Filthy Edna 2
Available to buy online from the Lil' Monkey web shop
The Edna battery box uses either a single unprotected 18650 flat top (or button top) 3.7v li-ion battery, or a simple 1s1p 18650 li-ion battery pack.
Unprotected 18650 cells are more size consistent than protected cells, more cost effective, more readily available and more likely to be legitimate !! The best cells are manufactured by LG, Panasonic, Sanyo and Samsung. 18650 cells are currently available up to 3500mAh.
The individual 18650 battery (unprotected) is fitted into box in a battery holder, for reliaible connectivity. Essential electronic protection for these batteries is incorporated in the battery holder, with additional protection incorporated in the lamp electronics and battery management software.
The battery holder is connected in the battery box with RC connector. Care should be exercised with this connector as it could of course be damaged by careless handling. The advantage of seperate battery holder, over boxes with integrated battery spring clips, is that it is more serviceable, particularly important for caving lights due to the harsh environment they are exposed to.
The battery holder and battery should be loaded with red / black silicone battery holder leads visible at top of box, and with the RC connector to the side of the battery, as per photos. When inserting the battery holder (with 18650 battery) into the Edna box, take care to ensure that the leads are not damaged.
1S1P li-ion Edna battery packs should be fitted in similar manner.
There are two simple approaches to charging an 'Edna' 18650 li-ion battery, or battery pack. The Edna battery holder can be removed from the battery box and used as a charging cradle for the 18650 battery, in conjunction with Nora USB or Nora micro USB li-ion charger (available with lamp set or seperately). These chargers can also be used to charge a 3.7v li-ion battery pack, including 1S1P arrangement suitable for Edna. Alternatively, batteries can be removed from the holder and charged using any suitable 18650 li-ion charger.
The Edna box will also operate from simple 1S1P (3.7v) 18650 li-ion battery packs, with protection circuitry incorporated, and silicone leads. This is a widely available format, or easily constructed.
Knowing some fundamentals about li-ion batteries will help you get the best from these.
Edna box accommmodates unprotected 18650 flat top 3.7v li-ion battereries. Button top 18650 cells are also available in unprotected form, and will also work. Unprotected 18560 cells are around 65mm long.
Protected 18650 cells (also generally button top) are longer than unprotected, due to the addition of a protection circuit PCB on the end of the battery. Consequently, these are not compatible with the standard Edna battery holder. However, a battery holder is also available in format suitable for protected 18650 cells.
We would advice having a spare battery holder available in case of damage or failure. Additional / spare 18650 battery holders are available in Lil' Monkey web shop, see Lamp Accessories