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Getting at the heart of a 9-volt alkaline battery

April 16, 2015


I’ve read about this — that many alkaline 9-volt batteries were just a package of little quadruple-A batteries that could be extracted and, in a pinch, used in place of triple-A batteries — but of course I had to see for myself.

Today I found a 9-volt alkaline battery and broke it open and yes, it was full of little quadruple-A batteries and I successfully used them in place of triple-A batteries but I have to say that as tricks go this one may be too tricky to appeal to anyone who isn’t a dedicated (or aspiring) MacGyver.

The case for and against assaulting a 9-volt battery


Being able to use 9-volt alkaline batteries as an emergency source of triple-As sounds handy but who, these days, ever has 9-volt batteries in a drawer? They’re not used for much  any more.

It’s a toss up whether I see fewer 9-volt batteries or D-cells in the garbage (I almost never run across either). The most common batteries I find are, far-and-away, good-old double-As. The more modern triple-As are a distant second.

It is true that one 9-volt battery is about a third of the price of six triple-As and it’s true that alkaline quads produce 1.5 V, just the same as alkaline triples.

However, it’s also true that substituting quadruple-As for triples is fiddly for the fact that quadruples are a bit narrower and shorter than triples — 3.5 millimetres shorter to be exact.

A quadruple-A battery is 42.5 mm long and 8.3 mm in diameter — both smaller in diameter and shorter in length than a triple-A, which is 44.5 mm in length and 10.5 mm in diameter.

Also, I read that some of the quads used in 9-volt alkaline batteries aren’t always clearly marked for which end is positive or negative.

The actual assault on a  9-volt battery


If you’re going to try opening a 9-volt alkaline battery you should definitely wear gloves, in case yours is one of the kind that don’t use safe, tidy bundles of quadruple-A batteries.

All that’s required to open the thin metal shell of a 9-volt battery is something like a flat-head screwdriver and/or needle nose pliers; there are no welds, the metal is just folded. Both the positive and negative terminals are on the top of the 9-volt battery and the bottom is often nothing more than a piece of cardstock — gently prying that out is a good starting point and show you what you’re getting into.


The six quadruple-A batteries should be in shrink-wrap plastic and welded together — positive to negative terminals — with thin metal strips and the entire bunch will be connected by the last battery in the series to the two main positive and negative terminals of the 9-volt battery.

To separate the linked batteries, it’s best to use scissors to snip the metal strips. You will definitely need the extra length provided by the remaining bits of these strips in order to make the slightly shorter quadruple-As properly fit the slots meant for triples.


For a test, I replaced one of the two triple-A batteries in a LED flasher with one of the quadruple-As.

I was perhaps lucky that the quadruples I extracted had easily identifiable positive and negative ends. All I had to do was bend out the remaining flanges of the metal strips welded on either end to make sure the quadruple-A was firmly making electrical contact.

If I was doing it for real, I would have wound a strip of paper (not quite the full length) around the battery to pad out its diameter. Click the images to enlarge them.

  1. Slowcrow permalink

    How cool is this! Many alkaline 9-volt batteries are ritually tossed, when the clocks change, that have had minimal use in smoke detectors. (P.S. Like all the facts i state, i do believe that to be true…… Lol)


    • Didn’t mention it in the post but, given the state of the dumpster-dived 9-volt (witness the rust) I didn’t expect its contents — whatever they were — to have any charge left but lo and behold, more than enough to run a LED flasher light.


  2. Excellent information shared about 9-volt alkaline battery, Keep sharing this type of informative blog.


    • Technically…this comment is kind of ad spam. But on the other hand, a battery seller should certainly be able to comment on a post about batteries. 🙂


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