Are Expensive Batteries Worth the Extra Cost? | Hacker News Reader

Are Expensive Batteries Worth the Extra Cost?

wired.com

118 pointschaostheory44 comments

No mention of NiMh cells? Really?

NiMh cells used to be unsuitable for a lot of applications because of high self-discharge - a conventional NiMh cell will empty itself in a matter of weeks. This problem has now been solved by Sanyo and others, with a new generation of cells with vastly lower self-discharge. The latest generation will keep 90% of their charge after a year.

You can buy excellent NiMh cells for less than $2, often less than $1 if you buy in bulk. Good chargers can be found for $15. Compared to even dollar-store cells, it doesn't take long for that investment to pay off.

The AA Eneloop (the low-discharge formulation you mention from Sanyo) was tested by an obsessive at amazon.com (http://www.amazon.com/review/R2QVW9U1ISXVGV/ref=cm_cr_dp_per...) and found to have about 2100 mA-h of capacity. If you take the NiMh voltage (per http://en.wikipedia.org/wiki/AA_battery) to be 1.25, then a simple conversion yields:

  2100 mA*h = 2.1 A*h 
  => 
  1.25*2.1 V*A*h = 2.63 W*h = 9,450 W*s [3600 s per h]

I.e., about 9500 joules. This is on par with the Duracell and Energizer results in TFA. I found this encouraging.

This conversion does not take into account the drop in voltage that TFA did take into account, but that the above conversion did not (I assumed 1.25V throughout). But even if it ramped down uniformly from 1.25V to 0V, this would only cut power by a factor of two (and that's very much a worst case).

NiMh cells drop less gradually than alkaline; they tend to be nominally 1.2V for the entire useful lifetime of the cell. Just put a NiMH in an old device with a battery meter and watch it say 80% the whole time...

The Sanyo Eneloops are excellent, particularly for things you don't use often but must depend on them: LED torches, camera flashes & triggers, remotes, etc

The article compares two name-brand alkaline batteries to a zinc-chloride ("heavy-duty") battery. The results were as expected.

You can get cheap alkaline batteries. They're $1.99/10 at IKEA, for example. And they perform as well as name-brand alkalines.

http://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery#The...

The article doesn't mention what type of batteries used (for any of the brands tested), which is pretty poor. For some reason, I expect better of wired.

The author notes that most electronic devices have a threshold below which the battery is effectively useless, if not dead. I think a more useful comparison would be to measure the area under the curve until the voltage drops below the necessary level. Granted that devices may vary, but even drawing an arbitrary line at, say 1.0V would be more informative.

As others have noted, I'd like to see a comparison to the much-more-expensive "lithium" batteries. Despite the expense, I've adopted these in preference to alkaline, NiMH, or Eneloop batteries for my cameras. The lifespan is so much longer, meaning less need to carry spares or risk of running out, that they're worth that extra price. But I'm curious just what tradeoff I'm making really making.

Does anyone still use alkaline or zine-chloride batteries? I've switched everything to "pre-charged" NiMH batteries, since they don't self-discharge and are easily recharged. They're great for things like the rear taillight on my bike (which may sit unused for a long time, but then draw a lot of current), but also work pretty well for clocks and remote controls. And they're not very expensive if you buy the Amazon brand. (But watch out, four batteries come with enough packaging to ship a 747. I bought three four packs and couldn't live in my apartment until I called someone to come remove the waste! Almost.)

After buying a $40 premium charger which has very stringent standards (for some reason, any particular NiMh battery has about a 50% chance of being recognized as something chargeable after each use), I gave up on rechargeable batteries. If they've made them more reliable and less self-discharge-happy, it might be time to retry.

Yes, they've fixed this. They call them "precharged rechargeable batteries", but what that really means is that they don't self-discharge anymore. (And hence, are usable out of the box).

I've used them in everything for about a year now, and they work extremely well.

(They do self-discharge a little bit, but not enough to really matter. If you are going ice-climbing around the world for 8 months, bring lithium cells. If you want something for your bike light or TV remote, get a precharged rechargeable.)

I've had the same experience. The batteries seem to go bad really really quickly, and the recharge potential degrades extremely rapidly with re-use. After just a few charges, they will hold essentially no charge.

I did find a way to get the charger to recognize them. Get a screwdriver and connect + to +, - to - terminals of the dead battery with a live one. That puts a little charge in and the charger can then see that it's a battery and do its thing.

Then my expensive charger croaked. I got a new one, but I'm starting to lose the faith.

I have just the opposite experience. My current setup: cheap charger (sub £20, http://www.euroffice.co.uk/i/lcg2/Energizer-Maxi-Battery-Cha...) and simple rechargeables (http://www.amazon.co.uk/Uniross-AA-2700mAh-Performance-Batte...). I have 4 batteries and recharge them every two days and rotate. They last around 3 days (6hrs) on this torch http://www.fenixtorch.co.uk/led_torches/fenix-ld20-r4.html.

It bit over a year of nearly a day-to-day use and no degradation in power. They seem to behave just as they did a year ago. Perhaps the accurate measurements would show differently, but +-10mins on a 6hr scale is not that important.

Try a low self discharge battery. Less wasteful, more convenient, and you can reach in to a drawer a few months after charging them and know they'll work.

I've occasionally discharged my NiMH batteries low enough that my LaCrosse charger decides it's a dead cell. But shorting the positive terminal with a working battery in the charger (for just a moment), or putting it in a simpler trickle charger for a while (minutes? I usually forget and leave them for hours), always works.

Did he really just try to draw a scientific conclusion from a sample size of one?

> Yes, the Energizer has a higher stored energy, but it also has that small jump in the current that may or may not be real.

Your whole conclusion may or may not be real. I believe you that more expensive batteries are better, but you would think Wired would be able to afford more than one each to test.

I was wondering something similar: how much variance is there between same-brand batteries?

I did this for a science fair project literally over 30 years ago. The result was that the Radio Shack batteries that you got for free (they used to give 1 free battery a month) was better than Duracell.

Coincidentally enough, I judged a science fair on Saturday, and one enterprising 6th grader did the same. The results were that alkaline batteries were significantly better than other types (by about a factor of 2), and that the generic versions were slightly better than the name-brand (by about 10%).

I remember Consumer Reports doing a battery test. The big winners were Costco's Kirkland brand, as they fell only slightly behind the big name brands in longevity, but at a substantially lower cost.

It would have been very interesting to see where the Kirkland batteries fell in this test.

Why are the only options non-rechargeables?

Aside from a few kid's toys (which require 1.5v not 1.25 that rechargeables give) in our house all batteries are low-discharge NiMH AA or AAA (with adapters for the C and D variants) - there are 1-2 9-volts, but for smoke alarms and they last forever.

Sorry to bring this up, but what about the impact on environment? Sure, you can replace cheap batteries more often, but that means you're increasing the environment pollution by doing that (you need to recycle more batteries).

Battery lifetime may also change depending on current draw of the task at hand. It's not trivial to measure the energy content; you need to consider the application.

It will, and pretty much! Different battery types have also vastly different responses depending on the current draw. For example, http://data.energizer.com/PDFs/EN91.pdf (the first bar graph) shows one example of capacity vs. discharge current.

Packaging, markup and logistics are a big factor. Compare the Duracell "Pro" range which only come in bulk to commercial customers with the exact same cell in a different case (the familiar copper-top cell). I'd be interested in seeing if the "lithium" branded cells (which clearly aren't LiIon chemistry as the voltage is still 1.5ish volts) are worth the extra cash though.

Lithium batteries have a different use case. Their advantages are greater overall capacity, longer shelf life, lower weight, higher voltage (1.8), consistent discharge (low slope), better operation in low temperatures, less tendency to leak (IME).

Household electronics may not need these, but a spelunker powering his headlamp might.

The biggest use for lithium batteries is probably shake-and-bake production of meth. I saw a dude at Walmart with a cart full of Energizer Lithium batteries and those instant cold packs. I just laughed and moved on.

Lithium iron (the 1.5v) and other primary lithium cells (the 3v) are very important and most definitely a real battery, not just marketing. Stable voltage output over ther life (alkalines life is rated to 0.8 v), high capacity, wider temperature range (doen to -40), high peak current, and great shelf life.

LiIon is for rechargeable batteries. The 1.5V Energizers are almost certainly "lithium-iron", a.k.a. "voltage-compatible" lithium cells.

Yes, indeed. The marketing point appears to be lower self-discharge rate, but that's going to be pretty boring for a home experimenter to measure (like, 10 year shelf life - what's the shortest meaningful experiment time you can extrapolate from?)

Side Note - the Lower Self-Discharge rate is important for applications in which you are putting the battery out there in Gas/Water meters to run for 20 years. That isn't a shelf life of 20 years, that's actually _working_ for 20 years. Admittedly, most of the time the device it's powering is in a deep hibernation state, and only waking up once a day and doing a (very brief) radio transmission, but the tolerances become very important - particularly if you are deploying several million of these into the field.

Much less than 10 years. Temperature has a major influence on self discharge and useful discharge; the lithium batteries win for this. They also have more energy per cell. Lithium batteries are also lighter, and more shock resistant/leak resistant/durable.

I try to use CR123 lithium batteries wherever possible; they're pretty cheap at BatteryStation.

Lithium cells really do have a dramatically lower self-discharge rate. The most obvious application is in smoke alarms, where the current drain is usually less than the self-discharge rate of an alkaline PP3 battery. This has major implications for landlords, where a $2 battery might cost $60 to change.

Smoke alarms aside, there are few applications where lithium primary cells would make sense for the ordinary consumer.

Well if the warranty is only 2 years, I guess they can say it lasts 1000 years. When you complain that it only lasted 3 years, the warranty will already be up :)

Hmm, they are recommended for use in smoke detectors, think they might be slightly more careful about that if there is actually no benefit... Unless the conspiracy theory runs deeper than suspected :-)

neat analysis. I have a wireless keyboard that wasn't working well - would disconnect and go unresponsive. I changed batteries 2 or 3 times and the problems persisted. Finally I happened to change batteries to a batch of duracell batteries and the problems went away. Brand name vs. dollar store may vary on peak current capabilities as well as overall power density.

I'm really curious if the name brand batteries "good" ones vs the name brand "premium" ones actually have any difference.

You know, the "for digital electronics" batteries that are $1-2 more at the store. Just marketing?

Pre-charged (slow leak) NiMh for the win.

Though we really are overdue for a battery revolution.

That jump in the current of the Energizer can't possibly be a loose connection. There's a sudden global change in the value of the plot on either side of the zigzags.

Not touched on in the article, but the probability of leaking and corrosion when run down and left in a device seems anecdotally higher for generic batteries.

from 94 till i got a sharp zaurus pda in the noughties i used pdas like psion and palm/visor that required aa or aaa batteries. i tried duracell/energizer and at a pinch generics. i never had a duracell or energizer leak. the extra money was worth the peace of mind. using generics in other cheaper equipment was risking leakage.

as to power levels. when energizer came out for the first month or two they were better than duracells in terms of amount of power drawn by the psions (i kept a spreadsheet of mw) but i put that down to the supply chain not having stock languishing in warehouses for a new product shortening the length of the supply chain.

i eventually switched ti nicd and then nimh batteries and even lithium batteries originally meant for emergency torches. but with modern devices i really miss not been able to drop in 1-2 cheap batteries in a pinch or when far from the grid. it be nice if there were a modern smartphone/pda that could run off alkalines.

The ones at ikea last a good 2 days in a wireless mouse.

I've had been using the Costco Kirkland AAs for a long time, but I stopped last year due to a perceived shelf life issue.

In an attempt to reduce waste, I use a "battery rotation" in my house. They start in the kids toys. When they reach the "flake out" point (this is where the toy starts behaving like it's demon possessed, saying only one or two words of a song, playing it's "music" without anyone touching it, etc), they get tossed into a "drained" box where they are used in IR remote controls or LED flashlights (I have 15 LED flashlights, story in another thread). When the LED flashlights burn through them, I put them in my IR remotes. They last, literally, for months before the IR remotes kill them. Then they get recycled.

The problem I found with the Kirkland over the Energizer and Duracell (and I'll admit my sample size was two of their 48 packs) was that as I got to about the middle of the 48 pack, the unused remaining batteries wouldn't run the toys. They'd light the LED flashlights about as well as the batteries in the drained box. As this happened twice, my guess was that the Kirkland batteries don't have the shelf-life of the Energizers. I don't think it was environmental conditions--all batteries were stored in the same place and went through four seasons. Two 48 packs of Kirkland and I'm on my third 36 pack of Energizers, though I never hooked it up to a device to get an accurate measurement, so take it for what it's worth.

After getting frustrated with the Kirkland's I decided to bite the bullet and go to rechargable. I went with AA and AAA NiMh batteries. My kids have a lot of electronic toys, and they get rotated into and out of use as they get bored with them. I switched to all NiMh (expensive) batteries, last year (not sure if they had the "fix" that was mentioned about the Sanyo batteries but considering how quickly they stopped taking any charge after very few recharges, I'm guessing not). After the kids used the first set of toys (about 16 batteries worth), I stored them for about 2 weeks as usual (turned off, not removed, I know, I know). When I put them back in rotation, they were completely dead (I didn't measure, but I did put two in my Sony TV remote and no dice). This made the batteries worthless. Kids toys made in the last ten years require tools to replace the batteries and my battery charger only holds 4 batteries, so this is an all day ordeal of charging, watching, changing, charging and of course, figuring out how to get past the child-proof battery holder, putting the batteries in wrong or discovering the need to clean the terminals, unscrewing and screwing them back in.

I did find that if the batteries were fully charged prior to storage, they worked after rotation, but it seemed they didn't work very long.

I'd like to be a whole lot less wasteful (both money, time and materials). Does anyone have any experience with a specific brand of rechargable AA and AAA battery that retains most of its current charge when stored for up to 3 weeks not fully charged (I'll even go through the trouble of removing them from the toys if I have no choice), and from a cost perspective make sense for toys that require batteries to have a discharge rate similar to good Alkaline batteries?

Edit: Clarify storage conditions.

In late 2010 I bought "24 Centura AA LSD NiMH Rechargeable Batteries" from eBay (for $33, so just under $1.66 each) -- specifically the long-life kind, that was around when I heard of their existence.

I've used them in remote controls that sat for months and continued to work fine, and in wii-motes for similar periods. I haven't measured the life/performance much more carefully than that. Except I do have a nice LaCrosse charger that measures things and claims to be putting in an average of 2Ah, which compares favorably to the (2300 or 2600 mAh if memory serves) usually inflated rating that they claim.

The trick, though, is that with rechargeables (and especially long-life like these), you keep a small but sufficient stock of charged batteries ready. When something goes dead, the dead batteries go in the charger, and the stock (immediately) goes in the thing. By the time the next thing dies, the previous set is charged and ready.

If you have an Apple Magic Mouse that won't run on cheap batteries, yes.

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