From what I can see from the abstract - the full article is behind a paywall and I’m not spending $32 on it - Lithium Iron phosphate cells can lose capacity in a “memory-effect” process which appears from the abstract to be no such thing. Browse Articles | Nature Materials
Found it here. Memory Effect Discovered In Lithium-Ion Batteries - Slashdot
As ever with Slashdot, most people have not read the fine article, some of the comments are incredibly ignorant and some are from people who really know what they are talking about.
Thanks, Don! Looks like the discharge feature on my charger will be useful after all, for my eneloops (I don’t have any LiFePO4). Do you know of any studies on memory-effect in NiMH?
Memory effect as it is generally known doesn’t really exist except under very, very controlled conditions. MiMH “might” suffer it under very, very rigidly controlled circumstances. But the only time memory effect has ever actually been observed was in a spacecraft using computer-controlled chargers to “top off” the NiCd cells. Memory effect - Wikipedia
But cells do wear out. Especially when cooked. NiMH cells have a very small amount of water (?tens/hundreds of microlitres) and if overcharged, this gets electrolysed into hydrogen and oxygen which is vented and is therefore no longer available. LSD cells if brutalised will do the same but to worse effect. But discharging to 50% and then recharging with no overcharge over time will not reduce the capacity to 50% - which is what the memory effect is. Blasting tens of amps into and out of the cells for a short time will fix it. At the expense of overall life. I have some 30 year old NiCd D’s of very high quality that are about to be blasted by a fully charged car battery for a couple of seconds to melt any metal whiskers formed in the cells. When that doesn’t work, I’ll recycle them.