KeroZen
Chronic vapaholic
So the 8x LiFe cells arrived from China (and it was indeed the slow boat) They are A123 APR18650M1A and appear on the exterior at least to be genuine. Here's the datasheet:
https://www.batteryspace.com/prod-specs/6612.pdf
...but Fasstech also says that they are salvaged from unsold inventory of power tool packs etc and that some might be desoldered. I don't see any weld marks on mine though, they look like new. They might surely be old-stock, I don't think they are still in production.
I just charged one, it took around 850mAh in until the charger cut. Then the resting voltage slowly dropped down from 3.6V to 3.34V where it seems to have stabilized now.
Anyway, from the graphs above it looks like my 0.5ohm load (high power Nomad heater module) will make the cell sag somewhere around 3V for a good deal of the run. I like how flat the discharge curves look. Even more interesting is the 20A graph where the voltage dips then goes up again as charge drops.
The 30A CDR is very nice. Ability to fast charge up to 4A is also a very good selling point. And yes the incredible cycle life and slow degradation. And did I mention how dirt cheap they were?!
They shouldn't be discharged past 2V, as I read they get damaged like other Li-Ions, so a low-voltage protection of some kind is still recommended.
I'll test it in the Nomad soon but I'm afraid it will feel a bit anemic by producing only around 20W. That being said 30W is ample enough for on demand convection already so... we'll see!
https://www.batteryspace.com/prod-specs/6612.pdf
...but Fasstech also says that they are salvaged from unsold inventory of power tool packs etc and that some might be desoldered. I don't see any weld marks on mine though, they look like new. They might surely be old-stock, I don't think they are still in production.
I just charged one, it took around 850mAh in until the charger cut. Then the resting voltage slowly dropped down from 3.6V to 3.34V where it seems to have stabilized now.
Anyway, from the graphs above it looks like my 0.5ohm load (high power Nomad heater module) will make the cell sag somewhere around 3V for a good deal of the run. I like how flat the discharge curves look. Even more interesting is the 20A graph where the voltage dips then goes up again as charge drops.
The 30A CDR is very nice. Ability to fast charge up to 4A is also a very good selling point. And yes the incredible cycle life and slow degradation. And did I mention how dirt cheap they were?!
They shouldn't be discharged past 2V, as I read they get damaged like other Li-Ions, so a low-voltage protection of some kind is still recommended.
I'll test it in the Nomad soon but I'm afraid it will feel a bit anemic by producing only around 20W. That being said 30W is ample enough for on demand convection already so... we'll see!