Current Measurements from a D Cell

These measurements are from an alkaline D cell discharged through a resistance of approximately 10 Ohm.

In summary, under these conditions of use, this D cell was capable of delivering about 16 Watt-hours.

The raw data are:

date	time	current
7/27	12:30pm	160mA
7/27	1:00pm	158mA
7/27	2:30pm	152mA
7/27	3:00pm	150mA
7/27	5:00pm	148mA
7/27	5:30pm	145mA
7/27	6:00pm	145mA
7/27	9:15pm	142mA
7/28	9:15am	136mA
7/28	10:20am	135mA
7/28	5:00pm	133mA
7/30	12:57pm	123mA
7/30	6:53pm	120mA
7/31	11:30am	113mA
8/01	2:00pm	90mA
8/02	3:00pm	17mA

Energy Estimate for this D Cell

from	time	to	time	seconds	current	power (I²R)	energy (J)	cumulative (J)
7/27	12:30pm	7/27	1:00pm	1800	159mA	.25281W	455	455
7/27	1:00pm	7/27	2:30pm	3600	155mA	.24025W	865	1320
7/27	2:30pm	7/27	3:00pm	1800	151mA	.22801W	410	1730
7/27	3:00pm	7/27	5:00pm	7200	149mA	.22201W	1598	3328
7/27	5:00pm	7/27	5:30pm	1800	146mA	.21316W	384	3712
7/27	5:30pm	7/27	6:00pm	1800	145mA	.21025W	378	4090
7/27	6:00pm	7/27	9:15pm	11700	143mA	.20449W	2393	6483
7/27	9:15pm	7/28	9:15am	43200	139mA	.19321W	8347	14830
7/28	9:15am	7/28	10:20am	3900	135mA	.18225W	711	15540
7/28	10:20am	7/28	5:00pm	24000	134mA	.17956W	4309	19849
7/28	5:00pm	7/30	12:57pm	158220	128mA	.16384W	25923	45772
7/30	12:57pm	7/30	6:53pm	21360	122mA	.14884W	3179	48951
7/30	6:53pm	7/31	11:30am	30420	116mA	.13456W	4093	53044
7/31	11:30am	8/01	2:00pm	52200	102mA	.10302W	5378	58422

Dividing 58422 by 3600 (seconds in an hour) gives a little over 16 Watt-hours as the total energy of the battery.