Nec 900c Backup Battery

Some time ago, my gf was rather worried she got pregnant. Hence she rushed to the drugstore to get some tests. Those tests to my surprice, were the electronic clearblue pregnancy tests, which in order to function need a battery.

The test came and was about to goI was curius to see what was inside it so I took it apart only to find out a battery similar to my NEC900c backup battery, except the thickness, which was running outof juice.
Hence with the help of a penny which when inserted in the slot gave similar thickness with the original battery.

And now my NEC is working like a charm!

same trick worked for the TV remote, which suprisingly was using same kind of battery.

Panasonic CR2032 3V and was replaced with the CR2016 3V

Half the thickness, all the pleasure!!!
( I should copyright it lol)

How to make a NEC mobilepro 900 case for £2

Get an £1 double CD case from your local 1 quid shop like the following:











remove the white CD slips which are sewed on the back of it,










Get a car visor organizer for CDs for another £1













and after removing the internal reinforcement for easier sewing













and you got yourself a great and cheap case for your NEC 900c

Ugrading a NEC 900c battery and WIFI antenna "Battery hack"

I have had for sometime now a NEC Mobilepro 900C upgraded of course with the newest possible software and Cmonex is the one to take all the credit for that.






However the battery hasn't been keeping a very healthy charge lately which is more or less normal since it is quite a few years old to say the least.










While trying to open up the power pack in order to change the old Li-Ion cells with newer ones, I made a hole in it :(((











The problem was you see that having opened other batteries in the past for the same reason the plastics were far too strong and difficult to separate them.
This one on the contrary was very easy to open, and the plastics quite soft.

Thankfully I was lucky not to damage anything in the controller circuit, or the cells themselves. Also another lucky thing was the position of the hole. Why ? Here is why:

Sometime ago I got a short WIFI PCMCIA prism card which was not protruding from the NEC. Unfortunately this card needed an MMCX antenna to work and I had gotten a very cheap bare antenna from an Ebay seller in China.










The antenna is a bare PCB, a cable, a core on the cable and the mmcx connector.

I used to have it with duct-tape glued on the side of the screen (after a bit of chopping) since it has approximately the same width. Now however I could put it inside the battery!










When the battery is opened, there are four plastic chunks. Their function to keep the cells steady into position. And there is quite a bit of free space in there. Especially since the antenna is very thin. 2-3mm thickness.










Hence it can be very easily be placed at the side of the batteries, with no problems in space requirements.










the finished product :)


And some photos with the whole assembly.




















I have to say that I don't know if the antenna so close to the battery could cause any disruptions on the signal, but I will keep you posted

The new battery cells are not in yet, but are on the way so in a few days I will be able to enjoy, if all go well, a few hours of NEC 900 use.

Update:
The new battery cells finally arrived from Dealextreme.com and were put to good use immediatelly. The results were more than awesome. With the previous aged cells There was barelly enough juice to keep the mobilepro alive for 1:30 hours watching a movie. With the new 3000 mAh pack I can watch the same movie 3 times over with the processor ovelclocked !!!

The soldered batteries can be seen bellow. Not very elegant work I must admit, but it works like a charm

Cost of the hack:

1£ for the antenna,

11$ for the batteries

20€ for the wifi card

all and all, not bad I 'd say