TwiceFuzed
Newly Enlightened
- Joined
- Jul 5, 2015
- Messages
- 79
I pulled a mostly depleted nimh battery out of my headlamp tonight, it had a resting voltage of 1.24 volts. I thought I would run it dead in my solitaire to see what the voltage of the battery is when the light shuts off. The light ran for 38 minutes before it dimmed slightly then shutoff a few seconds later. I immediately removed the battery from the light and checked the voltage. 1.01 volts and recovering quickly.
I don't have a way to check the voltage of the battery under a load in the light, but I suspect the light shuts off at around 0.8 to 0.9 volts. Perfect for nimh batteries, this is also ideal if you are trying to cycle your batteries to refresh them. I don't think this light depletes the cell as deep as some chargers with the discharge function are capable of doing (at a lower discharge rate). I think this LED and driver are rated to pull about 350 ma. At a higher current, the cell will pull down to the cutoff voltage quicker than a cell discharged at a lower current. You could put a 'dead' cell out of this light into a low current draw device and squeeze a little more power out of it before it would be completely depleted. I don't know if it continues to draw power after the light shuts off. If it does, that would be less than ideal if you accidentally left it on for an extended period of time...
But you're talking about a $10 flashlight and rechargeable batteries that cost $1.50 each, it's not something to lose too much sleep over. I just thought I'd post my observations and thoughts for anybody that's interested.
I don't have a way to check the voltage of the battery under a load in the light, but I suspect the light shuts off at around 0.8 to 0.9 volts. Perfect for nimh batteries, this is also ideal if you are trying to cycle your batteries to refresh them. I don't think this light depletes the cell as deep as some chargers with the discharge function are capable of doing (at a lower discharge rate). I think this LED and driver are rated to pull about 350 ma. At a higher current, the cell will pull down to the cutoff voltage quicker than a cell discharged at a lower current. You could put a 'dead' cell out of this light into a low current draw device and squeeze a little more power out of it before it would be completely depleted. I don't know if it continues to draw power after the light shuts off. If it does, that would be less than ideal if you accidentally left it on for an extended period of time...
But you're talking about a $10 flashlight and rechargeable batteries that cost $1.50 each, it's not something to lose too much sleep over. I just thought I'd post my observations and thoughts for anybody that's interested.