> > Another is flashlights. Rechargeable Li-ion cells don't have the
> > LSD characteristics of "Eneloops" in my limited experience.

LiIon is normally known for very good charge retention.
As noted, it may be that protection circuitry impacts this.
I had a tray of about 50 small rectangular LiIon cells with no
protection circuitry that I stored for many years - perhaps 5.
I tested the O/C terminal voltage and was surprised to find them all
within about 10 mV of each other and well up in voltage.
LiIon have a VERY  approximately linear charge/voltage curve up to
about 60 - 70% of total capacity - at this point they hit the maximum
voltage limit (typically 4.3V for standard LiIon) and voltage and
charge state are less determinate. AFAIR my cells were well up towards
this knee point. I don't recall whether I tried a modest load or what
difference it would make.

FWIW best storage point for LiIon is just at the constant current /
constant voltage changeover knee.

LiIon are actually easier to charge properly than NimH and to know
where you are in the charging cycle.

Where energy density needs to be good but is not an utter concern then
LiFePO4 are THE battery of the future IMHO. Suitably managed they can
have far better cycle life than any other usual alternative and the
whole of life cost per cycle is less than for lead acid. You can get
AA LiFepPO4. but energy density  is worse than top NimH.  Energy
recovery efficiency is good to superb.



                   Russell
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