I suspected you may say that, I am using a Panasonic 600mAh three cell
     NiMH battery and this product will for all intents and purposes will
     never sleep, and so continuously draws 60mA from the battery. This
     includes the times when the battery pack is being charged!

     The voltage drop at this rate, say measured every 20 or 30 seconds is
     not large for my 8bit ADC to measure until the unit has about 1 minute
     of battery life left ... unfortunately my marketing guys would like
     something like 10, 5 and 1 minute warnings, typical eh? Anyway, they
     get what they are given.

     BTW: Thanks to the PICLIST I seem to have my battery charger problem
     solved, due to the fact the product is still working while being
     charged using the rate of change of voltage reaching a minimum did nto
     prove succesful, instead using the thermistor inside the battery pack
     proved far more useful, this was helped by the fact the battery is in
     a closed environment when being charged and so the heat it produces
     does not conduct away from the  battery and it warms up nicely.

     regards,
     SW.


______________________________ Reply Separator _________________________________
Subject: Re: Re[2]: Batteries
Author:  pic microcontroller discussion list <PICLIST@MITVMA.MIT.EDU> at
INTERNET
Date:    28/11/97 11:00


I would think so - you are not shorting it out, but getting a reasonable
current (few mA, normally) so you are loading the battery

> ----------
> From:         Scott Walsh[SMTP:Scott.WALSH@PLANTRONICS.COM]
> Reply To:     pic microcontroller discussion list
> Sent:         Thursday, November 27, 1997 8:37 AM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re[2]: Batteries
>
>      About putting a known load on the battery ... can you do this
> while
>      the product that is running from the battery is still working?
>
>      regards,
>      SW.
>
>
______________________________ Reply Separator _________________________________
> Subject: Re: Batteries
> Author:  tjaart@wasp.co.za at INTERNET
> Date:    26/11/97 06:45
>
>
> Andrew Mayo wrote:
> >
> > In order to reliably determine battery life, you really need to be
> able
> > to briefly switch a load across the battery which draws a
> predetermined
> > current and then measure the battery voltage. Battery manufacturers
> can
> > supply voltage/time curves for a given load, if you ask.
>
> This is exactly what we do to determine a 6 cell NiCd pack's state. I
> discharge it over a 47E resistor for 10s and measure the voltage under
> load.
>
> A few people have asked about good batteries to use lately. A very
> nice
> battery (but a bit expensive) is the Hawker (previously Gates) Cyclon
> 2V lead acid cells. They combine all the nice features of lead acids
> and NiCds.
>
> --
> Friendly Regards
>
> Tjaart van der Walt
> mailto:tjaart@wasp.co.za
>  _____________________________________________________________
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