A Spare-Emergency Cell Phone Kit

One of out latest small projects was to prepare a spare/emergency phone.

We got the idea when we noticed that an old unused phone used the same battery as two phone used by the family.

So we went forward with the idea of setting a spare cell phone kit.

1. We bought a new spare battery

2. We also bought a cheap chinese external charger for the batteries that we modified as a dis-charger. What we did was to connect a constant current flashlight LED driver and LED to the battery contacts. We timed the discharging till the electronics signaled a discharged battery. Thus we have the actual capacity of each battery, new and old (the latter have a significantly reduced capacity, but can still serve as a last resort power source)

3. We purchased a cell phone plan with no prepaid time that does not expire when not used (the increased charges of this plan are irrelevant since the monthly bill is zero when the phone is not in use.)

4. We refreshed the contacts’ registry in the cellphone memory and the SIM card

5. We added a USB charging cable in the kit.

Exluding the DIY battery discharger, the whole project is just that simple!