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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.

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    \$\begingroup\$ check manufacturer's data sheets \$\endgroup\$ – jsotola Sep 7 '18 at 1:23
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    \$\begingroup\$ This data could be buried deep inside datasheets or supplemental application data, so please research those first before asking us to do it for you. \$\endgroup\$ – Sparky256 Sep 7 '18 at 1:45
  • \$\begingroup\$ Remaining charge and chemistry determine voltage and batteries have resistance of their own and voltage drop over that resistance will affect output voltage as well. \$\endgroup\$ – K H Sep 7 '18 at 2:12
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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.

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  • \$\begingroup\$ "Coin cells." Relatively low risk of fire, even when excessively exceeding the maximum discharge current. 😉 \$\endgroup\$ – JRE Sep 7 '18 at 11:06
  • \$\begingroup\$ This is NOT true: "The maximum discharge rate is basically limited by the internal serial resistance of the battery" ---- It's Internal Resistance, no serial. It's the chemistry and capacity that limits the max current. Most batteries have very little internal resistance. Your answer would be much better if you removed the first sentence. ---- "There is a notion that internal resistance is related to capacity, but this is false" -Source: batteryuniversity.com/learn/article/… --- See also other section on internal resistance: BU-802a \$\endgroup\$ – Misunderstood Sep 8 '18 at 17:37
  • \$\begingroup\$ You can draw up to 50 Amp pluses and 20-30 Amp continuous discharge from an 18650 Lithium Manganese Oxide (LMO) Li-ion battery. See: batteryuniversity.com/learn/article/types_of_lithium_ion \$\endgroup\$ – Misunderstood Sep 8 '18 at 18:40
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LR41 batteries shorting across a multimeter provide about 220 mA of current

I thought this was peculiar because an L41 alkaline has a capacity of about 25 mAH. Alkaline batteries have a low discharge rate. This is a 10C discharge rate. Way too much for an alkaline. Higher discharge rate lowers battery capacity significantly.


A single cell, protected, lithium ion battery provides 1.4 A of current

1.4 A discharge rate for Li-ion is not excessive. It is about a 0.5C discharge for a typical 18650 Li-ion cell.

There are different types of LI-ion with different discharge rates.

LCO Li-ion should not be discharged at a rate greater than it capacity.

NMC Li-ion for power tools can discharge at 20 Amp.

LMO Li-ion can be discharge up to 50 Amp.

For more on types of Li-ion see: Battery University


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?

The three alkaline datasheets for an AA, AAA, and button cell show the peculiarities of alkaline.

Notice AA and AAA capacity at 25 mA discharge rate have about the same capacity. These two batteries use the industry standard discharge tests.

The button cell miniature alkaline has a max discharge of 80% of its 175 mAH capacity. And typical discharge is 190 µA.


AA Alkaline Datasheet

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AAA Alkaline Datasheet

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Miniature Alkaline

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