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> a tradeoff that renders a device incompatible with rechargeable batteries that are commonly used in the appropriate form factor I still think you're ignoring

by mmt 8y ago

> a tradeoff that renders a device incompatible with rechargeable batteries that are commonly used in the appropriate form factor 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.

Zak 8y ago
> You impliy that it's trivial to add rechargeables to the existing engineering for multiple chemistries with actually similar voltage profiles, without showing how. 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)
- mmt 8y ago
  > 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. 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.

by mmt 8y ago

Zak 8y ago

> You impliy that it's trivial to add rechargeables to the existing engineering for multiple chemistries with actually similar voltage profiles, without showing how. 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)

mmt 8y ago
> 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. 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.