Battery maH Reference
For more information on determining the capacity of batteries see this site!
See this page for a javascript calculator which will calculate how long your battery will power your application
|
Size |
Rating (mAh) |
|
“D” |
14,250 |
|
“C” |
7,100 |
|
“A” |
2,450 |
|
“AA” |
1120 |
|
“AAA” |
550 |
|
CR2032 3V Coin |
215 |
|
“N” |
800 |
|
9 Volt |
565 |
Note: The actual rating varies from manufacturer to manufacturer, this chart is just to get you in the ballpark.
LINK: Lithium Battery complete reference
Charge Rates
Fast Charging: > 1/2 C
Normal Charging: 0.2 C -> 0.5 C
Trickle Charging: 0.05 C ->0.2 C
deep cycle - is when a battery is almost completely discharged before it’s recharged
shallow cycle - only a small proportion of the battery’s capacity is used before recharge.
http://www1.electusdistribution.com.au/images_uploaded/recharge.pdf
Useful Conversions:
1Ah -> 3600 Coulombs of charge
1 mAh -> 3.6 Coulombs of charge
Problem #1: How many coulombs of charge are in a AA battery?
Assuming your AA battery has 1120mAh as listed above.
1120mAh means that it can source 1120mA’s for one hour. Recall that 1mA = 0.001 coulomb / sec
So, (1120 mA*h) *( 0.001 coulombs/sec)*(60min/1hour)*(60sec/min) = 4032 coulombs
Problem #2 How big of a capacitor would you need to store 4032 coulombs?
1 farad capacitor can store one coulomb of charge at 1V.
4032 coulombs * ( 1 farad ) = 4032 Farads
