Yaris Hybrid Won't Start

My mom has a 2 year old Yaris Hybrid with 20 000 km (~12 500 mi) on it. Today she notified me that the car refuses to start and there's a clicking sound. Below I've attached a video on what happens when trying to start the car. Anyone have any idea what's going on with the car?

The weather where my mom lives has been pretty cold for the past week, with temperatures going to -20C (-4F) and below. Last time the car was driven was approx three days ago. Personally I'm wondering if the 12V battery of the car could already be dead at this point. My guess then would be that the relay is trying to engage the HV battery but fails. Although that sound in the video is quide damn loud when compared to the HV battery relays on my GEN2 prius. I haven't seen the car live in this condition as my mom lives about three hours drive away so not exactly sure if the sound really is that loud as it seems on the video.

 

Not that I know of. This is the first time the car has had issues starting. The distances my mom drives when at home are rather short as far as I know and the car doesn't get driven every day. She does visit my aunt who lives near me every two months or so, which should charge the 12V battery as it's a 3 hour drive in one direction (6h total).

If it indeed is the 12V battery, then that's a really short lifespan as the car is only 2 years old. The car was due to go for yearly maintenance next thursday, but apparently didn't make it so far.

 

As far as i know, it has a 12V battery under the rear seat. After hearing of this I also thought that installing a battery maintainer will probably be necessary. Currently the car only has a block heater. Never thought that a maintainer would be necessary as non-hybrids have been fine in same use. Then again those cars probably had bigger 12V batteries as it was also needed for the starter motor.

Annoying how there is no warning for a low 12V battery, considering that at least on the Prius you can see the voltage from the diagnostic menu.

 

The car does indeed have a smart key system. Wasn't aware that it increases battery wear as my own Prius doesn't have one. Regarding the gas gauge, I don't know if it's normal for it to show empty on start. Very highly doubt that the tank would be empty anyway.

What's more odd about the dashboard is that on on one part of the video the TPMS light keeps flashing along with the parking light indicator. Also the temperature is constantly showing E instead of an actual value. Since it isn't my car though, I'm not fully aware what a normal startup looks like.

 

No, the outside temperature indicator, below the speedometer, to the right from the clock. It's showing E °C as the outside temperature. As to the fuel gauge, I don't know if it's supposed to show empty at that point since the car isn't mine.

 

That would be really odd, since the temperature in the garage according to my mom is about -13°C. Personally I've never seen a car that couldn't show temperature like that, even my Gen2 Prius goes well below -20°C.

Wish I could, however since It's my moms car and she lives 3 hour drive away, charging is out of the question at the moment. Will just have to wait for warmer temperature and possibly heat up the garage.

 

Thanks for all the replies. The problem was a bad 12V battery as many of you assumed. Thanks to the help of a neighbour my mom got the battery recharged and the car started normally.

The battery will get replaced and a battery maintainer might be installed.