(Note: there are several later addenda at the end of this question. If you're re-reading the question; it's probably better to start at the bottom.)

I recently asked, "Can fully drained NiMH AA batteries be recovered?". Within a day or so this question was closed as being a duplicate by people apparently not reading it (I had the answer to the "duplicate" in my very question), but I seem to have gotten that part sorted and it got reopened.

But it was then immediately closed again as, "off topic," with the message saying:

Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?

Unfortunately, I'm at rather a loss to figure out why this is off-topic or how to fix it. I've considered my question in light of the two answers to "Is asking on how to fix a faulty circuit on topic?" (ignoring that I'm not asking how to fix a circuit :-P) and I can't see where I'm going wrong.

Looking at the points in one of the answers:

The OP has no electronics experience and can only say "it's not working."

This seems clearly not applicable. I'm no expert, but I have a fair amount of hobbyist electronics experience, and in the question I give voltage measurements, demonstrate that I understand that all these cells are below the standard level for "empty" for NiMH, and indicate that I have test equipment and can build circuits of the sort I suspect may help fix the issue.

The device contains proprietary/custom chips (no documentation)

No; the devices are standard NiMH cells.

The circuit needs specialized equipment and knowledge for debugging

Not as far as I know, at least not in the context of EESE. Bench power supplies (obviously with current limiting), being able to build simple constant-current battery chargers (with manual time limiting) and the like are not "specialized equipment" for electronics hobbyists, much less technicians.

The circuit is part of a module that is in a "throw-away" circuit.

No, the module is intended to be re-used. (NiMH cells are intended to be recharged many times.)

It's really dead (wrong power supply voltage, lightning, blunt force trauma)

Well, that's the question I'm interested in learning the answer to. And given that a couple of answers did sneak in that indicate a couple of ways to attempt recovery, it seems that they're not guaranteed "really dead"; they might or might not be.

The complexity of the circuit and debugging is beyond what is reasonable.

I am no expert, but it doesn't seem "beyond reasonable" to me (which maybe should be further indication that it's not "beyond reasonable"), and the answers so far suggest what appear to me to be eminently reasonable, even dead easy, debugging/recovery suggestions.

Another answer says,

I enjoy answering repair questions if they are asked in a way beneficial to others, i.e. show some research effort. As I said here, "much can be learned about electrical engineering when troubleshooting existing circuits and looking for the root causes of [the] exact types of failure."

Well, I think my question demonstrates "research" effort: I explain what happened and provide clear diagnostic measurements that demonstrate the current state of the cells.

And I particularly agree with the implication that, even if something can't be repaired, the attempt to do so can be a great learning experience. That's very much what I'm aiming at here; I obviously don't care that much if I ever recover $5 worth of NiMH cells that can be easily replaced (and even if I do get them charging again, I am guessing that their capacity and perhaps lifetime will be greatly reduced), but I feel that the answers to this question are likely to teach me more about how NiMH cells work.

So does anybody have any concrete suggestions as to what I should change in my question above so that a) it can be re-opened, and b) it won't be voted "off topic" again? Or, even in light of the existing answers (which are along the lines I was looking for), is this question really off-topic for EESE and, if so, why?

EDIT: I just noticed that the edit logs also now contain information about who has closed and re-opened questions. Here's the sequence of happened, according to those logs.

  1. Question posted.
  2. Several people vote to close as duplicate of At what voltage is a NiMH battery empty?, apparently not realising that I had given the answer to that "duplicate" question in my question: "...well below the suggested full discharge level of 0.9-1.0 V."
  3. I add a note to the head of the question explaining that I know the answer to the "duplicate," and that's not my question.
  4. The question was then closed through voting: "Post Closed as "Duplicate" by Andy aka, ocrdu, Voltage Spike♦"
  5. The question was then reviewed by a moderators, and "Left closed in review as "Original close reason(s) were not resolved" by Voltage Spike♦"
  6. I then added another paragraph at the head repeating again, in more detail, that I know at what voltage an NiMH cell is considered "empty."
  7. The question was re-opened through voting: "Post Reopened by Math Keeps Me Busy, cjs, Voltage Spike♦"
  8. The question was then immediately closed again by a moderator, with no voting as far as I can tell: "Post Closed as "Not suitable for this site" by Voltage Spike♦"

Perhaps @VoltageSpike can chime in and explain why they think this post is not suitable? I've given my analysis above as to why it seems fine to me, including a detailed analysis against the criteria for off-topic questions that is linked in the close notice.

I'll happily accept feedback from other moderators, too.

In light of Voltage Spike♦'s initial (very brief) answer, I've found what seems to be a similar question that was quite well accepted (at 16 upvotes, at least 29 upvotes on the accepted answer): "Is it possible to revive a dead battery by passing a high voltage through it?". I'd be particularly interested in any pointers to the differences between my question and that one that make my question bad but that one good.

  • \$\begingroup\$ I will edit your question to see if it can be revived. \$\endgroup\$ Apr 14 at 12:19
  • \$\begingroup\$ Your edit doesn't really seem to address the problem. You've essentially changed my question into a completely different question about a certain failure mode that you're assuming I have. But I don't know if that's the failure my batteries suffered: I just know to what environmental factors they were exposed and what a measured about them afterwards, which I why I described those rather than a guess at what the particulars of the failure might be. \$\endgroup\$
    – cjs
    Apr 14 at 12:52
  • \$\begingroup\$ I will roll back my edit, if you like. Just trying to help. \$\endgroup\$ Apr 14 at 12:53
  • \$\begingroup\$ At any rate, I think I'm going to roll that change back. I'm not comfortable with asking a question about dendrites and fixing them when I have no idea if that's even the the current state of the cells; if likely is because of what they experienced that that should go in an answer, not the question (along with how to check if that's actually the problem, if relevant). If you can describe what's wrong with the question I am asking, rather than some different question, that would be a lot more helpful to me. \$\endgroup\$
    – cjs
    Apr 14 at 12:54
  • \$\begingroup\$ @MathKeepsMeBusy Yes, if you could roll back that edit, that would be great. It seems I can't do that. \$\endgroup\$
    – cjs
    Apr 14 at 12:55
  • 1
    \$\begingroup\$ I added a comment with a link to this post under the question. Doing so whenever discussing a post on meta is a good thing, which means that everyone who has something to say should do it here and not in comments, which distracts from the topic. \$\endgroup\$
    – Lundin
    Apr 15 at 9:43
  • \$\begingroup\$ @cjs I removed that note on top and the question is now in re-open review once more. I'm voting to re-open. \$\endgroup\$
    – Lundin
    Apr 15 at 9:46
  • \$\begingroup\$ @Lundin Thanks. Given my past experience with this question I am dubious about removing that note, but I guess we'll see how it turns out this time. \$\endgroup\$
    – cjs
    Apr 15 at 9:52

2 Answers 2


To point out what's on-topic and off-topic here:

Theoretical questions about battery chemistries, charging, design of charger circuits etc is of course perfectly on-topic.

Repair questions where the poster has demonstrated some basic electronics knowledge of the topic and have access to the necessary equipment to troubleshoot & repair (most of the time: multimeter, oscilloscope and soldering iron). Ideally these posts should have some background work posted such as measurements, schematics, datasheets or what else that's applicable.

Also they need to know enough of electrical safety to go through with repairing the device or otherwise answering the question would be plain dangerous (mainly applicable to VAC mains equipment but also to things like Li/Ion batteries).

This particular question is a bit of a grey area, it is a big vague but mostly OK I think. The main issue is that it's not really answerable in case it asks "can this particular cell here be recovered" - nobody knows that. But if it asks "how can you recover discharged NiMH cells" in general, that ought to be on-topic and there's an answer posted answering that question too.

What's not helping when a question is closed however, is to edit in rants about why the question shouldn't be closed in the question itself. Instead you should simply try to improve the question and add more details if possible. Doing so will put the question in a reopen review queue carried out by 3 other users (or a single moderator as was the case here). Arguments against the question getting closed should be posted in comments or indeed here at meta.

The duplicate used for closing the first time was a poor choice and perhaps unfair. As you noted yourself, Is it possible to revive a dead battery by passing a high voltage through it? would have been a much better choice.

After the post got closed it ended up in the review queue quite a few times and overall it's a bit of a mess with changing the question completely etc: https://electronics.stackexchange.com/posts/709595/timeline#review_368160

At this point I don't think there's a point trying to salvage this. But in general, edits should seek to improve the question, not change it to something else, in which case asking a completely new question is preferred.

  • \$\begingroup\$ The change that utterly changed the question (not done by me) was quickly rolled back, and the question has been the same as it originally was since then. In light of that, do you still think that the question is unsalvageable? \$\endgroup\$
    – cjs
    Apr 15 at 9:22
  • \$\begingroup\$ As for the "rants": I'm open to suggestions about what to do about that. But I don't really know what to do when people don't read the question to see that my question includes the answer to the supposed duplicate, and continue to suggest it's a duplicate even after I put a big note at the top pointing this out. (Thus the second note.) \$\endgroup\$
    – cjs
    Apr 15 at 9:24
  • \$\begingroup\$ As for the suggestion that I rephrase it slightly from "can this cell be recovered" to "how might one try to recover this cell," I'm happy with that; to me both are the same question. I will try that. \$\endgroup\$
    – cjs
    Apr 15 at 9:25
  • 2
    \$\begingroup\$ @cjs It probably could be salvaged if all those "rants" are removed and the question is left purely technical, adding as many details as you can. You could for example mention that you expect the voltage range of a NiMH cell to be between x and y volts, yet measure z volts. And indeed the more the question turns into a general one about recovering NiMH cells more so than how to recover this one specific cell, the better a fit for the site. If the post you linked answered the question though, then you risk getting it closed as duplicate once more (but correctly this time). \$\endgroup\$
    – Lundin
    Apr 15 at 9:29
  • \$\begingroup\$ I have cleaned up the "rants"; but I'm reluctant to remove the prominent notice at the start given that people voting to close as duplicate do not seem to be reading even the first paragraph of the question otherwise. And I have given the the measured voltages of the NiMH cells from the start; given that a good understanding of NiMH batteries is a clear requirement to answer this question, and anybody with even a not-so-good understanding knows the expected voltages under various circumstances, is that sort of thing necessary to put in to the question? It feels patronizing to me. \$\endgroup\$
    – cjs
    Apr 15 at 9:37
  • \$\begingroup\$ (I also note that, as the question was originally written, I received what I feel are one good and one excellent answer before it was closed. Do those answers seem off-topic for this site?) \$\endgroup\$
    – cjs
    Apr 15 at 9:39
  • 2
    \$\begingroup\$ @cjs The note on top shouldn't be there, it is very distracting. And also it is not necessary, you should leave such notes in comments. And if that doesn't help, indeed bring it to meta like you did. The answers seem fine and on-topic. \$\endgroup\$
    – Lundin
    Apr 15 at 9:41
  • 2
    \$\begingroup\$ It was clearly necessary because even when I had a more subtle version of it there, people were voting to close as a duplicate of the "at what voltage empty" question. If the close-voters are not reading the question, and not even reading the first pargraph of the question, why would they be reading the comments? (And also, I don't expect people answering or otherwise interacting with the question to have to read the comments; everything they need to know should be in the question itself. I edit to add further information if the comments bring something up that's missing in the question.) \$\endgroup\$
    – cjs
    Apr 15 at 9:49
  • 2
    \$\begingroup\$ @cjs If people cast close votes incorrectly, then that's their problem - we do have some problems with some people picking the wrong reason or being too trigger happy in closing posts. But as I tried to explain in the answer, the best way to appeal to re-opening is to just polish and improve the question further with edits of the technical content. Or alternatively bring it to meta. \$\endgroup\$
    – Lundin
    Apr 15 at 9:54
  • \$\begingroup\$ Well, I'm going to disagree with that to some extent at least: when a question is incorrectly closed, it's also a problem for the OP (and anybody else who would find an answer useful). As for further edits of the technical content, that strikes me as dodgy at best: given that there's nothing really missing in the original technical content (at least, not that I've been informed of), massaging the text while leaving the same essential meaning could be interpreted as trying to game the moderation system (and quite reasonably so, I think). \$\endgroup\$
    – cjs
    Apr 15 at 9:58
  • 1
    \$\begingroup\$ @cjs Wrong close votes is a different bigger problem though. Check out What should we do about the bad close vote culture of this site? Nothing really came out of it though. Lots of experienced moderators and veteran users also left the sinking ship as per the "Monica incident" some years ago. \$\endgroup\$
    – Lundin
    Apr 15 at 10:07
  • \$\begingroup\$ Upon reading your link I do see how there's apparently a problem with close votes on this site (mainly, I'll take your word for it as I don't read this site a huge amount). But that doesn't mean that individuals like my trying to get an answer don't have a problem. Just because there's a general problem doesn't mean that individual instances of the problem aren't a problem for individuals like me. \$\endgroup\$
    – cjs
    Apr 15 at 12:26
  • \$\begingroup\$ @cjs cough There's always electrical.codidact.com. It is somewhat more tolerant but largely got the same rules as here. \$\endgroup\$
    – Lundin
    Apr 15 at 13:57

Deep discharge is a nature of the beast scenario for batteries, and thus part of their every day use scenario. There's nothing to "repair".

I suppose I would have voted to close as a "use of electronic devices" question if I had seen the question before closing, and don't see a path to reopen, unless the question is changed to something like "what about battery chemistry makes recharging deeply discharged NiMH cells difficult?" -- but you don't get a guarantee that someone will give you tips on recharging them.

That said, the close queue isn't particularly good. Three different people can choose three different close reasons, and only one reason will be reported. There's also no way for any voter to select more than one applicable reason. That's the nature of our particular beast.

As an epiphenomenon to this, I suppose one can make noise about how the close reason given doesn't really apply, and you wouldn't be addressing every close-voter's issues.

FWIW, the SE format simply isn't amenable to some kinds of questions. It's hard to believe, though, that a simple search on the issue you're asking about wouldn't yield dozens of valuable hits.

  • \$\begingroup\$ Especially for things like this, where I feel there's some potential for explosion/fire/etc., I prefer to find answers in a forum where they can be reviewed by others, rather than just random web pages or videos on the net. \$\endgroup\$
    – cjs
    Apr 17 at 2:21
  • \$\begingroup\$ @cjs, as many would tell you, this isn't a forum. \$\endgroup\$ Apr 17 at 12:14
  • \$\begingroup\$ I was using the word "forum" in the sense of a place where people can review and comment on answers, not in the sense of "discussion forum." I am open to a better word for the sense I'm trying to convey, but I can't think of one myself. \$\endgroup\$
    – cjs
    Apr 17 at 12:17

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