LiFePO4 26650 3400 mAh cells tested

[Fulgeo]

Hey guyz I purchased 3 of these cells a short while back and wanted to post my results.
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2385

They are well shrink wrapped and measure to spec. The 3 cells measured 3.314v, 3.313v and 3.298v out of the box. After charging them on my e-Station BC6 and resting them a day they measure about 3.50v - 3.58v. The maximum discharge I can perform is 3A with my Triton charger. The first test I performed was a 3A load until 2.5 volts is reached. Here are the end results.

Cell #1 2925 mAh
Cell #2 2930 mAh
Cell #3 2996 mAh

I performed another test with a 3A load until 2.0 volts. The cell delivered 3174 mAh.

Things to note;

After draining down to 2.0 volts the cell bounced back up to 3.03 volts.

The cells under load dropped almost immediately to 2.8 volts then ever so slowly lost voltage till limit. My 26550 A123 cells for comparison drop to 2.85 volts. About the same.

Note that these cells are rated for 7A continuous drain and a 17A burst. In this category they differ from A123 cells. They also differ in that their max charging current is 3.4 amps.

Going to use these cells to drive a 5761 in a 3D Mag build using one of JimmyM's "magic pills" http://www.candlepowerforums.com/vb/showthread.php?t=231489

Happy Mods!

 

[Chodes]

Interesting.
The low voltage of the cells under load really takes a big bite out of the perceived capacity advantage.
ie , IMR26500 is an obvious cell to compare. The fact they hold about 0.8v or so higher but only 2300maH evens things out.
I have a 2D Mag 5761 with 3 x IMR26500 planned (with JimmyM driver). Should be similar run time to 3 x LiFePO4 but in 2D rather than 3D host.

I understand the LiFePO4s are safer than IMR cells. It's trying to work out how much safer that I'm struggling with.

 

[Fulgeo]

Interesting.
The low voltage of the cells under load really takes a big bite out of the perceived capacity advantage.
ie , IMR26500 is an obvious cell to compare. The fact they hold about 0.8v or so higher but only 2300maH evens things out.
I have a 2D Mag 5761 with 3 x IMR26500 planned (with JimmyM driver). Should be similar run time to 3 x LiFePO4 but in 2D rather than 3D host.

I understand the LiFePO4s are safer than IMR cells. It's trying to work out how much safer that I'm struggling with.

Have you seen these two vids?http://www.candlepowerforums.com/vb/showpost.php?p=3038464&postcount=9

 

[AW]

IMR is safe chemistry just like LiFePO4 and cells made with this chemistry will not vent with flames. The vid you refer to is a emoli LiCo standard cell which is unsafe when abused.

 

[Fulgeo]

IMR is safe chemistry just like LiFePO4 and cells made with this chemistry will not vent with flames. The vid you refer to is a emoli LiCo standard cell which is unsafe when abused.

My bad Chodes. As AW pointed out Emoli are not the newer LiMN chemistry. I would also like to know relatively speaking which has the safer non toxic chemistry, especially under catastrophic failure.

 

[Gazoo]

Hey guyz I purchased 3 of these cells a short while back and wanted to post my results.
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2385

Thanks for posting the info. It really helps as I have been curious about those exact batteries. What really impresses me the most about LifePo4's is their cycle life compared to anything else. Greater than 2000 cycles is nothing to sneeze at. Granted they don't have the capacity of other types of lithium's.... they are in a class of their own.

 

[Fulgeo]

Also wanted to add that I charged these cells on my e-Station BC6 which on these chemistries charges them at 3.6 volt cutoff. On the spec sheet that came with the cells they specify that you can charge them up to a max 3.8 volt cutoff. I basically played it safe and charged them like my A123 cells. The point I am trying to make is if I charged them more aggressively to the higher max cutoff point they probably would deliver more mAh. Just food for thought.