little monkey

FAQ 

Frequently asked questions, some real and some we've simply made up (most of them in fact) to save you having to ask. Nora insisted on answering some of these. Apologies in advance for her generally poor attitude. She can be a rather rude little monkey J 

Yes, we sadly are !! 

Why have you stopped manufacture of the Little Monkey & Hurricane?

In order to design and build the first of a new more versatile generation of li-ion powered caving lamps that are conceptually and operationally very different from traditional li-ion high end lamps. Read more  

What is the operating voltage of the Rude Nora?

The Rude Nora runs from 3.7v li-ion battery packs. Nora is the first high end lamp to run from 3.7v li-ion packs, now feasible due to advances in LED technology. This offers significant and obvious benefits of compatibility with AA and other non li-ion cells, particularly useful for expedition use, backup, etc. To date, it has invariably been necessary for high end caving lamps using li-ion batteries to be designed to run 7.4 volt packs minimum, and in some cases 14.8v packs (including our previous lamps the Little Monkey and Hurricane which use 7.4v packs). The Rude Nora represents a significant step forward in high end caving light technology, a new more versatile generation of high end lamps. The end of the road for high voltage lamps? We certainly feel that the development of high voltage caving lamps is an evolutionary dead and that 7.4v-14.8v battery packs are, effectively obsolete technology.  Rude Nora is unique amongst high end li-ion caving lamps.

What capacity are the Rude Nora li-ion battery packs?

The standard Rude Nora li-ion battery pack is a market leading 7.8ah using the highest quality Sanyo cells, 50% more capacity than our nearest competitor and at just 145 grams, 33% lighter.  We also offer a low cost (non Sanyo), super light weight 2.5ah pack for short trips, expedition and backup purposes, offering similar capacity at half the weight (< 50 grams) of the nearest equivalent. If required the Rude Nora battery box should readily accommodate 2 of the light weight packs. The Nora has been designed to accommodate a proprietary side by side cell arrangement. We have not manufactured our packs in custom shapes, so you are by no means tied into buying our cell packs. However, we believe you will struggle to find packs that compare in quality to our 7.8ah pack as competitively priced. If you do, please let us know. Please note that the packs are protected so that they cannot be discharged below a set voltage level where permanent damage would result. 

How much does the complete Rude Nora weigh?

The Lamp and battery box weighs 225g. The 7.8 Ah battery pack weighs 145g. The low cost battery pack weighs 45-50g  

Can I use AA batteries?

Yes, the Rude Nora can be used with 3 x AA batteries, alkaline or nimh. A low cost AA battery holder that fits in the Rude Nora battery box is available. Full output is achievable with good low self discharge nimh AA cells, the best example being Sanyo Eneloops*. It is worth noting that not all AA batteries can provide the high current draw of the rechargeable li-ion packs and full output will not necessarily be realised. This is accommodated by the lamp circuitry and all settings remain available, just at a reduced output level. Ironically, the plus side of this is that battery duration is extended, which is particularly useful as AA batteries do not have the capacity of li-ions. For previous generation li-ion lamps the voltage of 3 AA cells is too low to run the lamp, and the energy density of AA batteries would be too low anyway for these lamps.  

* While feasible to run the Rude Nora full tilt on good nimh cells, we would suggest that in the interest of battery longevity that you avoid using mode 6, i.e. full power spot and flood, as (without having a detailed knowledge of battery chemistry) we're not entirely convinced that pulling this level of current will do them a lot of good. If you know otherwise, then please let us know.  

Can I use other types of batteries?

Yes, the Rude Nora can be used with heat shrunk 3.7v packs of 3 x 7/5A or 4/3A nimh batteries, typically around the 4.5Ah mark. These packs have been used in Mk1 Petzl battery boxes by cavers for many years and are widely available. Significantly, they are very robust and more tolerant to a soaking than li-ions. They would therefore make an excellent spare battery that gets thrown in a pocket with little care, or potentially for those of you who may push the limits of the battery box and, and just like a diving canister lamp, occasionally conspire to flood it. The Rude Nora can also be used with proprietary heat shrunk battery packs constructed from 3 NiMh AA cells.

Do I have to buy your 7.8 Ah Sanyo pack?

No, we use Sanyo as they are the best batteries, and we use them in a proprietary 3 cell arrangement. I would imagine that there are plenty of cheaper battery packs on the internet (though I doubt you will get Sanyo cheaper) and we have no issue with you using these. We deliberately used a proprietary arrangement for this exact reason. If a plane lands on me tomorrow then you won't be stuffed. While I worry about this now, I probably won't much care after the event :-) Input voltage should never exceed 6 volts maximum

and polarity should be observed. In the interest of circuit efficiency and compact design Nora is protected from this to an extent. Incorrect polarity could potentially cause damage. Therefore take care if using own battery arrangements or if disconnecting/ connecting red plug inside battery box for cable routing.    

Can the Rude Nora be used with 7.4v li-ion Little Monkey battery packs?

No, sorry the Rude Nora is not compatible with battery packs used by any 1st generation high end lamps, including the Little Monkey and Hurricane. This generation of lamps used high voltage packs typically 7.4v (14.8v in some instances) in order to realise suitable output from the LED technology. To avoid any confusion or problems, please note that the Rude Nora is therefore not compatible with battery packs used by Stenlight, Viper or Scurion(tm) .

What rechargeable AA batteries do you recommend?

We recommend low self discharge nimh AA batteries, typically around 2Ah capacity. All other nimh AA batteries are a false economy. Low self discharge cells will hold there charge and will not deteriorate over time at the same rate as higher capacity nimh batteries. Sanyo are of course the market leaders, and it is hard to look beyond Sanyo Eneloops. Of course, alkaline batteries are also compatible, but as stated above, you'll get plenty of light but don't expect full output.

I have my own battery arrangement in mind, can I buy just the Rude Nora lamp ?

Yes, you'll need to contact us. The Nora is particularly well suited to this as it can run on lower voltage arrangements (3.7v Li-ion packs and 3xAA), as compared to previous generation high end lamps (typically 7.4v +). This has obvious advantages surrounding battery pack versatility and autonomy, with various easily configured helmet pack arrangements. Maybe fitted up to a Petzl Duo battery box or mk1 Petzl Zoom box. The availability of the latter is now extremely limited, you'll do well to get hold of one. Lamp only option not currently available. 

Can I buy a just the Rude Nora battery box?

Yes. Very soon.

http://www.customduo.co.uk/Pages/RudeBox.aspx 

What size is the Rude Nora headset and how much does it weigh?

The Rude Nora headset is extremely compact, and has been optimised to accommodate the latest high power LED technology, which have become increasingly efficient and produce less heat relative to output than a few years ago. Consequently, the Rude Nora is considerably smaller than any high end caving lamp capable of providing sufficient cooling to sustainably run the latest LEDs. The Rude Nora lamp housing is just over 50mm diameter, 23mm deep and weighs in at an astonishing 100 grams (to be confirmed). To get this into perspective, the nearest equivalent lamp that offers the cooling capacity of the Rude Nora is considerably bigger and at 166 grams, weighs 65% more.  

Why does the Rude Nora have big fins?

The Rude Nora headset is machined from aluminium. The external fins are essential to maximise surface area and provide effective heat dissipation for the LEDs. The LEDs are also more efficient the cooling they can be kept. Take a look at the first generation of high end lamps. It is noticeable that some have effective cooling, such as the Little Monkey, Hurricane and Scurion(tm). Others lamps did not. Ineffective cooling will either shorten LED lifetime and impact on performance, or limit a lamps ability to sustain high output as a result of circuitry controlled shutdown at elevated temperature. Equally, this is why retrofit modules such as Customduo are very realistic about the level of output that they produce. 

The Nora has been designed to optimise heat dissipation and keep the lamp efficient and reliable based on the LED technology now available. LEDs are sensitive to heat, and management of this is crucial. The Nora is significantly smaller than would have been necessary to suport this level of light output just a few years ago. As LED technology improves further (more light per watt equates to less heat generation), the level of heat sinking required will reduce and smaller lamps will no doubt be feasible. However, as the material cost is of very little significance versus the machining costs (at least for high end stuff manufactured on this side of the planet), which typically increase with precision manufacture, don’t anticipate reduced cost. It would be a lot easier for us to have machined a massive heat sink, but there is a critical balance. If a lamp does not have good heat sinking be wary J.

What LEDs does the Rude Nora use?

The Rude Nora uses the latest Cree XM-L LEDs, the brightest and most efficient available providing around 160 lumens/ watt and significantly is the first caving lamp to use this technology in conjunction with an equally important XM-L specific optic. The Rude Nora has been designed from ground up with these LEDs in mind. We didn't want to shoe horn them into an existing product. Those familiar with LED technology will know that these LED have been available since late last year (2010), but importantly they are only now available in the choice of colour bins that are best suited to caving lamps. As we almost certainly purchase more bare LEDs than any other caving lamp manufacturer, we have access to the best bin XM-L LEDs and we have carefully selected these for the Rude Nora.  We don't drive the LED with the full rated current. Other manufacturers utilising this technology have stated that this further raises efficiency, resulting in a long lamp runtime. Theoretically two of these LEDs could produce over 1500 lumens, but at this output level they are sadly much less efficient. We see no reason to argue with this.

What is the beam profile produced by the Rude Nora?

The Rude Nora has two LEDs, one focused to produce a smooth narrow spot for distance (carefully optimised, not too spotty of course) and the other positioned forward without an optic to provide a smooth full flood. Our preference is to avoid pencil beams (the classic novice trap, in our opinion), that although superficially appear bright, are not overly practical from a caving stanpoint and are often irritating when mixed with a full flood LED. The two LEDs can be operated both independently and simultaneously at a range of versatile power settings. While the XM-L LEDs may have been available to an extent since late 2010, suitable optics were not immediately available. It takes a little time for the optics manufacturers to catch up when new LEDs are first released. For us, fiddling an existing optic (designed for different LEDs) to fit was not an option. The efficiency of the optic is of equal importance to the LED. Consequently, we have been dealing directly with the worlds leading LED optics manufacturer, so that the Rude Nora can hit the ground running with the highest quality and best efficiency optics available. The Nora is the first lamp that we are aware of that incorporates an optic designed specifically for the XM-L LED. The cheapest alternative is not always the best. For example, take two lenses with the same beam angles. The first product is 20% cheaper, but it has lower efficiency, i.e. its power loss is higher. To reach a certain lumen output figure with the cheaper lens, you will need more power consumption for the solution – which shortens LED lifetime – and eventually you may need to acquire more LEDs.  

What is the light output of the Rude Nora?

The Rude Nora can produce around 850 lumens running at the lamps full power on both of the Cree XM-L LEDs (cool white), at around 150-160 lumens/watt (@ 350mA), the most energy efficient LEDs available (i.e. lots of light using less battery power). The Neutral tint around 800 lumens. In our opinion, caving lamps have reached frankly ridiculous levels of output, more than anyone could ever need. It's a caving lamp and there are more important considerations. We havve set our position out to produce a lamp that we hope will be head and shoulders above all other lamps, regardless of price (and RUD E Lumens). We refuse to get into a lumens war on who can produce the most light, and we therefore made a conscious design decision to keep the Rude Nora sensible (though it could be argued that 850 lumens is still somewhat excessive). That's just our opinion. Take it or leave it. All you need to know is that if you point a Rude Nora, or any other stupidly bright light, in the wrong face then don't complain if you get beaten to death with it J 

Fortunately the Rude Nora has a practical range of power settings so you should comfortably be able to avoid this.

Please explain the basic operating sequence of the Rude Nora?  

The operating sequence, or ' User Interface' is basically what happens when you start pushing the GO button. To realise this, configuration of the LED driver circuits is controlled by a microprocessor, as you would expect in a high end lamp. Rude Nora has two advanced current control circuits, one for each of the LEDs, so that these can be operated both independently or mixed together.

The interface allows easy selection of various power settings for both the flood and spot LEDs, operating either seperately or together, without any requirement to pre-program these settings. More detailed information on the User Interface can be found at here. 

User Interface

Experience shows us that some cavers want a simple user interface (on/off works for a lot of folk) and others want their lamp to be highly configurable with numerous variants of beam profile. Hopefully you will agree that we've hit on the perfect balance.

The Nora has 7 power setting, 4 regular caving settings, plus 3 other (two very high and 1 very low setting), and features our integrated 5 stage battery 'fuel' gauge. It is also possible to toggle back and forth between any of the regular setting and high spot output (or turbo); easily and whenever you wish to, for example, if you want to take a look down a deep pitch or up a high aven.

Anyhow, it's easier to see how this works on this simple flow chart.

Is it possible to just have the distant spot LED on high?

Yes. Cavers for the most part tend to find a balance of light output and battery duration, and consequently weight, that suits them. Some people want (or need) more light than others. High spot is a setting that is particularly useful for looking down a pitch or up a high aven, usually for a quick look and then back to a more practical all-round setting (yes, we all know folk who are an exception to this...). Consequently, the Nora has been set up so that it is easy to toggle back and forth, at will, between the general caving settings, and high spot setting.   

Why does the light come on when I plug the battery in?

A few reasons, but most importantly as a fail safe, so that if you ever have a dodgy intermitttant battery connection, or possibly switch failure, then there is a fighting chance that you will be able to use the lamp to some extent. Also, so that you immediately know that the lamp is working when you connect battery pack.  

Have you got any beam photos?

It's on the job list. We are not especially skilled with a camera. Update, we can't be bothered.

How do I know how much battery capacity I have used / have remaining?

Most (but not all) high end lamps incorporate a fuel gauge so that the user can at any time determine the level of battery pack capacity remaining. However, you invariably can't see it when you are wear your helmet with lamp. Of course you can take off your helmet, but there is a better way...

The Rude Nora features our innovative 5 stage visual battery fuel gauge. This system was incorporated in our original Little Monkey and Hurricane lamps. When the fuel gauge is initiated the Rude Nora will flash a number of times from 1 to 5 flashes to indicate the remaining battery capacity. This highly accurate fuel gauge system is unique amongst the high end caving lamps. You can easily and quickly determine the level of battery capacity without removing your helmet and counting how many little LED lights are on/off.  

To activate the fuel gauge, when lamp is 'Off', push and hold button. Fuel gauge will operate, and then lamp will subsequently default to mode 7 (ultra low). Next push is back to 'Off'.   

Will the Li-ion battery packs shut off and leave me without light? 

Yes and no. Eventually they will shut down because they incorporate essential circuitry to protect the battery pack, but 'no' as the Rude Nora features smooth progressive power reduction which kicks in when the li-ion battery pack is almost 'flat'. See following question, and also 

Does the Rude Nora shut off the higher power levels as the battery pack discharges? 

No, The Rude Nora features smooth progressive power reduction* as the battery capacity drops and gets close to full discharge; the first high end lamp to achieve this. This is highly desirable feature in any caving lamp, and allows the battery to be eeked out when almost flat so that you will unlikely ever be left without a degree of light. It's not a new concept, and has historically been referred to as 'slow death', but has (until now) been difficult to achieve for high end lamps that use li-ion battery packs as these shutdown at around 2.75v per cell rather than draining all the way to 0v like e.g nimh cells. To date, high end lamps at best, monitor the battery capacity via the fuel gauge and shut off higher power settings to the user when the battery is getting low. Our original lamps, the Little Monkey and Hurricane both used this slightly crude yet essential approach. However, the Rude Nora can sustain light output long after such first generation lights have shut off, several days in fact.

*Ironically, this smooth progressive power reduction or 'long tail', once the batteries are almost spent, was never historically a problem. Caving lamps running on say 3x1.2v nimh cells (3.6v) achieve this 'long tail' by default. The issue higlighted only relates to high voltage lamps using li-ion packs, e.g 7.4v, where it is necessary to shut down the battery packs for protection once they have dropped to around the 5.75-6.0v level.  

What are the power settings and durations?

The Nora features a wide range of power settings, running the twin LEDs simultaneous and / or independently. The highest output power setting will run for several hours and at the other end of the spectrum, the 7.8 Ah li-ion battery pack will power the Nora for around 400 hours.

How much power does the Rude Nora use when the battery is connected but the light is not on?

Like all high end lamps, the Rude Nora uses a microprocessor 'brain' and momentary switching to provide the versatile levels of control that are characteristic of, and expected from such advanced equipment. When the battery is connected, the lamp is 'alive', on stand by, and some battery power is consumed. On stand by, the Rude Nora, draws just 0.006 mA, insignificant as compared to self discharge of the battery pack and overall battery pack capacity. Consequently, if not used for extended period of time, battery packs should not be left connected as they will eventually discharge the cells to shutdown point at approx 2.75 v per cell, and then 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. In reality/ theory, a full battery at this drain would take well over a year if left plugged in, just to reach pack shutdown voltage.

I do a lot of surveying (I'm great and find loads of new cave). My current lamp has a magnetic switch and I have problems with compass bearings. Will the Rude Nora affect my compass readings?

No, the Nora does not have a magnetic switch or any circuitry that we believe will cause an issue. If you want to be super cautious  then an aluminium screw set couldn't harm.  

What is the Rude Nora headset made from?

The Rude Nora lamp housing is CNC machined from a high strength grade aluminium alloy, and the design has been optimised to provide an effective balance of surface area (for LED cooling) while achieving an acceptably compact design. We feel that the Nora is the perfect size, not too small and not too large. The body has subsequently been finished with a bang up to date, 2012, here and now, glossy gunmetal grey finish. The forward mounted flood LED is mounted on a similar grade aluminium alloy insert, or thermal facia (tastefully anodised in a range of complimentary colours) and thermally connected to the main body to provide effective cooling. The plastic optical front window is extremely resistant to abrasion. It is unlikely that you will need to replace it at any point unless you happen to be a little bit special when it comes to killing stuff. Replacement windows are available at low cost. The switch is positioned on the rear of the headset so that it is protected against abrasion and doesn't continually get knocked. As a consequence the Nora does not require any form of travel lock or remedial protection against accidental switch on. Any requirement has simply been designed out by orientating the switch in a protected position. The Nora uses a new waterproof double O ringed momentary switch, and for good measure this is protected by an interchangeable waterproof switch boot. An O ring creates a waterproof seal between the body and the optical window. This seal should be maintained with high viscosity silicone grease available from the Online Shop. 

What finishes are available on the headset? 

The Rude Nora headset is CNC machined using the latest UK based state-of-the art facilities and high end machines to achieve a finish second to none. The aluminium headset is subsequently polished prior to anodising to realise a beautiful glossy gunmetal grey finish. We are not providing other anodised colours as these are fundamentally a decorative process and do not posses the wear resistance of gunmetal or black anodising. 

The Nora is however stylishly trimmed in 6 anodised colours, 'Britsh Summertime Grey'  'Monkey's Arse Red'  'Dream Sump Blue'' (Bleu siphon de rêve) 'Swiss Gold'  'Purple Nasty' and 'Ornella Muti Orange' ; within the lamp housing where wear is not a consideration.

An optional range of complementary anodised fixings is also available, including coloured aluminium lamp fixing brackets. 

What is the optical window made from? 

Figure it out for yourself.

Sorry about Nora, she got out the wrong side of the bed today J 

Incidentally, Nora has no bezel restricting the light output. The window extends to the full diameter of the lamp, to gain maximum light angle from the wide angle 'flood' LED. The Nora is unique amongst lamps using this arrangement in that the 'flood' LED is positioned well away from the inside edge of the lamp to avoid any 'clipping' of the light output by the aluminium body. Don't worry about scratching the edge, the window is extremely robust; and if you manage to kill it over time, then low cost replacements are available. We bought far more than we could ever envisage using, scales of economy and all.

Please explain the different lamp fixings?

As standard, the Nora comes with stainless steel screws and locknuts. If you want to bling up your lamp, and want to shave off a few micro grams, anodised aluminium fixing screws and nuts are available in a range of colours complimentary to the Nora. There is also a titanium screw set available. Anyone who doesn't love a bit of titanium lacks soul, or maybe just isn't an engineer.  To be honest, the titanium and aluminium fixing are more about styling than weight. You'd have to be the worlds most obsessed weight weenie to argue otherwise, over the few grams saved. As standard the aluminium alloy lamp bracket has either a plain anodised or gunmetal 'British Summertime Grey'  anodised finish. The lamp brackets are also available in a range of colours, 'Monkey's Arse Red'  'Dream Sump Blue' (Bleu siphon de rêve)  'Swiss Gold'  'Purple Nasty' and 'Ornella Muti Orange' . There is also a brushed stainless steel blade mount bracket available.

What is the Rude Nora battery box made from?

The Rude Nora battery box is CNC machined from a tough engineering plastic, as used by the best diving canister lamps. This is robust and light weight and we felt that it would wear better and more attractively when bashed around on the back of the helmet than an anodised aluminium box. It also allowed us to thicken up the box walls versus aluminium to improve the dive potential (and this proved fruitful when we comfortably pressure tested a lamp to 100m). As the battery box, unlike the lamp housing, has no cooling function there is no heat related requirement to construct this from aluminium. We also felt that it is the best material from which to potentially achieve a waterproof design, the weakest area of high end lamps to date, and has the further benefit of avoiding the dreadful metal clanking when bashing an aluminium box along the roof of a cave. The lid of the box is sealed with a substantial O ring and locked on with two miniature stainless steel toggle clasps, not dissimilar to those used by diving canister lamps to achieve a water tight solution. This seal should be maintained with high viscosity silicone grease available from the Online Shop. We do not recommend using conventional silicone grease. The battery box is held firmly onto the helmet with shock cord or industrial cable ties to allow a degree of flexibility and avoid potential problems associated with rigidly fixing to helmet with bolts. The lid can be secured easily and neatly with 40kg (90lb) Kevlar braid supplied. Probably adequate to belay a small child, but please don't try this. We have spare battery box lids, but will mock if you manage to lose it. In order to give the box every chance of being dive proof we went for an external fixing lid, rather than an inset arrangement, that fits inside the top lip of the box, and also to avoid any cave abrasion on the main body of the box which would inturn lead to leaking. Due to availability from manufacturer in France, battery box toggle latches no longer have locking holes, so don't bother buying a dyneema locking cord. Very few people have done so far anyway.

How is the Rude Nora fitted to the helmet?

The Rude Nora lamp in standard form is fitted to the helmet with an anodised aluminium alloy bracket. The bracket is removed from the lamp (2 screws), and three holes are drilled in helmet. The aluminium bracket is pulled into shape when these are tightened. The lamp can then be refitted to the bracket, and angled to suit. Additional aluminium brackets are available if you wish (for whatever reason) to have a second helmet set up and ready to take your lamp. The aluminium lamp brackets as standard are plain anodised for wear and appearance and made from a high strength alloy. They are also available in a range of attractive colours and complementary fixings are available. For those of you who have a need to remove the Nora headset from you helmet, or those who haven't moved on from mining lamps (don't get me started) there is an optional stainless steel blade mount. 

The Nora battery box is attached to the back of the helmet with shock cord or releasable industrial cable ties to provide a secure yet impact flexible fixing. Four small holes are required. We supply drills of the correct size for fitting if necessary, see accessories page. This arrangement balances the helmet well and avoids irritation of cables getting caught. The cable can be run inside of the helmet. The cable is made of extremely durable and flexible cut-resistant material (polyurethane jacket) designed for extremely harsh operating conditions such as construction machinery and industrial robots. In contrast to lower cost PVC cables, you'll do extremely well to break it. 

Is a longer cable available?

No  

Will the Rude Nora fit my helmet. I use a petzl Elios?

Yes, the Nora will fit beautifully on an Elios (by accident more than design). The Elios is a little different than the regular style of helmet used by cavers, and does create difficulties for helmet mounting lights in general. The significant issue is that the Elios cradle is attached through the back of the helmet, resulting in an annoying battery box mounting obstruction.  The Elios is also available in a very compact childrens size. We wouldn't dream of recomending a lamp like the Nora for a child, but interestingly a (adult) customer (with a lovely, yet little head) has just fitted a Nora to a childs size Elios and it works really well. Full details of fitting to an Elios will be provided in the 'fitting guide' shortly.

Is there going to be a blade mount option?

Yes, see above question. A brushed stainless steel blade mount is available. 

If I drill my helmet, is the sky not going to fall down?

Probably Yes. Drilling holes in helmets is essentala for the mounting of any serious caving lamp. Am likely to lose the will to live if I have to explain this in any detail, so courtesy of the World Wide Web;  

The Modification of Helmets for Caving and Cave Diving

By necessity helmets have to be modified in order that they can effectively be used for caving or adapted to suit the requirements of a particular task within the caving environment. Invariably holes will need to be drilled in the shell so that lamp brackets or reserve lamps can be fitted. Petzl for example provide a drilling template for mounting the Duo to their helmets. Cavers drill helmets; as they principally use helmet to mount lamps and protect from light bumps. You will ofcourse come across 'helmet wankers' who have a different perspective, and a fairy tale to support their case.

If holes are drilled in sensible positions and kept to a minimum they are unlikely to have an adverse effect on the overall strength or protection offered by the helmet shell but obviously this can't be guaranteed.

Drilling holes into a helmet shell technically invalidates its certification as Personal Protective Equipment (PPE) and may have an adverse effect on the amount of protection provided by it so anyone who modifies or uses a modified helmet must be aware of, and fully accept, the potential incurred risks of the modification beforehand and during subsequent use.  

ps. if you feel the need to ask this question, and please don't take offence, but might we suggest that you consider a different leisure activity (or whatever leisure category you wish to lump caving into).

How do I charge my Li-ion battery pack?

Although the charging algorithm for li-ion cells is relatively sophisticated, this is sorted out by the compact 1.5A mains charger and battery pack circuitry. Consequently, charging is a simple plug in and go scenario, red light - charging, green light - fully charged. 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. Charging times will vary for different cell packs, and are obviously longer for our high capacity 7.8 ah packs as compared to the super light weight 2.5 ah arrangement. The charging time for the standard, 7.8 Ah Sanyo pack is around 7 hours from flat. There is no fast charge deal for li-ion batteries, they don't work like that.

Is a US or European mains charger available?

Yes, even though this means pandering to nations that have not yet figured out what side of the road to drive on, and have silly types of domestic mains socket in your houses J

Sp

Sorry, nothing like a bit of xenophobia. It's our damp weather. 'British Summertime Grey'  

We have a stash of adapters (or you could just grab one on ebay),  

Can I charge my Rude Nora in the car? 

Yes, there is a 12v input 3.7v li-ion car charger available for the Nora. The Nora car charger plugs into your car's cigarette lighter and charges your lamp while you're driving (as you might expect). Intelligent IC chip recognises a fully charged battery and automatically switches to saver mode to prevent overcharging and short circuit. 

Incidentally, we still have a good stash of 12v input 7.4v li-ion car chargers for 1st generation high voltage lamps, with connectors compatible with Little Monkey, Hurricane, Scurion(tm), Stenlight. After all, an expensive caving lamp is about as useful as a chocolate tea pot if you can't charge it up. See Customduo Scallywag charger.    

I do lots of cycling; will there be a bike handlebar mount?

Good for you, and NO. Caving lamps are no more optimised for cycling than cylcing lights for caving, and it will rain in hell before you convince us otherwise. (Initial response heavily edited).

No need for that attitude. What about a headband?

Seriously though, the Nora is a no compromise helmet mounting lamp for CAVING. Adapting it as a bike or running lamp is a compromise we are not prepared to make.