On 5/5/2016 4:23 PM, Mr Macaw wrote:
On Thu, 05 May 2016 22:10:00 +0100, My 2 Cents wrote:

On 5/5/2016 3:01 PM, Mr Macaw wrote:

Hacking LED flashlights
https://www.youtube.com/watch?v=M0iD8_qq4FU

I haven't watched the whole video, but if you want to charge a Li Ion at
a decent speed, you need to regulate it to 4.2V maximum or it'll catch
fire.

That's the whole point of buying this flashlight... it must have a
Joule Thief circuit but it doesn't have the ferrite toroid core. I don't
see a capacitor either... it does have the transistor and resistor.
How'd they do it? Why didn't they go ahead and make it a two D cell
flashlight? It is a two cell flashlight with half the capacity not
used. Some of the Dollar Tree flashlight you can break three tabs of
the spacer and use a lithium 18650 instead of the 3 AA batteries. No
low discharge protection though if you leave it on for days it will kill
the battery, otherwise just recharge it in your lithium battery charger.
How a Joule Thief Works, https://www.youtube.com/watch?v=0GVLnyTdqkg