AA battery (1.5 V alkaline) · Ø 14.5 × 50.5 mmBattery holder (ABS)Red (+) / black (−) wire

Black plastic holder, AA batteries side by side, red and black wire
Varies with the number and type of batteries · Example shown: single-AA holder

Power supply

Battery holder

In simple terms

What is this?

A plastic holder that keeps batteries side by side; it connects them all one after another like a chain.

What is it for?

Adds up the voltage of several batteries and carries it to the circuit with wires.

Where do you see it?

The battery compartment of remote controls and flashlights.

How do you spot it?

A plastic box; one red wire and one black wire come out, and red is the positive one.

Caution:

Connect red to plus and black to minus; put the batteries in following the markings on the holder.

Technical definition

A plastic holder that holds the batteries and makes the series connection between them. The red wire is the positive terminal, the black wire the negative. Types with a switch and a cover exist; for a 9 V battery, a snap clip does the same job.

2 × AA3 V

4 × AA6 V

WireRed + · black −

Schematic symbol Same in IEC and ANSI

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

Pins 2

1Red wire (+)Plus end of the first battery in the chain+

2Black wire (−)Minus end of the last battery in the chain−

Features typical

2 × AA: 3 V (alkaline) · 2.4 V (NiMH)
3 × AA: 4.5 V (alkaline) · 3.6 V (NiMH)
4 × AA: 6 V (alkaline) · 4.8 V (NiMH)
Capacitance: As much as a single battery (series connection)
Contacts: Spring to the battery's minus end, flat contact to the plus end
Example part: 4 × AA holder (6 V, alkaline)

Common mistakes

Inserting the battery backwardsFollow the mark in the holder: the spring meets the battery's flat (minus) end. A single reversed battery drops the total voltage by as much as two batteries.

Thinking series connection increases capacityConnecting in series raises the voltage, not the mAh. A pack of 4 AAs has the capacity of a single AA.

Connecting 4 alkaline AA cells to a 5 V circuitFresh 4 alkaline AA cells give about 6.4 V; that is too much for 5 V ICs. Use 3 AA or 4 NiMH.

Test with a multimeter

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

Take a measurement

Where it is used

Breadboard powerRobot and motor projectsPortable sensor

Try it in the Lab