Author Topic: Rechargeable Alkalines?  (Read 6012 times)

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Online tooki

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Re: Rechargeable Alkalines?
« Reply #50 on: December 30, 2024, 01:23:04 am »
So… because Apple has strong brand loyalty (which, I will add, may be the result of their design decisions, not because of fanaticism), it gets held to a higher standard than its competitors?!?  :-//

Where did I write that?  I just wrote that their high brand loyalty allows them to take more liberties when it comes to building in obsolescence through software.  You can argue whether it is moral or not independently of that.
Well it is what you argued in the original criticism. How come you criticize Apple for only providing 7 years of phone software updates, when everyone else struggles to deliver 3 years? That is a huge double-standard.

Perhaps those 7 years of support are a reason Apple has such brand loyalty.
 

Offline Siwastaja

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Re: Rechargeable Alkalines?
« Reply #51 on: December 30, 2024, 07:47:08 am »
Yes, I've had similar problems. I have a smoke alarm which starts beeping when the voltage is just below 8V.

Are you sure and how did you measure?

Smoke alarms use integrated circuits that do ESR analysis on they battery, basically with short current pulses every now and then. This is crucial to their operation because the only thing which really consumes power in a smoke alarm is the alarm itself, and it only activates in real emergency, and it has to work. But batteries have two orthogonal aging mechanisms, capacity fade and ESR increase. In very low power application like smoke alarm the ESR increase dominates. But open-circuit voltage of the cell is relative to loss of capacity, you can't see the ESR increase with the 10Mohm or 1Mohm input impedance of the multimeter. You need to measure under load to decide if the battery is decent for the smoke alarm. And this is exactly what smoke alarms do.

I found this out 20 years ago as a smoke alarm started beeping low battery alarm and instead of just replacing the 9V battery, I measured it with a multimeter and it was reading more than 9 volts, so I was quite confused first. Yet, replacing with a new battery fixed the issue. Took some thinking to figure out what is happening.

You really need to measure under load to see what is the actual voltage at which the device stops working.
« Last Edit: December 30, 2024, 07:49:29 am by Siwastaja »
 
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Offline tom66

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Re: Rechargeable Alkalines?
« Reply #52 on: December 30, 2024, 11:32:22 am »
So… because Apple has strong brand loyalty (which, I will add, may be the result of their design decisions, not because of fanaticism), it gets held to a higher standard than its competitors?!?  :-//

Where did I write that?  I just wrote that their high brand loyalty allows them to take more liberties when it comes to building in obsolescence through software.  You can argue whether it is moral or not independently of that.
Well it is what you argued in the original criticism. How come you criticize Apple for only providing 7 years of phone software updates, when everyone else struggles to deliver 3 years? That is a huge double-standard.

Perhaps those 7 years of support are a reason Apple has such brand loyalty.

I didn't criticise Apple for providing 'only' 7 years of updates because it was not a criticism!!  ???  I simply pointed out that some companies have very high brand loyalty and this allows them to build other forms of obsolescence into their products, like not supporting new features on hardware that can support them, because they don't sell iOS. 
 

Online ejeffrey

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Re: Rechargeable Alkalines?
« Reply #53 on: December 30, 2024, 07:21:12 pm »

- Another problem, both NiCd and NiMH have memory effect.  (NiMH has less of it, but still has some memory).  Unless they are fully discharged once in a while, in practice they might have a much shorter running time than expected.

Memory effect is overblown.  Yes, it technically exists, but it wasn't a major problem except after many cycles with equal discharge depths.  The problem with NiCd batteries and incomplete discharge was that at the time they were popular, the cheap charging circuits that most home users bought were slow chargers that were strictly timer based. They would charge at something like C/10 for 8 hours then reduce to a maintenance trickle charge at C/50 or something like that.  If you didn't discharge fully before putting them back in the charger, they would overcharge.  At these charge rates, NiCd batteries are more tolerant of overcharging than other chemistries in that they won't explode, but it does cause degradation.  That's why the advice was always do to a "complete" discharge, to avoid capacity loss from overcharging on cheap chargers.

NiMH battery chargers by contrast almost always use peak voltage detection and/or temperature rate of rise.  This allows accurate charge termination, and in turn both faster practical charge rates and avoids dependence on the starting state-of-charge.

Quote
- Yet another problem for rechargeable batteries is the temperature.  In cold weather they behave very poor (high internal resistance, lower than nominal capacity).  The device they try to power might not even start at freezing temperatures.

Alkaline batteries also lose performance when cold.  In both Alkaline and NiMH, performance starts to degrade at 0C and has lost significant performance at -20 C.  It's not really a significant difference.  If you want cold weather performance, lithium primary cells are generally better. 

Quote
- And yet another (sideways) problem might be the self-discharge rate.  Where alkaline batteries might need replacing once a year or even rare, a rechargeable might need to be recharged every 3-6 months, depending on its self-discharging rate.

LDS NiMH (which are almost all the cells on the market now) last for several years.  They still don't have the shelf life of an unused alkaline cell (7+ years), but it's enough to not really be a problem for the vast majority of cases where there is any significant load.  I even use NiMH batteries in remote controls.  There are still a few non-LDS cells on the market.  However. they are now the specialty item targeting high power devices like camera equipment.
 
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Online Halcyon

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Re: Rechargeable Alkalines?
« Reply #54 on: December 30, 2024, 11:42:54 pm »
LDS NiMH (which are almost all the cells on the market now) last for several years.  They still don't have the shelf life of an unused alkaline cell (7+ years), but it's enough to not really be a problem for the vast majority of cases where there is any significant load.  I even use NiMH batteries in remote controls.  There are still a few non-LDS cells on the market.  However. they are now the specialty item targeting high power devices like camera equipment.

I've replaced all my batteries from AAA through to D cells completely with Ikea AAA and AA NiMH cells (for C and D size applications, I use Panasonic battery adapters; Part No. BQ-BS2E8SA and BQ-BS1E8SA respectively). To charge, I have a Powerex MH-C980.
« Last Edit: December 30, 2024, 11:44:43 pm by Halcyon »
 

Offline IanB

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Re: Rechargeable Alkalines?
« Reply #55 on: December 31, 2024, 01:52:16 am »
I've replaced all my batteries from AAA through to D cells completely with Ikea AAA and AA NiMH cells (for C and D size applications, I use Panasonic battery adapters; Part No. BQ-BS2E8SA and BQ-BS1E8SA respectively). To charge, I have a Powerex MH-C980.

I found those battery adapters to be of less use than I expected, since many devices taking C and D cells expect the full size positive button of a regular D cell, rather than just the smaller AA size button. Some spring contacts slip right over an AA button without touching it.

There are, however, genuine NiMH C and D cells, from Tenergy, for example. I have bought their Centura brand and found it to work reliably. The downside is that it takes a long time to charge an 8000 to 10 000 mAh D cell (charging current is limited to about 3.5 A, if you even have a charger that can do that).
 

Online Halcyon

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Re: Rechargeable Alkalines?
« Reply #56 on: December 31, 2024, 02:07:01 am »
I've replaced all my batteries from AAA through to D cells completely with Ikea AAA and AA NiMH cells (for C and D size applications, I use Panasonic battery adapters; Part No. BQ-BS2E8SA and BQ-BS1E8SA respectively). To charge, I have a Powerex MH-C980.

I found those battery adapters to be of less use than I expected, since many devices taking C and D cells expect the full size positive button of a regular D cell, rather than just the smaller AA size button. Some spring contacts slip right over an AA button without touching it.

There are, however, genuine NiMH C and D cells, from Tenergy, for example. I have bought their Centura brand and found it to work reliably. The downside is that it takes a long time to charge an 8000 to 10 000 mAh D cell (charging current is limited to about 3.5 A, if you even have a charger that can do that).

These particular adapters have their own terminal to mimic the size of the D cell. (the C-cells don't, they literally just "pass through" the terminal on the AA cell itself, via a hole). The AA positive terminal connects internally to the D-cell adapter itself.

The only reason I went with adapters was because: (1) I only have one product that uses C cells (that's a kitchen scale). I don't have any use for D cells at the moment, so rather than holding onto batteries, might as well just have adapters on-hand. (2) I don't have a charger capable of charging C or D-size cells, and I probably won't buy one anytime soon as their use is rare.
 

Offline IanB

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Re: Rechargeable Alkalines?
« Reply #57 on: December 31, 2024, 02:27:18 am »
These particular adapters have their own terminal to mimic the size of the D cell. (the C-cells don't, they literally just "pass through" the terminal on the AA cell itself, via a hole). The AA positive terminal connects internally to the D-cell adapter itself.
That's interesting. I might have to look at them again.

Quote
The only reason I went with adapters was because: (1) I only have one product that uses C cells (that's a kitchen scale). I don't have any use for D cells at the moment, so rather than holding onto batteries, might as well just have adapters on-hand. (2) I don't have a charger capable of charging C or D-size cells, and I probably won't buy one anytime soon as their use is rare.
I don't have a charger for C or D cells either. What I do is put them in series and charge with a constant current from a bench supply. If I use a low enough current I can just leave them for several hours and watch the voltage until they are charged.

I bought the C and D cells to use in lanterns in case of a power outage, for which the high capacity is a definite advantage.
« Last Edit: December 31, 2024, 02:29:08 am by IanB »
 

Online Halcyon

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Re: Rechargeable Alkalines?
« Reply #58 on: December 31, 2024, 02:48:01 am »
I bought the C and D cells to use in lanterns in case of a power outage, for which the high capacity is a definite advantage.

That's the obvious trade-off, particularly if you're in an area where long power outages occur, the higher capacity might be worthwhile. However, you could also argue that buying more AA batteries would give you the same capacity, but whilst they are not being used for emergency power, you can cycle through them in other devices.

I have 2 containers, one which contains fully charged cells, and another for used or depleted cells. Once I need to change batteries, I go for a fresh set and the empty ones go into the box for charging once I have accumulated enough to throw them on the charger. That way everything eventually gets used and exercised.
 

Offline ConnecteurTopic starter

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Re: Rechargeable Alkalines?
« Reply #59 on: January 23, 2025, 03:40:01 am »
I don't think laptops ever used rechargeable alkalines.

Where they did exist they were a fairly novelty product. I think the one that I remember using was only rated to around 10 recharge cycles.  The novelty was they weren't much more expensive than a conventional alkaline and they had 1.5V output.

Most likely you had an early laptop with a NiMH battery, those definitely existed (and some even had lead acid batteries, like the Apple PowerBook 100).
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.
 

Offline IanB

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Re: Rechargeable Alkalines?
« Reply #60 on: January 23, 2025, 04:38:41 am »
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

Nobody called you a liar. You can be mistaken about things, and that's OK. Perhaps it isn't what you thought it was.
 
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Offline tggzzz

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Re: Rechargeable Alkalines?
« Reply #61 on: January 23, 2025, 11:04:55 am »
I don't think laptops ever used rechargeable alkalines.

Where they did exist they were a fairly novelty product. I think the one that I remember using was only rated to around 10 recharge cycles.  The novelty was they weren't much more expensive than a conventional alkaline and they had 1.5V output.

Most likely you had an early laptop with a NiMH battery, those definitely existed (and some even had lead acid batteries, like the Apple PowerBook 100).
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

Wow.

You pop up after almost a month, and make a comment like that.

Looks like two people's prior assessment is correct:
https://www.eevblog.com/forum/chat/rechargeable-alkalines/msg5763473/#msg5763473
https://www.eevblog.com/forum/chat/rechargeable-alkalines/msg5763541/#msg5763541
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline tom66

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Re: Rechargeable Alkalines?
« Reply #62 on: January 23, 2025, 11:36:34 am »
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

:-DD  OK then dude.  Send us a picture of this mythological battery.  Till them it's your word against ... well, battery science, for one.
 
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Online 2N3055

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Re: Rechargeable Alkalines?
« Reply #63 on: January 23, 2025, 11:57:23 am »
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

:-DD  OK then dude.  Send us a picture of this mythological battery.  Till them it's your word against ... well, battery science, for one.

Well..

Lithium is alkali metal...  8)

And he is right. There was, some years ago, a period there marketing term "Rechargeable alkaline" was used. I have no idea how it mapped to real life/science.
It didn't last long though...
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Offline tom66

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Re: Rechargeable Alkalines?
« Reply #64 on: January 23, 2025, 12:23:35 pm »
As has been established, rechargeable alkalines did exist, but really, no one made a laptop with such a battery in it, because it wouldn't have survived more than 10-20 cycles in use. They were primarily sold to consumers as a cost-competitive alternative to non-rechargeable alkalines where you could get around 10 uses from the cell before it was disposed of. Each use could expose considerably less capacity, like the second use would be 70% of the capacity, then 50%.

It only made sense as a battery in disposable form because you wouldn't be able to commercialise a product where the battery pack had to be thrown away in its entirety and replaced less than a month later, when other battery technologies existed with far better cycle life.
 
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Offline Zero999

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Re: Rechargeable Alkalines?
« Reply #65 on: January 23, 2025, 01:24:54 pm »
I recall having a Toshiba laptop with a non-chargeable battery in the early 90s. I can't remember what chemistry is was, only that I always ran it from the mains because it was dead when I bought it second hand from an auction.
 

Offline tom66

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Re: Rechargeable Alkalines?
« Reply #66 on: January 23, 2025, 01:26:59 pm »
I recall having a Toshiba laptop with a non-chargeable battery in the early 90s. I can't remember what chemistry is was, only that I always ran it from the mains because it was dead when I bought it second hand from an auction.

Intended as being non-rechargeable (single use) or just failed from too many charge cycles/being too old?
 
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Offline tggzzz

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Re: Rechargeable Alkalines?
« Reply #67 on: January 23, 2025, 01:36:35 pm »
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

:-DD  OK then dude.  Send us a picture of this mythological battery.  Till them it's your word against ... well, battery science, for one.

It is valid to call the OP's bluff, but just indicating the manufacturer and model would be sufficient :D

Might be difficult to take a photo of a laptop that's been thrown out long ago, e.g. my OmniBooks 300 & 600.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline Zero999

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Re: Rechargeable Alkalines?
« Reply #68 on: January 23, 2025, 01:49:59 pm »
I recall having a Toshiba laptop with a non-chargeable battery in the early 90s. I can't remember what chemistry is was, only that I always ran it from the mains because it was dead when I bought it second hand from an auction.

Intended as being non-rechargeable (single use) or just failed from too many charge cycles/being too old?
Single use I believe, although it's possible I'm mistaken, as it was over 35 years ago.
 

Offline macboy

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Re: Rechargeable Alkalines?
« Reply #69 on: January 23, 2025, 06:21:44 pm »
I can entertain the notion that some company did in fact have a rechargeable alkaline battery for a laptop-style computer back then.  Yes we can agree that rechargeable alkaline is not a good technology, but it could hypothetically be economically viable. Some people may be stuck thinking of rechargeable batteries as we know them in contemporary products... that is, an internal, permanently installed, and generally irreplaceable part of the whole. This is the way modern cell phones, laptops, Chromebooks, etc. treat the battery. It wasn't always like that. Think back to your oldest Nokia cell phone (if you are over 40). It had a battery door, as did every single other battery powered product, rechargeable or not.

Imagine this: the hypothetical laptop-type device runs from (for example) 8 AA primary/disposable alkaline batteries, or you can buy the rechargeable pack. Those 8 AA's might cost approximately (example) $8. Single use. Imagine that the company offered its rechargeable pack for $24 (3 times the cost of standard alkalines, just for the sake of argument). Maybe they promised 10 to 20 charge cycles. Let's say a person could actually get 12 cycles from it. Then it costs the end user $2 per cycle. That sounds like a bargain compared to $8 for disposable batteries. If the cells were properly vented (like the "Pure Energy" brand rechargeable alkalines I remember from back then) and the pack itself was sealed well enough to mitigate any eventual leaks, then the concept could work. This rechargeable battery is not designed nor intended to last the entire life cycle of the product. It is a consumable item, but it still saves the customer money. Just consider that this is a possibility.
 
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Offline IanB

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Re: Rechargeable Alkalines?
« Reply #70 on: January 23, 2025, 08:04:33 pm »
Along these lines, I could imagine a device that was alkaline or rechargeable. Either you put alkaline batteries in it, or you put the (optional) rechargeable battery pack in it. The rechargeable battery pack could easily have been NiCd as was common early on.
 
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Offline ConnecteurTopic starter

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Re: Rechargeable Alkalines?
« Reply #71 on: January 23, 2025, 09:08:13 pm »
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

Nobody called you a liar. You can be mistaken about things, and that's OK. Perhaps it isn't what you thought it was.
Or perhaps you are wrong.
 

Offline Zero999

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Re: Rechargeable Alkalines?
« Reply #72 on: January 23, 2025, 09:13:21 pm »
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

Nobody called you a liar. You can be mistaken about things, and that's OK. Perhaps it isn't what you thought it was.
Or perhaps you are wrong.
You're the one making an extraordinary claim and therefore has to carry the burden of proof.
 
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Offline tggzzz

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Re: Rechargeable Alkalines?
« Reply #73 on: January 23, 2025, 09:25:05 pm »
Well, I don't appreciate being called a liar.  The battery pack said "rechargeable alkaline" right on it.

Nobody called you a liar. You can be mistaken about things, and that's OK. Perhaps it isn't what you thought it was.
Or perhaps you are wrong.

The person making the claim is the person that has to justify it. Attempting to reverse that is a classic troll tactic.

I claim (1) the moon is made of green cheese and that (2) only 363 angels can dance on the head of a pin. You prove those wrong.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline Gyro

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Re: Rechargeable Alkalines?
« Reply #74 on: January 23, 2025, 10:00:26 pm »
Well..

Lithium is alkali metal...  8)

And he is right. There was, some years ago, a period there marketing term "Rechargeable alkaline" was used. I have no idea how it mapped to real life/science.
It didn't last long though...

The electrolyte in NiCd and NiMH is also alkaline of course (KOH).... Although I doubt the OP will concede that it was either of those.
« Last Edit: January 23, 2025, 10:07:30 pm by Gyro »
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