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Home › Batteries › No. 6
Regular battery

No. 6 battery

1What it is2Other names3Facts4Buy it
  1. 1

    What it is

    No. 6

    No. 6 is a regular battery, much bigger than an AA. It gives 1.5 volts.

    Search Amazon for No. 6As an Amazon Associate, KnowYourBatteries.com earns from qualifying purchases.

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  2. 2

    Names you might see in the store

    All of these are the same battery. Any of them will work.

    R40905FLAGIgnition Cell
  3. 3

    Quick facts

    Size
    Much bigger than an AA
    Power
    1.5 volts
    Keeps in a drawer for
    About 5 years
    Rechargeable?
    No, use once
    Found in things like
    Vintage transistor radiosIndustrial metersVintage cameras
  4. 4

    Where to buy it

    As an Amazon Associate, KnowYourBatteries.com earns from qualifying purchases.

    Amazon searchEnergizer listings, any pack sizeSearch Amazon for Energizer No. 6
    See results on Amazon →
    Amazon searchMulti-packs from any brandSearch Amazon for No. 6 multi-packs
    See results on Amazon →
    Amazon searchDuracell listings, the same batterySearch Amazon for Duracell No. 6
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See it at real size

No. 6 next to a US quarter and an AA battery. “Real size” matches your hand once your screen is set up in Measure it.

No. 6US quarterAA

What do the letters mean?

Battery names are a code. Here’s how to read No. 6:

No. 6Common retail name for this cell
No. 6Physical cell: 67.0 × 172.0 mm, 1.5V carbon-zinc

The same battery from each brand

BrandTheir name for it
Official nameR40
Shop nameNo. 6

Exact measurements

Width
67.0 mm (2.638 in)
Length
172.0 mm
Voltage
1.5V (empty at 0.9V)
Energy stored
35000 mAh
Weight
—
Made with
Carbon-zinc
Works between
-10 … 60 °C
Official code
R40 · ANSI 905

Questions people ask

Is No. 6 the same as R40?

Yes. They’re the same battery with different names. You might also see R40, 905, FLAG, Ignition Cell.

How long will a spare keep in a drawer?

About 5 years if it stays cool and dry.

Can I recharge it?

No. Never try to recharge it.

No. 6
No. 6Regular battery
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1What it is2Other names3Facts4Buy it