1.5v Lithium AA rechargable batteries

[steves1977uk]

BM, have you tried these batteries?... https://www.batterystation.co.uk/xtar-1 ... es-4-pack/

The Eneloop Pro don't seem to last very long in my Fluke 289 multimeter. Would those Xtar ones fare any better?

Thanks for any advice.

Steve

[Burgerman]

Depends what you mean by last.

If you mean stand by shelf or not turned on life, then most nickel metal batteries/cells are much worse than lithium. SOME but not all, and certainly not the "high capacity" eneloops can have an extremely long shelf life and still be charged after say 18 months or 2 years. Depends what you are looking for or what you buy. They also can be hard to charge correctly. But I use the white ones with less cycle life, less capacity and long shelf life.

If you want ones that have high capacity so they dont die while using it intensively, and you charge regularly then the fancy 2450mAh ones would be best.

As for lithium AA cells they are "fragile" and have a built in inverter that takes the lithium 3.7V and reduces it to 1.5V. That wastes efficiency. Some of them also have a residual current drain. Which ruins the stand by shelf life. Some dont. Bare lithium cells have a great very slow self discharge and will stay charged a long time. But then the fact that you are storing them full is also bad for them! So I stick to the white eneloops in my Fluke 289. Alhough those ones should work OK. Dont buy any that are on amazon or ebay... Those are junk! Tried that already.

[martin007]

Don't you like disposable alkaline batteries?

[Burgerman]

No. Why would you use those for anything in 2024?

Possible exception, a clock. Or doorbell. Everything else is better served by rechargables. Be they lithium or nickel metal.

[martin007]

No. Why would you use those for anything in 2024?

Possible exception, a clock. Or doorbell. Everything else is better served by rechargables. Be they lithium or nickel metal.

Alkaline batteries are comfortable and cheap.
I use them in clock, TV remote control and flashlight.

[Burgerman]

For things with extremely low drain, like a clock, they make some sense. But decent ones dont cost much less than rechargables. And of course that means you get to use them 500 times...

In something that just needs to provide some voltage and has almost zero drain current like a clock then they make sense as they have a very long shelf life, low discharge rate.

For anything hat draws any sort of normal current like cameras, radios, RC stuff, most TV remotes, your house phone, shavers, torches, and so on, then decent low self discharge cells make more long term economic sense. And you dont need to waste £5 of fuel in search of a new battery when something doesent work! Every few months, collect them all up and recharge the lot! Nothing then ever goes dead. And even your clock goes forever.

For anything that has a high drain like toys and things with motors in, dry cells like energiser or duracell dont work well at all. Internal resistance far too high. The device stops working when the battery is still about 2/3rds good.

So it all depends... Lithium has extremely low self discharge, and low internal resistance. Best of both worlds but it is too high voltage for many things. So they started making those AA/lithium things with built in buck inverter... Those die regularly if you take too much current.


Also if you take an alkaline battery that is not dead, and the more charge remaining the better, you CAN recharge it half a dozen times. If you are careful, do it slowly, and take a lot of care! It gets to around 90% of original charged state. Then they get hot and can pop and spew out some clear gunge. So only if you know what you are doing! PL8...

[martin007]

A multimeter consumes little energy...

[Burgerman]

Yours may. The fluke meter steve is talking however is a computerised logging meter and it samples at very high frequency, has an iluminated screen, and stores data for retrieval/graphing over time. Its a computer running all the time it is in use. It isnt quite a low drain device. When it is sat on the shelf turned off, all that matters is shelf life (low self discharge cells like enneloop white or duracell etc are best). When in use they do use battery power relatively quickly. And so a low resistance cell like the white eneloop ones give a long runtime and so will good alkalines in this case.

This is an in between case. So a set of duracell or other low resistance cells like the duracells, will work almost the same. With the difference that you can recharge them when its been used for a day. Or every 6 months or so if unused to make sure they are full and ready to go without re-buying new ones...

So either alkaline or long shelf life white eneloop rechargable will both work well. But eneloop will be cheaper and always full.

[martin007]

I understand.
Which model is it?

[Burgerman]

Steves? Same as mine.
Fluke 289

[martin007]

Also I have Fluke.
But of a lower range...

[Burgerman]

I have a cheaper one too. Its battery lasts forever. But it cant do many of the things the 289 can. For e.g monitor and graph the battery idle current over a few days on my van to find out what was sending the battery dead. Every few hours a current of 1A or so started up for around 40 mins, before dropping away to 125mA eventually. Turns out its the body control module that doesent like the computer that controls the ramp/kneel system. So I fitted a 50w solar panel and charge cntroller. It graphed this over time.

And it can show me the actual voltage while charging at high frequency on the PL8. It shows, average rms voltage, peak high voltage, peak low voltage, amount of AC current on the DC charge, etc. And can log these things.

If I connect to the house wiring, I can see the AC frequency, peak to peak voltage, RMS voltage above and below the 0V point, the shape of the waveform, the peak voltage which isnt the 240V you expect but around 320V which is why it hurts! And thats 640V pos peak to negative peak. And thats why i really hurts!
And I can log this over time.

But its massively more than I need really. I just like good tools.

[Burgerman]

I also have a basic one, the 17B. Made in china..

Good enough for most stuff. But its not certified and calibrated. And it reads around 0.15V out on a battery for e.g. Thats close enough for most basic things. Its quite accurate on DC currents, or resistance though. So its the one I use on many basic things. More than the heavier 289. That has huge certified accuracy, and many decimal place digits. And can read things that the 17B cant. Like peaks etc. But its all most people inc me really need.

[steves1977uk]

These are the batteries I have BM... https://www.panasonic.com/global/energy ... p-pro.html

I use my Fluke seldomly, so maybe I should charge them every 6 months or so. Also would charging them via the PL8 be a better option rather than the charger they came with?

Steve

[Burgerman]

Look on wikipeadia about eneloop. Those ones are great for high drain devices that need caacity and low resistance. But terrible for staying charged when on the shelf. You want the lower capacity white ones. They have 12 months sat on the shelf and still 70% full.

It doesent much matter what you charge nickel metal with. They are very hard to charge and know when to stop. Basically when charging at around 1/3rd C at CC only, you stop the moment they "peak" as the voltage rises and then starts to fall. So it it falls by say 5mV then they are full. After this the energy just goes into making heat... So you can also tell by feeling when they start to get hot. But if charging a bunch in series then you end up not seeing that peak as they are all at different stages. At this point a slow 14 hour charge at the 10 hour rate (they are very inneficient) is the best way to ensure that all end up full. And the slow charge rate doesent make a crp load of heat once they are full. Best to do that wen they are pretty much used up.

With AAs I can use the PL8 but I mostly use my dedicated cell charger the Xstar Dragon...

It does AAA and AA and almost any type of cell that I use for hobby stuff as long as its cylindrical. So lithium 21700 (tesla type) cells used in my RC transmitter, 18650, in many things, as well as a dozen others. Very useful, also tests and measures capacity too. So you know when to dump old cells...

https://www.fogstar.co.uk/collections/x ... n-br-4-bay

[steves1977uk]

Thanks BM! I'll order one of those Xtar Dragon chargers and some white eneloop AA batteries.

Steve

[Burgerman]

Its a bit overkill just to charge your multimeter. I got one as I have a good few 18650 cells, 21700 cells etc here. Used in lots of hobby stuff. And torches etc. And because I have AAA and AA in many TV style remotes for heating, doorbell and alarm stuff and light controllers and stuff.

Its just convenient to grab the cells from everything at once and charge the lot in a marathon evey now and then so everything is full! Including 3 multimeters, other tools. If not something is forever crying at me.

It can charge different cell types, sizes, chemistries all at once. So when one is done just swap for another one. Individually. Every time I hear it beep I change a cell! By the end of the day everything is charged for another period.

But if you have a mix of lithium and NMH cells laying around its useful. And you can use it to est them too. So you choose test. It charges full, discharges completely and safely and then recharges full again. Leaving you with a capacity out and in in mAh for each cell. Taes a long while. But you can bin the cells that show reduced capacity. So you dont end up with a mix of knackered cells and good ones all mixed up together!

It does say that your eneloop pro cells are 85% charged after 12 months. So those ones should be OK.
https://www.panasonic.com/global/energy ... p-pro.html

If you look at the wiki page for eneloop you will see theres loads of eneloops, and all are a bit different. Some are good for storage even 3 years or 5 years. Some less so.
This is a good page too.
https://www.wikiwand.com/en/Nickel%E2%8 ... de_battery

[steves1977uk]

That's why I'm thinking the Panasonic charger isn't fully charging the Eneloop Pro batteries properly, hence they're losing charge faster. That's why I want to get a better charger BM.

Steve