Look Inside Kona Electric Battery And See Real Capacity

I emailed that site 2 years ago and asked them where they got the 67 number from. They told me that they "guessed".

True, and if you integrate power output over that full voltage range you arrive at a total energy capacity. If you divide that by the Ah rating you get that nominal voltage. It's a convenient way to characterise the cell without worrying about a complicated voltage curve.

We've unaware of that number or if a low-end buffer is used. The missing piece of info is the cell voltage when the Kona's dash says 0% SoC.

 

The cell published data plotted out shows that it's quite nonlinear under 10%. Another challenge is that we don't have a way of precisely measuring OCV in the car. The best we can do is take data while low-power AC charging with the Minimum setting applied to minimise charging power, yet externally support the on-board systems that allow OBD cell or pack voltage to be read.
The data I plotted here against the published OCV is while driving, so that averages to cell voltage under moderate load and that offset of course reflects the cell resistance.

 

Okay, Vid, who are you really and which lab do you work for? Just curious.

_H*

 

... which is far more conservative than what many of us will be doing with our Konas while we wait ...

 

Fantastic way to repurpose used cells. At .3C I can see why they don't heat up. I've seen others do this. With the recall on the Kona EV's their is likely to be lots of these available. Good time to start a business repurposing.

 

Interesting.. If the calculation is correct, the pack would have over 73kw at 100% charge..
So capacity would be 4.18V x 180Ah (3x60Ah) x 98 (cell no) = 73.7 kw. That seems a lot higher than the 67 kw that some claimed that the pack has..

 

Very interesting thread. The very 1st pic included that shows that "LGCHEM" type of batteries -- WHERE IS THAT PANEL? Is it easy to see from under the car? or does it require removing something to expose that?

FYI ... I have had all RECALLS & Service Campaigns done to date. I don't usually charge to 100% but though I'd give it a try to see what my cells charge to at full charge.. I've included a pic from SOUL SPY =>>

 

Hey Vid, what's the name of your business? We're considering building an off-grid home and I've wondered about just this idea of using repurposed EV cells for storage (but I don't have the DIY chops to DIMyself).
I'd be interested in learning more about a company like yours.
Thanks, Nate

 

Your calculation is incorrect because the voltage is not maintained over the full discharge range, as EE noted.

 

So, what is the actual capacity then?? How do you calculate it?