We all know that the biggest problem after being affected by a natural disaster or a Zombie Apocalypse , is loss of the electric grid. And all phones specially new ones have short battery life of 8h if we are realistic. All cellphone towers have backup generators or battery banks enabling them to work of grid 48h or more and would be on priority list to get grid power back. So here is my creation a cellphone for survival you charge it and put is in your bug out bag and you are prepared. This cellphone has got 52days stand by and 12h of talk time . This is an old reliable Nokia 3510i from the good old days when phones didnt brake down :) it has a factory 1100mah battery and what i did is added 4 new 1100mah batterys on the back and increase the battery life by factor of 3.
Step 1: Geting a Phone and Batterys
I had chosen a old Nokia since they are reliable and dont use much battery as new ones, you can use and phone just pick one with most standby time Gsmarena.com for reference. I had some of old battery s laying around you can buy new ones if you want but i measured this ones they had 90% capacity left so i used them.You pick what best for your phone to fit on it:)
Step 2: Preping the Batterys
Prepping your battery's they all have 3 or 4 more pins my had 3 so i applied solder on the plus and minus the middle pin is not used so no need. Dont worry batt wont explode when exposed to your soldering iron .
Step 3: Conecting the Batterys
Solder your connections so plus of each is connected to plus and minus to minus . We are paralleling all the batterys s we keep the same voltage and increasing the capacity.
Step 4: Mounting the Batterys
I dried a hole on the back of my case so i can put the my cables thru . After fitting it and i put some electrician tape to isolate the connections so they dont short out . I mounted my battery's temporally with tape and then used hot glue to make a more permanent .
Step 5: CoNeCtInG the Bat to the Phone
Ok now it gets interesting , since my original bat what old typ 4 pin . I had to open the old bat and ant take the protection board . Some phones will not power with out this board since the middle pins send temp of the battery to the phone for protection . Tip ( if you don't have the old bat , connecting a 100k resistor between the two middle pins will fool the phone and it will power on )
After taking the board out put wire on the board and connect it to your cell
Step 6: You Are Ready
After connecting the wire i made a small change i could not get the wires to get in the battery compartment when i put the battery cower. So i took the wire from the battery and soldered them to the pcb i took out of the old battery . I pureed hot glue on all the connection places to secure them and prevent mechanical and electrical damage.
Step 7: Congratulation You Are Ready for Anything
I hope you find this interesting post any questions and i will answer you.