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

["John A. Rupkalvis" <stereoscope@xxxxxxxxxxxxx>]

----- Original Message -----
From: "Linda Nygren" <lnygren@xxxxxxx>
To: <photo-3d@xxxxxxxxxxxxxxx>
Sent: Wednesday, February 07, 2001 12:40 PM
Subject: Re: [photo-3d] Ni-MH for Viewers


>
>
> Brian Reynolds wrote:
> >
> > NiMH batteries are supposed to lose about 1-2% of their charge per day
> > just sitting on the shelf.  If you keep a set in a trickle charger
> > before use you should be OK.
>
> That is about the same as Nicads, I guess. Too bad they can't be left in
> a viewer and maintain charge. Mostly a convenience issue.
>
> Thanks for the general battery info. Could you explain in what way NiMHs
> are "better" than NiCads and/or alkalines? -Linda
>

A couple of notes.  Portable equipment that use rechargeable batteries,
especially heavy-duty professional equipment, often either have a small
charger built in, or (especially for small, hand-held items) have a jack
into which a charger can be plugged.  Thus, the batteries can be recharged
without removing them from the equipment.  Wiring these up with some cheap
Radio Shack plugs, jacks, and wire is usually quite simple, except that the
charger chosen must be capable of recharging the complete battery
complement, not just individual cells.  I have wired up several items this
way, and although I have not done a viewer, I don't see why it would not
work as well.

Also, regarding cell life, many people do not carefully check and clean the
contacts on both the batteries and the battery compartment.  Any corrosion,
or even a thin film of grease (fingerprints on a new battery can be suspect)
will increase the resistance at the connection, causing a heating of the
battery, and lessened efficiency (shorter operating time, less recharge
cycles).

I use alcohol soaked medical pads (available at most pharmacies) to clean
the contacts in both the equipment and on the batteries before installing
them (as well as the contacts in the charger).  Seems to help.

JR