[sci.electronics] Alkaline-cell capacities

commgrp@silver.bacs.indiana.edu (12/23/88)

A British friend sent information from the catalog of STC Electronic 
Services (a U.K. electronic-components supplier), listing capacities 
of Mallory Duracells (tm). This information seems difficult to obtain 
in the U.S.

Larry Lippman wrote in an article on rec.ham-radio (25 June 1988):

>...Leclanche cells (carbon-zinc) do not have "simple" ampere-hour 
>ratings; the effective ampere-hour rating depends upon the load 
>current, whether the load current is steady or intermittent, and the 
>actual time periods involved.  In addition, one must also define an 
>"end voltage" - which is MUCH more variable with Leclanche cells than 
>with any other type of cell...
                                                      
Methods for testing, including those endorsed by the U.S. National 
Bureau of Standards, are described in _Eveready Battery Applications 
Engineering Data_ published by Union Carbide Corporation.

Several sources say that alkaline D-cell capacity is 9-10 Amp-hours.  
Manufacturers have recently claimed a process improvement giving 30% 
more life. Test parameters for the data in the table below are not 
known. The relative capacities which I have calculated and listed in 
the last column should be valid within any type and manufacturer, 
considering load/time variations as discussed above.

                                         Capacity
Mallory                       Capacity   relative
part no.    Size     Volts     (mA-hr)   to D-cell
----------+-------+---------+-----------+---------
                                     
MN1300       D       1.5        15000       1.00
MN1400       C       1.5         7000       0.47    
MN1500       AA      1.5         2250       0.15
MN2400       AAA     1.5          800       0.05
MN9100       N       1.5          650       0.04
MN1203 (1)           4.5         4400       0.30
MN1604               9.0          500       0.03

Lantern batteries:

PC908 (2)    F       6          20000       1.33
PC915        F       6          20000
PC918 (3)            6          40000       2.67
PC926               12          20000


Notes:
-----

(1)  MN1203 is the 3-cell battery used in Petzl (tm) headlamps from 
     France (many of which were seen on helmets of rescue workers in 
     TV news coverage of the recent earthquake in Armenia). The cells 
     are larger than AA, smaller than C; they are not commonly 
     available in the U.S.  An adapter for the Petzl lamp holds three 
     AA-cells which, as shown above, have only about half as much 
     capacity.

(2)  PC908 has spring terminals, PC915 has screw terminals.

(3)  PC918 and PC926 are double-width lantern batteries containing 
     eight F-cells in parallel pairs, and in series, respectively.

--

Frank Reid     W9MKV
reid@gold.bacs.indiana.edu

dhesi@bsu-cs.UUCP (Rahul Dhesi) (12/23/88)

In article <7200023@silver> commgrp@silver.bacs.indiana.edu writes:
>>...Leclanche cells ...

Just thought I would point out the the original LeClanche' cell was but
a primitive ancestor of today's zinc-carbon batteries.  I had the honor
of using a "real" LeClanche' cell a long time ago and it was worthless
because of its high internal resistance.  It's fine if all you want is
a trickle at 1.5 volts, but don't expect any real current from it.

Unlike the LeClanche' cell, the modern zic-carbon battery does not have
a cloth wrapping around the central electrode.  It's just a series of
layers of various chemicals in paste form.  The paste form prevents
mixing.  Cut one open and see.
-- 
Rahul Dhesi         UUCP:  <backbones>!{iuvax,pur-ee}!bsu-cs!dhesi

dhesi@bsu-cs.UUCP (Rahul Dhesi) (12/23/88)

In article <5283@bsu-cs.UUCP> I wrote:
    ...the LeClanche' cell, the modern zic-carbon battery does not have
    a cloth wrapping around the central electrode.

It doesn't have Plaster of Paris around the central electrode either.
-- 
Rahul Dhesi         UUCP:  <backbones>!{iuvax,pur-ee}!bsu-cs!dhesi