View Single Post
Old 03-09-2012, 03:45 AM   #153
_cy_ OP
Beastly Adventurer
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 5,037
Originally Posted by JoelWisman View Post
I was hunting for my card reader to post the pic above as you posted _cy_

Time will tell, that Li-ion is 7.4 volt and was down to 0.11 volts. As it happens I got it into normal range using its power supply through a 10kohm resistor.

I'm still charging it in the fireplace for a reason lol
assuming you are referring to two cell lithium cobalt 7.4 battery pack

procedure to recover lithium cobalt (4.2v max 3.7v nominal) is to charge at .01C until volt raises above 3.25v per cell. then charge rate .5C to hopefully full recovery.

recovered many a li-ion cell this method with Schulze isl 6-330d .. the new Powerlab 8 is hugely more capable. they call it a battery workstation instead of a charger for good reason.

charged many a lithium cobalt battery inside my fireplace insert with 1/4in steel construction. fireplace was the safest spot in the house. greatest danger from using li-ion (lithium cobalt) cells occurs during charging. lithium cobalt chemistry will accept a charge until thermal runaway (explosion) occurs at about 4.35v. this is why it's very important to only charge lithium cobalt cells with a charger that terminates charge at 4.2v. above link is from an article I wrote five years ago on Candlepower forums

Originally Posted by Anorak View Post
Shorai isn't A123. I'll try to remember to consult with a friend who has seriously abused A123 cells for a project. He wound up using Ener1 cells.
no Shorai isn't A123 .. but both use LiFePO4 chemistry. Shorai uses four flat prismatic cells wired in series, different size of prismatic cells are used to achieve desired amp hour rating. Ballistic and SYCL uses cylindrical A123 cells wired in series. then paralleled to desired amp hour rating. currently there are only about 12 different mfg of lithium cells in the world.

plans are to drill in later, advantages and disadvantages of prismatic vs cylindrical LiFePO4 cells

_cy_ screwed with this post 03-09-2012 at 08:21 AM
_cy_ is offline   Reply With Quote