After charging two Tenergy 2600mAHr 18650 cells using a UltraFire charger (3.7v @650mA), now the cells won't work in series. I dropped them in my newly configured Solarforce L2 (2x 18650) with a new Solarforce Led module and the unit will not come on. But when I use them in a single cell light, the flashlight fires up! Has the input impedence of these cells gone through the roof? Did I use the proper settings on the charger? How did I screw up these cells? On the other hand, I do remember leaving them in my truck on 30f temps one night. But the spec say they should handle that...right?
chiphead
chiphead
