Energizer Max 9V Battery (PP3)

The 9V battery is the rectangular block with two snap studs on top, and this is the Max alkaline version from Energizer. One cell comes sealed on a blister card. Where a cylindrical AA or AAA gives 1.5 volts, this single block gives nine, which is why the 9V has stayed the standard fitting for smoke alarms and for any device with a press-stud connector clipped inside its lid. The retail pack prints a five year shelf life, so a spare bought now and left in a drawer is still worth reaching for later.

Most homes have more 9V sockets than they realise. Mains-powered smoke and heat alarms often take one as the backup cell, battery-only alarms run on it entirely, and carbon monoxide detectors frequently do the same. Beyond the ceiling, it powers multimeters, guitar effects pedals, active bass and acoustic pickups, radio microphone belt packs, wireless doorbells and a good many older electronic toys. If you are replacing a cell, lift the old one out and check the top: a 9V sits in a moulded well and connects by a clip rather than by flat contacts at each end, so it is easy to tell apart from anything else in the drawer.

Each listing here is one cell on one card, and our minimum order is twelve of them, sold in multiples of twelve, which suits a landlord, a venue or anyone servicing several alarms at once on the same date. Alkaline cells are single use: they are not designed to be recharged, and a rechargeable 9V is a different product entirely. Fit the replacement with the clip pressed fully home until it seats, and note the date on the alarm so the next change is not a guess. We stock Energizer alkaline cells in AA, AAA, C and D alongside this one, plus lithium and silver oxide coin cells.

Which devices usually take a 9V battery?

Smoke, heat and carbon monoxide alarms are the common ones, along with multimeters, guitar effects pedals, active instrument pickups, radio microphone belt packs and wireless doorbells.

Is a 9V the same thing as a PP3?

Yes. PP3 is the long-standing name for the rectangular 9V cell with two snap studs on top, so the two terms describe one battery.

Can I recharge this cell?

No. It is an alkaline battery, which is a single use chemistry. A rechargeable 9V is a separate product bought with a charger to suit it.

What does the five year shelf life mean in practice?

The pack states five years, so a cell kept unopened and in date should still be worth fitting when you eventually reach for it.

How many batteries do I receive, and why is the minimum order twelve?

One battery per card. We sell these in multiples of twelve, so a single order covers a whole set of alarms or a full replacement round.