I have purchased a few new cells from www.mAhbattery.com, they appear to be focused on the vaping market but appear to be brand name cells for $3-5 per cell..
The Samsung 25R's are $3.13 for any quantity
Certain Sanyo's seem to be much more problematic than others.
The ones with a purple insulator ring have the worst record.
The heater issue is part of the reason why I invested in the SkyRC MC3K as it has a rock solid thermal management system and cut-off per cell.
My rule if it heats I let...
The metal casing isn't that thick and the rust is a deal breaker.
If they are less than 3V I put in recycle bin.
If they somehow still hold a charge I discharge at ~200 mA (only if can be done safely) and put in the recycle bin.
Great to see some use, these things are definitely not as friendly to the 'professional hobbyist' as the cylindrical cells.
I always thought those very flat ones were pouch / polymer cells and the prismatic cells ware the steel encased cells shaped like a Zippo lighter (with casing being...
You could rig up a series of Peltier coolers and fans to vent the heat outside and blow the cold air over the battery packs. Perhaps configure it only for higher draw days or very hot ambient conditions.
Just search Amazon or youtube for Peltier coolers, neat devices and can be run on your...
I beleive it says "SANYO" or "R1122" are markings required by law in Korea.
On most Sanyos there is also a 4 character code under embossed under the model number.
e.g.) 'N41B = October 9, 2009 production
I just pulled 6 of these from a Dyson vacuum pack so I suspect a fairly high Max draw.
It was 21.6 V / 1080 mAh and 23.5 Wh,.. cables in the pack were 16AWG.
Mine are the 'T11' versions.... The interweb suggests they are 1100 mAh and rated for max 1C (10A) continuous draw down to a 2.5V cut.
This could be an old cell with a high internal resistance.
I have had many that hold an excellent voltage but are incapable of supplying 1A during the test.
This is especially true if the resting voltage recovers significantly at the end of a CC discharge.
You may find that if you test at 500...
This biggest difference with the iMax B6 and the OPUS is the CC/CV discharge in the imax and CC discharge in the Opus.
I would also say stick with the same device for the duration.
As this is a hobby, I decided to invest in the SkyRC MC3K unit to fully control the testing (yes it is $90 USD...