From: Thomas T. Veldhouse on
SMS <scharf.steven(a)geemail.com> wrote:
>
> It's interesting to see what GP claims about polarity reversal at
> "http://www.nimhbattery.com/gp70aaahc-u4.htm" where it states:
>
> "Polarity Reversal Protection - Built In chemical protection against
> polarity reversal or over discharge."
>
> Are they just blowing smoke, or do they really have some sort of
> protection that other NiMH batteries lack?
>

Or perhaps they all now have it. I don't have a clue, but I never worry about
it in all honesty. I do pair my batteries when possible so that all the cells
expire at nearly the same time, but more so for the reason of maximizing
capacity and battery life than for avoiding polarity reversal.

> In any case, while you're correct that it's not an inherent trait of the
> device type, it is true that with devices like flashlights you want to
> be a bit more careful to not accidentally leave the device on and drain
> the batteries completely to 0%. ASAAR overstated the issue of course,
> but there was at least a grain of truth in what he said.
>

And then only in flashlights that have more than two cells. I think one cell
would have a very tough time driving a polarity reversal on only one paired
cell. I could be wrong.

> With ni-cads you could zap away internal shorts and also reverse
> polarity reversal. This is not the case with NiMH.

Not particularily relavent here ;-)

--
Thomas T. Veldhouse

We have more to fear from the bungling of the incompetent than from the
machinations of the wicked.

From: Thomas T. Veldhouse on
Allen <allen(a)nothere.net> wrote:
>> Don't have doubts. We have a mid-priced elipitical trainer that uses D
>> batteries for several mechanical and control functions and the adapters work
>> great in it with the 2100mAh Rayovac Hybrids in them. I use a C adapter in a
>> a large clock and have no trouble so far. We also have a few cheap
>> flashlights I have considered putting D adapters into, but haven't desired to
>> put batteries in a flashlight that cost more than the flashlight itself ;-)
>>
> Thanks. I may have to break down and try them.
> Allen

I bought these and have had good luck with them.

http://www.starbatteries.com/baad.html

They aren't too *baad* ... pun intended.

--
Thomas T. Veldhouse

We have more to fear from the bungling of the incompetent than from the
machinations of the wicked.

From: SMS on
Thomas T. Veldhouse wrote:

> And then only in flashlights that have more than two cells. I think one cell
> would have a very tough time driving a polarity reversal on only one paired
> cell. I could be wrong.

In my experience with polarity reversed cells it was always the center
cell of a three cell pack that went bad. I think you're correct
regarding a two cell device.
From: Thomas T. Veldhouse on
SMS <scharf.steven(a)geemail.com> wrote:
> Thomas T. Veldhouse wrote:
>
>> And then only in flashlights that have more than two cells. I think one cell
>> would have a very tough time driving a polarity reversal on only one paired
>> cell. I could be wrong.
>
> In my experience with polarity reversed cells it was always the center
> cell of a three cell pack that went bad. I think you're correct
> regarding a two cell device.

It could be any cell in a three+ cell series. Whichever completely discharges
first becomes the victim.

--
Thomas T. Veldhouse

We have more to fear from the bungling of the incompetent than from the
machinations of the wicked.

From: John Turco on
SMS wrote:
>
> John Turco wrote:
> > SMS wrote:
> >
> > <heavily edited, for brevity>
> >
> >> Why do you think that so few D-SLRs use AA batteries--only a few low-end
> >> models, and none from the top tier manufacturers.
> >
> > <edited>
> >
> > Hello, Steven:
> >
> > Pentax isn't among the "top tier manufacturers," in your opinion?
>
> Canon and Nikon are the top tier. Olympus, Pentax, and Sony (formerly
> the Konica-Minolta D-SLRs) are second tier.


Hello, Steven:

Well, Canon, itself, wasn't always "top tier," either. No matter,
as Pentax's equipment can match the "Big Two" in quality, if not
in breadth.


Cordially,
John Turco <jtur(a)concentric.net>