Batteries

[tarmactatt]

Very much in favour of both rechargable and disposable cells, on a case by case basis.

Your current options* (until a new battery chemistry is invented) are:

Disposable:
Akaline batteries:
1.5v per cell
+ good capacity at low currents (clocks, TV remotes, etc)
+ reasonably cheap.
- poor ability to deliver lots of power in a short time (current)
- can leak and damage your device

Lithium - (Energizer lithium etc):
1.5v per cell (sometimes slightly higher but most products don't mind)
+ Good for higher currents (bright LED torches, cameras etc)
+ Good capacity
+ Good (the best?) Standby shelf life.
+ Don't leak
- Expensive

Rechargeable:
NiMh - These are 'normal' rechargable AA or AAA. The original chemistry used to self-discharge while sat on a shelf, get some ones with newer chemistry which holds charge better, often advertised as Low Self Discharge (or, Ready to Use,, which should indicate they're not flat when you take them home from the shop!)

1.2V per cell (higher fresh off a charger, sometimes things act weird with the slightly lower voltage)
+ Available with good capacity (mAh number on the side)
+ Great power delivery, even when fairly cold
+ Don't leak

For something that uses up a battery or set of batteries in less than 2 - 3 hours, you'll get better performance/runtime out of NiMh rechargable batteries. This is even more of a factor at lower temperatures.

For low current draw (1*AA clocks, TV remotes, etc), you'll get longer use from alkaline.

That said: I've had a couple of devices damaged by leaking alkaline batteries, so I prefer rechargable where possible.

Do also bear in mind that 0.9v per cell is empty for NiMh, if you've an electronic device that keeps sucking power from the rechargable battery, you'll ruin them quite quickly.

Lastly, to get most out of NiMh, I recommend a charger which can monitor each cell (rather than dumb chargers which just cook cells in pairs, regardless of whether they both need charging).

I like the IKEA Ladda AA and AAA rechargable cells. I've not had a single one go bad (unlike my silver Energizer's from about 8 years ago which died after only modest use). I also like the IKEA Alkaline cells. I get 9v Duracell's from eBay because they're cheap (reading this thread, I've realised I need some more so I'll look at other brands).

*Rechargeable lithium ion batteries in the size of AA/AAA do exist but are complicated. For starters, they are 3.7V so won't work with most of your devices. They require a specific charger. Some have a charging/regulator circuit built into the the cell to make them 1.5v, but this reduces capacity and introduces a potential point of failure. I've not seen any mainstream/trustworthy brands selling them.

[jennyjj01]

... I also like the IKEA Alkaline cells. I get 9v Duracell's from eBay because they're cheap (reading this thread, I've realised I need some more so I'll look at other brands).

The yellow Alkaline batteries from IKEA were great batteries (varta again?)
BUT Ikea stopped selling them in 2021.
https://www.ikea.com/us/en/newsroom/cor ... ubb6aee8b0

You can still get them from eBay, but they MAY have already sat on the shelf a while.

*Rechargeable lithium ion batteries in the size of AA/AAA do exist but are complicated. For starters, they are 3.7V so won't work with most of your devices. They require a specific charger. Some have a charging/regulator circuit built into the the cell to make them 1.5v, but this reduces capacity and introduces a potential point of failure. I've not seen any mainstream/trustworthy brands selling them.

If Energy density is your thing, Lithium Ion 18650 cells are becoming mainstream. They are what many cars run on. (thousands of the beggars) You can get lamps and torches that take them.

[Frnc]

... I also like the IKEA Alkaline cells. I get 9v Duracell's from eBay because they're cheap (reading this thread, I've realised I need some more so I'll look at other brands).

The yellow Alkaline batteries from IKEA were great batteries (varta again?)
BUT Ikea stopped selling them in 2021.
https://www.ikea.com/us/en/newsroom/cor ... ubb6aee8b0

You can still get them from eBay, but they MAY have already sat on the shelf a while.

*Rechargeable lithium ion batteries in the size of AA/AAA do exist but are complicated. For starters, they are 3.7V so won't work with most of your devices. They require a specific charger. Some have a charging/regulator circuit built into the the cell to make them 1.5v, but this reduces capacity and introduces a potential point of failure. I've not seen any mainstream/trustworthy brands selling them.

If Energy density is your thing, Lithium Ion 18650 cells are becoming mainstream. They are what many cars run on. (thousands of the beggars) You can get lamps and torches that take them.

I have a torch with one in. Been in years, still works. Also my windup/solar/usb radio has two. Batteries are expensive but good. You should store lipo batteries roughly half charged. Some people say they don't like being fully charged or fully discharged. I've charged my torch one a couple of times, not that it needed it. I have a better charger now that gives info eg capacity.

[Frnc]

Spent a couple of hours making a spreadsheet just for batteries. Realised I never bought spares for my loupes. Sorted a few random AAAs and AAs for chucking. I also recorded where the batteries are. So now I have a good overview of all the dates, bought, best before, expected life, when to charge and check. Obviously some I have to guess. Annoyingly, EBL say "don't mix old with new" but don't have dates on them.

[Frnc]

here's what my spreadsheet looks like, or at least the top half of it

[Frnc]

note to Jenny, Duracell AAs I use for my keyboard and trackpad aren't on there, because they aren't prep related, are ancient, and get charged every week or two. I have 4 on the go and 4 charging or ready for use.

[Norma]

Any thoughts on battery chargers, please? I’m happy to pay for good quality that will last and charge quickly. Brand leaders seem to be Varta and Ansmann. Is there much difference or does it come down to personal preference ?

[tarmactatt]

Regarding "best" NiMh Cells, this website is good for comparing like-for-like (when the cell you're interested in has been tested):

http://aacycler.com/

For Li-ion rechargeable cells (e.g. 18650 cells which have been mentioned), and battery chargers, I like this review website:

https://lygte-info.dk/info/indexBatteri ... %20UK.html

For NiMh, I've not seen anything good on the shelf of Argos/B&Q etc, you're best going with something that will charge cells individually (rather than as a set) and has some kind of "smart" charging termination, VS the rubbish, "dumb" X current for timed charge types.

Not all the chargers reviewed on that website will do NiMh, check before you order one from AliExpress or eBay etc

[Frnc]

Anyone know of a 18650 tester that tells you immediately what % of capacity it's at? I have a charger that tells you, but I charged the batteries in the radio, put them in the charger, and started counting up from zero again! I was scared of overcharging as the radio said they were already full, so I took them out.

[tarmactatt]

Anyone know of a 18650 tester that tells you immediately what % of capacity it's at? I have a charger that tells you, but I charged the batteries in the radio, put them in the charger, and started counting up from zero again! I was scared of overcharging as the radio said they were already full, so I took them out.

The chemistry allows an approximation to be made from the voltage (as opposed to NiMh, which don't lose voltage in a linear fashion as they run down). Measure the voltage when the cell has been standing for a few hours or so (straight out of the charger the voltage will be slightly higher than "resting" voltage). 4.2V ish, is fully charged, about 3 is empty. Over 4.25 or below 3v is quite bad.

What charger do you have? If both radio and cjarger have correct electronics (lots of things don't!), then neither will over charge as they use Constant Current/Constant Voltage algorithm - apply eg.500ma to the cell until it gets to a certain voltage, then use the full cell voltage (4.2v) and reduce the current until 0ma.

This info good to know in a rolling blackout situation, your chargers will charge a flat lithium cell faster (in the Constant Current part of the charge cycle) than one that's almost full (reducing current while in Constant Voltage part of the algorithm).