Cell discharge mapping [Serious]

Take a look at this, pretty interesting. Revolectrix spent some effort on these cells


And also this, there’s some interesting details. In fact, at a quick glance I realize I had only skimmed it. There’s gems about vents, monitoring, balancing, SOC, etc.


One thing that’s standout about small packs made with these cells, you can regen a TON of current into them. Standard fast charge is 4C (10A). I believe someone did a long data logged test with 10C charge cycles monitoring temperatures. No problems. Searching for the writeup, no luck so far. 10C is 25A, and if sustained will charge the cell in 6 minutes. (CC/CV means it’ll take longer in practice)

Another thing is these cells can take a lot of abuse. The specs have a section on charging how to 4.2v. That’s +0.6v overcharge endorsed by the manufacturer. I think I remember folk on rcgroups consistently charging them to 4.2v for their lifetime with no explosions. I’ve drained packs to zero and revived them (more than once, but not 100% success rate).

EDIT found the link on abusive tests


The link to details, the title is " A123 long term: 1st 1,000 CYCLES done, 2nd +800cycles highC done, 3rd to 0V going on" lol

This graph came from a123 apparently. subtext says 20c charge rates are fine. wtf…

These are fantastic cells for a first build, as they will let you get away with a lot of mistakes that kill normal $400-600 packs.

Oh yeah, they also will do 70A bursts happily if you don’t let them get too hot.