Li-ion Battery Packs(under construction)
General
Little Monkey use high capacity and quality li-ion battery packs. The standard 7.8 Ah cell packs (the highest capacity helmet mounted pack that we are aware of) are professionally manufactured with all the appropriate and correctly configured protection circuitry. In fact, we might be the only manufacturer using the best available Sanyo cells. We also produce a low cost 2.5 Ah pack, almost certainly the lightest weight solution on the market. All of our cell packs are produced to a proprietry flat pack configuration, no fancy shapes or layouts to tie you into our product. Handy as it's impossible to predict the future for any small manufacturing business.
Knowing some fundamentals about your battery pack will help to ensure that you maximise the life of the packs. While li-ion battery packs are fairly robust, they are also 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. Fitted in your battery box, the cell pack will, with a little care, be well protected. Carrying spare cells is more likely to cause problems with wear and tear. If carrying spare packs take care to avoid severe impact and particularly water as they will likely break, and keep a watch on wear to leads and connectors.
Battery pack charging
Although the charging algortim for li-ion cells is relatively complex, this is sorted out by the 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. We obviously recommend the Rude Nora charger, though other suitable chargers are available if you know what you're doing.
Both a UK mains charger and 12v input car charger are available. We have a stash of UK-US-Euro adapters, and these are also widely available for peanuts (try Ebay). Alternatively, you could no doubt source a suitable li-ion charger closer to home.
Car charger - Charge your Rude Nora battery pack when you're on the road. Nora car charger plugs into your car's cigarette lighter and charges your lamp while you're driving. Intelligent IC chip recognises a fully charged battery and automatically switches to saver mode to prevent overcharging and short circuit. LED charging indication. Double flash (white) LED, battery charging. Continuous (white) LED, battery charged.
Battery pack storage
The capacity of li-ion batteries is reduced with age. This 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 full charge (optimum 40% 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. To explain this, be aware that Li-ion cells do not discharge to 0 volts. The protection circuitry does not allow this, shutting the cells down automatically in the region of 2.75-3.0v. The reason for this is that if li-ion cells are allowed to discharge below 2.5v they would be permanently damaged (fall asleep). So here is the problem, self discharge. If li-ion battery packs are stored in their discharged state, say 2.75v they will continue to ‘self discharge’ slowly over time below the cut-off level set by the protection circuitry. The protection circuitry is effectively helpless to do anything about this. On the up side, li-ion cells hold their charge rather well and self discharge is slow. A cell pack that is 40% charged can be stored for a considerable period of time, maintaining charge. If not used for extended period of time, battery packs should not be left connected as they will eventually discharge cells to shutdown point at approx 2.75 v per cell, and the the subsequent influence of deep self discharge (even though current draw has been shut down and is zero) could feasibly reduce cell voltage to less than 2.0v per cell at which point they would be destroyed.
Battery Charging
Li-ion cells have a relatively complex charging algorithm. As a very basic explanation, this involves charging at constant current for an initial period until the pack voltage is reached, followed by constant voltage charging with reducing current to zero when the pack is fully charged, and charging is automatically shut off. As a consequence there is no rapid charge high current option for li-ion packs. Don't be conned, a 3amp li-ion smart charger will not charge the cells any quicker than a 1amp charger. Infact a 1.5 amp charger is about optimum. We recommend using the optimised 1.5amp Rude Nora charger. Do not use li-ion chargers in excess of 2amp as this is the manufacturer rating for the Rude Nora battery connectors, and if nothing else, we are not minded to exceed this rating
Compatibility
The Rude Nora is compatible with a wide range of battery configurations, including li-ion, nimh and alkaline u to 6.0 volts input. The Nora is not compatible with battery packs used by the previous generation of high end lamps, such as the Little Monkey or Hurricane. This generation of lamps used high voltage packs ranging from 7.4v to 14.8v to achieve suitable output from the LED technology. To avoid any confusion, the Rude Nora is therefore also not compatible with battery packs from Stenlight, Viper or Scurion(tm).
In summary
Do avoid getting battery packs wet, it will kill them
Do avoid severe impact
Do keep them somewhere cool, around 15 degrees C
Do store part charged, around 40% is good*
Do not store discharged (as deep self discharge will kill them)*
Do not store connected to lamp
Do use our charger, or a suitable equivilent
Do keep a watch on general battery pack condition, particularly leads and connector
Do expect to purchase a new pack if it dies J
(*Better to store fully charged than fully discharged)
And a final word from Nora. If you know enough about batteries to have a question that we havn't covered, then you almost certainly know more than we do J
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