 LiFePO4 upgrade for laptop pack
|
|
|
Conundrum
|
|
Sun Oct 02 2011, 07:36AM
|
|
|
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4061
|
Hi all.
Well I finally got around to trying phosphate cells in my dead laptop pack (HP SPS-440704)
used indium solder to prevent damage to the cells and then reattached the tab stubs from the old pack.
Seems to work, obviously it doesen't charge or recognise the pack is in BUT it does run for about 20 minutes while disconnected from mains until the cell voltage drops below 3.1V
Now I just need to make a charge circuit for the beast.
Any ideas? these are 1350 mAh sorted and matched cells, so 1/2C would be 675mA
Needs to shut down when every cell goes over 3.6V i.e. full charge
FYI this is for my own personal use, I am well aware of the hazards of Li+ cells and have taken appropriate
safety precautions.
I did find out that to get a good match you need to measure cells under load i.e. 1A and if they drop by more than 0.1V then they are bad.
Thanks, -A
|
|
Back to top
|
|
Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob
|
|
Powered by e107 Forum System
|
