How long do rechargeable batteries last? Do they have 'memory' that needs to be drained before a new charge?

I bought about ten 2500 mAh Energizer batteries that recharge in their dedicated chargers. These batteries maybe the fault of my digital cameras short life. The camera went into their shop but they blame the batteries or charger. I've tried changing chargers and still have no luck. The batteries say it they can be charged over a 1,000 times. So far I may have otten 40. Any help?

Just so it's clear what type of batteries being questioned about...they are Energizer Rechargeable 'AA' size batteries marked 'High Energy' 'NiMH' Nickel Metal Hydride. Other markings read NH15-AA 1.2V 2500 mAh. Any help would be appreciated.

Rechargables are supposed to last several hundred charging cycles providing:
1. The battery voltage does not go down to a very low value
2. You use batteries till their charge goes low (as displayed by your appliance) and immidiately (not the same instant but within a reasonable time).
3. You do not have any mechanical damage on the batteries
4. The charger did not kill the batteries.

I have used rechargables for quite some time and have used one particular set for over 3 years.

salesman told me to completly discard rechargeable batties the first hald dozen times because, yes, they do have a memory. this is for large tools but may be the same for small batterys?

NiMHi batteries such as these do better if you keep them fully charged as much as possible. don't let them drain all the way- as that's one way to ruin them.

the other way to ruin them is by charging them too fast, which causes them to overheat, and degrades the cell. Or, keeping them in a charger for weeks on end- as many chargers will keep a trickle on the batteries to keep them topped off.

Rechargable batteries nowadays all run on litium. This is completely fine, except that, just like any other chemical, it degrades after use. Everytime you turn the camera on, or charge the battery, a small percentage of the litium dies out making it less usefull. This would mean even if you had only charged it for 40 times, if you had already turned your camera on and off 200 times, your batteries wouldn't last. My sugggestion? Get another brand or be more careful how often you recharge and use your camer.

My personal experience was that rechargeable batteries do not last as long as regular ones in anything (toys, etc) I didn't even get close to 1000 charges before I gave up and chunked them. Got tired of changing batteries all the time.