Re: [photo-3d] Re: Ni-MH for Viewers

[Linda Nygren <lnygren@xxxxxxx>]

Mark Shields wrote:
> 
> I've not had good results with Renewals except for short-term
> standby applications. They don't self-discharge, which is good.
> But they have only about half the capacity of ordinary,
> non-rechargeable alkalines. Also, while you can get 25-50 charges
> if they are discharged lightly (about 10% of rated capacity),
> if you discharge them deeply their capacity drops off very rapidly.

This would make sense in that Renewal Ds have worked well for me in Red
Buttons, where I will recharge them as soon as they get a little low
(i.e. the light starts to dim at all) or more often just "top them off"
before an anticipated long session of viewing, rather than deep
discharging them.  When I use AA's in a small tape recorder, I replace
them when there is an obvious problem with the tape speed, and they are
moderately if not deeply discharged at this point. Even here, I still
think I get close to 50 charges from a set (although I have not kept
records), but it is indeed noticable that the length of use I get from a
set of batteries tends to drop off with later cycles. The "half the
capacity" statement above might apply in a later recharge cycle, but I
do not think it is true in early cycles.

There was a review in Popular Photography on these a few years ago, and
I believe that they concluded that on initial use these have just as
long life as any alkaline, and with subsequent cycles the capacity will
*gradually* decrease. 

BTW, I would generally not use Renewals in applications like in
thermostats just because the length of time it actually takes to
discharge the battery is so long that using a rechargable would not be
particularly cost effective. I do use "fresh ones" in applications like
in a flashlight on a canoe trip where I want the longer useful battery
life (same as a regular alkaline), even if I have to wait until I get
home to recharge them. I would be packing them out, regardless. -Linda