DTR-1 Battery Tests

By Nick Dolezal

Note: no keyboard in any tests, only basic pen unit.
Comm port set to "serial", ethernet turned off.

A dumb QBasic second counting program was run.

Fullbright, HDD spun down, 25mHz, floppy disabled
3569 seconds (59 minutes)

Fullbright, HDD spun down, 8mHz, floppy disabled
4835 seconds (80 minutes or 1 hour 20 minutes)

Nobright, HDD spun down, 25mHz, floppy disabled
7700 seconds (128 minutes or 2 hours 8 minutes)

Nobright, HDD spun down, 8mHz, floppy disabled
~10431 seconds (~173 minutes or 2 hours 53 minutes)

A fully dimmed 8mHz DTR-1 lasts 292% longer on a charge
than a fully bright 25mHz DTR-1.

Note about the battery:

Nominal voltage: 7.2 volts -  9 volts
< 7.2 volts=<100% charged, whatever temp
7.2 volts=100% charged, room temp
9 volts=100% charged, hot
> 9 volts=<100% charged, very hot

Overcharging and getting the battery hot is a dumb thing
to do.  Repeated overcharging only hurts the battery.
Never trickle charge a NiMH (or NiCad) battery without
monitoring the voltage and temperature.  Normal NiCad
charges ignore this, and the batteries wear out quickly
and are unable to hold a charge because of this over-
charging.  (Not the urban myth "memory effect")

To charge the DTR-1 battery:

Don't fully discharge it.  This is a dumb thing to do.
I know the manual says so, but it was written by a guy
who can't spell or use correct, basic grammar.  Various
technical details aren't correct in the manual as well.

Discharging battery a few times won't hurt it too much.
Discharging ("priming", aka "conditioning") the battery
repeatedly hurts it and causes it to wear out.  You
prime a pump and condition hair, not a NiMH battery.
Batteries have a finite number of charge/discharge 
cycles.  Wasting them on priming is not a good thing.

Now, make sure you battery is cold (aka room temp).  If
it is a little warm don't be too worried, but if it is
hot don't charge it.  Overheated NiMH batteris emit
hydrogen gas which tends to explode under certain
circumstances with the electrodes.  It won't be a
Hindenburg, but it will sure ruin your battery and/or
Dauphin (most likely just the battery).  This may not
happen immediately, however; if you start getting about
ten minutes of battery life, try a new battery before
you give up on your Dauphin.

Now charge it and make sure the green LED is blinking.
When it stops, for heaven's sake, don't plug it back in.
It is as charged as it is going to get.  Check this with
a voltmeter.  No reason to overcharge it.  It should be
pretty hot by now, and as you know you shouldn't charge
a hot battery.

Well then, I hope this expandes your knowledge of the
DTR-1's battery.  Typical users get < 50 minutes and
sure not the advertised 2.5 - 3 hours!

Try upping the spin-down time to 30 seconds and setting
the LCD timeout at 10 seconds (system timeout at 127).
This will increase your battery life further.

Another bone I have to pick is the suspend mode.  It
isn't very good.  In fact, at times I think it sucks as
I have to shut off the Dauphin to be away from it for
any amount of time.

I think for maximum battery life, you should probably
think about running GEOS with the pen.  GEOS is very
fast, so you can get away with 8mHz (remember to re-
enable the cache).  Dim the screen and invert the colors.
(Use "LCD HELP" at the prompt if you don't know how to
do either).  Now when you want to suspend, just hit the
"=E" icon and tap "exit to DOS", then "Yes".  When you
restart GEOS, all your work and even your solitaire game
should be right where you left it.  Eliminate unecessary
drivers in your boot files and just jump directly to
GEOS.  A 2MB disk cache on a 6MB machine should be fine.
Make sure it doesn't swap out; look at the GEOS.INI
file and get rid of DISK.GEO (if found) and any swapfile
stuff.  Make sure you have EMM386 / HIMEM loaded (if you
use EMM386, make sure to have the exclusions in the
second edition manual).  Try turning off the memory test
in HIMEM and turn the BIOS's "quick boot" on for faster
booting.  Perhaps you could even leave turbo on until
it's booted then switch to slow?  You might also want
to download GEOCON 2.0, which allows you to get a pop-up
keyboard easily.  If you mouse is off, recalibrate and
nix the graphics stretching.  Don't load the zip drive
stuff if you don't have it connected.  Look at the MENU
command in help.com and set it up so a timeout of one
loads GEOS with a minimum set of drivers.  Do you really
need that VESA driver/VSAFE, etc?  Make sure KVTMOUSE,
SMARTDRV, HIMEM and EMM386 are loaded, though.  You can
even create a launcher for Windows 3.1 in GEOS so you
can run both.  If you get PalmConnect and Graffiti, you
can jury-rig Graffiti for GEOS.

Whew!  Well, have fun.

-Nick Dolezal / sdolezal@montana.com

© 1996 By Toby Reed / toby@eskimo.com