I am trying to figure out the maximum current I can pull from different battery types. Cursory research suggests this isn't a commonly reported values, maybe it is close enough to the capacity such that approaching it leaves battery life too short to care about it.
Some observations
- LR41 batteries shorting across a multimeter provide about 220 mA of current
- A single cell, protected, lithium ion battery provides 1.4 A of current
Questions
- Is there a way to predict the maximum discharge rate of alkaline batteries?
- Maximum discharge rate appears to vary with voltage/use – is there a relationship plotted for this phenomenon?
Specific details
Slightly used LR41 batteries in series have a higher voltage (3.3V) than my slightly discharged lithium cell (3.0V). Yet, an LED attached to the LR41 batteries is dimmer than the lithium cell. Current seems limited through one out of the three-series-LR41 batteries, though voltage appears to remain appropriately high. Curious about this relationship between remaining charge, maximum current, and voltage.
Best Answer
The maximum discharge rate is basically limited by the internal serial resistance of the battery and the heat generated through it.
It will vary depending the chemistry, packaging and so forth.
Usually these values will be given by the manufacturer.
However, you need to be careful not to draw more amps than the manufacturer specification if you don't want to get some nice fire.
Usually the discharge rate is given in x/C in which C is the capacity in mAh.
For example a 2200mAh battery with a discharge capacity of 2C means you can draw 4400mA, 0.5C would be 1100mA.
This is also given for the charging rate.