What's inside that £500 battery pack.
February 28, 2016 3:22 PM   Subscribe

Markus Fuller dissects a battery pack for some high end Swiss stereo equipment. There are some pretty generic materials inside some pretty high priced electronic goods. A nerdy but strangely mesmerizing video. Follow up post.
posted by Bee'sWing (38 comments total) 11 users marked this as a favorite
 
*sigh* Nagra, please.
posted by delfin at 3:28 PM on February 28, 2016 [8 favorites]


While Nagra also makes some high-end home stereo equipment, this is a battery pack for a $10k professional multitrack portable recording unit. I'm not defending Nagra at all in this (their response seems particularly tone-deaf), but I think in this territory, it's pretty much expected that the margins on equipment and accessories is quite high.
posted by strangecargo at 3:40 PM on February 28, 2016 [1 favorite]


High end battery packs for audio equipment are made up of the ground musical dreams of people who never learned to play instruments.

[So they should be cheaper because crushed dreams are pretty plentiful]
posted by srboisvert at 3:53 PM on February 28, 2016


"Bat-tree." I like it every time he says "bat-tree."
posted by mikeand1 at 3:58 PM on February 28, 2016 [3 favorites]


Wait until he finds out how much a Ferrari dealer will charge you for a new tail light.
posted by zachlipton at 4:10 PM on February 28, 2016 [3 favorites]


Having watched both videos (and the second is perhaps more interesting just due to his analysis of Nagra's response to the first video) I, like strangecargo, am not particularly up in arms. Big up-pricing of already super-hi end, specialty equipment? No surprise there. I'm also not surprised by the individual unavailability of the 6-cell battery pack. Consider:

-Nagra says Li-ion batteries are dangerous - markus agrees
-Nagra says the battery packs should only be serviced by professionals - markus makes the point that it is just a matter of unscrewing the enclosure and plugging a new pack in.
-Markus then says (rightly) that you shouldn't make your own battery pack unless you know what you are doing.
-BUT if the individual packs are available people would be tempted to buy multiple packs and field-replace them within the overall battery holder.
-They would also want to charge these multiple packs simultaneously, and start looking for third-party chargers, which might not be made to the same specs/quality
-Both of these practices could lead to situations where someone makes a mistake and then get lots of nice flames.

Consider:
-These kinds of battery packs are the reason why hoverboards have exploded.
-Using special fireproof charging bags is standard operating procedure for lots of industrial/commercial operations.

IMO Nagra did (almost) exactly the right thing:
-make a well-designed external enclosure for the batteries, with both mechanical and electrical protection mechanisms built in.
-make it easy to repair if necessary.
-make it clear the batteries should only be serviced by professionals.

Are the batteries over-priced? Absolutely, but there are lots of other hills I'd rather die on. Watching the videos was fun, though, on a slow sunday! If you like this kind of thing, and don't mind a bit more energy in your outraged electronics deconstructionist, check out the EEV blog for lots more fun curmudgeonissivity! My favourite is this post on the white van audio amp scam.
posted by ianhattwick at 4:13 PM on February 28, 2016 [13 favorites]


I had some AAAs leak out into the remote for an old Hitachi 18" TV we had sitting around for ages. Popped it open and did the baking soda/vinegar clean of the contacts and it now works maybe one time in 10. In conclusion then, batteries are a land of contrasts.
posted by turbid dahlia at 4:16 PM on February 28, 2016 [3 favorites]


I'm also not hugely outraged at this. This guy knows what he's doing. But NAGRA have to try and account for the million ways in which users could basically reassemble their battery packs into potential bombs. I imagine that there would be huge liability issues with allowing people to do this by themselves, including taking them on planes etc. Maybe it's overpriced - who knows? What are the specs of the unit? How much does it cost to produce the enclosures, etc.? But I'm not surprised NAGRA are not into consumer/DIY fixes for this.
posted by carter at 4:21 PM on February 28, 2016 [3 favorites]


I think the fact that Markus says "get the fire extinguisher ready, just in case this bursts into flames. I'm not kidding by the way" is a pretty clear sign of the reason Nagra isn't inclined to help their customers mess around with Li-ion battery packs. They've been kind enough to not smother the whole thing in glue and obscure screw heads, and people inclined to mess around with it can watch videos like this or use ifixit.com.

Yes, the official replacement pack is somewhat overpriced (though a lot more goes into making a low-volume unit than just the price of the cells themselves). What do you expect for an accessory for a $10K digital recorder?
posted by zachlipton at 4:23 PM on February 28, 2016 [2 favorites]


these are the same lithium cells Tesla uses for their battery pack . . .
posted by Heywood Mogroot III at 4:25 PM on February 28, 2016


pretty sure that there is no need for a fire extinguisher to just plug and unplug the internal 6-pack, which is what he is arguing for if you pay attention. you can test the 6-pack units in isolation. plugging them into something doesn't suddenly make them more dangerous.
posted by andrewcooke at 4:27 PM on February 28, 2016


Is this a business opportunity? Could you make replacement packs cheap enough to undercut Nagra without sacrificing quality and safety?
posted by Pope Guilty at 4:48 PM on February 28, 2016 [2 favorites]


the postman's McGuffin from Diva
posted by hortense at 4:50 PM on February 28, 2016 [1 favorite]


Conceivably, but you have to ask yourself how many of these recorders there are out there, how many owners want replacement battery packs, how many of them want unofficial replacement battery packs for their very expensive equipment, how many of those owners won't do it themselves, and how screwed will you be in the unlikely event something goes wrong (whether or not its your fault). I don't think it would prove to be a very lucrative hobby.
posted by zachlipton at 4:53 PM on February 28, 2016 [2 favorites]


Sorry, all my battery-hate is still focused on Batteriser.
posted by ryanrs at 5:03 PM on February 28, 2016 [1 favorite]


I particularly enjoyed the way, after the huge 'Nagra precision hand-assembled Swiss engineering' wankfest that preceded it, the tray on the super-duper magnetically-clamped CD player... stuck.
posted by Devonian at 5:07 PM on February 28, 2016


Super cars have been having that wank fest for decades. No one buys super cars for their reliability or economical maintanence, and no one buys gold infused gummy bears for the taste.
posted by Brocktoon at 5:12 PM on February 28, 2016


Sure, people pay a premium for Nagra equipment, but they are paying that premium for Nagra's expertise in designing audio equipment, and if you take apart the audio side I am sure you will not find the same commodity hardware you could buy at Radio Shack. But this battery pack, not so much.

It is totally commodity hardware and it is being sold at a markup of north of 90%. This is a 50 watt hour battery pack and you can buy a 600 watt hour pack *built using the same cells* for the same money (I know this because I mess around with electric bikes.) No amount of "quality engineering" can account for that markup.

The reputation lithium batteries have for catching fire tends to be based on the (easily compromised) "soft pack" cells used for RC applications rather than the metal-cased 18650 cells, FWIW.
posted by pascal at 5:18 PM on February 28, 2016


I think you mean 900% markup
posted by RustyBrooks at 5:19 PM on February 28, 2016


What's an order of magnitude among marks? Can't we all just get along?
posted by spacewrench at 5:23 PM on February 28, 2016 [1 favorite]


Yes, you could say it that way. What I meant was that 90% of the selling price was markup.
posted by pascal at 5:24 PM on February 28, 2016


I don't know Nagra products - the last time I encountered the brand, it was in the context of portable tape recorders used by radio reporters. They were superbly engineered and pretty much the last word in having the right gear for the job. Nagra was just about a generic noun in that business.

Severely good engineering counted for a lot then. It does now, but the difference is - it's far easier. Audio in the digital domain is a solved problem, and it doesn't matter who aolders the bits together. I could never have begun to build a tape recorder that did the job as well as Nagra could, but I can design and build a digital audio recorder on my kitchen table that will have essentially the same specifications where it matters as anything Nagra can do.

Of course, Nagra can still build superlative mechanicals, and I appreciate the delicious feel of high-end knobbage as much as the next geek. Now, though, that's really just for show. You can get something like a Zoom portable digital audio recorder for a couple of hundred pounds that is well-designed mechanically and will go and do the job as well and as reliably as anything Nagra could make at any price. Nagra could make something with far higher-end aesthetics, and that may be a joy to possess, but it won't do the actual job any better.

So you have to charge more, otherwise you won't be adding any value.
posted by Devonian at 5:36 PM on February 28, 2016 [5 favorites]


Just a note, he's not upset at the price of the unit, he's upset at Nagra not making a $40 replacement part available which would eliminate the need to spend hundreds on another entire battery unit.
posted by Cosine at 6:01 PM on February 28, 2016 [3 favorites]


The reputation lithium batteries have for catching fire tends to be based on the (easily compromised) "soft pack" cells used for RC applications rather than the metal-cased 18650 cells, FWIW.

I would assume the batteries used in hoverboards are the same type as Nagra used here (and a pic on this page seems to show they are using the same style 18650 cells). Of course, I would agree that well-designed li-ion batteries are safe -after all, most of us are reading metafilter on devices with li-ion batteries inside. The problems hoverboards have seen aren't due to punctures or mechanical damage (as might be more common with flat-pack li-poly batteries) but more likely due to charging and discharging too quickly, over-charging, and maybe short circuits due to frayed wires.
posted by ianhattwick at 6:02 PM on February 28, 2016 [1 favorite]


Great teardown. In terms of the position 'is it a rip-off?', the answer is both yes and no.

On a cost basis, it certainly can appear that way when considering that they're charging £450 for a battery pack that on a component basis is £30. If strictly taken on a materials basis even with housing, battery management system, connectors, labour, etc, the total cost of production / distribution of the battery unit may not even top £100.

On a value basis, it depends. From a battery point of view, battery cells are complicated pieces of engineering for a number of reasons. Not in the least that storing electrical energy chemically is, as he says, essentially a small bomb waiting to happen. In that view, not all 18605 lithium-ion cells are the same. The form factor is one consideration, but each manufacturer will use different formulations and the cells will have different characteristics. Further, the battery management system (BMS) may be a 'dumb BMS' that works purely on a voltage basis, or it may be smarter BMS that works on a number of different factors. It's not always immediately obvious from the controlling circuitry what's going on behind the scenes.

In the battery world (and there is a battery world, because batteries literally run the devices that run the world), there a huge array of manufacturers and products. A Sanyo cell may operate differently from a Samsung cell. One may perform better in high-drain situations, one may perform better in low-drain situations. There's premium batteries that hold up better under high number of charge/discharge cycles. There's a differing factors in terms of the low-voltage cutoff, rates of charge, and temperature dynamics.

Good consumer electronics firms will have testing laboratories, either in house or on contract, that test all the different cells in a number of ways. Further, the battery manufacturers will also test in house, as well as submitting to a number of different quality assurance firms. The ultimate end-producer will also catalogue batteries by batch number, and will be taking returns from the field and doing repairs.

While it may *look* simple – a box, a battery block, a few circuit boards, a temperature sensor, and soldering, the reality is much more complex. Which battery block? How are they soldered together? What's the circuitry designed into the BMS?

A simple example is the level and quality of soldering and pack engineering. Battery packs that are subject to vibration must be soldered in a different way than battery packs that will not be. Consider the battery pack in a portable audio recorder – which may literally go off to war – versus the one in an automobile versus the one sitting in a stationary UPS system. And that's just the soldering points.

Consumers buy outcomes, and they buy those outcomes from brands. The same person who is going to buy a $10,000 piece of audio equipment is going to expect everything that brand does is high performance. From the device itself to the battery pack. The customer that will spend £450 on a battery pack is most likely doing professional-level work with the equipment, and if it breaks or fails, they lose money. Therefore, consider that you're not only buying a block of battery cells, but you're also buying the name and guarantee of performance that comes with it.

Consider the company's data from being in the audio business for, say, 20 years building battery operated devices. They will have service records and tons of information on the performance of different battery cells from different manufacturers over time. They will be receiving dead battery packs and modifying future battery packs. At the same time, they will be attempting to reduce the complexity of their circuit design – for reliability's sake – based on all of that information.

And they will be doing this because the person that's paying £450 for a pack 1) wants a pack that will perform, and 2) he says it himself in the video – the pack lasted 7 years under reasonably constant use. Which is a huge win for a lithium ion battery system designed in 2006/2007. Basically, if you break that down to a cost per year, that battery pack cost £64 a year. And I'll imagine the user received much more than £64 per year of use out of it.

Consider a theoretical price/performance curve where a poorly engineered pack costs £50 and fails 10% of the time over the life of the product, a good pack costs £200 and fails 5%, and a great pack costs £450 and fails 1% of the time. Now consider that you make your income from using this piece of equipment. Let's say you record live concerts for bands.

Now, you're renown for your work, and you're recording a once in a lifetime reunion of a major national band. Which piece of equipment do you want with you? The one that fails 10% of the time, 5% of the time, or 1% of the time? What is the cost to saving money in this case?

Because to get to a pack that fails 1% of the time takes a lot more money than to get to a pack that fails 5% of the time. Because to reduce the failure rate, you are studying every failed pack. You are analysing performance data in deeper review, and and so on. That means more people at the company, which means more administration and payroll tax at the company. Overall more cost.

So when watching this, while I found the teardown fascinating, I find the asserting that the company is playing poorly to be out of line with reality. Similar to Apple's lawsuit against Samsung. That wasn't about the rounded edges on the iPhone or the button or the look and feel itself. It was about all the costs it takes for Apple to get to that UX/UI experience. There are real costs to engineering products at different levels. And the £450 for the battery pack isn't about the price of the components in the pack, but the costs to run the company that produces a pack you trust with your own business content and brand.

In fact, in professional circles, it's not uncommon to change out battery packs way before they fail. If batteries have a mean time of failure of 3,000 charge cycles, some organisations will change them out after 1,000 or even 500. Because it's not the cost of the pack. It's the cost of what happens when the pack fails? My guess is that a £450 battery pack isn't going to fail all that often – and may well last an impressive amount of time.

That's not down to the battery cells, but rather all the knowledge that went into choosing that battery cell, and that battery management system, and that kind of solder, and that style of connector, and that piece of foam, and testing all the possible configurations of that, and having a system that tracks performance of that battery cells / pack over time, and the people that can run an organisation with that level of focus on quality / longevity.

I heard a great example at a battery conference of why some packs are worth more than others that use the same cells. Two chefs can go to a market and buy the same ingredients – the same flour, the same cheese, the same meat, the same olive oil, etc. One chef will make a meal that you'll pay £10 for, and the other will make a meal that you'll pay £100 for. Same ingredients, 10x price difference. One chef has more knowledge of how to combine them and more experience making something that commands a 10x price premium.
posted by nickrussell at 6:26 PM on February 28, 2016 [12 favorites]


these are the same lithium cells Tesla uses for their battery pack . . .

I can't wait until Tesla ditches 18650 cells. Hey, let's throw away 20% of the volume of the battery!
posted by Talez at 6:31 PM on February 28, 2016


What devonian says X a million. Their analog mechanical compact tape recorders were like something James Bond would own. These days a Tascam digital 4-track with built-in stereo mics capable of doing CD quality audio runs $99. If you think you can hear the difference between CD quality and anything 'better', you're probably fooling yourself.
posted by sexyrobot at 6:39 PM on February 28, 2016


That wasn't about the rounded edges on the iPhone or the button or the look and feel itself. It was about all the costs it takes for Apple to get to that UX/UI experience. There are real costs to engineering products at different levels. And the £450 for the battery pack isn't about the price of the components in the pack, but the costs to run the company that produces a pack you trust with your own business content and brand.

Not just UX, their electrical engineers are outright fucking bonkers about quality. If you ever wanted to see a massively overengineered piece of electrical equipment.
posted by Talez at 6:46 PM on February 28, 2016 [1 favorite]


It's almost as if we were not talking about a battery pack where a third of the cells had failed. And this is not a highly demanding application, I would be very surprised if this recorder drew more than a few watts.

You can try to compare this to Apple if you like, but I'd suggest this is more like charging $200 for a mains cable than it is like charging $200 more than other phones with comparable specs.
posted by pascal at 7:18 PM on February 28, 2016


MetaFilter: the delicious feel of high-end knobbage
posted by um at 7:37 PM on February 28, 2016 [3 favorites]


Having been in and around pro audio and film production, I can see both sides, to some extent.

On Nagra's side, they have a reputation to uphold. A customer expects that when they get a Nagra battery pack for their Nagra recorder, it's going to work, just like the recorder itself... no guesswork, sterling warranty, utterly dependable. If they don't get critical about any old battery replacement, then now your Nagra is only as good as the punter who replaced the batteries.

There's also legal risk - if a Nagra battery pack malfunctions and causes any damage or injuries, Nagra is on the hook. If they condone or permit end-user replacement of batteries and one of those causes problems... they're still on the hook.

On the other side... as a confirmed hacker, I tear into any old thing and have been known to fix salvaged gear with parts lifted from other salvaged gear. And when I was technical manager for a production facility, damn straight I figured out how to second-source parts if I thought we were being gouged. But in both cases taking full responsibility for these actions.

I also know that a manufacturer will try to make markup wherever they can, to cover low or no margin in other areas. One editing system manufacturer I once represented in the early 90s was making a whopping markup on stock SCSI harddrives, saying they were "special".

A middle ground for Nagra might be to have an exchange program on the battery packs, or make them available but only through a dealer who does the changeout and a test.
posted by Artful Codger at 7:49 PM on February 28, 2016 [3 favorites]


Why is there no standardization for larger battery packs? I get that phones and laptops need custom shapes, but miscellaneous low volume products like this should leave batteries to someone else. I guess RC batteries are standardized but they're also known for catching fire so maybe not the best thing to standardize on.
posted by miyabo at 8:01 PM on February 28, 2016


Also, if you like the somewhat niche genre of Australian electrical engineers ruthlessly criticizing shoddily made electronics on video, EEVBlog is your place.
posted by miyabo at 10:12 PM on February 28, 2016 [2 favorites]


If you think a $99 Tascam or Zoom has the same reliability or sound quality as professional grade gear (which Tascam does make at professional grade prices ) just because "digital," you've clearly not worked with both amateur and professional equipment nor developed your ears. Digital does make relatively good sound possible for less money than analog did, but there's still analog circuitry in the signal chain and cheap digital is not as good as good digital is not as good as great digital (A/D and D/A conversion, as well as things like interfacing with other digital devices). And inexpensively made gear isn't going to hold up to use and abuse the way good gear will.
posted by Candleman at 11:19 PM on February 28, 2016 [1 favorite]


> he's upset at Nagra not making a $40 replacement part available which would eliminate the need to spend hundreds on another entire battery unit.

Even if Nagra doesn't want you opening the metal box & replacing the pack yourself, will they not service the battery box and put in a new pack for you? Even at a relatively high cost (say 30 to 90% of new), that would solve all the concerns about safety and also about wastefulness. The customer wouldn't have to worry about it being a bad cell or two or something broken in the other parts in the box. Bad cells could be properly recycled. If they do offer service, they could have pointed it out in their response (link to cached copy as original appears gone) to Mr. Fuller's video 70.
posted by morganw at 11:23 PM on February 28, 2016


Designing a safe battery pack isn't exactly a black art. There are very standard Smart Battery Specification designs, but some pack manufacturers will cut corners to skimp on costs, hence possible fire.

A standard battery pack has an off the shelf SMBus controller chip that monitors cell voltage, battery current and temperature. There are charge and discharge MOSFETs that prevent over charging and over discharging, a logic fuse that blows if any cell reaches over-voltage and a thermal fuse if the temperature limit is exceeded. The battery chip also includes a coulomb counter gas gauge.

Externally there is a battery charger, which in this case uses a standard LT4101 charge chip.

Nothing special in there that would justify a cost of $500.
posted by JackFlash at 12:48 AM on February 29, 2016 [1 favorite]




The YouTube channel, AvE does tear down videos (BOTLR "Bored of Lame Tool Reviews") that may be unintelligiable due to extreme Canadianisms.
posted by bonehead at 11:22 AM on February 29, 2016


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