Battery life for low power draw devices

[paulsiu]

For application with low power draw of less than 100ma, are there difference in battery life between an alkaline battery and a lithium disposable like Energizer Ultimate? Based on various post here, Lithium would be more noticable on high current draw items like camera flashes.

 

[vicv]

True but they do still have more capacity. Now whether that's worth it to you for the extra cost is another matter.
Plus no leaking

 

[LEDphile]

Energizer provides discharge curves for both their alkaline and lithium batteries at https://data.energizer.com/

An L91 (Lithium AA) is good for ~3500mAh at discharge rates under 100mA, with a reasonably consistent output voltage over lifetime. The E91 (Alkaline AA) is good for perhaps 2700mAh at low discharge rates when discharged down to 0.8V. As the voltage over life is less consistent than with the L91, you may see lower capacities if the low voltage cutoff of your device is higher than 0.8V/cell.

 

[xxo]

At .1 A the L91 has about 4.5 Wh vs about 3 Wh for a typical alkaline AA. At 2 Amps, the alkaline AA's will drop to around 0.7 Wh, while a L91 will only drop to 3.2 Wh.

 

[paulsiu]

Hi, the charts aren't exactly the same so it's hard for noob to read, but you are saying that the Lithium will last longer?

 

[vicv]

Being that they have 50% more energy at low draw, yes

 

[ikanode]

Given the longer life and no leakage, I’ve switched 100% to Energizer AA & AAA lithium. I watch for them on sale then buy a bunch. The lighter weight is great in some applications.