Li-ion, I'm in the dark about. If I charge my camera and and store it for only a couple of weeks, it needs a fair amount of time (?) to peak charge
There are
no memory effects with Li-ion batteries.
"Memory" occurs with NiCad and NiMH because the electrodes crystallize, reducing the surface area exposed to the electrolyte... This reduces or even eliminates the battery's ability to deliver and/or accept a charge. When one of these batteries are discharged and recharged, the crystals begin to dissolve which increases the battery's performance again.
some types, (Ni-Mh) claim "no memory", and some (Ni-cad again) can be ruined by a total discharge
It's true that NiCad is far more sensitive and that NiMH. I don't think NiMH is immune to what people commonly refer to as 'memory', but it is very resistant at the least.
Generally speaking, one reason NiCad is prone to memory effects is it suffers from crystallization on
both electrodes: NiMH only has this problem with its cathode. The alloy used for the anode in NiMH batteries will vary from manufacturer to manufacturer... I don't know this, but I might conjecture that NiMH batteries the claim 'no memory effect' probably have an anode material that resists crystallization. The NiMH cathod is pretty much the same thing used in NiCad batteries and suffers the same problem.
If I charge my camera and and store it for only a couple of weeks, it needs a fair amount of time (?) to peak charge
There are many Li-ion chemistries. I understand that some are superior to others in terms of holding a charge, but for the most part, Li-ion batteries do much better than NiMH in terms of self-discharging. The type of Li-ion batteries used for cameras may self-discharge more rapidly than those used for laptops, for example.
Typical lithium ion or NiMH (nickel metal hydride) batteries last longest (that is, accept the greatest number of full charges before displaying diminished charge retention)
I usually see cycle life for Li-ion batteries used in computers around 500 cycles. NiMH, is about 1200 and NiCad is over 2000 (as long as your battery doesn't completely crystallize!
)