View Single Post
Old 04-29-2013, 04:07 PM   #238 (permalink)
bennelson
EV test pilot
 
bennelson's Avatar
 
Join Date: Jan 2008
Location: Oconomowoc, WI, USA
Posts: 4,435

Electric Cycle - '81 Kawasaki KZ440
90 day: 334.6 mpg (US)

S10 - '95 Chevy S10
90 day: 30.48 mpg (US)

Electro-Metro - '96 Ben Nelson's "Electro-Metro"
90 day: 129.81 mpg (US)

The Wife's Car - Plug-in Prius - '04 Toyota Prius
90 day: 78.16 mpg (US)
Thanks: 17
Thanked 663 Times in 388 Posts
Quote:
Originally Posted by Xist View Post
That was Mother Nature showing you what she thinks of electric cars! :P
Well, 99.9% of all the ones damaged in that storm were gas-powered, so I'm going to take that comment with a grain of salt, er, ok maybe a couple of gallons of salt-water..

Yesterday, I did some work on the car, mostly disassembling the lithium cells from the pack, and giving it a car wash. That of course caused the weather report to be rain for the next ten consecutive days....





Today, I took one of the 8-packs of cells and "War-Charged" it. I've tried finding some good info on how to bring up the voltage of lithium cells that are completely discharged, and frankly, I haven't found any good techniques that actually work!

I have borrowed fancy lithium charger, but it won't connect and actually charge unless the cell has a certain minimum voltage of about 2 volts or so.

The only thing that really works is jumper cables!

I've rigged up a block of cells (24v-ish) to a pair of 100ah flooded-lead acid batteries (in this case in my electric riding lawn mower...) and let the batteries try to parallel themselves to each other. But with one pack at over 24V and the other at zero, it tries to do it at a fair amp-rate. My Harbor Freight meter only goes to 10 amps, and it was higher than that... I'm guessing about 20 amps or so, which is one-half the C-rate of the cells.

After testing amperage 15 minutes later, it was charging at about 10 amps. And yes, I was using my good thick jumper cables, wearing safety glasses, was outdoors, didn't have small children around, etc. etc. Still, "Kids, don't try this at home."

Once charged and with the cover removed from the pack of cells, about 2/3rds of them measured 2V or higher! I'm excited because it means there's a pretty good shot that a fair number of these cells can be saved!

I'll have to cycle them all through a few times to know for sure, but we'll see.

Out of the first 8 cells I pulled out of the car only ONE of them was good, measuring a capacity of 40ah (50AH faceplate rating) while the other 7 were all completely shot!
__________________


300mpg.org Learn how to BUILD YOUR OWN ELECTRIC CAR CHEAP
My YouTube Videos
  Reply With Quote