Monday, July 16, 2012

LiFePO4 Cell disassembly

Yesterday I decided to open up this Mottcell 39 Ah LiFePO4 cell that reads almost 0V and has had problems in the past (the postive terminal was a bit swollen and disformed, and I heard some strange noises from the inside, so I put it away for good)
Like all the other cells in my Battery Energy Storage System, it comes from a Prius PHEV kit that can be found at
This cell is made of 3 13Ah cylindrical cells hooked up in parallel, let's see how: 

Removing terminals

0.08V => not a lot :-(

There is a top glued to the rest of the cell container

Scew driver to open

Looking good ...

Some white stuff... insultion foam or something like this maybe 

Top off

Terminal bars lifted, showing the insulation plate

Plate removed, now we can see the top cylindrical cell, taken all the width
Bad news, the white mastic is blocking everthing, and I can not lift the cells out of the shell

Cutting and cracking the plastic shell with saw & pliers

One side is gone giving me easier access and showing the way the cylindrical cells are connected to each other (reminds me my RC models battery, their cells were connected like this)

That's what I thought, once diconnected the cells show different individual voltages

It looks like the last one, at the bottom shows more damage than the other with this brown smelly electrolyte liquid/paste

The top cell: I thought it was damaged at first, but removing this cartborad cover I could discover it is not so much; The positive terminal and negative outer shell are insulated from each other by a one millimeter plastic ring (at the junstion of the cynlinder and the the top plate) 

The bootom cell is really messy ...

No comments:

Post a Comment

Please Share this Post if you Liked it !

Please Share this Post if you Liked it ! Thanks !
Related Posts Plugin for WordPress, Blogger...