Eneloops: do the really make economic sense?

[schamberlin]

I've read many happy reviews of Eneloop low-self-discharge batteries here and elsewhere, but do they really make economic sense? It seems to me they're squeezed between traditional (higher-capacity and cheaper) NiMH on one end, and single-use alkalines on the other, with a fairly narrow range where they make sense economically. Here's my analysis of the best battery for a given replacement frequency:

• 2 months or less: standard NiMH
• 3 to 7 months: Eneloop (or other low-self discharge) NiMH
• 8+ months: single-use alkaline

This analysis depends greatly on the predicted lifetime of the Eneloop battery. And I mean lifetime in years, not charge cycles. How long do you expect to keep using that new Eneloop? 5 years? It seems pretty likely to me that by 5 years, either the cell will no longer be performing well, or you'll have replaced it anyway with some newer technology. Use a different number if you want, but I think 5 years is probably on the high-end of what you could expect.

The best price I've found on AA Eneloops (including tax and shipping) is $3 per cell. Compare that to about $0.40 per cell for AA Duracell alkalines bought in bulk. In a five-year period, you'd have to replace those alkalines 7.5 times before you'd come out ahead by buying an Eneloop instead. That works out to replacing them every 8 months. When you use alkalines, do you really replace the batteries in your clocks, remotes, emergency flashlights, etc every 8 months? No.

On the other end, for things that get heavy use where you replace the batteries frequently (RC models, cameras, etc), you're probably better off with traditional NiMH batteries. If you're replacing/recharging batteries every 2 months or less, then there's not really enough time for the advantage of low self-discharge to pay off. Traditional NiMH will save you money, and give you higher capacities in this case.

Put it all together, and you get the three categories above, based on battery replacement frequency. That's a pretty narrow window for the Eneloop to hit. What's more, all the gadgets I have around the house fall into either the under-2 or over-8 month category, except maybe Wiimotes.

Have I overlooked something obvious? Is my battery usage atypical? LSD is certainly a nice feature, but just doesn't seem worth the trade-offs in most circumstances.

 

[Marc999]

Some good points raised.
I use alkaline batteries in my alarm clocks, smoke alarm and mini-mag light simply because they've been there prior to me hearing about lsd batteries.

I use lsd batteries [duracell - white or black top and eneloop] in my hand held GPS and dig.camera. Alkaline batts. just don't have the staying power in these devices.

I've had bad, albeit limited experience with high capacity nimh batteries, i.e. Powerex 2,700 batteries. High impedance or losing capacity in a matter of days.

So, once my dwindling supply of alkaline batts runs out, I'll switch AA or AAA usage to lsd batts.

Marc

 

[AnAppleSnail]

And I mean lifetime in years, not charge cycles.

The best price I've found on AA Eneloops (including tax and shipping) is $3 per cell. Compare that to about $0.40 per cell for AA Duracell alkalines bought in bulk. In a five-year period, you'd have to replace those alkalines 7.5 times before you'd come out ahead by buying an Eneloop instead.


Have I overlooked something obvious? Is my battery usage atypical? LSD is certainly a nice feature, but just doesn't seem worth the trade-offs in most circumstances.

I avoid alkalines in things where I replace the batteries frequently, or where I can't tolerate a leak. I nearly lost my favorite calculator (Had the thing for half my life now!) to a leaky crap-a-cell AAA. There are a lot of things I use alkalines for, but they're not right for others.

I use NiMH AAs in my flashgun, my EDC light. If I used Alkalines, I'd be buying around 3 per week on average. One of the main reasons people buy the Eneloop is that it is a consistently-performing battery with good quality control and little chance of damaging your expensive electronics.

 

[Zeroignite]

I was just analyzing this myself the other day. I assumed I was using Amazon prices, and bought a $40 dollar charger (that's how much the BC-900 sells for there) and $20 dollars worth of rechargeables. For a 60 dollar total investment, I could buy 72 Duracell alkaline batteries. Since the headlamp I intend to get uses 3 AAs per charge, that's 24 charges, or about 60-100 hours until breakeven using a mix of high and low. I think that I'd use that much within a year or two, so buying rechargeables makes economic sense.

Now, this light is gonna be used for caving. As such, I fully plan on charging batteries immediately prior to use. That case makes it obvious that I should get as high a capacity NiMH cell as possible, so that my light lasts as long as possible. However, I also intend on carrying several sets of spare cells. Eneloops would be ideal for this, since I can leave them in a bag and not have to worry about them holding power, while still being able to recharge when I do have to switch to them.

As a side note, I also found that there is no reason to use alkaline at all. Lithium primaries can deliver about three times as much power as alkalines, but they are less than three times the cost. Therefore, in terms of dollars per hour, they are actually a cheaper product, not to mention their superior drain characteristics, performance under load, and resilience to cold.

What I'd really like to do is some serious quantitative analysis of the costs and benefits of different battery types. It would kick *** if SilverFox would hand me some of his raw battery shootout data, so that my analysis would be based on more than trying to make guesses about the graphs drawn.

 

[schamberlin]

OK, what I think I'm hearing is that Eneloops (and similar) probably aren't replacing alkalines in low-drain or rarely-used devices, but they are replacing standard high-capacity NiMH batteries, despite their higher cost and lower capacity? That's a little surprising, but I guess if high-cap NiMHs are typically fragile, have trouble delivering the rated capacity, or have especially high self-discharge, then it might make sense.

Still, $3 per cell is mighty steep for a battery. Could go with something like Rayovac Hybrids for closer to $2 per cell, but they're seemingly not as well liked.

 

[SilverFox]

Hello Schamberlin,

Welcome to CPF.

Interesting analysis...

Here are a few other things to consider.

Eneloop cells tend to be very consistent from cell to cell, and after a few years of use, they tend to stay that way. This is the behavior of a very high quality cell. The new cells are performing as well as the initial release of cells.

Many people prefer to use LSD cells in long running applications because they have experienced alkaline cells that leak. When you factor in the hassle of a replacement or two, the cost of the alkaline cells becomes less attractive.

Another consideration is that before LSD cells were available, a typical family would buy a "brick" of alkaline cells and put them into storage for later use. However, people often found themselves with dead batteries while out and about, so they would stop in and purchase a 4 pack at the local store to make it through the outing. This tends to eliminate some of the bulk purchase savings.

With the introduction of the LSD cells, you can eliminate storage of excess cells, and simply charge them back up when they run out, or on a periodical basis. OK, you can't totally eliminate extra cells, but you can cut it down a lot.

The LSD cells are a little more work than alkaline cells, but people seem to be willing to do a little work to eliminate landfill waste.

High capacity NiMh cells have there place. If your application involves going through several sets of cells each day, you are better off with normal high capacity cells. However, if you only go through a set of cells once a week or longer, the LSD cells may work much better in the long run because of their cell to cell consistency.

Finally, economy involves more than simply cost. When you load cells into your camera for a special event, you expect them to work. The LSD cells seem to work better than the normal NiMh cells, especially when the special events are some time apart from each other.

Piece of mind, knowing that the cells will work, and that they won't leak, is worth a lot.

Tom

 

[jtr1962]

I've come to a different conclusion. Given their propesity to leak (and there have been a number of threads on this) alkalines IMO are no longer a viable option AT ALL. All it takes is one ruined device to negate whatever savings they may have given (and the savings, if any, seem minimal). So that leaves one with a choice of regular or LSD NiMH. If you go through a set of batteries every few days or less, and need maximum possible capacity, then regular NiMH may make sense. I say may because in the long run they seem far less robust than LSD NiMH. LSD NiMH, on the other hand, should probably last way more than the 5 years you stated. Even some Li-ion cells, which are a much more fragile chemistry, are managing to last 5 years. I've little doubt Eneloops bought today will still be viable a decade from now, perhaps even twice that long. Not so for regular NiMH or alkalines, however. So in the end, my conclusion is to use LSD NiMH for everything, except the niche uses where you absolutely need that extra 25% regular NiMH can deliver. In some cases (wall clocks for example), the economics may be marginal, but even there things even out in time. 10 years of replacing an alkaline once a year more or less equals the cost of an Eneloop, and I'm sure an Eneloop will last 10+ years in such light duty service.

There are also other costs associated with using alkalines. What happens when you run out of cells, and must run to the store? Unless you have stores within walking distance, transportation costs to the store can easily negate any potential savings alkaline may offer. And it's far less convenient to run to the store to buy new cells, as opposed to simply popping them in a charger. With today's LSD cells, I really don't get the attraction of using disposible cells. I suspect among those who have tried both, they feel likewise. It's just a shame I rarely see LSD cells for sale in retail stores. They usually only have the problematic high-capacity ones.

 

[firefly101]

Ok something you didnt really consider on effective for costs and comparisons.

Eneloops can be recharged 500 times atleast And if you recharge them every year or even 2 years you will have a battery if needed that is 75-85% capacity.

Duraloops on Ebay you can get for $2 a Battery, atleast I did, and Hybrids are more common.

Alkaline at .40 for the generic brands is good but have a 7 year shelf life. Duraloops have unlimited. Imagine charging the battery every year for 500 years. lol Close enough to unlimited.

Alkaline are convience batteries IMO for the moment, but once they are drained a little then what do you do? You cant recharge them or top them off? So if you use them in lets say tactical weapons optics you throw them out, like they do in Iraq with just 1/3rd the life used up!

I agree for a person that ISNT going to use the rechargeable feature alkaline are better cost, but who that buys such batteries dont do so for that feature?

Lets assume $3 and see with 500 cycles that would be 0.6 cents per cycle charge or per battery. Compared to .40 each alkaline then they are 70 times more cost effective than an alkaline.

Plus as someone else said they dont go in a landfill.

Hybrids make sense, I cant see for anyone that wants long storage as well as multiple charges wouldnt want them? Also we dont know HOW long they will hold some sort of charge so unlike my NiMh that were stored just 3 years and lost capacity these little guys would probably be fine.

Again as someone else said most buy the batteries and after a few years (unless you get very fresh you only get about 5 years) you can end up with low or dead batteries when you need them, and most just go to the store to buy them. Cold is a factor also, alot who camp dont realize how cold it gets even in Spring and Fall, enough to lower Alkalines performance.

Lithiums are great and at $1.10 each on Ebay you cant beat as well as Lifespan of 15 years and maybe even more? But again once used thats it.

Personally if I wanted to store Batteries for a few years or even a year I would buy Lithiums for the Disposable, and Hybrids for rechareables. I know I would be able to count of BOTH to do what I need without issues even in colder weather.

Alkalines also bust, I had one bust in my eotech sight. I dont think I will ever use Alkalines again, I feel they shouldnt make them anymore (.40 cent battery that can ruin a $600 device!). They Should go strait to Better priced Hybrids and Lithiums energizer should lose their monopoly in about 5 more years then you will see lithiums everywhere at better prices.

 

[TorchBoy]

Re: Eneloops: Do they really make economic sense?

Have I overlooked something obvious? ... LSD is certainly a nice feature, but just doesn't seem worth the trade-offs in most circumstances.

Other posts seems to have done a good job covering this. I'd say you have some fair points on low drain devices but I would say you've ignored or not realised a few points regarding uses in higher drain devices:

* How quickly non-LSD cells die, and I don't mean just go flat. Their self discharge can quickly deteriorate to the point where the cells go flat in just a few days. Unless you're always using near new cells, this brings your crossover point down to a couple of days, not months.

* Non-LSD cells just don't seem worth the trade-off - a few % greater capacity for the frustration of finding flat batteries, worrying about how much charge the cells will have on any particular day, and time-consuming maintenance programs.

* As mentioned by others, Eneloops can be relied on to give what they're supposed to. No unbalanced cells a few months down the track.

* After 5 years I fully expect my Eneloops to still be going strong. If that's the case they won't get replaced, just (perhaps) supplemented with "Eneloop 2" cells.

* According to SilverFox's tests Eneloops hold their voltage under load quite well and can give a high output.

Considering those points, I standardised on Eneloops for my caving, where higher capacity might be desirable. But they don't give that much more capacity and I don't go caving every day.

 

[lctorana]

I'll make a slight correction to your post:

• 2 months or less: Eneloops
• 3 to 7 months: Eneloops
• 8+ months: Eneloops

There. That's better.

 

[tslrc]

I'll make a slight correction to your post:
There. That's better.

 

[schamberlin]

Thanks for all the replies! I don't deny the advantages of the LSD batteries, if someone wants to give them to me for free. My question is more about what mix of battery types would give me the least cost solution for all my battery needs over the next ~5 years.

After having read the comments, I don't believe it makes financial sense to use Eneloops in things like clocks. If you also factor in non-financial considerations such as reducing landfill waste, eliminating chance of leakage, and general reduced hassle, then it could make sense, but I wouldn't say it's an obvious win. The 7x price difference vs basic alkalines is very difficult to justify for devices where you rarely replace the batteries anyway.

For replacing standard NiMH cells, I think I'm more convinced of the value of LSDs.

What I finally did was order some Rayovac 4.0's, which I got for $1.15/cell shipped. They're not as great as the Eneloops, but from what I've read they are still a decent performer, and only 2-3x more expensive than alkalines instead of 7x. Since I'm a notorious tightwad, I feel better about that.

 

[KiwiMark]

traditional (higher-capacity and cheaper) NiMH

I would dispute the 'higher-capacity' part, unless you are just talking about 'fresh off the charger' capacity. Give the traditional NiMH cells a few days and their capacity won't be any higher than the low LSD cells. I have been testing some of my traditional cells and even the fairly new ones lose over 10% of their charge within 24 hours of charging. I have one year old 2600mAh cells that can supply 2185mAh fresh off the charger or 1940mAh after resting for a day - not really higher capacity compared to Eneloops, probably significantly lower (I'll test my Eneloops this week, they were purchased at the same time).

 

[Marduke]

I have to laugh every time you say they are more expensive than alkaline, when NiMH are well over 100 times cheaper in the long run.

Also, did you factor in the cost of item replacement when an alkaline cell inevitably leaks?

BTW, I've never paid full price for NiMH cells. The most I've ever paid was $1.25 each for Duraloops. My ROV Hybrids and Duracell 2650's cost $0.05-$0.20 each.

You can get some amazing deals if you look for them.

 

[Light Sabre]

If what I'm seeing is correct the non-LSD NMH's mAh's are dropping. The one kind of Rayovacs that are in the green package at Walmart don't say on the battery or on the package what the mAh rating is. I think someone said they were only 1400 mAh. Energizer has dropped their 2500 mAh horrible batteries down to their old 2300 mAh formula. At Target, the Targus LSD batteries say they are 2200 mAh. Not sure if that's real, or just hype. Using my BC-900 charger and testing the Duraloops their mAh are almost all identical with the mAh rating of the battery even across many packages. I have a handful of different brands of non-LSD NMH and both Hybrid and Duraloops and the Duraloops are the most consistant of them all mAh wise and charge time wise.

FYI: the Duraloop AAA's are on sale at Target (was just there today) at $10 for a package of 4.

 

[TorchBoy]

I realised after posting that many of my reasons are not purely economic. Is there an easy way to apply an economic value to landfill? I suppose it all depends on the assumptions we make. (If we assume that we'll eventually want to use the land for something else we'll have to spend money later on cleaning it up.) For that matter, how much embedded energy are in Eneloops? That is, how much more energy do they take to make compared to alkalines?

 

[Bullzeyebill]

schamberlin, you have gotten some great post here from people in the know. Eneloop cells have been discussed and rediscussed here on CPF. Please use google, cpf only at the top of every CPF page, and plug in Eneloop, or Eneloops, or any combination you might want to use. Thousands of posts about Eneloops available to you, as well as dozens of threads. Silver Fox is one of our authorities on all types of batteries and cells. Go to the batteries, elecronics, etc forum here on CPF, and look at the sticky threads. We can help you here in this thread, but the bulk of the info is out there for you to research. Happy hunting and :welcome:

Bill

 

[schamberlin]

I have to laugh every time you say they are more expensive than alkaline, when NiMH are well over 100 times cheaper in the long run.

Well, it all depends on your usage pattern, but if you're comparing to typical alkaline use cases: If you replace your clock's battery with a 50 cent Duracell once a year, versus a one-time purchase of an Eneloop for $3.00, you'd have to run that clock on the Eneloop for six years just to break even. For it to be over 100 times cheaper, you'd have to operate the clock for 600 years. I don't think I'm going to live that long!

The most I've ever paid was $1.25 each for Duraloops. My ROV Hybrids and Duracell 2650's cost $0.05-$0.20 each.

Where are good places to hunt for LSD batteries online? I looked long and hard for Eneloops, and couldn't find anything better than $3 per AA cell, shipped. I thought I was doing well to have found the Rayovac 4.0 AA cells for $1.15 each.

I've seen some recommendations for Thomas Distributing, but when you factor in shipping, they're $27 for 8 AAs. The best deal I found was from MyBatterySupplier via the Amazon Marketplace: $23.45 for 8 AAs, with free shipping.

 

[schamberlin]

@Bullzeyebill: Thanks, and sorry if I've already become irritating in my first day! I did read many other threads on Eneloops on CPF and elsewhere before posting. Most of what I read discussed the technical side of Eneloops, and not a consideration of them from an economic standpoint. I'll keep looking, but I think my question is basically answered at this point.

 

[Mr Happy]

Most of what I read discussed the technical side of Eneloops, and not a consideration of them from an economic standpoint.

It's not all about money! You can buy the cheapest available car that will get you from A to B, but will you enjoy owning it? And if you don't enjoy it, will you begrudge the money you spent on it?