I wasted so much money on AA batteries because I missed this tiny detail

I pulled my camera out last week to shoot a few photos, and I instantly remembered why I don’t like using this thing: it takes AA batteries. My wireless mouse takes one AA. I have three Xbox controllers that all take AAs. Over time, constantly swapping dead batteries and watching devices chew through them has given me an actual “ick” for anything that relies on AA cells.

But, as it turns out, there’s a lot more going on with AA batteries than I ever assumed. I’d ignored the text and markings on the packaging for years, but when I finally paid attention, everything clicked — and all my battery-related problems basically solved themselves. Consider this my attempt at redemption, so no one else repeats the same mistakes I did.

Why did I ignore the battery markings for so long?

Please let me explain

Credit: Amir Bohlooli / MUO

Heavy Duty. Super Heavy Duty. Extra Heavy Duty. Pro Max Heavy Duty. Titanium. Long lasting. Lasts 10 years. “The last battery pack you ever buy.” You’ve seen these. So have I. I dismissed them all as empty marketing fluff and assumed none of it meant anything. To be fair, I was right — those phrases do not mean anything. But their presence on the packaging was distracting enough that I ignored the text that does matter: the codes that tell you the chemistry and how the battery will actually perform.

I’d like to believe I’m not the only one who fell for this. Most people probably treat AA batteries as a single category (I say to myself). You grab whatever’s on the shelf and assume the only differences are “how long it lasts” or “whether it’s rechargeable.” That assumption is wrong. The markings on AA batteries matter — and once you understand them, the entire category stops feeling random.

AA batteries aren’t all the same

Not every piece of text is an advertisement

Credit: Amir Bohlooli / MUO

Let me waste a few more seconds of your time, because this story is exactly what made the whole thing click for me. If you find it boring, scroll ahead — the AA battery guide table is waiting for you. But I'll make the story worth your time.

My camera takes four AA batteries. I used to have a set of rechargeable ones for it, but I hadn’t used the camera in so long that I couldn’t find them. So I bought a pack of cheap non-rechargeable AAs. The camera lasted for about ten shots, then shut off instantly. No low-battery warning. Nothing.

Surely, despite these batteries both being cheap non-rechargable AAs, there's a difference between LR6 and R6? What do they mean?

So I put in another pack of batteries, and the camera didn't even turn on. I could hear tiny relays clicking inside when I flipped the switch, but nothing else. No LCD, no beep, nothing. What happened? Did this guy sell me discharged batteries? Is this a scam? I grabbed my multimeter and it showed 1.5V. What’s going on?

Credit: Amir Bohlooli / MUO

I swallowed the questions and instead I went scorching all my shelves and bags looking for my rechargables. I found a whole lot of AA batteries, and to find out if they're rechargable or not, I had to read what's on them. That's when I noticed codes like LR6-BP4 or R6P AA UM-3. Surely, despite these batteries both being cheap non-rechargable AAs, there's a difference between LR6 and R6? What do they mean?

What the AA battery codes actually mean

Translating LR6, R6, HR6, and friends

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Close Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Credit: Amir Bohlooli / MUO

Let’s decode something like R6P AA UM-3:

Code Meaning R Round cell (cylindrical) 6 Size code for AA P “Power” or general-purpose zinc-carbon (the cheap stuff) AA Retail name (just repeats the size) UM-3 Japanese JIS code for AA (again, the size)

Most of this is redundant. But the chemistry code is the key. And once you know the other codes too, you realize that “AA battery” is not one product. There are several chemistries, and they behave very differently.

Code Chemistry Internal resistance Open voltage High-current performance Rechargable R6 Zinc-Carbon 250–400 mΩ 1.5V 🟥Terrible ❌ LR6 Alkaline 80–150 mΩ 1.5V 🟧OK-ish ❌ HR6 NiMH Rechargeable 20–30 mΩ 1.3V 🟦Excellent ✅ FR6 Lithium (Li-FeS₂) 60–90 mΩ, very stable 1.8V 🟦Excellent ❌ KR6 NiCd Rechargeable 25–40 mΩ 1.3V 🟦Excellent ✅

Don’t use R6 batteries for your camera

You're throwing away money

Credit: Amir Bohlooli / MUO

There you have it — AA batteries, demystified. But if you really want to put this topic to bed (like I did), we need to talk about why you shouldn’t use R6 or LR6 batteries in a camera or any other high-current device. Before I understood any of this, I assumed the only difference was capacity. Cheap batteries die faster, expensive ones last longer. Same voltage, so the camera should work either way. I was wrong.

High-drain devices like cameras, flashes, and game controllers, pull a lot of current. Batteries have internal resistance, and when you pull high current, voltage drops. This is exactly what my camera was doing. It would turn on with alkaline LR6 cells, but the moment I used autofocus or flash, it would instantly shut off. And the batteries weren’t “dead” — they still worked fine in a mouse. The load just pulled the voltage below the camera’s minimum threshold.

Here’s an example at 5 amps (flash recharge spike):

Code Open voltage Internal resistance Load voltage @ 5A Load state R6 1.5V ~300 mΩ 1.50 – (5×0.30) = 0.00 V 🟥Full collapse LR6 1.5V ~120 mΩ 1.50 – (5×0.12) = 0.90 V 🟧Shutdown territory KR6 1.3V ~35 mΩ 1.30 – (5×0.035)= 1.12 V 🟨Stable-ish HR6 1.3V ~25 mΩ 1.30 – (5×0.025)= 1.17 V 🟩Stable FR6 1.8V ~80 mΩ 1.80 – (5×0.08) = 1.40 V 🟦Very stable

So yes, you save nothing by buying cheaper batteries. The device simply won’t function properly. This is why cameras love NiMH (HR6) and lithium (FR6). It's also why R6 zinc-carbon shouldn’t be used for anything more demanding than a wall clock.

All of these standards and codes also aply for AAA batteries.

How to tell if you’ve got the right batteries

Ignore "Heavy Duty" and read the tiny code instead

Credit: Amir Bohlooli / MUO

The next time you need AA batteries, consider the device you want to use it for. The degree of duty that's written on the batteries (like Heavy duty) is arbitrary. Just look at the codes and numbers.

Code Use case R6 Just avoid them.They’re barely cheaper than LR6 and perform terribly. LR6 For remotes, clocks, and low-drain devices. HR6 For anything high-drain (cameras, controllers, flashes, toys). FR6 For the best non-rechargeable performance. KR6 Only if you own ancient equipment.

Some brands include icons to hint at intended use. A clock usually means zinc-carbon (R6). A flashlight means alkaline (LR6). A camera icon could mean lithium (FR6). These icons aren’t standardized, but they can help you spot the obvious garbage.

For cameras or anything that draws a lot of current, NiMH and FR6 (lithium) AAs are the right choice. NiMH has the bonus of being rechargeable, which makes it the best long-term deal. The only catch is you’ll need a proper charger if you don’t already have one. I use a Camelion 4-slot charger and a Sony 2-slot charger — both handle AA and AAA without issues.

Sony Cycle Energy NiMH Compact Charger Compatible Batteries AA, AAA Brand Sony Battery capacity 1000 mAh Battery Cell Type NiMH

If you're going to use a charger, read the text on your charger. Unless it’s a proper smart charger (with temperature sensing, delta-V detection, or safe trickle at full), charging NiMH cells is vulnerable to the same phone charging myths we’ve finally outgrown with phones. Leaving them overnight in a dumb charger will overheat them, degrade them, or even melt the casing.

FR6 lithium batteries are excellent for cameras. They offer high capacity and very low internal resistance, which means they can handle heavy bursts of current without choking. They’re not rechargeable, but a single pack will last a long time in most cameras.

Energizer Ultimate Lithium AA Batteries Battery Type(s) Lithium Brand Energizer Capacity 3000 mAh

A quick warning when shopping for lithium AAs: always check the voltage. Most lithium cells on the market are 3.7V, not 1.5V. Those 3.7V cells use a completely different chemistry, and putting them in your camera is a spectacularly bad idea. You want 1.5V lithium primaries like the Energizer Ultimate Lithium series. And remember: if it’s rechargeable, it’s the wrong lithium chemistry for AA devices. Only the non-rechargeable lithium AAs are safe replacements.

What about USB-rechargeable AA batteries?

They're cute, but not practical

Image by Amir Bohlooli. NAN.

On some shelves, you’ll see USB-C rechargeable AAs that advertise 1.5V lithium 2200mAh. You might think: wait, aren’t lithium AAs supposed to be 1.8V and not rechargeable? Correct. And these are not actually 1.5V lithium cells.

Inside these USB-rechargable AAs, there's a tiny 3.7 Li-ion cell, plus a buck converter to regulate output to 1.5V, plus a charging circuit. So you're basically buying a small battery + lots of circuitry. The battery capacity (mAh) is never as high as advertised (because 2200mAh at 1.5V ≠ 2200mAh at 3.7V), and you’re paying for complexity, not performance. It's a cute idea, but a bad deal.

I went with Panasonic Eneloop HR6 (NiMH) cells in the end, and they’ve been rock-solid — every photo you see here was taken on my camera without it collapsing mid-shot.

I changed my mind about AA batteries

I wasted so many R6 AAs on my camera that I don’t even want to think about it. But those days are over. I’m fully on board with AA-powered devices again.

I used to be annoyed that Microsoft wouldn't just stick a a proprietary Li-Po battery in its controllers, like Sony does. But now, no more. When a proprietary battery in a device dies, you’re stuck. When a device uses AAs, you just swap cells and move on. I proudly confess that AA batteries weren't the problem. I was.