D10 whines when battery is weak or getting weak?

[dealgrabber2002]

I recently bought a used D10 Q5. I had it for 2-3 weeks and was working fine. But then last night when I used it on high, I noticed it whined. But when I changed the battery, the whining stopped. I read a few threads stating that it's a lottery whether or not you will get a D10 that whines.

Here is the question I want to ask. I been using the same eneloop in the D10 for 2-3 weeks. Did I get a D10 that whines or was the D10 working the battery too hard while it's weak (been using it everyday on low and high) causing it to whine? Thanks.

 

[MrGman]

As the voltage of the battery sags the current draw goes up to keep the same power level due to the regulation control of the driver in the light. this is normal its doing its job. However the high current level pulsing through the inductor is reaching a level where its causing mechanical vibration and therefore creating sound waves that you hear. Does not necessarily mean that anything is wrong, a lot of inductors will hum from the pulsed current going through them. In your light's case its a way of knowing that the batteries are getting drained down and closer to recharge time. There is nothing you can do to fix it or stop it other than keep the batteries topped off.

 

[dealgrabber2002]

As the voltage of the battery sags the current draw goes up to keep the same power level due to the regulation control of the driver in the light. this is normal its doing its job. However the high current level pulsing through the inductor is reaching a level where its causing mechanical vibration and therefore creating sound waves that you hear. Does not necessarily mean that anything is wrong, a lot of inductors will hum from the pulsed current going through them. In your light's case its a way of knowing that the batteries are getting drained down and closer to recharge time. There is nothing you can do to fix it or stop it other than keep the batteries topped off.

Thanks.. nice to know I have a built-in low battery warning lol. Sounds good to me.