N900 Bicycle Power and Attached Containment Systems (universal)
 

I have been using my N900 integrated with my bicycle for a few years and it might be useful to spread the knowledge.
There is plenty of discussion on integrating and powering smartphones and headlights with bicycle dynamos or solar for long range touring over at http://crazyguyonabike.com I am using images from that site too.

I have a folding bicycle that I had a Shimano hub dynamo built into the new front wheel, there are several other brand hub dynamo/generators available, they seem to be the most reliable method to generate electricity but they are also expensive both to buy and to have installed. There are also tire sidewall friction generators or bottle generators but these are most useful for when you end up out after dark and need to power lights to get home not for the higher demand of a smartphone.
http://upload.wikimedia.org/wikipedi...L_on_Giant.jpg
http://upload.wikimedia.org/wikipedi...cle_dynamo.jpg

I use A Shimano hub dynamo to power lights and to run a home made power converter that turns the 6 volt alternating current into regulated 5volt direct current supplied to a USB port. There are several commercial converters from cheap eBay junk to some very good, the price seems to be about $100 and up to get a good converter system.that is tough, reliable, and able to reliably charge in a wide band between just above walking pace speeds to long fast downhill runs. There seems to be a good consensus at crazyguyonabike.com that the best is the German B&M E-Werk dynamo power converter system though there are others.
below are two links to some older pics of my system then one of the e-werk.
http://www.crazyguyonabike.com/forum...pic_id=1181051
http://www.crazyguyonabike.com/forum...pic_id=1181052
http://www.starbike.com/images/BUMM/361_zubehoer.jpg

I have found that if you are riding a loaded bicycle with camping/touring gear up a moderate incline your speed will probably be too low to charge a phone but enough to power modern high power LED head and tail lights designed for dynamo systems. However if you will be on a good flat or easy hills you will generate plenty of power without actually feeling any additional load.

For reliable phone power running your backlight, GPS, CPU intensive apps, or 3G data where there are moderate to steep rolling hills I usually plug the dynamo USB power directly into a USB battery pod. I have a Yoobao Dual USB port Long March 11200mAh. This can take a charge from the N900's 110/220AC mains charger as well as the bicycle dynamo system, a car charger, or any power source with a microUSB jack. Some of the bicycle chargers especially the E-Werk power converter can be accessorized with a rugged cache battery designed to mount to the bicycle frame but this is not as large a capacity as the Long March battery pod. I have not run this dead yet but it should be good for at least five days at moderate consumption, though the N900 can really burn amp/hours when all the gadgets and CPU are running at full power.

http://www.maikai.co.uk/media/catalo...l/o/long12.jpg

I find that any phone holder system that tries to hold it with a foam or rubber clamp that I have tried doesn't securely hold a phone or GPS and will eventually bounce your phone out onto the highway, probably when you are doing a 70km/h downhill next to traffic. There are some car and motorcycle mounts for the N900 that may need modification or mating to a bicycle handlebar clamp to hold the phone securely but there is still the issue of weather, I have not tried any of these and cant comment. I ended up getting a universal GPS/phone waterproof enclosure that was a bit large for the N900. I made a tray from chloroplast (like cardboard box) sheet form an election sign that I cut and secured with hot glue to center the N900 and made an area on one side to hold the charge cable safely. This phone holder has a soft plastic touch screen cover that lets clumsy touch finger interaction but keeps the weather out, there is also a weather resistant port for a power/charge cable. The waterproof holder had a bicycle handlebar clamp and quick release connection to the actual phone enclosure which broke, I secured the enclosure itself permanently to the handlebars with zip-ties through the vents on the back which works fine.

http://www.extremepda.com/assets/images/SM032-ALL.jpg

Since the phone is inside a weatherproof capsule I interact with it using the touch screen and a modified Nokia BH-214 Bluetooth multimedia headset with a 3.5mm stereo jack for headphones. The BH-214 comes stock with a battery good for 6-7 hours of music or talk. I replaced the battery, which I describe in another post, with a battery good for about 24 hours of audio or talk. if the weather is good I attach a large safety pin to my collar and clip the somewhat flimsy clip of the BH-214 to my collar. If I suspect rain I will stick the BH-214 in a sandwich bag with a rubber band around a longer set of headphones to keep it dry.

http://www.accessoryarena.com/htmls/...=59654&v=thumb

Here are some quick links I found web searching for the things I mention in this post:

This is one place that sells the USB battery pod:
http://www.xengadget.com/products/21...filiateid=1008

This is what many consider a great dynamo power to USB converter, I want one:
http://www.starbike.com/p/Busch-M%FC...RK-361-3707-en

This is the weather resistant phone enclosure I am using:
http://www.amazon.com/Navitech-Water...284712-4490337

If you want to see what a hub dynamo looks like or some of the friction powered alternatives visit the Peter White Cycle Shop site linked below, it has plenty of info and pictures about dynamo lighting and power systems. He also is the exclusive importer/distributor to the USA for many of these German systems and components and charges a serious markup for them so prices of dynamo systems if purchased in the US vs the UK/EU are sometimes very high so shop around, see starbike.com link above. http://www.peterwhitecycles.com/

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Interesting read. I do a bit of cycling myself but I am one of those muddy-hooligan air-suspension cross-country types.

I am actually most interested in your "Yoobao Dual USB battery".
What sort of battery life do you get from it?
Looking for something like this for camping etc.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

I carry a small 7amph battery and a 50w inverter. Lasts me a good few days. But would love a front hub motor. On the motorbike, I use the n900 with gloves on the tank bag, because I can.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

I think it would have been better if you put pictures throughout your text because there are so many details we will get lost as we've never seen some of these things before.

Some ideas
#1 Bionx

This has regenerative breaking (page 9) can be mounted to your folding bike and is lightweight and I believe it has a 6v port on it and it can be put into regeneration mode while you are going down hill.

#2 Goal zero has a couple of packs differing in size that would work if you want it separate from the bike.

#3 Cellphone wrist holders

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

I threw some pix up and added some answers to the ??? in the thread.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Sixwheel' For mountain biking I just bring the pod too as I dont have a dynamo installed on that bike, too much up and down to take a good charge and the risk of snapping off the USB port.

King Ralph', an inverter? I figure the 11A/h is fine for me and delivered via USB powers most of my gadgets. I also have a lithium 18A/h battery that I use with a 25w solar panel and have a small inverter for camping.

aironeous, some of these converters will work with the 6 volt magneto takeoff on those bolt-on 49cc bicycle gas motors. I think most regenerative electricalbicycle motors use 12-48 volt systems but I am sure there is a smart way to tap these for phone charging. If there is a 6volt port though everything is easy, maybe this is for standard bicycle lighting options? I considered a wrist holder but in the end decided the phone was safer on the bike in a wreck.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Hi Biketool,

What a timing! I just returned full of questions from a 3weeks bike trip around Iceland testing my self powered n900 system and here you posted this at the same time. Maybe you can enlighten me ...

I have a SON dynamo hub with the E-werk. I bought it because it's the only device currently that can deliver 12V from a bike, and I'm planning to use that for charging a netbook. So far I only tried with the N900 and standalone chargers, and I'm quite happy of the 100€ investment (and the starbike.com service).

I don't have the additional cache battery sold with the Ewerk (52€ for 1400 mAh), because I had a small solar charger of 2200mAh (Vaude LP2200, http://www.rucksack.de/rubriken/arti...aign=ide/vaude) with cable input up to 7V/1000mA and USB output 5V which is even more functional. But the solar panel is so ridiculously "slow" that I'll have a look at others like Long March.

My setup idea charging was: dynamo -> E-werk on 7V/1000mA -> Vaude cache battery -> N900, that would receive a neat current, charge and play music to me while recording my GPX track with Mappero and display my speed and location.

However, the N900 refused to charge that way, whether I use the Nokia-provided USB charging cable from the cache battery or another cable. I tried powering the N900 directly from the Ewerk (this time set up on 4.9V/500mA, but I also tried 5.6V, and current up to 1000mA to simulate a wall socket charge) on an easy road where i could maintain a 20km/h speed (i.e. enough for the E-werk to deliver a neat current). In the best of the cases, the N900 would do this: the N900 would recognize the power (i.e. switch on if off, or have the battery icon pumping) and the lamp blink. But the lamp blinks green instead of orange, I had never seen that. After 2 green blinks, it stops. the N900 doesn't charge.

If i stop the power input and restart (i.e. I disconnect the cache battery or stop cycling), the same pattern will happen: 2 green blinks, then nothing.

Have you noticed this pattern? Or any other reader who tried to charge his N900 without the Nokia tools? Even though I always tried as well with the Nokia-provided USB cable at the end of the chain. Is the Long March working perfectly with the N900, switched on and off? And able to charge
*
I ended up charging spares NB-5L battery (I have 3) with a universal battery charger (http://www.me2solar.com/pixo-c-usb-u...y-charger.html). I can recommend it, as it can take USB3 current (900mA) and even deliver 7.4V (for dSLR batteries) while having an input at 5V. The drawback of this was that I had to swap batteries every day, and the setup is fragile (the battery is kind of loose in that universal charger, but it's the point as it's supposed to accomodate any battery) on bumpy roads.
*
For the handlebar case, I picked up the only model at the nearby DIY shop, a chinese 12€ case made for iphones, the N900 fits tightly, is waterproofed, the touchscreen works well and it hold toght to my handlebar even when the rocky roads made my back and butt sore for hours.
*
It feels so good to have the comfort of the N900 tools (phone, gps, music, wifi) without getting off the saddle and without paying attention to the power (well, provided one cycle a decent amount of KMs every day). I hope I can solve that N900 not wanting to charge directly.
*
Cheers,

jb

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Ended up getting a Long March after reading this thread.
Not put it to the full test but seems to charge my N900 OK.
Only charges from the 1A port and not the 2A, for some reason the N900 doesn't think the 2A port is a charger (checked in dmesg).

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Why so complicated?
1: http://www.amazon.de/Nokia-DC-14-Fah.../dp/B00475BGHA
2: http://toddlerontour.com/universal-u...14-conversion/

Done! :D

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

even simpler since it already comes with usb instead of 2mm

http://www.bike2power.com/products/

Seems like it would be an even better system if there was storage inbetween, like a DC-8 strapped on handlebar between dynamo regulator and phone so the dynamo charges the dc-16 and the dc-16 charges your phone constantly anyway. I suppose eventually you would need to charge the dc-16 manually, but it should go for a long time.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

As far as the e-werk I think you will be dissapointed at the charging rate for a netbook.

For those pointing out the bottle tire sidewall friction dyamos my experience in testing is that a sidewall dynamo is fine for occasional LED safety lighting but will put a noticleble load to drive traditional incandescent headlight and taillight combo or a smartphone on the minimum battery maintinence (not actually charging) amperage.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

JBD, the N900 may need a modified charging cable with the data leads shorted if your battery pod doesnt negotiate a charging rate.
Easiest way to do this is to split the outer insulation on a USB cable and use a soldering iron to short the green and white wires together with while carefully leaving the red and black power wires alone. You can seal it up with some shrink tube.
http://en.wikipedia.org/wiki/USB_cable
The E-werk is great for charging a smartphone once you get past the N900 requiring a smart charger to accept power.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Thanks, I will try that.
I found more details on http://talk.maemo.org/showthread.php?t=38230 as well as reports on different cache batteries.

What happens when you charge your Long March battery pack with the dynamo while it's connected to the N900? If you cycle fast enough, do both devices charge, or the long march charges X minutes then delivers current to the N900 x minutes, or ... ? I don't want to loose any "cycling energy", so the current must go somewhere, either in the N900 either in a cache battery, ideally without changing cable connections.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Both devices should charge.
If you can't pedal enough to keep the long march charging the N900 will still charge until the Long March is flat (which is going to take a while).

Edit...
Just tested this and you can't charge a device and the long march at the same time.

Although I can't test it 100% if you supply the long march with power the outputs disconnect.
When you stop pedalling the input voltage will drop and the long march will start charging the N900 until pedalling resumes.

You could therefore ...
...have a switch on the lead supplying the long march to kill the supply and start charging from the long march.

...create a switching arrangement that will switch the supplies around so you can keep both charging or only the long march charging with the above arrangement.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

don't know about DC-8, but DC-16 simply won't do :mad:
it can't charge & discharge @ the same time :(

side note: the DC-16 i got a couple days ago has nothing close to the promised 2200 mAh
barely makes it to 1100 after two complete charge / discharge cycles :mad:

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

I have not tried the whole system together, maybe I need to make a bypass system that wont try to force power into the USB out port but will funnel power direct to both the phone and pod when the dynamo is turning.
Sadly many of these battery places flat out lie, fortunately we have guys like Dr_Frost_dk doing tests for us.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Maybe i should my N900 in the E-Bike build im doing, i will be using it a few times to get speed measurements from one off those SPEED gps programs :)

But im not going to use a dynamo when i have battery's on board :p, also the dual scud last enough time for me :)

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Hello everyone.

I've been charging my N900 from solar for the past year or two using various methods. I am currently doing final testing of my proto USB solar charger Maximum Power Point direct regulator which charges to a maximum of 800mA from a 5w solar panel (ie %80 efficient into the battery). Before I tried this I direct charged my batteries in an adapted external charger. An external charger can be easily modified to run off a bicycle dynamo with a low dropout full-bridge dynamo and some decent capacitance.

When designing any solar or alternative power solution there are two things to consider, the load and source. Work out exactly what your requirements are--the load--and design an appropriate charging solution to meet those needs in the required time-frame--the source.

First thing with a Nokia N900 (N9 too?) charging solution is this. You absolutely need to short the data lines out. Most off-the-shelf chargers do not have this. You need to open the charger up and either solder the data pins (bear in mind this will render the charger useless for i-poh) or make a special charging cable.

There are also several other factors which determine whether the Nokia N900 will charge properly. There are multiple factors at play here but the main thing to remember is that the phone does actually negotiate with the charger to see if it can supply enough current (it seems to do this more than once actually). The first time this is checked by the phone is to see if the power supply cannot at least a few hundred mA in the first few seconds. If the phone senses the charger cannot supply this current it clamps the charging current at 100mA (95mA exactly). Ie if the phone senses that your charger is not capable, your phone will be little more than "trickle-charged" during the duration it is plugged in.
After that it seems to do another check a few seconds later at 500mA, if alls well it can accept a sliding range of current above 500mA which seems to be dependent on a couple of things, my guess is the main one is current the SoC (State of Charge) of the battery at any given point.

If you think this is battery charging hell, you should see what the i-people have to do to get their devices solar charged.

Here is a helpful page
https://en.wikipedia.org/wiki/Univer...rging_adapters

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Hello everyone.

I've been charging my N900 from solar for the past year or two using various methods. I am currently doing final testing of my proto USB solar charger Maximum Power Point direct regulator which charges to a maximum of 800mA from a 5w solar panel (ie %80 efficient into the battery). Before I tried this I direct charged my batteries in an adapted external charger. A home-built external charger can be easily modified to run off a bicycle dynamo (as opposed to off a solar charger) with the addition of a low-dropout full-bridge rectifier and some decent capacitance.

When designing any solar or alternative power solution there are two things to consider, the load and source. Work out exactly what your requirements are--the load--and design an appropriate charging solution to meet those needs in the required time-frame--the source.

Every single solar charger bar 1 or 2 on the market right now are glorified external battery chargers with a little bit of solar attached designed to look good. The best way to do solar properly you have to do it yourself (I realise this thread is about dynamo charging but many of the same principles apply).

First thing with a Nokia N900 (N9 too?) charging solution is this. You absolutely need to short the data lines out. Most off-the-shelf chargers do not have this. You need to open the charger up and either solder the data pins (bear in mind this will render the charger useless for i-poh) or make a special charging cable.

There are also several other factors which determine whether the Nokia N900 will charge properly. The main thing to remember is that the phone does check the charger to see if it can supply enough current--it seems to do this more than once actually. It's been mentioned that the phone "negotiates" as per the USB spec, which in effect it does do, but there is no bus or data communication between the phone and the charger to enable this process. The first time the charger is checked by the phone is to see if the power supply can provide at least a few hundred mA in the first second or three (yes that quick). If the phone senses the charger cannot supply this amount of current it clamps the charging current at 100mA (95mA exactly). Ie if the phone senses that your charger is not capable, your phone will be little more than "trickle-charged" the duration it is plugged in.
After that the phone seems to do another check a few seconds later at 500mA, if alls well it can accept a sliding range of current above 500mA which seems to be dependent on a couple of things, my guess is the main one is current the SoC (State of Charge) of the battery at any given point.

If you think this is battery charging hell, you should see what the i-people have to do to get their devices solar charged.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Just curious how much time are you getting off of a double scud now?

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Thanks, very useful. If you post the chip numbers and describe or post the schematics it would be great!

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

BTW I think I will be hacking the Yobao Long March battery pod with an independent 1000ma charging circuit so that I can charge and discharge at the same time when running the dynamo.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Since the thumb boost i get something like 4 days, but i really don't use my N900's very heavily, for just GPS?, don't know, all i have used it jspeed to measure speeds from time to time.

So it is not that i need to make a bike charger, thou it is very simple when you have battery power, i can just put a DC-DC circuit in and set it to 4.2V and plug it in my DIY charge port that you can see in my battery thread.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Thumb boost?

Also big thanks to dr_frost_dk for pointing to the e-cigarette USB chargers a great super inexpensive source for ~500ma 3.6v(actually 4.2v) li-ion charging circuits and the exhaustive battery testing!

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Thumb:
http://talk.maemo.org/showthread.php?t=84829

And yes those chargers are DIRT cheap and work very good, i use them on flashlights and such, don't take up much space and have and indication light and the best part you can now charge from pretty much anywhere, something that is not in short supply now a days is USB ports :)

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

There are essentially two approaches I've used with LM2596 regulators so far. The first approach is 6v solar panels into an external regulator. This is the system adaptable to a standard 6v hub or bottle dynamo setup. The second approach is my current approach and uses Maximum Power Point (without the tracking) regulation and 12v solar panels (18-20v open circuit, 16v maximum output).


=====================================


A few of us have been making ultra-low cost MPP regulators based on LM2596-adj regulators and documenting it on fieldlines.com. Here is the thread:
http://www.fieldlines.com/index.php/topic,146685.0.html
The actual Power Point regulation is done by regulating the solar panel before it gets into the regulator. I've used an LM723 regulator, OperaHouse uses zenar diodes. Both do the same thing, turn the LM2596 on when the maximum power point is reached. The LM2596 switches at 150k. Large capacitors store the energy while the solar panel voltage (and power rises). This happens all very quickly. The LM723 regulator has the advantage that the power point is adjustable, it's an old but efficient and robust regulator.

The LM2596-adj boards you buy on ebay have a number of pitfalls. OperaHouse gives some good advice on the thread above on how to find the best of the bunch. These boards most likely have counterfeit LM2596 chips as in bulk (1k) the chips themselves are more expensive than the boards cost including shipping anywhere in the world. These chips also are soldered (some may be welded) to the board so heatsinking can be difficult.

EDIT: The chips on the LM2596 boards are almost guaranteed to be FAkE. The genuine LM2596 pins are staggered. The ones on ebay are inline.

=====================================


The photos show a plain LM2596 regulator with current limiting (current limiting ie 3 pot LM2596 regulators are less efficient than single pot regulators) as you buy them on ebay. They are installed in a gutted external charger as you buy them from dealextreme at low cost. There is low-ESR capacitance (the most expensive part of this regulator). I used a 6v solar panel and made my own connectors out of Deans style connectors (really like them). This regulator is not a Maximum Power Point one as there is not enough headroom on the solar panel. This system (ie not a MPP regulator) would work well adapted to work off a 6v dynamo with the full-wave bridge rectifier as suggested above.

You could make an external charger or a USB dynamo charger this way. Keep in mind however if you make a Nokia USB charger you will need a decent amount of current on the port when you connect otherwise it will be current limited to 95mA. You could do this by spinning the wheel in the air before you connect the n900 (and then hop on straight away and cycle). This or install a switch on your handlebars or something like that to cut in while you ride. There are also problems with voltage rising on the input capacitors with dynamos, it could be worked out by monitoring the voltage levels. It doesn't appear to be a problem with the MPP regulator and 12v solar from what I've found.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

I've been using an Oyama OY340-2L solar panel with a built in liPo battery. works very well but needs exposure to quite a bit of light. I plug in a bigger panel or charge via usb when i need to top it up. It has a 4Ah cell for storage and can give 5v at 2.1A. Very interested in the bike dynamo type though.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

My take on this thread, would be to get a few pcb protected lipo's, a dc powered lipo charger, and a sepic (single ended primary inductive converter) to get a constant voltage (with variable wattage/amps) to always squeeze every watt of power out of the dynamo when its kicking out lower voltages. albeit at an a effeciency loss to get the current produced at lower dynamo voltages, but the energy would be wasted anyway so its a net gain as far as dc/dc sepic conversion effeciency.

Thats how i charge my vlra's using a 20w solar panel, since my sg-4 morningstar won't use the wattage produced below ~14v to charge the batterys. The sepic takes a voltage as low as ~3v depending on the IC/board, and boosts it up to whats needed, or bucks it down if the voltage is too high, though the charger can handle well above the panel max voltage (21v), that may not be the case with a dc powered lipo charger expecting 12-15v like the tenergy one i have.

Use that to charge ~25wh of lipos with a dc powered charger and a sepic to get enough volts (at the expense of reduced amperage/watts, but its better than wasting the power produced), stuffed into a waterproof SS waterbottle with the charger and sepic.

Then just use either a 5v regulator, or another sepic to charge your n900 from a female (water resistant) lead coming out of the bottle.

SEPIC dc/dc converters are pretty neat for getting every last watt out of low voltage sources, by boosting them up to whatever voltage is necessary to charge. Great for dynamo's and solar panels when they can't kick out enough volts to power the charger, though you lose a few % in effeciency lossses, i'd wager theres a net gain from the otherwise wasted low voltage power boosted to whats needed. And you get overvoltage protection, since any voltage above what the sepics set at, is buck'd down at a higher amperage.

Joule thief circuits might be worth looking into as well, to get enough volts when your source voltage is too low to power the charger in question. You'd want to implement some kind of voltage regulation though, sepic boards capable of 10w are cheap on ebay though, i'd just buy one of them. If you know what your doing though, designing your own voltage regulator/buck/boost/current limiting board, is fun too.

Just don't use a non-regulated joule thief as your usb output supply. Theres nothing to stop overvoltage damage to your usb devices, assuming your dynamo can pump out high voltages. But using a zener diode, a resistor, a transistor, possibly a few caps, and a inductor, its a cheap way to diy a boost dc converter.

And then just hook up one of those 5v 3a regulators/another sepic to a female usb jack with the center two pins shorted, and connect that to your phone.

I built a 6 cell usb nimh charger with a sepic, and it works great for a simple battery pack for my n900. My current project is using lipo's instead of nimh's in a similar application.

Another thing to take into account, is you may want a simple rf low pass filter, since i would assume power coming from a dynamo/dc motor/altenator is fairly dirty frequency wise, and possibly even ac depending on your dynamo/generator. But most voltage converter boards already have the circuitry to accomplish that, and its easy/cheap/a better option to just spend a few bucks on a sepic regulator.

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

Is anybody using the bike2power case with the n900?

If yes, does sometimes the power button get pressed
while the phone is in the case?

It seems to be of good quality and especially waterproof.
Looks a lot better than the cheap stuff on ebay.

Thomas

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

The bike2power sales team replied to my inquiry:

"I measured the inside space of the case. The case will fit a phone up to 75mm x 140 mm x 35 mm, which means Nokia N900 will fit perfectly. There are 3 foam pads provided to adjust for various phone thickness, and flexible strips to hold the phone in place."

I'm just not sure if I'll spend $35 for shipping from the US to Germany ;)

Re: N900 Bicycle Power and Attached Containment Systems (universal)
 

The "bikeconsole" arrived today. The original product is Tigra BikeConsole Universal 4.8".
I've ordered mine from Cyclewiz located in the UK. For the US Bike2Power offers a reasonable deal.

The N900 fits nicely, there is room for a second battery or other little extras. You can access the volume keys while riding which is good for zooming the map in "marble".

As you can see in the picture, the case is freely rotatable, landscape mode is no problem. The rain protection worked too :D
The black sticking-out-thing in the picture will soon be cut off once I've determined the best position.

Bonus points for the integrated headphone and USB cable, I'll probably add some on-the-go charging device later on.