I bought 4 pieces Olight protected IMR 550 mAh for use in Elzetta and SF.
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decided to try to insert into HDS and look at the work of battery protection today.
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Interestingly, the protection of the battery itself has not worked yet.
Good info, you got 1 hour 44 minutes of decreasing brightness, ending with dimmed light flashing. (<1 lumen @ 3v)
yes, when using a protected battery, IF a high Lumen mode (20+) is requested when the battery is near empty, it will trigger protection and shut the light off. otoh, as you confirmed, the HDS steps down to sublumen blinking at 3v, so Protection will not be triggered. Yes protection is at 2.7v, but there is sag when demanding high lumens. A battery at 3v will trip protection if high lumens are requested.
HDS battery detection is automatic. So if you remove the battery when it is at 3v, and put it back into the HDS (bad idea), that turns off the 3v shutoff (the HDS thinks its a Primary). If you then try to use high lumens, it will immediately trip protection.
The battery protection circuit is working the way it is supposed to. The HDS LiIon battery low voltage trigger is also working properly.
When using LiIon in a light with no built in step downs, it is important to know battery voltage. It is a very good thing that you are using protected batteries. Best to recharge long before 3v.. good to recharge at 3.6v, which is half empty.