Re: Thoughts on industrial design

On 4/29/2025 10:48 AM, Radey Shouman wrote:

Frank Krygowski <frkrygow@sbcglobal.net> writes:
 

On 4/28/2025 8:47 PM, Radey Shouman wrote:

On the other hand, if you want to experience the depths of true
"off",
just let that atavistic 12V battery run down, and prepare to find an
experienced mechanic with a jump starter just to get the door open,
never mind rolling down the windows.

>
I've had two 12V battery incidents with my Kia EV. Despite having a 64
kw-hr battery full of electrons (at something over 300V), the car
would not start. Some parasitic loss had drained the very conventional
12V battery down to a voltage too low to fire up* the electronics. One
was a complete mystery, the other was a device plugged into an outlet
within the car.

 Seems to be a common mode of failure.  All the old systems still run on
12V, which is good for safety.  I would not want to deal with live 300V
circuits.  With a conventional car, one is aware when the battery is
dying: the car cranks slower, or not at all in cold weather.  With an
electric car it's a bit of a research project.

It's not just full EVs. Our neighbor owns a Prius hybrid. The traction battery is much smaller capacity than mine, but much more than the car's standard 12V battery.
One day he had the same problem: Lots of juice in the bigger battery, but the 12V wouldn't crank the engine, so he asked me for a jump. That was the first I was aware of this oddity.
--
- Frank Krygowski