Follow up to: I forgot

I can now close out the outstanding rechargeable cell mystery posted in I forgot.

Recall that I was having recollection pains, having managed to ‘lose’ two AAA rechargeable !.5 V lithium cells, similar to the type seen below.

I found them a few minutes ago, while dealing with a recurring seasonal problem that now arrives every winter.

I have a couple of remote controls that simply activate selected 13 A mains sockets, and save me having to mess around with numerous power switches on common items, or distant items.

While these are more or less excellent, they suffer one major issue – once the temperature falls below something between 5-7℃, the damned push buttons begin to stop working, and no amount of pressing will get the remote to issue its commands.

This is so predictable I’ve given up dealing with the problem, and just open one up, and use a metal link to bridge the contact areas on the PCB. Much simpler and far less frustrating.

It’s truly weird – the problem can be corrected by cleaning the elastomer/conductive buttons, but that generally only last for a few days, then things are dead again. I’ve hunted around for anyone that might have analysed this failure mode and explained WHY the falling temperature might cause some sort of contamination to stop the rubbery little button from conducting, but haven’t seen anything being discussed.

I’m not sure, but it does look as if something migrates out of the elastomer pad, as the contact area on the PCB seems to need to be cleaned before reliable operation fully returns.

As regards my missing lithium cells.

Seems I thought it might be a good idea to check if falling cell voltage on the ordinary AAAs in the remote might lead to early onset failure, so decided to throw in the lithium goodies, since they regulate the lithium power source’s voltage (over 3.7 V) to a constant 1.5 V.

Sad to say, this made NO difference, and the remote was still dead to it own keypads.

And, of course, I promptly forgot I had put my shiny new rechargeable lithium AAAs in that remote.

🙄

I forgot

I’m not sure if my memory is as bad as I think, or if I’m just not as ready to lie as some people are when THEY forget.

I’d even been looking for a nice example from one of my ‘bad days’ as an excuse to use this meme, just for fun, when a genuine example arrived.

I really can forget what I’m doing while I’m doing it, but there is a reason – and it’s simply that what I’m doing might happen to remind me of something I have to do, and I start thinking about it. The danger of that being if it’s something that needs to be thought about, then that’s what I do – at the expense of what I’m in the middle of doing already.

Recently, I came across a clearance sale of rechargeable lithium-ion AA and AAA cells, crucially, NOT the type that are just normal rechargeable lithium-ion cells manufactured to the dimensions of AA and AAA cells, but the more recent innovation which includes individual charges and buck circuits inside so they can provide 1.5 V DC, rather than the usual 3.7 – 4.2 V from such cells.

While I’m perfectly happy with my collection of NiMH cells, and they power most of my AA and AAA toys (unless they HAVE to use a traditional chemical cell – never use alkaline, they will LEAK and kill your goodies, especially if you forget them), there are some that will NOT operate from the NiMH voltage of about 1.2 V on load, and DEMAND the full 1.5 V of a traditional cell – and these active lithium-ion cells are just the job.

However…

With a mixture of options, you have to be careful what you use and where you use it.

Most are obvious. The standard chemical cells are fairly easy, and nearly all live in the same type of device, and their end of life is obvious, and usually spotted the same day the cell dies.

Previously, everything else had been easy, since it would, by default, be NiMH.

Not so with the new lithium-ion option ☹

These end up in my more demanding goodies, mostly not in continuous use. I’m also using these cells in devices where I want to find out if they’re better in use than NiMH.

I THOUGHT I was being careful and conscientious – but learnt that wasn’t the case.

I ‘lost’ four of them, until I realised I’d thrown them in my bike lights one night, just to see how they looked, then forgot all about them as I hadn’t really been planning to go cycling, but for a change in the icy weather (to not icy).

That prompted an audit, since I noticed I still had empty space in my cell storage box.

That was some weeks ago now, and I have to admit that I’ve managed to lose TWO AAA cells, with not the slightest clue where they might be.

I now wander around the house looking for something that uses AAA power that I might have forgotten about, and can’t understand where they’ve gone. After all, I must have fitted them to something battery powered that I use, and on that basis should be using it at some point, and should therefore find them.

But, no, and I’ve even resorted to digging up stuff I seldom, or no longer use, just to check the battery compartments – which are always empty, since I don’t want to lose anything to battery leak corrosion.

NOPE

Well, that didn’t work.

The ploy of writing a post often triggers something, just to make the post redundant.

Not this time 😢

STILL have the slightest idea where those missing AAs are.

But I’m sure they’re laughing at me from their little hideout.