Flashlight vs Charger

Russianesq

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Oct 18, 2006
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[FONT=Arial,sans-serif]There are plenty of comments on CPF about charging batteries (lithium ion ) and then having them rest before using them in a flashlight to avoid popping an incandescent bulb or burning out the LED. [/FONT]
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[FONT=Arial,sans-serif]There are plenty of comments on CPF about charging batteries (lithium ion ) and then having them rest before using them in a flashlight to avoid popping an incandescent bulb or burning out the LED. [/FONT]

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I think you mean NiMH, not Li-Ion. The former (most of them, anyway) will SD to lower levels within a few hours or days, but the latter will not. They'll stay topped up for months at a time.

Did you perhaps recently confirm this the hard way? I can't really tell from your post. :thinking:
 
I was just interested if fellow CPF members used the light right out of the charger or allowed time for the flashlight to rest.

Question was aimed to figure out if any chargers were overcharging the batteries.
 
More expensive chargers have automatic shut-off when the batteries get "full," for lack of a better word.
 
I was just interested if fellow CPF members used the light right out of the charger or allowed time for the flashlight to rest.

Question was aimed to figure out if any chargers were overcharging the batteries.
Using which light right out of the charger? Allowing time for which flashlight to rest? If you mean a flashlight with a fully integrated rechargeable batt pack and included charging system, most of those can be used right off the charger. I don't know of any rechargeable flashlight where the instructions tell you to rest the cells before use (sounds to me like that would be a poorly designed system).

Some chargers overcharge cells, some don't. Did you have a specific charger in mind? Perhaps this thread should be placed in Flashlight Electronics - Batteries Included.
 
The lights in my collection that I am concerned about are as follows:
- TigerLight (NiMH)
- G&P Scorpion (Li-Ion)
- Inova T4 (Li-Ion)

Did anyone have any problems with factory chargers = overcharging and damaging the light = :poof:
 
I think you mean NiMH, not Li-Ion. The former (most of them, anyway) will SD to lower levels within a few hours or days, but the latter will not. They'll stay topped up for months at a time.

Did you perhaps recently confirm this the hard way? I can't really tell from your post. :thinking:
Self discharge is part of the picture, and for all intents and purposes it does not apply to Li-ions. However, the other issue with cells of any type fresh off the charger is cell temperature. As they are charged, all cells heat up to some degree. The quicker the charge, the more heat. And if these "hot" cells are then put into use immedediately you can increase the risk of instaflashing. The reason has to do with how the added heat can reduce the voltage drop of the cells. A cold cell will have a slower chemical reaction within the cell as it produces electricity. So the voltage drop will be bigger when in use. That's why NiMh cells can be nearly uselss in very cold weather, the chemical reaction is too slow to produce the needed voltage and current. A "hot" cell fresh off the charger will not only have a higher voltage to start with, but the voltage will not droop as much when in use. Many of the hotwire combinations that are pushing the limits rely on this increased "cold cell" voltage droop to prevent insta-flashing.
 
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