I am sick of using lithium polymer batteries lately. After using a battery for one month, it discharges faster then before. Also, while recharging it, I need to stay close to it for safety reasons (overheat, overcharge, explosions: as recommended on many blogs). And finally, each time the voltage on one of the cells drops below a certain threshold, I throw away the battery (NimH charging is damaging the batteries).
Do you have any suggestion other than LiPo batteries? If no, what should I do to prevent all of these issues?
Get a better charger! I would recommend using an Icharger, 308DUO or 410DUO would do the job.
So those chargers will help me prevent throwing away batteries? Aren't they a bit too expensive?
Well it will save you money in the long run. Sounds like you're throwing away batteries which is never cheap! Spend some money on a good charger and your batteries will love you.
Never over discharge your batteries past 80-90%
Well it sounds like your house is going to burn down...
But no really lipos dont just kill themselves.
Get yourself a good charger...
This sounds like a problem of not charging your batteries correctly. What charger are you currently using? If you are using some cheap 15$ and it is ruining your batteries, you should probably invest in a better charger. The prices may seem high, but If you are relying on a bad charger currently, and wasting batteries because of it, you will end up spending less money.
I think you'd better read this Lipo battery guide:
To know more these Lipo battery knowledge:
"How to maintain the Lipo battery?"
"Lipo battery Safety"
It will tell you how tell charger and dscharge your Lipo battery.