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Comment by jchw

8 hours ago

I believe I have zero Alkaline batteries left in my house and I'm relatively surprised that pretty much everything works fine. If anything, I suspect the only problem is that some devices have an inaccurate account of how dead the batteries are. But I use Eneloops on everything, even things surely not designed at all to run on them. (And I reckon you could probably make more devices work if you really wanted to; adding an additional cell or two in series would surely give you a voltage that's in range, if you can figure out a good way to do it.)

Of course not all rechargable batteries are the same; there are a few different rechargable battery chemistries in the AA form factor. I like Eneloop Pros, though; they've been very reliable for me. I've been using them for years and I've never had to throw one out yet; supposedly they last over a thousand cycles with most of their capacity.

I have a weather station that takes two 1.2 V. The LCD screen is a bit dim compared to when used with fresh 1.5 V alkalines. Other than that, most things take the 1.2 V well. But they better do because alkalines reach 1.2 V with >50% capacity left.

I think I have only one device that uses AA - my central heating's radio thermostat. This thing has caused me untold hassle, which is only partially down to the batteries, but still...

Totally OT, but does anyone have a good link on how the thermostat gets paired with the boiler? I'm thinking of getting replaced and would like to talk to the gas fitter from a vaguely informed point of view.

  • Personally, I keep things simple. Got a new (pretty basic) Honeywell thermostat after a kitchen fire; thermostat was pretty old anyway. For wiring, you mostly have 2-wire and 3-wire although there are a lot of variations as you get fancier: https://nassaunationalcable.com/blogs/blog/a-full-guide-to-t...

    Number of zones in the house may affect things as may boiler only or AC being in the picture as well.

  • Thermostats (aka space temperature sensors) can have between two and eight wires. A boiler will usually have three: 24V power, call for heat, and common.

    If your boiler has inputs on the terminal block for a thermostat, I would highly recommend buying a wired one, the 24V constant power removes the need for batteries.

    If you can provide a link to your boiler’s installation and operations manual, I can tell you.

  • > good link on how the thermostat gets paired with the boiler?

    You should have a book with the boiler that says how your system is setup. They nearly always include schematics and are very helpful. Typically you can open a cover and see the wiring details as well.

    Forget about web sites, there are too many different ways a system can be setup, so even if they are not slop they can still be inapplicable for you. Once you know what you are looking at you can sometimes get useful information from the web, but until then you can't sort out what is useful for you.

    • Yeah. Have your manuals handy if you get a furnace guy/electrician in. My electrician actually wired up my thermostat wrong when I got a new thermostat in.

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Three things prevent me from eliminating all alkalines:

* smoke and CO detectors with low-battery voltage sensors calibrated to alkaline

* some older electronics (e.g. multimeters) using 9V batteries

* my non-contact voltage tester refuses to turn on using NiMH, for safety reasons presumably

  • There are 9V NiMHs, too. They just need dedicated charger.

    • Yeah, most of the devices using 9V are smoke/CO detectors which only accept alkalines. I don't use the few remaining 9V devices enough to justify buying a new charger.