switching most of my batteries over to Eneloops, but.....

On Sun, 14 Feb 2021 14:47:06 -0500, Witherspoon wrote as underneath :

Lidl do them on occasion 200mAh (not Eneloop - that is a brand name), or look for PP3 Ready to use rechargeables on eBay. But best of all are the

600mAh EBL Lithium-ion ones but you need a new different charger for those - Great longevity but 8.4 top voltage! . C+

Witherspoon wrote: =====================

** Don't try any of them in smoke alarms. Use only alkalines for that.

..... Phil

There plenty to choose from on eBay

If you have a "smart" charger and want to stick with it, there are NiMH cells out there with capacities up to 900mAH which could be used with the same charger - like this:

I believe Charlie+ is correct is saying that if you want to use rechargeable Li-ion cells, you will need a different charger. If you stick them in a "normal" charger" it will just tell you that you have a dud cell. I have seen them with capacites up to 800mAH

Alternatively, there are some Li-ion cells out there which have a built in charger, and a USB socket on the base, which means that they could be charged in situ ?

like this:

I would be interested to hear from anybody who has any of these.

Out of interest, you may like to note that I have a couple of Uniross NiCD PP3 cells, which must be at least 10 years old, but seem to still work ok - the downside is that the capacity is only 120mAH, but thats enough for a few hours service on wireless microphone system.

The main point being that all of these current rechargeable solutions offer at least 4 or 5 times the capacity of the originals, so theres no need to even think about buying something with a capacity of only 200mAH

Also, dont forget that the original "dumb" chargers had insanely low constant current charge rates - I have one which runs at only 11mA. At that rate it would take at least a week to charge one of the latest generation NiMH cells

AT

=========================

** The only common application for 9V batts I know of which has both high discharge ( ie 50mA) AND regular use is a radio mic. I doubt the OP has any of them.....

What else are are high capacity , rechargeable 9V batts good for?

The self discharge rate ruins them for most jobs.

..... Phil

Well, I have a couple of wireless guitar belt pack things, but I guess they must use the same sort of technology as wireless microphones ?

The spec for the Trantec model I have quotes a battery drain of 50mA - so you were spot on with your figure.

A while ago I bought a new battery operated doorbell - one of those "ding dong - Avon calling" things, which has a single solenoid which moves out to hit one chime and then gets the other one on the way back.

I was astonished to see that its powered by a 9v battery, and yet more astonished when I discovered that the 120mAH NiCD will deliver the surge current required to shift the thing, whereas a 300mAH NiMH will simply not do the job. I have tried this out with 3 different NiCDs and a couple of the NiMH cells and the results are consistent.

Obviously the cells are in reasonable condition and have been charged to death prior to the tests.

Out of curiosity I am going to try out with Li-ion cells to see if the story is any different. Maybe theres more to this lark than meets the eye, and its not just about capacity.

AT

Maybe he's got an old transistor radio. I've got a portable tape player (not cassette, it's open reel) that uses I think two or four C cells for the motors and a 9V for the "brains".

I gather that there are a bunch of small electronics projects that use nine volt batteries, too. Arduino 9V battery connectors are something I've seen for sale a number of times.

Elijah

------ has no personal experience using an Arduino 9V battery connector

Eli the Bearded wrote: =================== Phil Allison

** LOL- had one like that when I was 12 years old - in 1964. 3 inch reels , non capstan drive. The 9V batt lasted well - the C cells, not so much. ** But not likely to be heavily and regularly used.

My ESR meter ( Bob Parker ) uses a 9V batt - but gets about 1 short use a week.

..... Phil

Abandoned_Trolley wrote: =======================

** Of course, just no actual mic capsule.

** I have dealt with a few of the beasts .....

** What a POS design !

A fresh 9V alkaline will deliver about 8 amps into a short as will a NiMh.

Have you tried adding a 2,200uF 10V cap in parallel with the batt? Good for about 0.1 Joules

** Some items draw very high currents, small digital cameras for example. Alkaline AAs give poor life times, NiMh are far better - but need regular topping up. Same goes for camera flash guns using AAs.

..... Phil

Well, I was considering the other firms making such 9V batteries these days (Tenergy, etc), but the reviews paint a horrible picture on Amazon.

So, what I did was take the 18650's out of dollar store cell phone power banks, put two in series for roughly 7.4V, and have been using that for some 9V items I have. Voltage is a bit low and it almost has to be mounted externally, but most things I use it with seem happy. And

I kept the charger guts for when they need recharged. Might not look pretty, but it works and a lot cheaper then even a new 9V alkaline.

On Mon, 15 Feb 2021 12:49:06 +0000, Abandoned_Trolley wrote as underneath :

You have to be careful of the sales hype, stating a high capacity raises battery sales so : AFAIK real PP3 capacity maximums are mAh approx: NiMh 200 (same for the LSD types). NiCd 200 Li-ion 600 Li-Fe Never seen or used one so unknown. Some of the quoted capacities on eBay are pure bullshit - so Situation Normal! The Li-ion ones have a BMS inside so no reason why the ones with uUSB feed shouldnt work OK but real capacity you have to test and see: presumably the converter will take up some of the room that should be battery capacity so expect less than 600 in true capacity. C+

I got my parents a starter set of Eneloops a while back and they've been very impressed. When it came to looking for myself I also noticed a lack of 9V Eneloops.

I've had some decent results with the Amazon Basics 9Vs, but I'm not a very heavy user. My DMM uses one, and the others are primarily for final testing a type of guitar preamp that I repair for people.

I'm not sure if they hold up under heavy usage, but considering I use them infrequently and they're still charged when I do, I can't complain

Bradley Bowman wrote: ====================

** Those are Alkaline types, so non rechargeable. ** Amazon also have a Lithium version with 10 year shelf life.

..... Phil

Ah, my mistake, I was unclear. The ones I'm using are the Amazon Basics Ni-MH variety. I didn't notice they had Li-ion ones as well when I bought a set.

Bradley Bowman wrote: ==================

** In a DMM ?? Don't you get tired of having to recharge it ? ** Not Li-ion, non rechargeable lithium.

There are lots of sub types of "lithium" - most commonly they are 3V cells. So three inside a 9V unit.

.... Phil

Well, no.

That's what impressed me. I didn't really expect them to work as well for me as they do at a pretty low price point. They might not be the right choice for a heavier user though.

Gotcha, I was skimming too quick that day. I see the ones you're talking about now. After a closer search, I realized the Li-ion 9Vs I saw then weren't Amazon Basics brand -- though they "looked" like the Amazon Basics at first blush (same color scheme).