Is Energizer trying to kill rechargeable batteries? They're sure trying.

[DougPenhall]

I am not sure if it chalks up to stupidity of the consumer in the US or what but really I think it's the chargers and the cells are fine, though someone with more money than me would have to do a test to see if a charger really does make a difference. Aka someone buys a cheap Duracell charger and batteries and uses it together as the package says and then buys a pack of the same Duracell cells and uses them in a good charger. Though I am not even sure if such a test is necessary as we all know what would likely happen.

I bought a Lenmar R2G charger that came with 4 Lenmar R2G AA batteries plus two more packs of 8 additional batteries.

The first thing I did was try 4 of those batteries in a 2 port sprinkler timer. They worked for a few days, then got drained completely. I then tried to charge them in the Lenmar charger and it blinked red indicating that all 4 batteries had gone bad. I happen to have a Tenergy 4 port LiPO/PB/NiMH battery charger for my RC helicopters, so I decided to make a plastic tube so I could put all 4 batteries in series and try charging them on the NiMH setting. They charged with no problem and are working fine and now charge fine in the Lenmar charger. This basically means that the Lenmar charger is crap and won't charge dead NiMH batteries that are perfectly fine. Had I not had the Tenergy charger and some persistence I probably would have believed the Lenmar charger and thrown them away.

I've since bought a much better sprinkler timer, but these batteries still don't work in it, so I'm stuck with the only application of these batteries being one of my remotes. They work great, but all my other devices require LiPOs.

 

[DougPenhall]

they would rather pay $5 for a pack of 4 alkalines and be on their way.

$5 for 4? Try $8 for 40.
http://www.frys.com/product/6292860
(By the way, they suck)

 

[GarageBoy]

Why does that baby swing running on D batteries not use a rechargeable sealed lead acid or something?

But another thing I really like about rechargeables is the way that they inspire what we might call a 'culture of abundance' rather than a 'culture of scarcity'. Alkaline batteries cost you money every time you use them. They can't be recharged. You have to throw them away and get new ones every time they are used up. Because they cost you, there is a desire to conserve them. Don't use that light (or other device) unless you REALLY have to because this is costing money. Put up with poor performance as the light dims because they're still working. You don't want to throw your money in the garbage too soon! Even if you're getting 30 of them for a few bucks at Costco, it's still costing money. And when they run out, you will be without batteries until you go out and get more. Rechargeables, on the other hand, cost a negligible amount of electricity to recharge. And you don't have to go anywhere to buy them when they are drained or wait to have new ones shipped. So you use them as much as you want. And if you're doing something with friends, you lend them out because they cost you nothing. No more conserving batteries just because you don't want to waste money.

That is exactly the reason I love Li Ions replacements for CR123 based lights, and why I babied my Surefire and abused my Fenix; the Fenix cost me nothing to run, and I didn't have to toss things in the garbage every week

 

[SaraAB87]

I think energizer already killed rechargeable batteries for most people with their 2500 mAh cells! The 2500 mAh "D" cell they make, it really wouldnt surprise me if they have one of those cheap and nasty 2500 mAh cells stuck inside! My sister works at walgreens and told me she came across some leaking energizer AAA batteries! Doesn't surprise me in the least! Energizer cells are pure crap...even my own 2300 mAh energizer AA cells are showing higher internal resistance on charging now! Going to order some eneloops soon and be done with it!

I cannot speak for their newer cells but I too was sucked in by energizer and the fact that since they are a name brand that their rechargeables would be more quality than the generics, I had terrible performance from energizer cells. Now I can understand why someone would be put off from Rechargables for life if they had these batteries. No wonder Sams Club has (mostly) switched from Energizer to Duracell batteries even after they carried only Energizer for more than 15 years (I have been shopping there a long time). The only good ones are the lithiums.

Anyone remember buying the huge 24 packs of AA energizer alkalines and running them down in a Walkman cassette player, I sure do! Thank gosh we have eneloops now, and no I don't still use a cassette player though I still have a few around here.

 

[StorminMatt]

Anyone remember buying the huge 24 packs of AA energizer alkalines and running them down in a Walkman cassette player, I sure do! Thank gosh we have eneloops now, and no I don't still use a cassette player though I still have a few around here.

I don't think you can even buy prerecorded tapes anymore. And even though I've seen new blank tapes available on which you could record music, chances are most people no longer have a cassette deck that actually works. I'm not sure you can even buy a new one.

Anyway, the whole idea of burning through alkaline batteries with a Walkman brings up a point. Specifically, battery companies must be hurting BIG TIME these days. Why? Because we no longer burn through alkaline batteries like we once did. Rather than burning through alkaline batteries with a Walkman, we now listen to music on phones with proprietary (or, if you have an iPhone, inaccessible) Li-Ion batteries. And cameras virtually won't work on alkaline batteries (if we are talking about cameras that can actually work on alkalines). These days, alkalines are only used for remotes, clocks, and the odd flashlight, toy, or other device that uses batteries - mostly low draw stuff that doesn't burn through batteries. In other words, the proprietary Li-Ion battery pack (along with the general unsuitability of alkaline batteries for digital cameras) has certainly HEAVILY cut into the profits of battery manufacturers.

 

[zespectre]

You would be amazed how many people are aware of NiMH and even LSD-NiMH that still buy alkalines. Unless it's a device they use near-daily, they just can't be bothered with the higher per-cell cost, additional expense of a charger, and the "hassle" of recharging.

NiMH and even LSD NiMH are still not appropriate for all applications, especially super low draw, long duration items like smoke detectors/CO detectors and a lot of clocks/calenders.

 

[ST Dog]

I don't think you can even buy prerecorded tapes anymore. And even though I've seen new blank tapes available on which you could record music, chances are most people no longer have a cassette deck that actually works. I'm not sure you can even buy a new one.

Sure you can http://www.radioshack.com/family/in...+decks&filterName=Type&filterValue=Dual+decks

Turntables too http://www.radioshack.com/family/in...llCount=22&f=PAD/Product+Type/Turntables&pg=1

As for battery manufacturer profits, that's why they are marketing other types now. You can even still buy carbon/zinc heavy duty batteries, go figure. Like most other industries though. They are made somewhere else, labeled for different brands, and then marketed. I doubt may cells are produced in any western, industrial country anymore, mainly due to the environmental regulations.

 

[idleprocess]

NiMH and even LSD NiMH are still not appropriate for all applications, especially super low draw, long duration items like smoke detectors/CO detectors and a lot of clocks/calenders.

Indeed, but the people I was referring to were using alkalines for everything because they have some hangup or conceptual issue about recharging batteries aside from cases where they have no choice like proprietary li-ion batteries for cell phones, cameras, etc.

 

[SaraAB87]

I don't think you can even buy prerecorded tapes anymore. And even though I've seen new blank tapes available on which you could record music, chances are most people no longer have a cassette deck that actually works. I'm not sure you can even buy a new one.

Anyway, the whole idea of burning through alkaline batteries with a Walkman brings up a point. Specifically, battery companies must be hurting BIG TIME these days. Why? Because we no longer burn through alkaline batteries like we once did. Rather than burning through alkaline batteries with a Walkman, we now listen to music on phones with proprietary (or, if you have an iPhone, inaccessible) Li-Ion batteries. And cameras virtually won't work on alkaline batteries (if we are talking about cameras that can actually work on alkalines). These days, alkalines are only used for remotes, clocks, and the odd flashlight, toy, or other device that uses batteries - mostly low draw stuff that doesn't burn through batteries. In other words, the proprietary Li-Ion battery pack (along with the general unsuitability of alkaline batteries for digital cameras) has certainly HEAVILY cut into the profits of battery manufacturers.

My camera works on AA batteries, one of the canons that still use AA. Also the reason the Walkman burned through so many is the reason the cassette deck would actually become slow and your music would sound slower when the batteries were dying, you put fresh batteries in and it worked perfect again.

This is a problem but there are still many battery draining devices on the market, lots of video game accessories and controllers especially the Wii ones burn through batteries, there are also a ton of children's products such as leapsters and innotabs that can burn through 4 AA's a day. My Skylanders portal takes 3 AA's and some people report it dying within 2-3 days with alkaline but I can get a few weeks with 3 Duraloops. Though I think some of these products are going to be moving to li-ion soon like everything else which will hurt the battery industry even more. Video game controllers will definitely have chargable battery packs this gen but the Wii remote is still relevant and the Xbox One controller still uses AA but you can get a li polymer pack for it. Most of the other toys kids have will use 2-4 AA per year or less per toy so those won't sell AA batteries as much. Lets not forget the Tamagotchi which is simply the king of draining 2032 size coin batteries, though bandai stopped making the tamagotchi for the US market in 2010 and their last model was a larger size and used AAA's.

 

[jtr1962]

My camera works on AA batteries, one of the canons that still use AA. Also the reason the Walkman burned through so many is the reason the cassette deck would actually become slow and your music would sound slower when the batteries were dying, you put fresh batteries in and it worked perfect again.

This is a problem but there are still many battery draining devices on the market, lots of video game accessories and controllers especially the Wii ones burn through batteries, there are also a ton of children's products such as leapsters and innotabs that can burn through 4 AA's a day. My Skylanders portal takes 3 AA's and some people report it dying within 2-3 days with alkaline but I can get a few weeks with 3 Duraloops. Though I think some of these products are going to be moving to li-ion soon like everything else which will hurt the battery industry even more. Video game controllers will definitely have chargable battery packs this gen but the Wii remote is still relevant and the Xbox One controller still uses AA but you can get a li polymer pack for it. Most of the other toys kids have will use 2-4 AA per year or less per toy so those won't sell AA batteries as much. Lets not forget the Tamagotchi which is simply the king of draining 2032 size coin batteries, though bandai stopped making the tamagotchi for the US market in 2010 and their last model was a larger size and used AAA's.

I have to say I would honestly be really surprised if people used alkalines in devices which go through one set a day. That gets seriously expensive, especially if you pay the typical retail store prices for alkalines of $4 per 4-pack, or more. That said, I do remember my sister's in-laws spending about $30 a week on batteries for their children's toys. I rarely saw them, but I would have loved to have a long talk with them about the benefits of rechargeables. Devices where you go through one or two sets of batteries a year are another story. Things where you can drain a set of batteries in a day-ouch! Those are tailor made for rechargeables.

 

[SaraAB87]

I have to say I would honestly be really surprised if people used alkalines in devices which go through one set a day. That gets seriously expensive, especially if you pay the typical retail store prices for alkalines of $4 per 4-pack, or more. That said, I do remember my sister's in-laws spending about $30 a week on batteries for their children's toys. I rarely saw them, but I would have loved to have a long talk with them about the benefits of rechargeables. Devices where you go through one or two sets of batteries a year are another story. Things where you can drain a set of batteries in a day-ouch! Those are tailor made for rechargeables.

I don't think I have ever had a toy that drained that much even as a kid, I am not sure if its due to kids leaving things on when they need to be turned off, but apparently some people complain about certain toys draining a set of AA alkaline within a day or 2, I think mainly the leapsters and innotabs have this problem and some of them use 3 AAA making it worse since most dumb chargers can only do 2-4 batteries. Yes these devices have optional AC adapters but that requires being tethered to an outlet and they do make charging packs for these things but those are just 3-4 AA Rechargables packed into a plastic shell and we all know how well those work, they ,simply don't. I have had very bad experiences with charger packs at least those that are 2-4 AA Nimh strapped into a plastic pack with either a USB or wall charger included. Most don't work after a few charges, most others have the same experience except in rare cases. If you have a leapster or innotab and kids you basically NEED the type of Rechargables and chargers talked about on this site. Moreover people should know that buying kids a tablet that takes AA especially 3 AA is a bad idea if you don't want to buy batteries constantly and for the cost of the device, software and batteries you could probably afford $500 for an iPad easily and not have to buy batteries. But I don't think people realize how bad the draining is until they get the device and their kids won't put it down.

My personal experience with the skylanders portal is that the batteries will last at least 3 weeks with Duraloops but I am guessing kids play more than my 1-2 hours every couple days and I really don't want to have to play skylanders for 8 hours straight to find out how long the portal really lasts. I am also pretty sure it turns off automatically if its not used for a certain amount of time but it does stay on the whole time you play the game. In case anyone is unfamiliar skylanders is a video game played with action figures and you use the portal to transport the figures into the game. There are wired versions of the portal but apparently they don't work on the Wii because I have tried and I am playing on the Wii which means I need 5 batteries, 3 for the portal and 2 for the remote. I don't really care because I have tons of Rechargables. My point here is for parent with kids this could get seriously expensive but I guess if you can afford skylanders figures then you can afford batteries for the remote and portal although it is money being unnecessarily spent especially if you were spending $30 a week on batteries you could buy the most premium rechargable battery gear with the cost of 3 weeks worth of alkaline and you wouldn't have to spend more money on batteries for a long time. Also all that alkaline going into the trash.....yikes...

But judging by the type of consumer I talk to this is what people are doing, picking up a pack of batteries at the store every time their kid needs them..warehouse club members at least buy the bulk packs as I did when I was draining batteries in the Walkman, I don't recall having to buy more than 2-3 huge packs of those energizer AA's a year so it was better than getting alkaline at the store. I do see a ton of people buying the bulk packs so that is at least somewhat encouraging.

Also add to the battery draining list of toys the furby, that thing is insane, one of mine killed a set of 4 eneloops in under a day (and also got very hot in the process) bad idea to keep it on for a really long time. I don't have it anymore nor do I have any of the new model furby so I can't comment on those.

 

[frank10]

Why does that baby swing running on D batteries not use a rechargeable sealed lead acid or something?

That is exactly the reason I love Li Ions replacements for CR123 based lights, and why I babied my Surefire and abused my Fenix; the Fenix cost me nothing to run, and I didn't have to toss things in the garbage every week

My guess is the swing maker doesn't want Li batteries in the product for safety concerns. Also, they can pass the battery cost onto the consumer.

 

[Wrend]

NiMH and even LSD NiMH are still not appropriate for all applications, especially super low draw, long duration items like smoke detectors/CO detectors and a lot of clocks/calenders.

Actually, they can work fairly well for many of these devices too. They may just need to get changed out for charged cells a little sooner than these devices would go through alkaline cells. With the regular Eneloops, you're talking about roughly 2/3 run time compared to alkaline cells, and with the Eneloop XX cells, maybe roughly 5/6 the run time.

I use AAA Eneloops in a portable RF synchronized alarm clock, for example, and they last for more than a year. I just switch them out once a year to make sure that the alarm clock doesn't run out of juice and fail to wake me up. I also use them in my TI-89 calculator, remotes, wireless keyboards and mice, and they can last a year or more in those devices as well.

Also, keep in mind that the alkaline cells' voltage discharge curve is more linear as it discharges it's capacity, so much of the capacity may be lower than the device needs to run sufficiently, while Eneloops' discharge voltage curve is more of an S-curve, and they will maintain a voltage higher than 1.2V per cell for 90% or more of their charged capacity.

 

[y_p_w]

My guess is the swing maker doesn't want Li batteries in the product for safety concerns. Also, they can pass the battery cost onto the consumer.

Uh - price. Most toys don't even come with batteries. Someone sees the price and doesn't factor in that 3-6 D cells are going to cost $5 or more. And a lead-acid battery is going to need a charger, and most of these toys are meant to be moved around without cords. How much does all that stuff add to the price? Additionally, those lead-acid batteries will inevitably sulfate when unused and uncharged for a few months, and then what kind of complaints will they have?

I do remember using a 90s era Sony cordless phone with a sealed lead-acid battery. Eventually the battery was gone, and the generic replacements were at least $10 and the OEM battery was at least $15. This thing was the size of 3 AAs. Eventually I ended up getting a Siemens Gigaset 2.4 GHz DSS phone. The greatest thing about that phone (still working today) is that the handsets could take a pair of any NiCad or NiMH AA batteries and charge them when placed in a cradle. They had a listed 12 hour talk time with 1200 mAh AAs, but I'm thinking were much longer with higher capacity batteries. Right now I've got Eneloops in all of them except for one. The batteries do die after several years, but that's normal. Most people who replace those proprietary battery packs in cordless phones end up getting lousy quality aftermarket equivalents with low capacity and poor life. I put in top of the line cylindrical cells.

 

[SaraAB87]

Uh - price. Most toys don't even come with batteries. Someone sees the price and doesn't factor in that 3-6 D cells are going to cost $5 or more. And a lead-acid battery is going to need a charger, and most of these toys are meant to be moved around without cords. How much does all that stuff add to the price? Additionally, those lead-acid batteries will inevitably sulfate when unused and uncharged for a few months, and then what kind of complaints will they have?

I do remember using a 90s era Sony cordless phone with a sealed lead-acid battery. Eventually the battery was gone, and the generic replacements were at least $10 and the OEM battery was at least $15. This thing was the size of 3 AAs. Eventually I ended up getting a Siemens Gigaset 2.4 GHz DSS phone. The greatest thing about that phone (still working today) is that the handsets could take a pair of any NiCad or NiMH AA batteries and charge them when placed in a cradle. They had a listed 12 hour talk time with 1200 mAh AAs, but I'm thinking were much longer with higher capacity batteries. Right now I've got Eneloops in all of them except for one. The batteries do die after several years, but that's normal. Most people who replace those proprietary battery packs in cordless phones end up getting lousy quality aftermarket equivalents with low capacity and poor life. I put in top of the line cylindrical cells.

I am guessing a baby swing isn't used all that much, unless your baby somehow gets addicted to it, and I am not going into that here, but most parents I know probably used it 30 min a day per baby, so maybe replace the batteries every couple months. As far as i know they have been using D batteries in baby swings for years and years. As far as I can see here we aren't talking about a large quantity of batteries unless you have a lot of kids, which in that case then you have to realize that everything will be more expensive no matter what. The baby will outgrow the swing within a year most likely so we aren't talking about something that is getting 4-5 hours a day use or more like a leapster or innotab that a kid can't put down.

I just happened to be in GameStop during the GTA V launch and they were pushing alkaline batteries with a hard sell like I have never seen before, they had a special table set up with batteries and everything, they were charging $6 for 4 Duracells... Sigh.. I proceeded to inform people about eneloops. I don't think anyone listened but it was worth a try. It's scary to think about how much money people have spent on batteries for video game controllers!

 

[y_p_w]

I am guessing a baby swing isn't used all that much, unless your baby somehow gets addicted to it, and I am not going into that here, but most parents I know probably used it 30 min a day per baby, so maybe replace the batteries every couple months. As far as i know they have been using D batteries in baby swings for years and years. As far as I can see here we aren't talking about a large quantity of batteries unless you have a lot of kids, which in that case then you have to realize that everything will be more expensive no matter what. The baby will outgrow the swing within a year most likely so we aren't talking about something that is getting 4-5 hours a day use or more like a leapster or innotab that a kid can't put down.

I just happened to be in GameStop during the GTA V launch and they were pushing alkaline batteries with a hard sell like I have never seen before, they had a special table set up with batteries and everything, they were charging $6 for 4 Duracells... Sigh.. I proceeded to inform people about eneloops. I don't think anyone listened but it was worth a try. It's scary to think about how much money people have spent on batteries for video game controllers!

OK - two parter.....

I have a lot of experience with baby toys over the past few years, although never a baby swing. Jumpers, crib toys, motorized mobiles, fancy electronic pens (Leapfrog TAG), etc. There is absolutely no standardization, and we've used everything from AAs, AAAs, 9V, Cs, and Ds. I figured that we'd use some of these so little that I ended up getting "heavy duty" batteries at a dollar store for some of them. And it worked out when some of these came in 3-packs and the devices took 3 cells. However, a lot of these now use AAs, although I still only used alkalines most of the time. I know it's a waste, but often I didn't feel like pulling out a screwdriver all the time.

The AA/AAA NiMH batteries I use are for flashlights, headlamps, and radios. If I need 3 I keep the sets together. Some devices I have use 4 like cameras and a USB power supply. Those I have no issue swapping out as interchageable. I try to have ones I can identify as sets without marking them. I've bought several of the Eneloop sets at Costco, and they have two shades of blue for the AAs and two shades of green for the AAAs. Even with the same colors, the date codes are enough to identify a set.

As for batteries and games, I remember my old Atari Lynx. I did get a set complete with AC power adapter, but for playing on the road I went to Costco and got NiCad rechargeables from the 90s. They were Saft overnight timed chargers and batteries. I don't think they were great by today's standards, but NiCads were the only viable rechargeable option at the time. I was a college student with limited funds, so I knew that I wasn't going to be able to afford operating that thing on alkalines.

 

[y_p_w]

I do remember the disaster that was the Rayovac Renewal (later just the Rayovac Rechargeable Alkaline). I'd bought the 4 position AA/AAA charger and even went crazy once and got the 8 position one that also charged C and D cells, and even got some Cs for use in a Cateye bike headlight. Those original chargers were only made in the US, were only made for their rechargeable alkalines, and were interesting. I remember if I put a completely charged battery in there, the light would turn off almost immediately. I could never get that out of any other rechargeable battery. However, the one thing I remember about those was that their C and D cells were high capacity cells that weighed as much as any other alkaline and had the initial capacity to match them.

Later they changed their chargers to ones that were designed to auto-detect NiCad, NiMH, or rechargeable alkalines. They were then made in China and didn't seem to have that quick turn off when a fully charged alkaline was placed in there. Even though I already had some of the earlier chargers, these were the cheapest "smart chargers" (the 4 position AA/AAA version was only about $10) I knew of on the market and they could charge odd numbers of cells with each cell charged individually. I used this a couple of these for my first NiMH batteries. At least until one of them overcharged their alkalines, which leaked into the charger and damaged it. So I called up Rayovac and without having to send it in they sent me a full set of rechargeable alkalines and a new 4-position alkaline/NiCad/NiMH charger that also charged C/D cells. They didn't even ask me if it was the larger charger or just the version that did AA/AAA. I know it wasn't a great charger, but this was my introduction to NiMH batteries, as my older timed chargers were wholly unsuitable for them.

The market for C/D rechargeables barely exists. Energizer Battery Co doesn't even make or design any rechargeable batteries or chargers and I don't believe they have for more than a decade. The ones they did make weren't very good compared to what other companies (mainly Sanyo) produced. They simply buy from suppliers now. I doubt they're trying to kill the market since they're not a leader in the market. It just fills a niche.

 

[SaraAB87]

OK - two parter.....

I have a lot of experience with baby toys over the past few years, although never a baby swing. Jumpers, crib toys, motorized mobiles, fancy electronic pens (Leapfrog TAG), etc. There is absolutely no standardization, and we've used everything from AAs, AAAs, 9V, Cs, and Ds. I figured that we'd use some of these so little that I ended up getting "heavy duty" batteries at a dollar store for some of them. And it worked out when some of these came in 3-packs and the devices took 3 cells. However, a lot of these now use AAs, although I still only used alkalines most of the time. I know it's a waste, but often I didn't feel like pulling out a screwdriver all the time.

The AA/AAA NiMH batteries I use are for flashlights, headlamps, and radios. If I need 3 I keep the sets together. Some devices I have use 4 like cameras and a USB power supply. Those I have no issue swapping out as interchageable. I try to have ones I can identify as sets without marking them. I've bought several of the Eneloop sets at Costco, and they have two shades of blue for the AAs and two shades of green for the AAAs. Even with the same colors, the date codes are enough to identify a set.

As for batteries and games, I remember my old Atari Lynx. I did get a set complete with AC power adapter, but for playing on the road I went to Costco and got NiCad rechargeables from the 90s. They were Saft overnight timed chargers and batteries. I don't think they were great by today's standards, but NiCads were the only viable rechargeable option at the time. I was a college student with limited funds, so I knew that I wasn't going to be able to afford operating that thing on alkalines.

If you have kids you would have to have some kind of system for Rechargables and they would have to be taught about them, which would require them to be old enough to at least comprehend things. Also sometimes there are so many toys that you couldn't possibly have Rechargables in all them without spending a fortune and losing some batteries and if they are lost that would be bad. I would suggest getting a bulk pack of alkalines for these purposes, obviously in the more high drain toys or more expensive toys that you intend to resell when your kid is done with them I would put Rechargables in those but otherwise most toys won't eat through even one set of eneloops in the lifetime they will be used. So it's definitely not wrong to use alkalines in some applications, especially if its throw away toys. They have bulk packs of batteries on slickdeals often and you can get them at places like the Home Depot, if you don't have Sam's or Costco memberships.

My cousins didn't have problems with batteries when they were babies, and they had a baby swing that took D batteries. But of course everything is more expensive now than when they were young enough to use a baby swing. Now they have a Wii, and a million other gadgets now that the kids are older and I give them 20 alkalines and they are gone in a couple weeks. I can only imagine how much they are spending on batteries, and I see them with the expensive little packs of batteries too.

 

[ALW248]

Why does that baby swing running on D batteries not use a rechargeable sealed lead acid or something?

To prevent baby from touching 100v.

 

[Arilou]

I do remember the disaster that was the Rayovac Renewal (later just the Rayovac Rechargeable Alkaline). I'd bought the 4 position AA/AAA charger and even went crazy once and got the 8 position one that also charged C and D cells, and even got some Cs for use in a Cateye bike headlight. Those original chargers were only made in the US, were only made for their rechargeable alkalines, and were interesting. I remember if I put a completely charged battery in there, the light would turn off almost immediately. I could never get that out of any other rechargeable battery. However, the one thing I remember about those was that their C and D cells were high capacity cells that weighed as much as any other alkaline and had the initial capacity to match them.

The iGo rechargeable alkalines do that. It's not quite immediate, but if you put in a fully charged battey, the charger will turn off after a minute or two. AFAIK, these are made by Pure Energy, the same company that made the Rayovac Renewals. They don't seem to make the C and D size batteries any more.