Post by thread:[OT] Batteries that have memory

This was bothering me a bit coming home from work. Remember the older rechargeable batteries that you needed to run all the way down because if you didn't they'd only be able to charge up to a certain point? It was said that the batteries had a "memory". It struck me that batteries having a memory was either somehow a quantum description or simply a popular descriptive term. What causes that? Is it simple chemistry or something else? Lindy

On Tue, 1 Jul 2008, Lindy Mayfield wrote: > It struck me that batteries having a memory was either somehow a quantum > description or simply a popular descriptive term. What causes that? Is > it simple chemistry or something else? It's a misused term that is now firmly embedded in our culture. Years ago there was some system that drained a set of nicad batteries down to the EXACT same level before recharging, repeating this process hundreds of times. They found that it caused the batteries to become perminantly damaged so they could no longer charge up past that point. Nicads in normal use NEVER would encounter this issue. But a VERY similar issue is that they need to be reconditioned if not drained and charged correctly. It's a chemical thing, yes. So now we are stuck with everyone calling it 'the memory effect'. -- Ian Smith http://www.ian.org