Newsgroups: comp.robotics
Path: brunix!sgiblab!darwin.sura.net!howland.reston.ans.net!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!ames!koriel!sh.wide!wnoc-tyo-news!nkkgw!damned!hattori
From: hattori@csrd.nkk.co.jp (Mato Hattori)
Subject: Re: help...battery power
In-Reply-To: andrew.jenkins@pcohio.com's message of Mon, 21 Feb 94 09:32:00 -0500
Message-ID: <HATTORI.94Feb24114755@gaea.csrd.nkk.co.jp>
Sender: news@nkk.co.jp
Organization: NKK corp.,Tokyo,Japan
References: <24.4345.2500.0NB2D631@pcohio.com>
Date: Thu, 24 Feb 1994 02:47:55 GMT
Lines: 31

In article <24.4345.2500.0NB2D631@pcohio.com> andrew.jenkins@pcohio.com (Andrew Jenkins) writes:

    Lead-acid (and NiCad I think) cell-voltage is more charge dependant, though 
   they generally can handle much larger current draws, have significantly 
   larger charge capacities and are, of course recharge-able. I noticed that 
   alot of people in this conference are using a Gates X-Cell rated at 2.0V, 5 
   A-Hr. It might be a little bit heavy for your application though, so maybe 
   something more like a standard C or D-cell might be more appropriate.

Here's my idea of choosing lead-acid or NiCd batteries.
If you need batteries last long, you may choose lead-acid.
If you need batteries small and light weight, you should choose NiCd.

The book I have says that assuming batteries has capacity of C
(Amp-hours), Lead-acid batteries can provide maximum 2C Amps at a time
where NiCd's maximum 10C.  If, for example, your DC motor consumes 2
amps peek current, you need 1 amp-hour Lead-Acid battery for 30
minuites long, or 200 milli-amp-hour NiCd batteries for 6 minuites
long.

Additionally, recently spread NiMH (Nickel Metal Hydroid) is more
efficient than NiCd.  NiMH has double capacity (Amp-hours) with same
size and weight of NiCd.

Hope this helps.

--
Mato  Hattori                      Computer System Research Department,
email : hattori@csrd.nkk.co.jp     Electronics Research Center, NKK Corporation
voice : 81+44-322-6483 (office)    1-1 Minamiwatarida Kawasaki-ku
      : 81+44-246-9665 (home)      Kawasaki-city, 210 JAPAN
