Questions on Zenith-183 batteries and power supply

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2 total messages Started by David Apfelbaum Fri, 22 Mar 1991 18:28

#558

Author: David Apfelbaum
Date: Fri, 22 Mar 1991 18:28

56 lines
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	My Zenith-183 (8088, 10M harddrive) is suffering from a dead battery. 
Because of the way the power system is designed, the computer is
unusable.  (The circuitry that detects a low-power situation and
inactivates the computer is wired solely to the battery.)

	I have talked with the people at Heath/Zenith and they want $175 for a
replacement battery-pack.  They also recommended I get the
power-supply-circuit "re-tuned" so that it is producing the proper
voltage levels, which would cost an additional $65.

	Now knowing what I do about modern power-supply design and the price of
hi-capacity nicads, I feel that I am being "Taken".  The battery pack
should cost less than half the price that they are asking.  And can the
power supply circuit even be "Tuned"???

	But there is another problem.  The computer charges the battery-pack
whenever it is plugged in -- Not just when the power is off!  As a
result, the battery pack gets seriously trashed!  According to one
Zenith person that I talked to, I am supposed to run the computer off
the batteries until they die, and then continue by running off the power
supply.  This is inconvenient when I am running long number-crunching
programs.  And while this will make the batteries last longer than they
currently do, they will still be wearing out faster than they should be
as nicads only have a limited number of charge/discharge cycles.  (It is
also not mentioned in my owners manual -- How convenient for them! :-(

	I did talk to the people at Heath/Zenith about hooking up my own
battery -- or just disconnecting the charging circuit.  They assured me
that if I were to try such a thing, I would surely burn out my computer.
 Now this is something that I wish to avoid.  However, it strikes me
that if such a thing was possible, Heath/Zenith would be the first to
deny it -- Based on the profit motive.  And it can't really be all that
difficult!

	So my questions to the net are: (1) Is it possible/feasible to hook up
my own battery?  And if so, how?  And (2) Is it possible to disconnect
the charging circuit without damaging the computer?  Or just limit it to
charging when the computer is turned off?  I have no problems with
building my own external charger, if it's necessary.

	Does anyone have any ideas?  It really irks me to just be "Taken"!

		Thanks,
			-David Apfelbaum.


===========================================================================
David Apfelbaum              Student (mostly Math/CS) at Carnegie Mellon.
5266 Beeler St.              INTERNET, BITNET, etc: da0g+@andrew.cmu.edu
Pittsburgh PA 15217                      Alternate: da0g%andrew@CMCCVB
(412) 683-7216               UUCP:   ...!harvard!andrew.cmu.edu!da0g
===========================================================================
#include <std_disclaimers>   /* CMU is not responsible for my babblings. */
#include <std_quote(s)>      /* Beware of Hackers carrying screwdrivers. */
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Re: Questions on Zenith-183 batteries and power supply

#563

Author: Ron McCarty
Date: Tue, 26 Mar 1991 18:40

33 lines
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In article <EbuYnNG00VovAiVVVG@andrew.cmu.edu>, da0g+@andrew.cmu.edu (David
Apfelbaum) says:
>
>        My Zenith-183 (8088, 10M harddrive) is suffering from a dead battery.
>Because of the way the power system is designed, the computer is
>unusable.  (The circuitry that detects a low-power situation and
>inactivates the computer is wired solely to the battery.)
>

I don't understand. My 183-92s batteries have been dead for almost a
year now but it hasn't prevented me from using the machine. I simply
 removed the battery pack and use it exclusively on ac with the
powerpack. I have had no problems doing this.

>
>        But there is another problem.  The computer charges the battery-pack
>whenever it is plugged in -- Not just when the power is off!  As a
>result, the battery pack gets seriously trashed!  According to one

This is why i didn't bother to buy new batteries. Given the deficient
design of the machine (the fact that the batteries are always charging)
I could see that the new batteries were just going to get trashed the
way the originals did. And you are right, using it off batteries until
they die is not the way i want to use my machine. I usually have access
to ac and prefer to have the machine plugged in. The batteries (when I ha
had them) were a nice backup when the power went off or for those rare
occasions when i didn't have access to ac. Ironically, it is the fact
that i always used ac rather than the batteries that destroyed the
batteries.


Ron McCarty
Penn State Erie

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