[Victor]

I had a loan prius from my dealer over the weekend whilst I wait mine. This is an EU version of course.

I pressed the EV button and it worked well. Later, I had just come down a mountain (see Stelvio thread) and the battery was fully green but I could not switch to EV again (I was stopped at the time). The message was something like "EV mode is currently invalid"

So why would that be? I can only think that the battery was hot due to the extended recharge coming down the mountain and it disables EV until the battery has had a chance to cool.

Any other ideas?

 

[Daniel]

The other usual reasons would not have applied in your situation:

EV mode will not engage if:

1. The ICE is running but has not yet fully warmed up;
2. You are travelling faster than 34 mph;
3. You are accelerating; or
4. The SOC is at 3 bars or below, or is at 4 bars but on the verge of dropping to 3.

Since none of those applied in your case, I believe you are right about the battery temperature.