I'm a new member in this community. I always liked flashlights but i was unaware that there were people addicted to them.
I have a cheap 3xAAA flashlight that i modded with an R2 drop in. I use it all the time in my work (i'm a mechanical engineer and i work in a brick producing plant). The main feature is an adjustable magnetic base that allows me to attach it to any machine and point it anywhere.
At this point i want to upgrade to something more bright, more reliable and with longer runtime, but i want to do it on a tight budget.
I'm thinking of buying the ultrafire 501-B flashlight with the XM-L T6. I can get it for 14 USD in ebay.
What made me open this thread was the charger. After googling a while, i'm convinced that i can have a very good charger for a very low price. I don't need a fancy cradle charger, or multi bay charger, just something that i can attach to a 18650 and charge it saflely acording to the cc/cv algorithm.
I was going around the TP4054 IC, when i found this board:
Ebay Item number: 330699360128
It uses a TP4056 IC, has 1A output current, but can be adjusted to other currents by changing one resistor. It follows cc/cv algorithm. If i can charge a 18650 battery with a 1A current then this is pretty much plug and play.
This leads me to my first question. Is it safe to charge a 18650 battery, let's say a 2500mAh with 1A current?
On the other hand, if i connect this to an USB port (maximum output of 500mA) or a wall cell phone charger (also 500mA), then, even with this resistor setting, the current going to the battery will allways be lower than 500mA, right?
Another issue is the battery temperature. On this board the monitoring of the battery temperature is disabled. I believe thats also true for the majority of the chargers out there, but still i have safety concerns. So i had an idea,and i would like to know your opinion. This chip as a built in thermal feedback, that regulates the charging current to prevent the die from overheating. I was thinking that if i place the battery on top of the chip while charging, and if by any reason it overheats then it will also heat the chip reducing the charging current. Will this work? Any of you guys have experience with this board or IC?
Previously i was thinking of modding the flashlight so that the battery could be charged inside, but i'm not so sure now. Is it safe to charge the battery in a so tight sealed enviroment?
This thread is mainly about the charger but please fell free to give me your opinion about the flashlight also.
Thank you guys!