Below, please.
------ Original Message ------
From: "Lee Hart" <[email protected]>
To: "Peri Hartman" <[email protected]>; "Electric Vehicle Discussion
List" <[email protected]>
Sent: 10-Sep-19 11:18:12 AM
Subject: Re: [EVDL] li ion battery in cold weather
Peri Hartman via EV wrote:
So the correct conclusion would be, for those cars which have poor
winter range, that the cell internal resistance is too low to heat the
cell ?
Yes; too little self-heating to be useful.
Also, that the cell voltage is lower during cold temps (while under
load), resulting in less Wh ?
The voltage *under load* is lower. You can get few KWH out before it falls too
low *under load* to be safe to continue using.
Note that the KWH are all still in there -- you just can't get them out. Think
of a bucket of water that's half-frozen. You can only get out the half that
isn't frozen. But let it warm up, and the rest of the water is still there.
In other words, when cold, the voltage drops below the safe minimum
rated value ? But if warmed up, the voltage rises enough to use the cell
longer ?
Ok, then why don't battery heaters - which I thought the Bolt & Tesla
have - give a good winter range ?
-- There is a computer disease that anybody who works with computers knows
about. It's very serious, and interferes completely with your work. The
trouble with computers is that you 'play' with them! (Richard Feynman)
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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