Little Monkey

Li-ion Batteries

Li-ion Battery Packs 

Lil' Monkey caving lamps use high capacity and quality li-ion battery packs, professionally manufactured with appropriate protection circuitry. Our cell packs are produced in an industry standard flat pack 1s2P configuration (2P or 3P for Nora1). The Edna battery box can accomodate very simple 1s1p packs (also fits in Nora boxes for extra light weight option or reserve). No fancy proprietary layouts to tie you into our product.

As a consequence Lil' Monkey battery pack failures are extremely rare, and many years reliable service is typical.


Knowing some fundamentals about your battery pack will help to ensure that you maximise the life of the packs (or individual 18650s). While li-ion battery packs are fairly robust, they are potentially susceptible to damage particularly from severe impact, temperature and water ingression. Our lamps have been designed to best protect the battery packs in operation, while maintaining a practical helmet mounted solution for underground use. If carrying spare packs take care to avoid severe impact and water as they will potentially break. A hard case waterproof container is advised.

Note - li-ion battery packs will shut down at a set low voltage level (around 2.75v). However, Nora / Edna lamps have been designed to deliver a light for an extended period from fundamentally flat battery packs, minimizing the risk of being left without light. 

Battery Pack Charging

Although the charging algorithm for li-ion cells is relatively complex, this is sorted out by the Nora charger and battery pack circuitry, and consequently the charger is a simple plug in and go solution. Red light, charging. Green light, fully charged and automatic charging shut off. Battery packs can be part discharged or part charged without consequence. There is no rapid high current charge option for li-ion packs. We recommend using the Nora USB or Nora micro USB charger. Do not use chargers in excess of this rating. Although charging is automatically shut off on completion, it is always advisable to disconnect battery packs from chargers when charging has finished.

Battery Pack Storage

The capacity of li-ion batteries is reduced with age. The chemical process that relates to this is accelerated with increased temperature and charge level. To realise maximum battery life, cell packs should be stored around half charge and in a cool and dry environment (around 15 degC, do not freeze). Under no circumstances should battery packs be left discharged for an extended period, in order to avoid self discharge below 2.5v and permanent damage.

Battery Pack - Lamp Connection

Battery and lamp connectors are polarized so correct polarity is ensured. Battery connections should be made outside of the box, and battery pack orientated in battery box, with wires and connectors down inside wall of box (opposite side to cable entry). Battery is best inserted with wires from heat shrunk battery pack positioned to the bottom of the box. Take reasonable care when fitting battery pack that battery and lamp wires do not get trapped / damaged, and also when charging. We suggest using Nora vinyl stickers (supplied) to mark battery pack and charger, in order to avoid any potential mix ups with similar equipments. To maintain good water integrity, high viscosity silicone grease can be used on battery box O ring.


The JST connectors used on Nora battery packs are robust, and the industry standard battery connectors for radio control equipment etc.  They are ideal for making battery connections in a compact box. However they are not unbreakable; hence why we have flagged this up on the website and lamp instructions We recommend that you take a degree of care, and be a little sympathetic when connecting / disconnecting battery packs, else you will need to either repair them, or purchase a new battery pack (we do not repair battery packs; they are manufactured for us, as manufacturing or working on li-ion batteries in this day and age is a sticky one, and best left in our opinion to pro battery pack manufacturers).


Nora caving lamps are compatible with 3.7v li-ion, and 3 series cell NiMh / alkaline (using 3xAA holder). The Nora is not compatible with high voltage li-ion packs, typically ranging from 7.4v to 14.8v, connection to which could result in damage. In order to maximise efficiency, Nora has a level of protection against high voltage and reverse polarity. However, always ensure correct battery polarity, to avoid potential damage to lamp. Take particular care when using AA holder, that the battery polarity is correct, and to avoid damage to lamp connecting cable within battery box. Nora lamps are not compatible with Scurion 7.4v packs or similar high voltage equipments. 

In Summary

  • Avoid getting battery packs wet, it will potentially kill them (or at least the protection circuit) 
  • Avoid severe impact. Do not puncture.
  • Store batteries / battery packs somewhere cool, around 15 degrees C
  • Store batteries / packs part charged, around 50% is good (if not using for extended period)
  • Do not store batteries discharged (as potential deep self discharge could cause damage)
  • Do not store batteries or leave unsupervised in battery holders outside of battery box
  • Use Nora charger, or a suitable equivalent
  • Keep a watch on general battery pack condition (avoid damage to leads, wrap and connector)
  • Take care to avoid damaging connectors etc when connecting / disconnecting battery packs
  • Do not use or charge a potentially damaged battery or battery pack
  • Dispose of dead battery packs at suitable recycling facility
  • Do not short circuit or reverse polarity batteries
  • Keep away from children .......... and the technically challenged.  

We do not take responsibility for injury to persons or damage to property from cells or chargers. These should be used and charged under supervision, stored safely, appropriately maintained and correctly disposed of if there is any suspicion that they have been damaged.



Individual Batteries / Battery Holders


An additional note of caution using individual unprotected li-ion batteries! We can not under emphasis the degree of care required if using unprotected batteries. Li-ion batteries store a lot of energy when fully charged, which can be released very rapidly in event of failure. Use matched cells with same level of charge. We would suggest that you charge these as a pair. Never use batteries with damaged outer sheath. Keep a careful and continuous watch on condition of the battery skin, especially close to the positive terminal. If necessary add an additional skin (battery specific heat shrink). Always use two cells in Nora battery holders to avoid short if placed in contact with conductive surface. Take special care when fitting battery in to a battery holder, most particularly at the positive end of the battery, which is very close to the negative battery casing. Ensure that positive button of battery is properly aligned and located centrally on positive terminal of battery holder. (Best practice is to orientate positve end of battery in to holder first, followed by negtive end). Ensure that battery skin is damaged by +ve or -ve battery termainal when fitting battery into holder. If battery skin is damaged and battery is not inserted fully and properly, and without due care, it is possible to effect a short circuit between the battery +ve and -ve case*. This will almost certainly result in the battery flaming / catasphopic battery failure. On a practical level, any indication of a short circuit (e.g. sparking) when inserting a battery into a holder, immediately remove battery. Failing this, then step well clear. 


Care of and use of unprotected batteries is entirely at your own responsibility and risk. 

(* Most likely to be an issue between the positive battery connection and the -ve batttery case, for both unprotected and protected cells. Protection circuits on protected cells, or circuits built on to our battery holders do not gaurd against a short in this area).