I have a concern and require advice. Currently, I have a small wooden draw that I use to store all my 18650 batteries. All the batteries are stored in pairs within their own plastic cases. The drawer contains 10x Panasonic 3400mah NCR18650B (unprotected), 4x Nitecore 3100mah IMR18650 (protected), 4x Panasonic Xero 3600mah 18650 and a Fenix ARB L37 12000mah battery pack. I charged all my batteries to capacity using a Nitecore D4 charger before storing them in the drawer, ready for use. What I am noticing is that all the battery cases are warm to the touch by a noticeable 2 degrees Celsius warmer than the room temperature. Room temperature is a nominal 20 degrees C. Should this battery warmth be of concern? Are they going to catch fire, explode, etc? Or is this normal behaviour and I should not give it a second thought?
did you try putting an empty case in that drawer to see if it felt warm also? It may be just a coincidence or just the plastic is creating a differential with the air in the case vs the air outside, I doubt it’s the batteries, unless your feeling them right after you took them off the charger.
I store knives in plastic case with bubble wrap under the knife and I notice it tends to make the oil in the knife pivot leach onto the bubble wrap, which may not be an identical effect to yours, but I wouldnt worry much about this.
Phew! That's a relief. You were right. I opened 3 boxes and felt the batteries therein. The batteries were at a "normal" room temperature and the plastic cases felt warmer than the batteries. How strange. Thanks again.
Perhaps the plastic is somewhat of an insulator, and feels warm to the touch the way a good winter coat feels warmer to the touch than, say, a block of metal. Just returning more of your body heat to your fingers instead of absorbing it all.
No, it wasn't that as such. The actual air in the drawer felt warmer. In fact, just holding my hand about 2cm above the batteries, I could feel heat being radiated. The issue wasn't about heat conductance away from my fingers/hand, as I well know how depending on the properties of a material, some items feel cooler than others whilst actually being at the same temperature, e.g. water at 10 degrees C is going to feel cooler than a wooden handle also at the same temperature. No, the plastic cases felt noticebly warmer than even the wood of the small drawer they were in. What I think may have been a large factor was the fact that we have had air temperatures in the mid 30s C of late. It could be that the air in the drawer was significantly warmer than the air in the room as the cooling was in operation. Therefore the batteries and cases were warmer than the rest of the room and perhaps it was that that was fooling me.
