Re: Best Strategy for Occasional Battery Use?

ASAAR wrote:
On Tue, 17 Jul 2007 02:30:16 -0500, Ron Hunter wrote:

Again, nonsense. Full discharge is not needed, or even desirable. And your contention about discharge cycles is unsupported by facts. I VERY rarely fully discharge my NiMH batteries, either by self-discharge, or by use, and they last for several years. This idea of monthly charging is just a way to uselessly expend recharge cycles.
It's also a way for the SMS FUDmeister to spread more FUD. :)


"http://www.buchmann.ca/Chap10-page3.asp"; has some good information on care and feeding of NiMH batteries. What I found interesting, and what's been echoed by other posters on rec.photo.digital, is that the actual number of cycles you usually get from NiMH batteries is often much less than the often quoted 300-500 cycles. Buchmann states that the Army (U.S.) was getting only 100 cycles from NiMH batteries in the 1990's, and Paul Rubin who often posted in rec.photo.digital (and was a fan of NiMH batteries) said: "I've never seen a NiMH battery last anywhere near the vendor's claims of 300-500 charge cycles. 150 or so is the best I've seen despite a fairly careful charge/discharge regimen."
I have never used one that many times, so I really can't say for certain. And your description of 'careful' doesn't match mine at all. Maybe that is why you don't seem to get good performance from them.

Speaking of FUD, SMS has been very careful to avoid mentioning the
number of charge cycles *most* people get from their batteries over
their usable lives, both NiMH and Li-Ion. Unless batteries are in
heavy use, probably needing to be charged daily, they'll never
approach the manufacturer's claimed number of charge cycles. From
how you've described your camera usage in the past I'd think that
you might not need to charge Eneloop batteries even as often as six
times per year. If the batteries remain useful for six years, that
would still only represent 36 times the batteries would have been
recharged, far less than Sanyo's 1,000 cycle claim. This doesn't
mean that Sanyo's number is suspect. Just that you have to know how
the batteries will be used to evaluate how many charge cycles to
expect. If Paul Rubin never got more than 150 charge cycles from
his NiMH AA batteries, that's only what a reasonable person would
expect. But for SMS to use this as the basis for his claim that
NiMH has many fewer charge cycles than Li-Ion batteries is deceptive
at best and probably a lie. In fact, Li-Ion batteries probably are
rated for fewer lifetime charge cycles than NiMH batteries.

Different uses of the equipment almost certainly changes the number of charge cycles, and the total life of any battery. My wife charges her cell phone almost daily, never letting it get more than 1/3 discharged, according to the battery charge display. I, on the other hand, use my cell phone much less, and charge it about once a week, usually when if is only at a 1/3 charge, or when it beeps for recharging. It doesn't take an engineer to figure that my battery is probably going to last longer, but for fewer recharge cycles before the cell phone is replaced.
.

Relevant Pages

  • Re: Dpreview selector: AA batteries?
    ... NiMH don't reach their theoretical life end until five years and the latter ... a reduced number of charge cycles in NiMH batteries? ...
    (rec.photo.digital)
  • Re: Camera zaps NiMH batteries
    ... cycles for NiMH batteries, and many claim 1,000. ... for 1,000 charge cycles and RayOVac says that one of their Hybrid ...
    (rec.photo.digital)
  • Re: Camera zaps NiMH batteries
    ... NiMH batteries have a very limited number of charge cycles before ... If they stop holding a charge, ...
    (rec.photo.digital)
  • Re: Dpreview selector: AA batteries?
    ... But NiMH batteries don't last forever either. ... a reduced number of charge cycles in NiMH batteries? ... even if the LiIon battery holds up to that kind of use ...
    (rec.photo.digital)
  • Re: Best Strategy for Occasional Battery Use?
    ... couple hundred or more flashes per session, regular batteries NiMH ... batteries is that for maximum life, NiMH batteries should be cycled ... yet the number of cycles of NiMH batteries is fairly low ... the vendor's claims of 300-500 charge cycles. ...
    (rec.photo.digital)