hot temperature

Hallo I have a R.E1+ FS 27.5 Model Year 2015 but with a new 520 watt battery (replaced under warranty some months ago).
The new problem is this: if I let the bike stop under the sun, the frame where the battery is located becomes warm and the power train system goes into recovery (I think) by blinking a red led for 1 hour or more. In this period the bike does’not work at all and is not possible to try any reset.
After that it starts again well as before.
Thanks for any help an sorry for my poor english.

Maurizio