I recently asked Can I trickle-charge (constant current) NiMH cells in parallel?. Looking at the answers and on further reflection, some points now stand out to me.
First, This question has a major fundamental flaw in that it shorts the two batteries together (doh!), as pointed out by one answer. I've for the moment accepted that answer because that's obviously a problem that needs to be addressed before my real question (what are the implications of using a shared constant-current power source for two NiMH batteries in parallel?) can be addressed.
It seems to me that fixing this is fairly simple: just put a diode in front of each battery. This could of course raise its own issues, which I'd love to hear about. I've asked in a comment on the currently accepted answer, but received no reply.
At any rate, this question needs either an edit changing that key point (and invalidating that answer) or needs to be asked again without that fundamental error. (I don't find the question "can I short two batteries together" interesting, and so feel no urge to leave it on the site.)
Second, the answer has been downvoted at least twice and has more downvotes than upvotes. I'm at a bit of a loss to understand what's wrong with it (none of the downvoters explained how the question should be improved), though I have a couple of ideas. One is the fix above; perhaps people were downvoting because shorting batteries together is stupid. (I don't see that as a good reason to downvote, rather than just explain that it's a bad idea, but each to his own.) Another is that I did not explain in the question (though I did in a couple of comments) that I have indeed read up on NiMH battery charging in a textbook, and perhaps people are downvoting because they believe I've done no research on this. (One comment suggested reading a data sheet; the explanations their of NiMH behaviour seem to me clearly far inferior to the textbook chapter I was reading.) Summarising what I've read would also be a change I'd make to the question.
Possibly related to above, the other answer on the question ignores any issues of charging in parallel and seems to be trying to address whether I can trickle-charge NiMH at all (he seems to say no, which directly contradicts my textbook) and a claimed requirement for external voltage limitation that I don't understand (and is not mentioned in the textbook, which textbook seems to imply there's no need for such a thing). I've asked about this in comments on that answer (perhaps I'm missing something big here), but received no reply.
At any rate, to get towards what I'm aiming for (assuming it's not completely stupid for reasons I as yet have no clue about), I need to do a rewrite of this question that appears to totally invalidate one answer and maybe invalidates another answer (if it was ever valid in the first place) and a comment on the question. This seems like it would introduce a fair amount of confusion, and so I am thinking it may be better just to create a new question with the errors fixed and details about the textbook source added.
If I did do this, I'd want to delete the old one since, as-asked ("can I short batteries together" due to an error in the schematic, though that's neither the title nor the intent), it's not a question of interest to me. Worse, without editing, it looks like and might be confused with the new question. (Not to mention that the majority of voters seem to think it's not a good question to have on the site.)
So what's the best way to put the idea of shorting batteries together behind us and ask the question I want to ask?
The downvote issue seems to be resolved: either someone removed a downvote or the question got several more upvotes. I'm going to assume that any that remain are just the usual random rather than indications of serious problems with the question.
It appears that there's disagreement on whether connecting the batteries together without backfeed protection really is a problem or not. Given this, it seems better to keep the discussion about it all in one place instead of distributing it over separate questions.
So I'm going to rewrite the question to use a new schematic with the backfeed protection diodes and include "are these necessary?" as part of the question, which will leave the current answer relevant (albeit answering only part of the question).
Thanks for the help with and discussion about this.