Re: Mugen Power Batteries
 

A solar charger is great as it charges no matter what rain hail or snow hehe no need to buy a wheelbarrow to carry any batteries that way.

Re: Mugen Power Batteries
 

@shadowjk:

I stand corrected, of course.

The terms 'charger' are generically but incorrectly used by the manufacturer and users alike. I followed that mistaken use of the word. I also referred to the standard battery as being Lithium Polymer. It is in fact Lithium Iron.

To those who don't know: the software in the 'phone manages battery charging. Usually this is done by monitoring battery voltage and other data This facilitates a faster charging rate up to a safe point and thereafter a prolonged but typically limited trickle-charge. The 'charger' is really a transformer that supplies a constant voltage and charge rate.

Cheap 'desktop chargers' often claim to have similar charging ciruitry, but I would not rely on that. NEVER leave batteries on a desktop/trickle charger for more than a few hours at a time and regard them as backup charger only.

Keep the charger away from paper/other flammable materials and monitor battery temperature throughout the charge process. Perform as much charging via the phone as possible - this is your best policy for prolonged and safe battery life.

Store batteries in a cool, dark space and if they get cold warm them very gently before charging. Never carry exposed batteries in your pocket - the contacts could be shorted out. Use/rotate spare batteries to ensure their voltage does not drop too far as this may result in a 'dead' battery that cannot be re-charged.

I hope this clarifies the matter and am indebted to shadowjk for pointing out the shortfalls in my Quick Reply - these are important matters.

Re: Mugen Power Batteries
 

I have been using cheap batteries and cheap chargers for three or four years without observing any of the precautions you suggest. How often would you expect problems to occur?

Since cheap batteries are available, typically, for less than $5, why are precautions such as never carrying spare batteries in your pocket necessary? You say that the risk is a dead battery that cannot be recharged. I have never had that happen, but if it did, I would be out less than $5. Expensive Nokia batteries, on the other hand, might justify such care.

Re: Mugen Power Batteries
 

Typically these desktop chargers are built using emergency battery protection chips. They're meant as second line of defense in case the primary charging circuitry fails, or if the device doesn't shut down by itself before battery becomes empty. Because they're not meant to actually have to do anything in normal use, their trip points are set outside the typical operating range of the battery.

In the long run this stresses the battery, making its capacity decay much more rapidly than normal.

Re: Mugen Power Batteries
 

This makes sense, though with cheap batteries, one solution would be to throw out your batteries every so often and buy new ones.

I don't suppose you could recommend a charger that DOESN'T have this problem?

Edit: Besides buying a second N900 :)

Re: Mugen Power Batteries
 

Hey people, my mugen battery arrived today and i just wanted to chime in and give a sorts of update:

the back cover comes with a switch that flips the white strip telling the camera if the cover is open or not.

Charging it for the first time now and will be back later if theres something to tell about :)

Re: Mugen Power Batteries
 

I also got the replacement back cover today for the Mugen 2400 mAh battery.

Camera and changing microSD-cards work now.
A photo with the old and new back cover is attached.

The battery lasts about 48 hours in normal (moderate) use from fully charged to the state it has to be recharged (as the picture of BatteryGraph shows)

Little too expensive though, I think, but otherwise I recommend it if one needs longer battery life with N900 and do not want to reboot to change for a backup/secondary battery. (Would be nice if N900 would have some kind of hibernate state where battery could be changed without rebooting.)

Re: Mugen Power Batteries
 

Wow, a hundred bucks.

One could buy a 5800XM off fleabay or some other SH and have a desktop charger, second battery and an emergency phone all-in-one (5800xm has the same battery). Heck, even a broken one that still charges is nice.

I think for 100 one could get a 3rd party desktop charger and battery.

I see a desktop charger (usb plug, case and logic only) for $3.99 and a BL-5J for 17$. So 21 bucks for a battery that charges from USB.

Also, from $10 to $40, you can buy a battery pack with an USB socket and just charge the device in your pocket. Ranging from 4-AAA cheap to huge-Li expensive, some of those recharge away in the office. (I have one).

I'm not saying the Mugen solution isn't sweet, since there's no rebooting, but I don't think it's commercially desirable (from my standpoint).

Also, I was hoping for a flat cover, flush with the camera. Now it just looks overweight.

Re: Mugen Power Batteries
 

How did you manage to have a nicely descending battery bar graph? My battery status bar widget stays at 8 bars until the Mugen battery is dry, when it goes straight to the zero level.

Re: Mugen Power Batteries
 

Won't happen unless someone breaks laws of physics and chemistry, or changes Lithium-Ion to some other (yet unknown) material. LiPo-batteries is the best we can get currently and the size/mAh is what it is.

I have had it too.
Sometimes the charging levels seem right, often not; actually never they are exact right to show 2400 mAh.
It's a bug:
https://bugs.maemo.org/show_bug.cgi?id=9789

I wonder if new customers have this issue fixed and Mugen would have resistor instead of thermistor inside the battery?