UPDATE November 19, 2017: Since this post was made on October 3rd, 2017, I’ve done a number of additional tests on many more batteries. I’ll do a follow-up post eventually, but here are some new key results: first, the performance of a manufacturer’s AAA alkaline batteries is in no way predictive of the performance of a manufacturer’s AA alkaline batteries. As an example of that, Rayovac makes some of the lowest-capacity AAA alkaline batteries but some of the highest-capacity AA alkaline batteries. Second, there can be a surprising amount of variation within a manufacturer. Energizer is particularly poor in that respect, with their AA batteries manufactured in the USA and China significantly outperforming their AA batteries manufacturer in Indonesia and Poland.

For many years, I’ve been a loyal customer of Rayovac alkaline batteries. I thought they were just as good as Duracell and Energizer, they had strong reviews on Amazon, and they were cheap.

However, that worldview came to a shattered end when I read a review on Amazon for some Amazon Basics AAA alkaline batteries. In that review, the reviewer claimed to have measured the actual charge available in various brands of AAA alkalines, and they claimed that the Rayovac AAAs had performed especially poorly. Say it ain’t so! I decided to run my own tests, either to restore the honor of the Rayovac brand or to join the bandwagon throwing tomatoes at it.

For good measure, I decided to also test a couple of other brands of cheap AAA alkalines: the aforementioned Amazon Basics AAA alkaline, and the Harbor Freight AAA alkaline.

To do the testing, I used an Itech IT8511A+ programmable DC load along with some desktop software to control the DC load and record the results. One battery at a time would be placed in a single-AAA holder. The leads from the holder were split, with one pair of branches going to the load terminals on the front of the Itech and the other pair going to the “remote sense” terminals on the back of the Itech. By using separate lines for the load and for voltage sensing, I would avoid problems with voltage drop on the leads due to the current and the non-zero resistance of the wire. This “4-wire” arrangement is also used for measuring precision resistances for the same reason.

Battery capacity is load-dependent, with more capacity for lighter loads, so I used three different constant-current discharge rates for each brand of battery: 50 mA, 200 mA, and 500 mA. Those would simulate light loads like a remote control, medium loads like a toy, and heavy loads like an LED headlamp. I’d run each test with a fresh battery. The stopping voltage would be 800 mV for the 50 mA and 200 mA tests, and 500 mV for the 500 mA tests.

Why those voltages? That’s where the batteries were “dropping off a cliff” — i.e., almost entirely discharged. That’s also around the voltage where modern devices cease to work. Why 500 mV instead of 800 mV for the 500 mA trial? Due to internal resistance, the overall voltage was lower, and I saw that we’d be leaving something on the table if we stopped at 800 mV.

Here are some examples of what the discharge curves looked like in the battery analyzer software for each of the batteries at a 200 mA discharge rate:

 

 

 

After several days of testing, here are the results.

50 mA

1. Amazon Basics AAA alkaline — 1193 mAh
2. Harbor Freight AAA alkaline — 1078 mAh
3. Rayovac AAA alkaline — 1024 mAh

200 mA

1. Amazon Basics AAA alkaline — 937 mAh
2. Harbor Freight AAA alkaline — 829 mAh
3. Rayovac AAA alkaline — 604 mAh

500 mA

1. Amazon Basics AAA alkaline — 575 mAh
2. Harbor Freight AAA alkaline — 527 mAh
3. Rayovac AAA alkaline — 354 mAh

The Rayovacs were terrible! No wonder my Black Diamond LED headlamp, which pulls about 550 mA on its brightest setting and about 210 mA on its medium-intensity “side light” setting, always seemed to run through its three AAAs so quickly. I mean, look at those numbers: the Rayovacs at 200 mA had about the same capacity as the Amazons at 500 mA. The Rayovacs managed only 60% of the capacity of the Amazons at 500 mA. Ouch.

Admittedly, the problem was less pronounced at the lowest current drain in the test, but the Amazon batteries still had about 15% more capacity than the Rayovacs.

All of the batteries were fresh. The Rayovac batteries and Amazon batteries were obtained from Amazon, and the Harbor Freight batteries were obtained in person from my local Harbor Freight.

Don’t be fooled by the lower starting voltage of the Rayovac batteries in the 200 mA test screenshots above (1.48 V versus about 1.6 V for the other two). I did the test several times to make sure. Notably, they always started up above 1.6 V under no or light loads, so the cells were fresh, and since the same battery holder was used for all of the brands of batteries in all of the tests, it wasn’t an artifact of resistance in the holder.

Roughly 10% behind the Amazon batteries on every test — but way ahead of the Rayovacs — were the Harbor Freight batteries. Note that these are the Harbor Freight alkalines, not the Harbor Freight “heavy duty” batteries that they often give away in promotions. Still, they’re usually on “sale” for about $0.21 per battery, so they’re still pretty cheap. If you can get the Amazon batteries for less than about $0.23 per battery, that might be a better value, but I’ve found they’re usually slightly more than that.

Rayovac: it’s been great, but we need to break up. I’m an Amazon or Harbor Freight battery guy now.

I’d often wondered whether there really were any differences among the major AA and AAA alkaline battery brands. Sure, Duracell and Energizer both put out numerous ads claiming to have the best battery life, but I figured that was nothing but boisterous marketing. Surely they must be about the same, right?

How wrong I was. You can indeed buy a bad brand-name battery. But I’m getting ahead of myself.

To answer the question, I decided to measure the actual usable capacity of AA and AAA alkaline batteries from the major brands under conditions simulating light to heavy loads. I wanted a rigorous, repeatable experimental setup, so I used an Itech 8511A+ programmable DC load on my lab bench to drain the batteries under precisely controlled constant-current conditions and recorded the data points on a PC. Each battery was in a properly sized battery holder, and it was connected to the load with a 4-wire setup.

Lest anybody claim I’m in the pocket of Big Battery, I bought all of the batteries I tested at retail, and I took no money from anybody.

I will admit that the testing scope kind of snowballed out of control and as a result took a lot longer than expected. I could test only one battery at a time, and when light loads met high capacities, it would take several days to complete a single test (of three) for each battery.

Fortunately, it turned out that a lot of batteries were crap, so some tests went unexpectedly quickly.

AA battery results

Energizer, Duracell, Amazon Basics, and Rayovac were the contenders in the alkaline AA ring, with two Duracell sub-brands represented (Copper Top and Quantum) and four Energizer manufacturing locations in the field (Poland, Indonesia, China, and the USA).

Round one? A light load, specifically 50 mA. While that level is still well above what you’d see in a very light load like a wall clock or a garden watering timer, it turns out that all of the batteries were pretty much the same there: 2700 mAh +/- 10%.

Why not test even lighter loads? Time constraints. The capacity in milliamp hours (mAh) is the number of hours of run time multiplied by the load in milliamps. That works the other way, too, so you can find how long a test took by taking the capacity in mAh and dividing by the current in mA, giving hours. A 2700 mAh battery at 50 mA already takes over two days (54 hours) to test; testing at 10 mA would take about a week and a half. I didn’t have that kind of time or patience, but somebody else did.

As the load was stepped up to 200 mA, which you might see with a flashlight on “low”, some differences among the brands emerged!

With a 200 mA load, there was more than a factor of two difference between the worst performer (the Energizer Max AA manufactured in Indonesia) and the best performer (a Duracell Quantum). The Coppertop Duracell sub-brand was near the top, as was the Rayovac, while the Amazon Basics options had middling performance not far ahead of the worst Energizers.

Oddly, the performance of the Energizer batteries was very strongly tied to the manufacturing location. The Energizer batteries made in China performed pretty well — right up there with the Duracells and Rayovac. However, the Energizer batteries made in Indonesia and Poland were terrible. The Energizers made in the USA were pretty good but not great, sitting somewhat back from their Chinese brethren.

The same trends held at the 500 mA level, similar to a reasonably bright LED flashlight. The Amazon cells and the Indonesian and Polish Energizer cells occupied the rear again, with only about half the capacity of the Duracells and Rayovac, which were again in the lead. The American and Chinese Energizers rounded out the front group, about 15% off of the best performer, the Duracell Quantum.

The take-aways from the AA tests:

1. Duracell is a safe choice for AA alkalines
2. There isn’t much of a difference between Duracell Quantum and Duracell Coppertop
3. Avoid Amazon Basics AAs
4. If you buy Energizer AAs, check the top of the cell (by the positive terminal) to make sure they weren’t made in Indonesia or Poland

Half-time assessment

The Energizer bunny sure has a good side and a bad side, at least based on the AA tests. Energizer fanboys aren’t going to be happy.

On the other hand, Duracell partisans are probably feeling pretty smug. The Copper Top (and Quantum) cells were consistently great in the AA tests.

Other than the Energizer results, the big surprise for me was how poorly the Amazon Basics cells fared. Since those are also made in Indonesia, and since certain tell-tales on them look very similar to the Indonesian Energizers (but not the other Energizers), I can’t help but wonder if perhaps both Amazon and Energizer sourced some AA batteries from the same OEM in Indonesia. Just speculation, nothing more.

On to the smaller batteries. Would the same relative brand results hold? Spoiler: no.

AAA batteries

I did a limited test of cheap alkaline AAA batteries last year, but this time around I looked at the brand name offerings. Alkaline AAAs from Duracell (Coppertop and Quantum), Energizer, Rayovac (Fusion and normal), and Amazon Basics were in the running. All of the Energizer AAAs I found were made in the USA, unlike with the AAs.

At the 50 mA level, which would provide data that would be useful for selecting the cells for your TV remote, even the worst performer was only 15% back from the best performer. Thus, for light-load applications, just get whichever of them is cheapest and don’t worry too much about it.

Things got more interesting at the higher drain currents, which would be relevant for things like LED headlamps, flashlights, or radios.

The best and worst options at 200 mA were both made by Rayovac: the normal alkaline Rayovac was the worst, but the Rayovac Fusion was the best. Close behind the Rayovac Fusion was the Amazon Basics AAA. Energizer and Duracell were mid-pack and about even with each other.

At the highest drain level, 500 mA, the Rayovac Fusion option blew away the competition, while the normal alkaline Rayovac was dead last. I mean, dead first. I mean… it had by far the lowest usable capacity, only about 50% of that of the Fusion sub-brand. The Amazon Basics option was pretty good, and the Duracell and Energizer entrants were both closer to last place than to the front-runner.

In other words, the AAA results were entirely different than the AA results. Just because a manufacturer can make a good AA battery doesn’t mean they can make a good AAA battery, and vice-versa. Or, in the case of Rayovac, they clearly know know to make a good AAA battery but choose not to apply that knowledge uniformly across their product lines.

The take-aways from the AAA test:

1. Duracell and Energizer are about even in AAA land, but neither are particularly good
2. Amazon has a decent AAA battery even though they’re bad at AA batteries
3. Rayovac Fusion alkaline AAA batteries are really good at high loads, but the normal Rayovac alkaline AAAs are terrible
4. For light loads, everybody is about equal. The only real differences are at higher loads

Conclusion

Duracell was consistently decent, though not always the best. Energizer was surprisingly inconsistent based on the manufacturing location used for a particular lot. Rayovac was great for AAs, great for some AAAs, and terrible for some AAAs. Amazon’s “Basics” house brand was roughly the opposite: great for AAAs but pretty bad for AAs.

Now I need to figure out what to do with all of these terrible Polish and Indonesian Energizer AAs…

 

I’ll admit: when Tyler and I went elk hunting last year in western Colorado, we were a bit under-prepared. It’s probably a good thing that we didn’t harvest an elk then. Even the mule deer buck that we saw — but didn’t take, lacking a deer tag as we were — would have been a challenge to handle properly. This year was different.

This year, we had more firepower: two rifles instead of one. This year, we had a better season: “1st Rifle” instead of the much later and higher-trafficked “3rd Rifle”. This year, we had a better spot: near Yampa, Colorado in a game unit (GMU 231) with a history of excellent success rates.

Perhaps most important of all, this year we had more time. Whereas last year had been a quick overnight, this year we spent three days in the country.

That time began with a three hour drive from Denver, lunch at a small-town diner in Yampa that had friendly bad service, and a drive deep into the nearby Routt National Forest. Once we’d set up camp — just a tent, none of that RV nonsense — we set out for a late-afternoon hike.

Rifles in hand, orange on our heads and backs, we began trudging cross-country through the forest. The goal was to reach a series of clearings that had appeared on satellite images of the area, connect with a trail near the Flat Tops Wilderness boundary line, and continue pushing to higher elevations in the wilderness in search of bull elk. Very little snow had fallen that season, and daytime highs were still in the 60s, so we thought the elk were still likely to be up high.

We hiked, and the hours sped by. No elk.

Despite a lack of animals, there was an abundance of elk sign. Scat and tracks littered the ground, much of it appearing to be relatively new. We felt optimistic we were going to find a big bull every time we glassed a new clearing. That optimism continued right up until twilight and the end of legal hunting for the day, but the only woodland mammal we had seen was a porcupine. We began the multi-mile hike back down the mountain and out of the wilderness towards our camp. The increasing darkness was a bad time to discover that my headlamp batteries were nearly dead.

Fortunately, Tyler’s headlamp was bright, so he led the way on the trail. As the first hour of the return journey bled into the second hour, I felt myself becoming increasingly drained. That was compounded once we exited the forest on a road and found ourselves still over a mile from our tent. The wind hadn’t been noticeable in the forest, but once on the road, the 30-50 mph gusts were strong enough to send my hat flying off of my head. Oh — and the road to camp was uphill the entire way.

By the time we made it back to camp, elkless and hours after nightfall, I was so exhausted that I didn’t even want to eat dinner. All I wanted to do was crawl into my sleeping bag and shut my eyes. Lucky for me that Tyler had the presense of mind and stamina to make burritos and tea. Hot food and drinks have an amazing way of reinvigorating the body, and I felt immensely better afterward.

It’s probably for the best that we didn’t take an elk that evening; it would have been a very late night, and stamina would have been an issue.

The winds shook the tent through the night, and their howling was punctuated by occasional sharp crashes as nearby trees and branches thundered to the ground. Sleep was minimal.

Yet, once 5:00 a.m. arrived, it was not particularly hard to get going. Yes, we were both sore, but we were also excited for the possibility of a successful hunt. Oatmeal and tea served as a quick breakfast, and then we drove my Outback down the road a ways to try a different spot. We were hiking in before sunrise.

After following a trail through the forest for a couple of miles, we found a multi-acre clearing on a grassy steep hill, so we left the trail to investigate. About 100 yards up the hill from the trail, we sat down on some rocks to glass the area; that location offered not only a view of most of the clearing but also of nearby ponds and more distant fields. Several quiet minutes went by before Tyler quietly yet excitedly whispered “Look!” and pointed to a mule deer. The young buck was about 150 yards away in the clearing and was moving uphill. He stopped for a moment, broadside to us, and then continued. Not long after that, several orange hats became visible in the woods; perhaps the buck had caught wind of those hunters and been pushed away from them.

We hunted some more in the immediate area before starting the hour-long hike back to the car for some lunch. All the way back, friendly sunshine was interspersed with angry dark clouds, but nothing save for a few flurries fell, and the temperature remained pleasantly cool. We took lunch in camp chairs by the car and packed up when the sun seemed unlikely to come back for the day.

Snow began to fall. Warmer jackets came out. We drove to the end of the road, Stillwater Reservoir, to start an afternoon hunt.

On the drive there, we had a brush with calamity. I was taking the washboarded dirt road a little — ahem — quickly, and an unexpectedly large bump suddenly jarred Sam. The TPMS light instantly lit up on the dashboard. A walk around the car showed no obvious problems except for the passenger-rear tire having a somewhat lower pressure than the others. I decided to check it again in a few minutes and drove on.

The snow was starting to accumulate by the time we made it to our trailhead. We decided to take only one rifle, my stainless steel Weatherby .308, since the other rifle, a 7mm Rem Mag, was not stainless and would thus be more vulnerable to rust. Thus equipped, we set off on the trail, which followed the reservoir for a short while before turning uphill into the wilderness.

It was a really nice hike, and it was easy to explore areas off of the trail, but we saw exactly zero animals of any sort. In hindsight, they were probably hunkered down out of the snow. Just before the Devil’s Causeway, we turned around. The snow was coming down in earnest by that point; our tracks from the hike up were quickly becoming nearly invisible.

Back at the car, Sam’s tire had lost a little more air, but not too much, so I felt comfortable driving back to camp.

It was a properly cold night. Inside the tent, it remained just above freezing, but it was probably in the mid-20s outside. In the morning, Tyler and I lazily let dawn arrive before mustering the courage to get out of our warm sleeping bags and greet the day. Around that time, we heard the sharp crack of a rifle shot. It would be the only one we would hear on the entire trip.

With the temperature low and having hunted the nearby terrain already, we struck camp and headed back into town for breakfast at the diner.

When we walked in, it was obvious we weren’t the only ones with that idea. Pretty much every head in the place was covered with a blaze orange hat. Service was again friendly-bad, and I’m not sure a big-city health inspector would have been thrilled with their methods, but it was a nice change of pace from camping.

On the way out, we struck up a conversation with an older hunter who seemed to have some experience with the area. It seems that we weren’t the only ones to get skunked. According to him, in previous years his friends had filled their tags on the first day in that unit, but something was different this year. He hadn’t seen anything, and while his friends had seen an elk or two, they had apparently missed shots on their only opportunities. I felt a bit better knowing that the problems weren’t unique to us.

Still would have been nice to get an elk though. Next year!

There was an article today about a boy who was tracked down for a heart transplant using the GPS in his mother’s cell phone. Since it was a “matter of life or death,” the location information was released without a warrant.

Even though the outcome was positive, I’m not sure that I like the precedent. True, GPS technology is in phones to aid in location determination during emergencies. And, yeah, the paranoid could remove the batteries or simply not carry phones. I just don’t like the notion that I could be tracked without my permission.

(This post is part of the 100/100/100 challenge)

I enjoy reading the prognostications of outsiders.

In the March 2007 edition of Wired magazine, there is a well-written article by Steven Gulie about deep-brain stimuation for the treatment of Parkinson’s disease. In it, the author presents a first-hand account of his experience being implanted at Stanford with a neurostimulator. What he fails to mention is the manufacturer of that neurostimulator; it was almost certainly made by my employer.

I was particularly interested in these two paragraphs of the article:

“The system can be fine-tuned after the operation by activating various electrodes, shifting the affected area by a millimeter or two. The doctors can also tweak the frequency and amplitude of the electrical stimulation, modify the pulse width, and make other adjustments to the software through a remote control. Wireless? Software? Now that’s brain surgery 2.0.

I asked Henderson [the physician] about features still on the whiteboard: What will be in rev 2.2 or 2.5? He thinks the next release of the stimulator will sense chaotic activity in the brain and turn itself on only when needed. That’s on a par with current heart pacemakers, which no longer mindlessly zap you with a steady pulse but actually look for a problem to fix. The next-gen device will also probably be transdermally rechargeable, so you won’t need surgery to get new batteries.”

I am proud to say that I drew on that whiteboard and worked on that next rev today. I know exactly what will be in the next stimulator, so I find it very amusing to read his predictions. Will it be rechargeable? Will it incorporate a sensor?

Maybe — I’m not telling.