Using flashlight at low or medium brightness for outdoor walking/hiking in winter evening. The most important property I am looking for is the safety. ie, the stability/low temperature of the cell during usage and storage.
The Battery chemistry FINALLY explained article emphasizes on power and high current drain without developing about safety. NCR type is not mentioned.
For brand names 18650 cells of capacity in the range 3000 to 3500 mAh. If I have the choice of IMR (Sony), INR (Samsung, LG), NCR (Sanyo). Which is the safest?
I am normally a careful person. I have a good charger (Nitecore Intellicharger new i2) and a multimeter to check voltage to make sure I use the cell within the good voltage range. If I carry spare cells during a hike, it is stored in a hard case designed for 18650 cell storage.
The prefix used by manufacturers doesn’t indicate the actual chemistry of the cells, some examples from 2 studies where they analysed the elements in the cells :
from : Design Strategies for High Power vs. High EnergyLithium Ion Cells
soINR18650-MJ1, but it’s not NMC but actually LMO (edit : I missread) all samsung INR, which are actually NCA except 25R which is a mix of NCA and NMC, LG INR M36 is also a blend etc, basically it doesn’t mean anything.
As for safety I remember reading that NMC and LMO where a bit better than NCA, but I don’t know much about this, there is some studies result when googling NCA LMO NMC safety that are probably worth a read. That said, if they’re not abused, there is not much risk.
Edit :
Refer to datasheets, Charge is always >0°C, storage and discharge usually down to –10~–20°C
