Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
AFAIK it originated long ago when they tried to use NI Cad's for standby emergency power applications. The batteries were continuously trickle charged and when the emergency came along they found the batteries had nowhere near as much charge in them as they should have had.
It seemed they only "remembered" the tiny amount of trickle charge they were getting all the time.
It has of course since blown up to an urban legend and every poor battery management excuse is blamed on that effect.
Keep in mind what the batteries are designed to do and use them that way to get most of the benefits out of them.
They do not last indefintively either. Charge them up, run them down, charge them up again, works great for Ni Cads.
For other types of batteries an entirely different charge/ discharge regime is called for.
I seem to remember reading a lot about that on the net so there must be sites you have not yet found, try searching with different key words or check battery manufactorers web sites for more info.
good synopsis, Klaus. It was a real problem with early Ni-cads, the situation nowadays has been greatly improved with newer Ni-cads and NiMH batteries. Equating "memory-effect" to an urban legend is a good analogy, it seems to come up as a red-herring whenever a battery setup isn't working properly...