I didn't use my Kindle 3 for over a year and it didn't seem to charge when I plugged it in for several hours. I tried holding the switch in the on position for 15 seconds several times but had no luck, it wasn't charging at all.
I used a fast charger (5V, 2A), and the orange light turned on. After a few minutes, it turned off. I when the charging light turned off, I unplugged it, hold the power slide for some time, and plugged it again. Each time I did that, the light stayed on longer. The light didn't turn on immediately after I plugged it in, it took like a minute to do so.
I did this for 3 days, and on day 4, the empty battery page disappeared and Kindle started! I couldn't believe it, seems like these small loads reborn my kindle. Now, this kindle and its battery are about 7 years old, and the battery clearly is old and worn out. At this time, it lasts about 4 or 5 hours, and I gets "fully charged" (light turns green) after an hour on the fast charger. I'm still charging it twice a day, hoping battery life may still improve a little. I'll probably buy a new battery, but I'm still glad I was able to get it back from death.