I have purchased a Voltage Alert Pen from Aliexpress.com recently and found the pen is required to supply 3.6+ Volt to light the included white LED with a button, not two AAA batteries.

You will know usually LED flashlight need 3 or more alkaline batteries.

Since of it, I had released another order of AAA size Li-Ion battery and charger.

Today I have received the AAA size Li-Ion Battery, 10440(Brand Ultrafire) and successfully turn in operative.

To fill in the space of the empty one battery compartment, I have made an ordinary discharged AAA battery a dummy battery with wrapping aluminum foil, like the photo.

I think the way of making a dummy battery will be pretty useful when we apply that kind of Li-Ion battery to existing application.

I will not explain furthermore the know-how because everybody could understand the situation easily.

About This Instructable




Bio: an electric engineer with State issued license
More by wonstoneyoo:Lazy Boy's RF Switch Box Li-Ion Battery Pack to replace 9V Battery for DMM Voltage Alert Pen Hack 
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