Little Monkey


... filth



Filthy Edna 2
Available to buy online from the Lil' Monkey web shop


monkey proofed

Filthy Edna 2

Edna 2 Battery Box

Filthy Edna 2

The Edna 2 battery box uses a single, unprotected 18650 flat top 3.7v li-ion battery. These batteries are now widely available to the regular consumer. 


The Edna battery box has a screw on lid at the opposite end to the lamp cable exit. The lid has an O ring for a water tight seal. A spare O ring is supplied with the lamp, and these are also available in our Lamp Spares shop.

The Edna battery box can be attached to back of helmet with suitable shock cord, or zip ties etc, according to user preference.


A flexible, impact tolerant approach, widely used by cavers for mounting battery boxes and battery packs on helmets!  

The individual 18650 battery is fitted into Edna box in a battery holder, for reliable connectivity.


Essential electronic protection for li-ion batteries is incorporated in the Edna battery holder. Additional protection is incorporated in the lamp electronics and battery management software.  

Unprotected 18650 cells are more consistent in size than protected cells, more cost effective, more readily available and more likely to be legitimate !! The best 18650 cells are currently available in capacities up to 3500mAh.


The Edna 2 battery box will also accomodate low cost 1S1P 3.7v li-ion battery packs. Widely available format, or easily constructed. Our Edna packs use an individual NCR18650 3500mAh cell, with battery protection circuitry and RC connector. 

Edna 2 is also available as a lamp only option (3.7v li-ion), without Edna battery box for your own creative solutions. Examples could include a Petzl Duo box which stripped out can accommodate a 1S2P 3.7v li-ion pack (or 1 x 18650 Edna protected battery holder), an original Petzl Zoom box, or other battery box recovered from retired caving light. 


Remember, keep 3.7v li-ion batteries dry or expect to damage protection circuitry etc.

For further essential guidance, including battery and cable management, and li-ion battery charging options, see Edna 2 Batteries