You might want to start here first:

http://www.vencon.com/articles/nicd2.html
http://www.qsl.net/eb4eqa/batt_charger/batt_charger.htm
http://www.greenbatteries.com/documents/Battery_Charger_FAQ.htm
http://www.digibattery.co.uk/ni-mh_store1.html
(you'll have to append the following links because they will carry over to the
next line)
http://www.panasonic.com/industrial/battery/oem/images/pdf/Panasonic_NiMH_ChargeMethods.pdf

http://data.energizer.com/batteryinfo/application_manuals/nimh_application_manual.htm

Current regulated trickle will work but occasionally they should be charge
cycled with a good NiMH smart charger.

Rick

Benjamin Bromilow wrote:

> Hi all,
>
> I'm needing some battery backup in my next project. I'm planning on using a
> 3v NiMH cell. I'm hoping on a simple trickle charge system. Do I need
> anything more complicated than a current limiting resistor? If not, what
> resistance do we assume the battery will have under charge?
> Forgive me if I'm looking at this incorrectly.... The Yausu battery web site
> suggests this is possible but doesn't give examples to explain the value of
> R required.
>
> Ben
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.