Yes, so in practice I probably could only get about 70-80% of the energy
out, I presume. And then I need to step up the voltage. Complicated.
Peri
------ Original Message ------
From: "Jay Summet via EV" <ev@lists.evdl.org>
To: ev@lists.evdl.org
Cc: "Jay Summet" <j...@summet.com>
Sent: 16-Apr-20 8:12:16 AM
Subject: Re: [EVDL] custom battery
The other issue with Capacitors is that the voltage goes down quickly, and to
get all the energy out you need to be able to make use of the widely varying
voltage range.
Jay
On 4/16/20 11:00 AM, Peri Hartman via EV wrote:
Ok, I did a little bit of research. Anyone care to double check this ?
Here's one for $42 at unit quantity. 1200F, max voltage 2.7V
https://www.digikey.com/product-detail/en/tecate-group/TPLH-2R7-1200SL60X74/2085-TPLH-2R7-1200SL60X74-ND/9930298
Energy is
E = 1/2 CV^2
where E is joules.
Joules to watt hours is
Wh = 0.000278 J (approx)
So,
Wh = 0.000278 * 1/2 * 1200 * 2.7^2
= 1.2 Wh
If that's correct, I'd need about 100 of these to have an operating energy
capacity of around 100Wh. (My original parameter was 150Wh for a battery, but
that included margin to ensure only charging between about 15% and 80%.)
I'll say right now that 100 caps at $40 is a non starter :)
Peri
------ Original Message ------
From: "Peri Hartman" <pe...@kotatko.com>
To: "Electric Vehicle Discussion List" <ev@lists.evdl.org>
Sent: 16-Apr-20 7:06:38 AM
Subject: Re[2]: [EVDL] custom battery
I'm looking at supercaps. I appreciate that a few people have suggested this,
though I don't know yet whether it could be done economically.
Peri
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