Re: Thoughts on industrial design

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.

I happened to have a spare motorcycle battery on hand and charged. I
used that to "jump" the car's 12V battery, and all was well. It
doesn't seem to require much current to kick the electronics awake,
energize the relays, etc.

At least one electric car owner I know had to call a tow truck just to
find a guy who could figure out how to get to the 12V terminals.  The
door and hood latches, naturally, did not work.  There was some sort of
secret trap door somewhere, with which the tow truck driver was
familiar.

The car does have a "utility mode" in which the big traction battery
tends the 12V. That's mostly intended for things like camping, where
one might run lights, etc. off the 12V.
>
(* Note the archaic term still in use: "fire up," as with a steam engine.)

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