution can either be replacing the trigger values in ECU to lower values or creating an alternative control using a Rpi or Arduino to control this process.

I don't even know where to start, but if anybody could give me some guidelines about the can codes to switch the fan or air conditioner of the battery on and off and also to read the temperature of the battery modules that would be greatly appreciated.

Alternatively, if somebody knows how to replace the trigger temperature values in the ECU that would be great.

Thanks in advance.

 

[elm70]

The trigger is 35C, but it works only when the car is "on"

I guess your issue is to keep the battery cool while parked, which it may be impossible.

I'm not sure how much can be done over the can bus while the car is off ... I know that the PhevWhatchDog can read data from can bus only while the car is on

 

[episani]

Everything in that car works using the canbus.

Maybe some parts of the vehicle are off, like the ECU, when the car is off, but I would imagine they can be switched on again using the canbus.

Even the power switch of the car must use the canbus to switch everything on.

I believe the fan/aircon of the battery should work while the car is being charged and after finishing a trip till the battery temperature is "estable". Even when the car is parked, if the temperature goes up in the "battery chamber" the fan should be triggered.

I would probably lower the temperature to 30 or even 25.

One of the things that causes more degradation is leaving the battery charged at high temperatures!

In Queensland, in summer that's very likely to happen!