posted 23 years ago
The trick here is that typical consumer electronic devices (phones, camcorders, music players ..) don't make good dischargers. It's in the interest of the electronic device to stop using the battery as soon as it doesn't give enough power to fully run all the electronics :- the result of running a phone on a battery giving out too low voltage or intermittent current could be catastrophic for the phone. So, they all have cut-outs and fail-safes.
But, what is best for the battery is to be discharged fully, all the way until it's giving out nothing at all. Bear in mind, however, taht sometimes individual cells can fail, and although all the others are working, the overall output of the power pack is drastically reduced. Unless you fancy taking the pack apart and testng/replacing cells this is new battery pack time.
It's quite popular, for example, for the chargers which come with camcorders to include a separate discharger circuit. They can do this as the batteries are separate, and usually charged outside the camcorder. This is how the above-mentioned battery reconditioning service works; they have generic charger dischargers for the cells in most all types of battery and discharge/recharge or replace individual cells in the battery pack to bring the pack as a whole up to full function.
I don't know about your phone, but I wouldn't be surprised if you can get a custom discharger for your phone batteries. Try google for your phone model number and "discharger". If you can get one it may well be worth a few full charge/discharge cycles.