1. https://amzn.com/B00MNV8E0C
A consumer need only be "burned" once to form or strengthen the perception that rechargeables are an inferior good.
Oh, and where are we on the capacity front?
That is lower under extremely light loads than the best alkalines, but crosses over at a bit over 12 hours constant runtime since load has a relatively small effect on NiMH capacity, but a huge effect on alkaline capacity.
> A consumer need only be "burned" once to form or strengthen the perception that rechargeables are an inferior good.
Alkalines can leak corrosive electrolyte and destroy devices. This is a fairly well-known issue, but it doesn't seem like "always use rechargeable batteries so you don't ruin your stuff" is a widespread meme among the average consumer. I wonder why that is.
It's probably safe to say that the average consumer can't be bothered with anything that isn't LSD. The fact that another option even still exists hurts the overall branding, if you will, of the product category.
> That is lower under extremely light loads than the best alkalines, but crosses over at a bit over 12 hours constant runtime since load has a relatively small effect on NiMH capacity, but a huge effect on alkaline capacity.
Then we've reached parity, assuming identical size and at least close-enough weight. Is size identical (or smaller for NiMH)? Last I handled some, weight seemed comparable.
Now that we have, take a look at when that happened. More importantly, take a look at when that happened at an affordable price point. Compare that to when NiMH first started gaining popularity and what the (price-competitive) capacities (and self-discharge rates) were then, keeping in mind that's what formed consumer perception.
Total elapsed time of product existence may not be the best metric for perception change, but it'll at least give you a starting point.
> Alkalines can leak corrosive electrolyte and destroy devices. This is a fairly well-known issue, but it doesn't seem like "always use rechargeable batteries so you don't ruin your stuff" is a widespread meme among the average consumer. I wonder why that is.
I can think of two reasons. The first is that a "fairly well-known issue" isn't a well enough known issue. Suppression of bad press (or word-of-mouth) is likely the impetus behind large battery brands replacing even fairly expensive ruined electronics when customers complain to them.
Secondly, the relative frequency of the two is vastly different. One ruined flashlight (or even Garmin or whatever) every few years (though I think it's really more like decade-plus) sticks in the memory much less distinctly than having ones TV remote stop working every week or having that same flashlight never work (because one only uses it occasionally, maybe not even monthly).
There's no mystery here.
That's probably true. Unfortunately, that larger mAh number is always going to tempt people. Some heavy users do go for the higher capacity with a full understanding of the disadvantages, but that's not the majority of the market.
> Then we've reached parity, assuming identical size and at least close-enough weight.
Eneloops came out in 2005. Their capacity hasn't changed, though the service life of later versions is longer and the self-discharge is even lower. The 1000 charge cycles and 75% charge after a year of the original was entirely acceptable for consumer applications. I don't see a size difference between a 4th-generation Eneloop AAA and a random Duracell alkaline, but I don't have calipers to measure precisely. NiMH batteries are heavier than alkalines, but I suspect this is insignificant in most consumer applications. Disposable lithium batteries that can substitute 1:1 for alkalines are lighter than either, with higher capacity.
And there's part of your answer as to why a consumer might try rechargables and still reject them, even today: self-discharge too high.
> Eneloops came out in 2005.
So 13 years ago, whereas NiMH was 1989, or a 16 year spread. Wait at least another 3 years. Actually, wait until only LSD is readily available. Then wait the number of years until how long it will have been from then since 1989.
> I don't see a size difference between a 4th-generation Eneloop AAA and a random Duracell alkaline, but I don't have calipers to measure precisely.
The specs are probably available, but the more important question isn't whether your particular Eneloops are small enough, but if the vast majority (and AmazonBasics and if there's any other popular enough brand) are.
Tiny variations in size can not just prevent the battery from going in in the first place, but, worse, keep it from coming back out.
My camera, laptop, smartphone, kindle, etc all have their own rechargable battery, so what is left is mostly my Ikea tradlos, kitchen scale and car keys (plus associated stuff that i forget and which therefore can be assumed not to need all that much recharging) which all runs on the super small batteries (2032? 3220? something like that), that I haven't seen as a rechargeable model.
No doubt this will change with kids, but until I have them they won't matter.
Higher self-discharge (loss of charge when not in use) offers more capacity, and only extremely low-drain devices will last marginally longer with alkaline.
There are Li-ion button cells such as 2032, but their voltage range is higher than the disposables and their capacity is quite low. Their applications are fairly niche.
Possible counterpoint: getting a Li-ion 14500 confused with a AA and putting it in an incompatible device is bad.
Just keep a couple extra charged and ready around the house that you can swap in if necessary.
It would not surprise me to learn that the designers of a consumer electronic device did a bad job, but I'd describe not working with 1.2V batteries when a device is intended for AA or AAA to be a pretty major design flaw.
[0] https://lygte-info.dk/review/batteries2012/Amazon%20basic%20...
That seems plenty long for something like a TV remote, if "run" includes the amount of time that buttons are depressed.
> It would not surprise me
This is inconsistent with your original comment that claims "a little surprise".
Consumer behavior responds to actual products, not someone's standard of engineering design.
TV remotes are pretty low-drain, to the point that most people probably wouldn't notice their battery runtime unless asked to observe it. A more compelling argument for NiMH in devices like that would be that alkalines often leak electrolyte that can corrode and damage a device wile NiMH is nearly immune to that kind of problem.
None of which matters if the device won't actually run on NiMH.
I guess the history is relatively tough to research these without having lived through it, since that's before the popularization of the web.
An interesting more modern use case is Apple's wireless keyboards when they used AAs. I'd suggest you check that out.
> I am not surprised that such a design flaw exists
I'd strongly suggest you consider the complexity, cost, and efficiency tradeoffs involved in RF (and other analog) silicon design, especially in miniaturized consumer products, before characterizing certain decisions as flaws.
Sometimes, worse is better.
> TV remotes are pretty low-drain, to the point that most people probably wouldn't notice their battery runtime unless asked to observe it.
That's my point. What they notice is how often they have to change (or recharge) the batteries. Historically, with rechargeables, that's been way too often.
To be fair, anecdotally, I've noticed this with some cheaper/off-brand alkalines, as well.
> A more compelling argument for NiMH in devices like that would be that alkalines often leak electrolyte that can corrode and damage a device wile NiMH is nearly immune to that kind of problem.
I think "often" is, at best, an exaggeration. Do you have published numbers to back that up?
My impression based on personal experience is that during the normal, useful life, it is vanishingly rare. I've only ever had leakage damage occur from fully-discharged (usually through self-discharge after over a year of disuse), and that was replaced by the battery manufacter, one of the advantages of paying more for brand-name.
I will almost always characterize a tradeoff that renders a device incompatible with rechargeable batteries that are commonly used in the appropriate form factor, or that causes the device to turn off before the majority of the energy in the battery has been used to be a flaw. I'll stipulate that it's probably usually a business decision rather than an engineering failure.
Incompatibility with rechargeable batteries is a hard no-buy from me as a consumer for almost any portable electronics.
> Do you have published numbers to back that up?*
I don't. I suspect people who have numbers about this (battery makers) really don't want to disclose them. My perception that alkalines leak often comes from moderating /r/flashlight. I've also seen it in person quite a few times, mostly with devices belonging to friends or family that aren't used often.
I still think you're ignoring history as well as exaggerating "commonly". Even alkaline wasn't the first primary cell chemistry type. You impliy that it's trivial to add rechargeables to the existing engineering for multiple chemistries with actually similar voltage profiles, without showing how.
> a business decision rather than an engineering failure
A distinction without a difference. The engineers are there to support the business, not a future armchair critic's ideal of excellence.
> I suspect people who have numbers about this (battery makers) really don't want to disclose them.
Certainly the manufactuers don't want to disclose numbers for consumer products. However, if it were as often as you suggest, I would expect there to be numbers, after all these decades, from someone like Consumer Reports.
Also, there's a reasonable chance that industrial versions have published numbers.
> My perception that alkalines leak often comes from moderating /r/flashlight.
Is that a forum where commenters tend to report such experiences with full data (numerator and denominator, including when the numerator is zero), or are they more likely only to complain at failure?
Are they representative of the average consumer's usage patterns?
> I've also seen it in person quite a few times, mostly with devices belonging to friends or family that aren't used often.
As I mentioned, this is consistent with my own personal experience. However, because this is subject to (a weird backwards version of) Survivorship Bias, I come to the opposite conclusion.
Put another way, it's likely that some huge proportion, if not all, of alkaline batteries will leak (perhaps even catastrophically) if left sitting around long enough. The key here is "long enough". Since the vast majority of users actually remove and discard way before that point, it's too rare in practice.
Even if NiMH did not exist, not being able to operate with batteries below 1.2V wastes the majority of the capacity of an alkaline. I think that's a valid criticism of almost anything in consumer electronics. It requires a very good excuse before it should be considered acceptable.
Furthermore, anything relatively recent should be able to use NiMH as a matter of compatibility with batteries a significant minority of consumers have, and for environmental responsibility.
> Is that a forum where commenters tend to report such experiences with full data
Of course not. I suspect data like that about consumer products is not available to the public at all, though there are some scientific studies on alkaline battery leakage as a phenomenon (the first one I found was paywalled).
> Are they representative of the average consumer's usage patterns?
Probably. Regulars almost never use alkaline batteries, so when people post about that, it's usually their first post. They're not collectors, hobbyists or heavy users, but people who encountered a problem and thought "I bet there's a subreddit for that". (We have 35K subscribers)
Please unpack this a bit to make sure it's not a strawman.
1.2V is just a nominal voltage, just like 1.5V nominal. Fully-charged open-cell voltages are above 1.25V and 1.6V, IIRC, though that is, of course, irrelevant. What matters is voltage under load, at all possible loads for all consumer devices.
Even if nickel chemistries have flatter discharge curves, they still slope downward, and that voltage can drop below 1.2V.
Their voltage also doesn't bounce back when load is reduced. Engineers deal with real-world usage, not contrived benchmarks where a cell is taken from full charge to flat at constant current.
What consumers are actually saying is that real-world rechargables don't work in certain real-world devices, while alkalines do. They make no claims about specific voltages. That's on you, so it's up to you to show that a particular voltage cut-off is the problem and that the same device ends up using only half the alkaline's capacity. Otherwise, you put up a strawman to knock down.
Rechargeable batteries remove the loss aversion associated with ensuring the batteries in a device are fresh, as there's essentially no extra cost to recharging a battery that may still have significant energy in it. Modern NiMH does not develop a permanent memory effect, and rarely even develops a temporary one.