can i use an old nokia 3310 to charge my 2 spare batteries for my n900??

3310 akku
li-ion
4 contacts +,-, 1 pin is to check if its an li-ion or ni-cd battery, bsi
3.6v
1000mAh

n900 akku
li-ion
3.7v
3 contacts +,-,bsi
1320mAh

edit:

i would say ....

+ to +
- to -
the battery type pin with 74.5kohm resistor to -
and the fourth one to bsi...

could that work that way??

That'd be freakingggg awesome

Isn't 3310 NI-MH?
http://www.amazon.co.uk/Nokia-3310-N.../dp/B0000CDU3D

i don't know

but will say this, check if it is Ni-Mh or Li-ion/LiPo

if it is Li-ion/LiPo then yes you can, i have an old sony ericson i use to charge various Led lamps i have made over the years.

One thing to consider is that if the phone thinks the attached battery is an 'alien battery' like my SE says, then it will not charge with more then 100-250mA, this means that is will be SLOW.

Else if the nokia you have has the usual pins like the N900, then you can modify the nokia phone to kinda fit the BL-5J battery and use the nokia phone as a 'desktop' charger

when you connect an 75.5kOHM resistor between 2nd and 4th pin u can use an li-ion battery..... i have assembled it like sayd above... it seems to charge...^^

10:03 3.68v
10:15 3.72v
10:37 3.78v
11:07 3.82v
11:40 3.93v

which voltagedoes a full bl5j have``??

between 4.15 - 4.23V will be a good place to start or end

ok it works ... but have some issues...

1. it charges only to 4.1 V what means about 90% charge
2. my first 3310 charged battery fell down from ybout 40% charge to 0% within a second..

but it works...

for everyone who want to know how to do it....

put the 3310 on tha table with charger connector faceing to you and display down ....

pins from left to right....

+5v , BC , BSI , -

solder between BC and - aresistor with 75,5 kOhm

connect + to + , - to - and bsi to bsi....

on the bl-5j bsi is the pin with an white circle and nothing in it...

when connected you should be able to powr on the 3310...

and i found out when i shut down the 3310 and let it charge about an hour longer after it said battery full it is at 97%

remember if you are a bit crafty you can do this with all phones, all phones that use lithium battery's that is, but it has been a very long time since any phone has used NiMh battery's

One phone that comes to mind is the N95, it has the same 3 pins as the N900, you just need to mod the back so the BL-5J can fit in it, but again, any phone will do, no matter if it's Nokia, SE, Samsung etc....