Do Li-ion batteries have the "memory" problem?

There is more than one kind of Lithium-Ion battery out there- the different types use different ions. I’ve never worried about “memory effect” in the Li-Ion batteries I have and have never noticed a problem. I’ve been told explicitly by people who should know that Li-Cobalt and Li-Ferrous-Phosphate batteries do not exhibit the memory effect.
I don’t know whether NiMH batteries have it or not. I’ve been told that they don’t.
Li-Ion batteries all seem to have a relatively short calendar life in that they lose capacity over time whether or not they are in use. NiMH batteries don’t seem to have this problem, or if they do have it it’s a lot less severe. I know of at least one electric car with a 20+ year old battery pack.

NiMH do have the memory problem but they are better than they used to be at coming back to full charge when recharging.
I’ve uniformly had the opposite experience with holding charges, the NiMH never last as long as a week. I have a Skil power screwdriver with Li battery that has sat in my toolbag for months between uses and showed no sign of diminished capacity. My cameras with Li-ion batteries can sit around for weeks between uses and a month or so between charges.
Note that in cold temperatures (close to and below freezing) the NiMH batteries are way more reliable as the li-ion battery chemistry slows down at that range.

To my knowledge, NiCad batteries are the only ones that have any appreciably memory effect, though Li-Ion batteries degrade quickly enough (especially at high temperatures) that memory effect is moot.

@dabbler Self-discharge is totally unrelated to memory effect. NiMH does have issues with self-discharge, but doesn’t lose a minimum of 15% of it’s maximum capacity per year like Li-Ion does. I know that car that @koanhead is talking about too, so I have to side with him here.

ah, I see total capacity will diminish yes agreed. I think the li-ion will hold what charge they have well though.

I’ve found, and heard somewhere, that Li-ion batteries provide a more consistent level of electricity before they get weak and drop to zero. So, a 9v battery will provide 9 volts much longer before it drops to 8, 7 etc. When they are depleted, they drop off fast. I have a multi-charger that has a drain setting that I use, and it works well to prepare my Li-ion batteries for a full charge rather than gamble with the problem. Some things are more sensitive to a less than perfect battery, like my camera, and other items aren’t like my remote. I only started using rechargables less than a year ago, so I don’t know if it’s helping or not, but I can’t imagine it hurts at all. All seem to be just as durable as when new.

Thanks to all of you for your responses.
There is another problem with rechargeable batteries that is separate from the memory effect and that is, that certain kinds of rechargeables must be kept charged (at least minimally) or they go totally dead and you cannot revive them. Does anyone know if this applies to NiCad, NiMH or Li-ion batteries?
I once had one of those Sonicare electric toothbrushes that I didn’t use for almost a year. Well, I believe that the battery discharged over time, and since I let it stay discharged for a long time, it died and I could not recharge it no matter how long I recharged it. The downside of this product is that the battery cannot be replaced. So, this $80 toothbrush was just garbage after that. Poor product design. Or at least they should have provided a warning that the battery must be kept charged.

had the same problem with a sonicare! it was so disappointing, I had left it unplugged for about a week and it was unrevivable. Fortunately the new ones cost less than they used to, so far my newer one seems less vulnerable to that problem, and has been left unwittingly unplugged for a week since and is ok.
Doesn’t really answer the question of what kind of battery was that first one, how can we avoid that sort of product !

I also had a digital storage device called MindStor (that was the brand), which was used to store digital photos and other files before the days of portable hard drives and USB. It had a rechargeable battery of proprietary format and non-standard shape. It was useful for taking along on trips if you didn’t want to bring along a laptop. (In those days, laptops were a lot bulkier and camera memory cards did not have large capacities.) Well, I let it sit around too long unused because I stopped going on trips. The battery discharged and died and could not be revived. What was worse, the manufacturer went out of business.
So the lesson learned is not to let rechargeable batteries stay discharged for long. But it would be nice to know if all 3 popular types, NiCad, NiMH and Li-ion have this problem.

@2davidc8 I have two wolverines that are similar storage devices for backup usage. They have Li-ion batteries. I leave them for months w/o charging and more often than not they actually still have substantial charge when I get back to them. If they are discharged I do find that the first charge after that does not last long but the next seems full strength. So If I know I’m going to be traveling I check them out ahead of time and cycle through the charging twice if needed.

Li-ion batteries generally have monitoring circuitry that draws a little current, so they do discharge even when in storage. It usually takes a couple of cycles to recalibrate that circuitry to make optimal use of the battery. Of course, that assumes that it doesn’t discharge all the way to cell reversal; if you do that then just get a new pack and try again. You generally want to store them with about a 40% charge to allow for that. Storing them with a full charge makes them degrade 2–5 times faster.

@jerv So it’s true, then, that you can’t let Li-ion batteries stay discharged for a long time. But are you also saying not to recharge them fully before storing them for a length of time? Wow, if you have many different batteries (because different devices require Li-ions of different sizes and shapes), it can get complicated keeping track of them all!

@2davidc8 It gets easier with experience. However, I personally don’t have any rechargeable batteries that are not in active use so its not an issue I face in my own life. My Li-Ion laptop and phone are recharged daily, my NiCad toothbrush is recharged when it goes dead (about every two weeks), and my car’s lead-acid battery takes care of itself. Nothing sits long enough to self-destruct.