KT controller not switching between 36 and 48v batteries

Hi, I have a strange problem with my 9FET 36/48v controller:

- I have been running the trike with a 36v LiPo battery and the LiPos are end of life
- I plugged in my 12S 44v battery charged up to 48.6v and...

The controller doesn't turn on. I have never had this problem with switching between 36v and 44v batteries on a 6FET 36v controller on another bike and here the controller is supposed to be 36/48v and it doesn't work.

When I first motorised the trike I used this very same controller and battery without any issues for a while. I changed to the 36v battery and I had no problems it was plug and play.

What do I have to do to make the controller recognise the 44v battery again?

No ideas?

Back in the good old days if the voltage was over 42v the controller concluded that the battery was a 48v battery and switched to 48v mode.

Here that is not happening, why?

I just spent another 20 minutes in the bike garage with battery, second BT controller...

The LCD4 will not turn on, if I hold down the on/off button while disconnecting the battery it flickers briefly on when the capacitors discharge to 42v or under. So I have deduced that the LCD4 is stuck in 36v mode for some strange reason - yes it is a 24/36/48v compatible LCD.

And of course it is Chinese New Year until the 20th so no help from there and we are having beautiful weather and the trike is stuck in the garage...

The "automatic" detection of battery voltage of KT controllers does not work really well.
I had always the issue that connecting a 48V battery when it is almost empty, the controller detected as a 36V battery...
I would prefer it to be selectable more than automatic...

For what you say I think that the LCD or the controller, or both can be toasted... I have already burned a couple of them using high levels of regeneration.

¡Muchos gracias!

Both work with 36v. I can't charge the battery much over 49v. I think I remember now someone saying that you need a fully charged 48v battery to make the LCD/controller switch...