4 ms·

Many devices can't deal with the lower voltage (1.2V vs 1.5V). About half of my AA/AAA devices don't work at all.

by moogly 8y ago

0xcde4c3db 8y ago
Many rechargeables are also slightly larger than typical alkalines. This can cause them to be difficult to remove from devices where they're inserted end-on, such as flashlights and Xbox 360 controllers.
Zak 8y ago
Those devices must have very short runtimes on alkalines. Even a 0.2A load on an alkaline AA puts it under 1.2V for most of its discharge capacity[0]. That's not an especially high load; it's the amount that will drain it in 11 hours of use, but if the device quits at 1.2V, it will only run for 4.5 hours. 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%20AA%20UK.html https://lygte-info.dk/review/batteries2012/Amazon%20basic%20...
- mmt 8y ago
  > it will only run for 4.5 hours 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.
  - Zak 8y ago
    I was surprised by the consumer behavior until I learned that it's motivated by a common design flaw. I am not surprised that such a design flaw exists, but I did not anticipate it specifically. Clear and consistent now? 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.
    - mmt 8y ago
      > I was surprised by the consumer behavior until I learned 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.
      - Zak 8y ago
        > I'd strongly suggest you consider the complexity, cost, and efficiency tradeoffs... before characterizing certain decisions as flaws. 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.

Many devices can't deal with the lower voltage (1.2V vs 1.5V). About half of my AA/AAA devices don't work at all.

by moogly 8y ago

Many devices can't deal with the lower voltage (1.2V vs 1.5V). About half of my AA/AAA devices don't work at all.

Many rechargeables are also slightly larger than typical alkalines. This can cause them to be difficult to remove from devices where they're inserted end-on, such as flashlights and Xbox 360 controllers.

Zak 8y ago

Those devices must have very short runtimes on alkalines. Even a 0.2A load on an alkaline AA puts it under 1.2V for most of its discharge capacity[0]. That's not an especially high load; it's the amount that will drain it in 11 hours of use, but if the device quits at 1.2V, it will only run for 4.5 hours. 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%20AA%20UK.html https://lygte-info.dk/review/batteries2012/Amazon%20basic%20...

mmt 8y ago
> it will only run for 4.5 hours 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.
- Zak 8y ago
  I was surprised by the consumer behavior until I learned that it's motivated by a common design flaw. I am not surprised that such a design flaw exists, but I did not anticipate it specifically. Clear and consistent now? 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.
  - mmt 8y ago
    > I was surprised by the consumer behavior until I learned 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.
    - Zak 8y ago
      > I'd strongly suggest you consider the complexity, cost, and efficiency tradeoffs... before characterizing certain decisions as flaws. 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.