How long should the 12v battery be able to run windscreen demist?

[Gaz911]

Hi, after charging my 2018 Prius phv I ran the front windscreen blowers while the charging lead was still connected. 

Due to the good old UK weather and heavy interior mist I had to press the start button a few times as it turned itself off after approx 5 minutes. 

This resulted in being unable to start the vehicle in either ev mode or combustion mode as the 12v Battery was flat. 

I managed to jump start via leads to my brothers car.

My question is has the 12v Battery failed or require replacing or is it just incapable of demisting a windscreen? 

Thanks in advance for any help you can give. 

[TonyHSD]

Hi, you should keep the car in ready mode if you about to use any electrics and draw any current from 12v Battery. You most likely just killed your Battery and you will need to fully charge it with external charger like ctek 5 for a good overnight charge. 

[johalareewi]

2018 plugin prius when connected to EV charger can be demisted using the remote A/C on the key fob. 

You can also do this while inside the car without having to turn the car on.  😉

 

[Gaz911]

On 2/2/2022 at 2:54 PM, johalareewi said:

2018 plugin prius when connected to EV charger can be demisted using the remote A/C on the key fob. 

You can also do this while inside the car without having to turn the car on.  😉

 

How do I do that? Just press the A/C button? 

I'm trying this now sat inside the car and nothing seems to happen? 

[Ancient Nerd]

AFAIR, you switch it on from the key fob.

I'm sure mine switched off when you unlock the car. 

I think the only effective way to demist when in the car is to switch on and use the demist button.

[johalareewi]

On 2/9/2023 at 11:08 PM, Ancient Nerd said:

AFAIR, you switch it on from the key fob.

I'm sure mine switched off when you unlock the car. 

I think the only effective way to demist when in the car is to switch on and use the demist button.

I have done it while charging up from EV charger and sat in the car.  Just press AC button on key fob.  Will demist for about 10 minutes.

You have to be connected to EV charger for this to work.