AA battery · Exterior view
  1. 1AA battery (alkaline LR6) · Ø 14.5 × 50.5 mm
  2. 2− terminal (flat end)
  3. 3+ terminal (raised end)
Cylindrical metal body, label, protruding plus end and flat minus end
≈ 14.5 mm diameter × 50.5 mm long
Power supply

AA battery

In simple terms
What is this?

A small portable bucket of energy; it comes full and runs out as it empties.

What is it for?

It powers a circuit without a wall socket; chain several of them one after another to raise the voltage.

Where do you see it?

TV remotes, wall clocks, toys and flashlights.

How do you spot it?

A cylinder; a raised plus at one end and a flat minus at the other; there is writing and markings on it.

Caution:

Place the plus and minus ends correctly; do not mix an old and a new battery.

Technical definition

A standard cylindrical cell, also known as a penlight battery. The alkaline type gives a nominal voltage of 1.5 V and is not rechargeable; the rechargeable NiMH equivalent is 1.2 V. Several AA batteries in a battery holder wired in series give 3 V, 4.5 V or 6 V.

Voltage1.5 V
Capacitance2000–3000 mAh
Size14.5 × 50.5 mm
Schematic symbol Same in IEC and ANSI
+

IEC 60617: the drawing style used in Türkiye and Europe.

Pins 2
1Plus (+)Protruding terminal+
2Minus (−)Flat end−
Features typical
Nominal voltage
1.5 V (alkaline) · 1.2 V (NiMH)
Fresh alkaline
≈1.6 V
Nearly done
≈0.9 V
Capacity (alkaline)
2000–3000 mAh (at low current)
Capacity (NiMH)
≈1900–2500 mAh
At high current
Usable capacity drops noticeably
Example part
LR6 (alkaline) · HR6 (NiMH)
Common mistakes
Charging an alkaline batteryAn alkaline battery cannot be recharged. A charger can make it heat up and leak.
Mixing old and new batteriesIn series-connected batteries a weak cell can be reverse-charged and leak. Use batteries of the same brand and freshness.
Leaving it in the deviceDead alkaline batteries eventually leak and corrode contacts. Remove them from devices you will not use for a long time.

Test with a multimeter

Test whether this part is good with the multimeter on the measurement screen.

Take a measurement
Where it is used
Remote controls and wall clocksPowering the breadboard with a battery holderToys and flashlights
Related lessons
What is electricity?
Module 1 · From zero to your first circuitMeasuring voltage
Module 2 · Measuring with a multimetersoonSeries and parallel
Module 1 · From zero to your first circuit
Try it in the Lab