Sunday 13 November 2022

balancing storage

As you may know I like to get things as right as I can and if you've read my blog (and perhaps more specifically this post about my battery storage) you'll know that I keep going on solving until I get a result I'm satisfied with. Well after a little testing I'm comfortable to report that I've found a balancing solution (thanks to that guy on Reddit) for a small amount of money.


If you follow the wires you will see +ve from the A side goes to the 24V +ve, the black to the 24V -ve and the white to the place where the two 12V batteries are joined in series to make a single 24V battery.

The box is as simple as it gets, it "powers" itself from the battery its attached to and The A and B labels on the box have an LED which lights up when they are transferring the power. The manual says this about how much power it sucks from the system.


so not much goes outside the system from this and it even prevents discharging a pair of batteries not being charged regularly from being drained to death.

Its wired up like this


and as you can see will even scale up to work with more batteries easily by just adding more.

So as you may observe in the top picture there is a small voltage difference between the batteries, but this is just a calibration problem of those cheap voltage displays. I just couldn't get it to be less than 0.5V by turn and so the small differences present the way they are.

I don't mind really because at a glance I can see big problems (like more than half a volt) then I don't need to look further. Now and then I see what the voltages are with my Fluke volt meter, and they've been good.

So basically this unit helps to keep the drift of one bunch of cells (the 6 cells within one of the 12V batteries) getting too far from the other bunch of cells (within the other battery). The ideal would be cell by cell comparisons but as each 12V battery is sealed that's not going to happen without surgery. However my experience is that this system works pretty well.

As I discussed my existing system was indeed drifting, which is not surprising when you stop thinking of maths and start thinking about 1) chemistry and 2) the reality of productions. Tiny differences exist in things (except perhaps those made for NASA) and these set up the beginnings of drift. Things like

  1. under load do all cells in a battery discharge the same? Does indeed each of the two batteries??
  2. what about under charging?
So this system basically works electrically "inside the battery" to keep the two bundles of cells together.

The best thing is that this little box only cost $15

Fantastic

Win Win

Friday 11 November 2022

Bose aftermarket spare parts

If you have bose headphones eventually you'll find yourself needing a new set of ear cups and the inside covers / liners.

I recently bought a set and things have improved since I bought sets for my QC-2's years ago, the ear cups actually fit now (required some surgery on the last set), however things still aren't perfect as all of the ones I've seen on eBay (and the like) for my QC35ii have flat inside liners, not curved like the genuine ones (as seen with my manky ones here) that I've removed:


and here


It results in the inside not being covered as it was before:


and so this area is likely going to suffer a little from my ear tips touching that (as you can see the marks on the top photograph if you look carefully) as it was previously covered and now isn't.

Ultimately I think this will reduce the life of my product, so I'll weigh my options, but as they're already nearly 3 years old I'm not sure they'll get the same usage (or if I can apply something else myself).

Just a FYI

Wednesday 19 October 2022

Skullcandy Indy ANC vs Bose Quiet Comfort Buds (gen 1)

In my view  the key to a good review is to consider the item from the perspective of intended usage and the price. So few reviewers seem to have a clue (or deliberately write dribbleShit because they want to get more free things to review - which explains why so many reviews are samey samey). So this is both a review of the Skullcandy Indy ANC buds and a comparison of them to a class leader in the field. Be careful in buying because the Indy are  not the same as the Indy ANC. If you haven't read my review of the Bose, then its here, and may help to clarify some matters in this comparison.

Summary position - money matters

If money didn't matter I'd be driving a Range Rover not a 1989 Mitsubishi Pajero, thus its important to say that I shop around and got the Skullcandy for AU$60 off eBay as an unwanted gift, and I regularly see them for less than AU$100 anyway. There is essentially zero risk of fakes because not only are they well priced to begin with, there is no real "cachet" attached to what is a budget brand anyway.

I got my Bose "cheap" off eBay too so lets just say that you won't get likely Genuine Bose for under AU$200 and RRP is AU$399. So from that perspective of "money matters" you have to ask yourself about value for money. If I had to say which is better I'd say they're both winners, but of different competitions.

What you see and what you get


The form factor or style of the Skullcandy buds is much more like the Apple or indeed "most of the market", which is neither here nor there, but as it happens I like it in some ways.

The buds are smaller and the stem actually makes handling them easier in some ways than the Bose QuietComfort (QC) earbuds, but what really stands out first is the case difference.


While the Bose case works well in a office (desk beside your monitor) or in the car (in the console) the Skullcandy case is easy to slip into a pocket of your jeans or a side of your backpack. This itself tells you about what they're for: outside and about (and I'll return to this when discussing ANC).

Opening and removing the buds to put in your ear shows that the Skullcandy are more about on the go than the Bose when trying to remove the buds and put them in your ear without the case being on a table before you.


and the little wing supports make a nice "grippy flexible handle" from which to pull them out and put them in.


and while the above pic really shows off the extensive nature of the Bose ANC microphones it also shows how "smooth  and slippy" they are when getting them from case to ear. The rounded shape is quite attractive, but to me the Skullcandy wins here for sheer practicality of usage.

To remind you of the way the Bose present when you open the case / charger to get them out:

QCB

A lovely presentation, but I've dropped them more than a few times when doing this on the move (and have learned to put them on a table top before putting them into my ears). 

Some pictures up close of the Skullcandy buds




showing the size, the ear bud and that there is a second part of the silicon to be the support (rather than it being one piece as per the Bose. I don't know if this is good or bad, but at the very least you can pick wing size (they're called Gel's on the Skullcandy) independently from tip size (for the difference in ear shape and ear canal size).

Points awarded there, but as it happens I'll say that I've found the Bose quite good (perhaps better) than the Skullcandy with respect to fit and fit comfort (and not falling out).

Verdict: slightly advantage Skullcandy

Wearing

The Skullcandy are nice and compact and sit discretely in your ears.


from this one can see the wing support at the back (as well as my hairy ears) and to get the best audio you need to perhaps (at least in my case) twist the stem a bit further down.

Either way fitment is critical for success and so the choice of the right size tip and perhaps the right size "wing" is important.

While doing (almost) everything the Skullcandy felt good and I was surprised that the few grams less weight did actually make a difference to ear fatigue over a few hours. Lighter has some benefits.

The only complaint I have was that if I bent over (say, to pick something up off the ground) they would fall out. Perhaps this can be remedied by some replacement tips that are memory foam instead of the silicone ones (but they won't likely be as durable). Either way I managed to be aware of this and it isn't often a problem for me

Verdict: advantage Bose

The Audio quality

This is where the Skullcandy actually surprised me, they sound a little better playing music than my Bose do. Better separation of highs from the mix and really good bass. Not "coloured" like Dr Beats are but somehow more like a clarity of lows one usually needs good speakers and a few meters distance from the speaker to achieve (my rule of thumb on speakers is at least 2 wavelengths of the bass frequency but with buds its actually an acoustically coupled tube).

I was tweaked to this possibility by the specification of the driver used in the Skullcandy Indy ANC being 12mm (reported here {and that's a pretty good review too btw}) ... that's about the biggest driver in this class of audio.

Lastly (and I didn't test this) there is an app that comes with the Skullcandy to actually work with your own hearing and compensate for any loss you may have in the audio spectrum. That's also best in class.

So for less money, if your music needs are as important as ANC then really, definitely give the Skullcandy a look

Verdict: slightly advantage Skullcandy

The ANC

I was "fortunate" in todays testing to have a cement mixer truck turn up next door.


This gave me a great background annoyance all morning, with changing pitches as the engine revved to power it and the hydraulic motor gave various whines.

ANC is a vexing issue and is seldom measured (personally I've never seen it done well) and has essentially no baselines in quantitative specification. Worse I'll say 95% of people who are interested in ANC have little to no experience in understanding actual ear-plug style hearing safety, how its measured (hint dB and phon), what the various scales of measurement are what frequency they cover. Look up some of these standards on the packet below if interested:

So basically its a bunch of kiddies and or dopes making subjective evaluations (usually from quiet rooms) without a clue. This is of course classic King Wang (the blind [usually wankers] leading the blind [and usually stupid]) stuff.

The Skullcandy buds (like the Bose) have an "Aware" mode as well as an ANC mode, but they have an ANC off mode too. This makes them just bluetooth buds which is quite interesting as you can evaluate how they sound without that "effect" being present. Additionally it shows something else about the Skullcandy: that there is a low "hiss" (or noise in audiophile world) which frankly isn't present in the Bose. The reality is of course that this hiss is only identifiable in a quiet room ... and if you were in a quiet room, why would you be needing the ANC? So you can turn it off with a simple gesture on the bud and it will always default back to ANC  being on when you power your buds back on again (I'll get back to that).

The difference between the ANC on these two are basically this:

  • the Bose is more quiet than the Skullcandy by what appears to be a few dB (which is a logarithmic measurement and if you don't know what that means let me say by "a noticeable amount").
  • the Skullcandy is perhaps slightly better at cancelling the low frequencies (assessment assisted by that cement truck) than the Bose which may work better on flights but may not block out "everything" as well (this can be an advantage which negates the need for the Aware mode when the hostie asks you if you want tea or coffee)
So I actually liked the level of pass through on the Skullcandy without needing to resort to the Aware mode.

Something that Bose users are aware of is the success of the Bose ANC buds is that it has limits, and when these limits are reached quite audible "clicks" are heard as transient peaks overwhelm the limits of the ANC  (everything has limits). These clicks (which if the loud noise is sufficiently lengthy can turn into a buzz) aren't uncomfortable but they show the limits of the system. 

The Skullcandies showed no such issues and seemed to gracefully fail to attenuate when the sound became loud enough. But remember you've got these things in your ears like a kids fingers right? So its not a problem.

This leads to the ultimate question here: whats the actual point of ANC?  
What are your expectations? 
If you're after something to use at the shooting range you've picked the wrong class of things to be wearing from the start. But if you're after more "muting the background noticeably enough to still be able to enjoy your music without having to turn it up to hearing damage levels" then both the Bose and the Skullcandy are quite good.

An anecdote: if I'm in a waiting room (say for my chiropractor) I have to put the Bose into Aware mode or I'll miss being called and feel like a dope when the receptionist waves at me to attract my attention. With the Skullcandy I don't need to do this because passthrough of the background is enough that I'll hear things without needing to turn on the Aware mode. Actually the Aware on the Skullcandy is so good at bringing up the speech in the background that I can easily listen to otherwise muted conversations (aka eavesdropping) if I chose to.

I'll leave this section with a note of "how much is too much ANC" in a world where "when its noisy we also need to be aware for our safety


... as that idiot found out.

So in summary apart from in the most noisy situations (like my old Pajero on long road trips) I find that the clatter of my keyboard being hearable as well as other small sounds coming in make the music listening experience better and drops the background noise (of say that cement mixer)  far enough away to be "thanks, that's nice".

Verdict: advantage Bose, but Skullcandy is sufficient.

The usage and operation

First up, the Bose are able to stop the music on the phone when you take the buds out, the Skullcandy don't have this feature. Myself I don't really care (because I can then use the phone control to pause if I'm missing something important in my music and don't know how to rewind).

Both Bose and Skullcandy have the ability to control the buds by touching them, things like:

  • adjusting volume
  • turning ANC into Aware
  • stopping and starting music
  • answering a call
  • accessing the "assistant" (Siri or Google or whateverthefuckelse) of your phone
They both do things differently and in some ways it takes time to learn to use either (just read a few reddit groups) however I'm going to say that I prefer the Skullcandy for the following reasons: most gestures are symmetrical (meaning that the same gesture works on the left side or the right) and those that aren't are logically different. This is the instruction sheet which the Skullcandy came with


so you can see that most (all but one) controls are the same either side you touch, but Vol up and down is (to my mind) more like the volume up and down on most stuff with buttons: left is decrease volume, right is increase volume. Its probably a lot more gestures than most people will use but as you get more familiar with them over time you'll perhaps find yourself using more of them

The Bose OTOH requires you to know which side you are double tapping (or tap sliding), and  actually has less features available with touch. Sometimes (despite having used them for longer) I still make mistakes with the Bose. More details here.

If I'm (for instance) driving and I wanted to take a call, with the Indy all I have to do tap twice, and to hang up tap twice ... which ever side happens to be more convenient (and I'm left handed so tapping the right side isn't my natural thing) while the Bose requires I do it on the right side.

Bonus points because the Skullcandy actually turn off automatically! and you can manually turn them off if you choose. Yes, as annoying as that may seem to others (Dunning Kruger types) it means that if you just take them off and put them down (and go and do other things) they'll turn off. 

That's great for a few reasons, not least of which is they won't go flat overnight and be useless the next morning when you may want to have them on for your commute. Further, you can turn them off and they'll probably last for weeks at 80% of charge and you can just turn them on with no loss. Imagine a situation:

You don't use the buds all the time (gasp, shocking right), you were you are driving, you take them off, forget about them and they're in the car (which you don't use every day) and have gone dead flat in the days it takes to go back to the car. It may even be that they go so flat as to never be able to be recharged again. Makes me wonder about some of the Reddit reports I've exactly read on this topic.

Something I've identified in my previous review of the Bose is that because you can't turn them off it may effect battery longevity:

 In contrast, with my QC35II's I (can) turn them off as I take them off and so they can sit for days or even weeks at somewhere around 50% and I know that will give the maximum life of the battery. I've had them since 2019 and the battery is doing well. I doubt that this will be the case for these.

Again, points awarded for the "inferior specification" performer the Skullcandy.

Verdict: advantage Skullcandy

Making calls

So, enough about you, what about them? (who makes calls you say?)

When you use these ANC buds you also give some level of ANC to those you're talking to. Now, my phone (and probably yours) has an excellent ANC system built right into it, but when I'm driving I can't actually talk on my phone (well I can, but it will cost me). So the other benefit of ANC buds is that it gives some of the Active Noise Cancellation to the other party on phone calls.

I first realised how good this was when making calls on my QC35ii over ear phones from my noisy 1989 Pajero on my over 2 hour trip home on the weekends from my job "in town". Its  not insignificant how much more tired you feel after a 3 hour drive home in my 4WD without using these headphones

Indeed exactly this was the very reason for me buying the Bose QC buds in the first place: making trips in my car (down to the city) when I could listen to music in the car without the stereo turned up to drown out the defining roar of the car, tyres, engine. rattling and clanking; but without over ear headphones.

Don't get me wrong, the QC35ii's are great, but: are sweaty in summer and difficult to put sunglasses on and off (or reading glasses to consult a map) when you're wearing them. So I bought the QCBuds to try ... and here we are.

I have heard some tests of the audio quality of what other people get from these buds (and have made my own which are not well presented, so I don't care to share them here. However this link is a reasonable exemplar (although I have problems with reproducing his outcomes on Zoom and Android recordings)



Instead I called a friend and drove (around bashing roads) in my 4WD talking to my mate with the Bose QC35, QC Buds the Skullcandys and the just using my phone (in my top pocket).

My friend reported that he couldn't tell the difference between the QC35ii's, the QC Buds, felt that there was a bit more noise (but still quite fine) with the Skullcandy and that my phone was the best. Pity I can't just drive and use my phone ...

Worth noting another friend reported (when doing an around the house test) that chip packets (being handled) or noise from taps was particularly disgusting on the Bose ... which sort of equals how I interpret the results from the above YouTubers findings.

What it says to me is that right now, the other user side of phone calls are not well serviced by any of the existing ANC systems when driving or in a noisy environment (and may never be without boom mics as used in aviation).

Verdict: equal

Findings and Conclusion

If you are the Range Rover guy, then I'd say get the Bose over the Skullcandy Indy ANC, but even for me its a matter of I wouldn't like to spend over $200 (and I didn't) for the Bose. If I had a quieter car (like a typical less than 10 year old sedan I'd be entirely satisfied with the Skullcandy, to the point of I'd sell the Bose. Indeed for walking around the house, doing some things in the yard or just being in the supermarket the Skullcandy takes the edge off and is sufficient.

Especially if you're after an occasional use set of buds for in the car (or delivery truck) then the Skullcandy are pretty ideal and in my view better than any "mid range modern car"  bluetooth audio" I've yet encountered.

If you can afford to drop the money on the Bose, go ahead. But if you're seeking a lower dollar spend then the Skullcandy Indy ANC are pareto principle winners IMO

Pareto principle: 80% of the benefits for 20% of the costs.

In this case its more like 30% of the cost.

HTH

Monday 10 October 2022

Wireless Charging Bose Quietcomfort Gen 1 earbuds

So a little while ago I bought the QuietComfort buds to augment my existing QC-35-II headphones. In particular I wanted them for in the car where I often want to take off and put on sun glasses and over ear headphones get in the way of that (and are diminished in ANC performance by the opening of the ear pad).

This is them in the case which is also the charging unit.

QCB

I noted that they had wireless charging capacity and I was interested to experiment. I didn't have any other product which wireless charged (well, ok an Oral B toothbrush) and so I wanted to test this. So I bought a wireless charger and had a go.

Well I was pretty shocked when I picked them up off the charger at how warm they were. Warm is bad because it heats the lithium ion battery and that actually degrades the battery life significantly. Worse, its not yet summer and so its only going to get worse.

To be clear this did not happen when charging via the USB-C port.

So some quick googling yeilded this link which as well as confirming the problem shows again just how ignorant most people are about things technical because:

  • it is not a copper plate but a copper coil (so failed school level science there)
  • the heat can indeed cause battery degradation (and is why many phone chargers have temperature cut offs on charge)


So to reduce the conduction of heat directly between the charging pad surface and the bottom of the case I then fitted some small silicone feet onto the case.


To provide an air gap between the case and the wireless charger surface. This made a big difference from what it was before, but its still way too hot. At this point I decided that I needed to know how hot it was and so pulled out my thermal camera and had a look. 


So this is what we're seeing with the air gap space to reduce the heat.


so the bottom of the case has cooled from 55C to 37C between images, but this means the battery is still likely to be at least that hot if not hotter when it was charging (and in particular when it was charging before the feet). This link from Battery University shows exactly what I mean.

Lastly Bose themselves give indication that buds should not be charged if temperatures are higher than 39C


suggesting also that there is no temperature cut off in the bud for safe charging if over temperature exists.

Conclusion

It makes me wonder if this is part of why its been removed from the "feature set" of the latest model QuietComfort Buds II ...  

Either way I'm not going to be using my wireless charger any more and it underscores another reason for why I think its a dumb idea.

Lastly, if you have a wireless charger of a different make I'd be interested to know how yours goes.

Thursday 22 September 2022

Bose QuietComfort Buds (the case as a stand)

I just discovered that the case that the (Series 1) buds come in can act as a nice stand to hold them (while on a desk or dash??) and not be charging


I spotted this little bit in the bottom of the case and discovered that you can just put them in nose down ...


which makes them easy to grab and put in your ear


so this makes the case much more appealing to me than it was.


HTH

Monday 19 September 2022

First generation Bose QuietComfort Buds (a review of sorts)

These things are not new, but its not quite 2 years since they were first introduced to the market (so they're not really old either). Yet Bose has just released the QuietComfort II buds (I'm going to call these the QCB's and QCB2's respectively) which some think are set to replace the model which I'm reviewing. That may be, but for now you can get this model cheaper. I got mine a lot cheaper by buying 'refurbished' ones for under AU$200 (and no they aren't fakes). This is them in the case which is also the charging unit.

QCB

No doubt you've seen many reviews already (if you are even remotely searching these things), so you'll know most of the basics on them. I'll skip that, and I'll also say from the start that this is not a typical review. Why? Well because I largely think reviewers are some combination of
  • wankers
  • idiots
  • technically inept
  • inexperienced kids
  • liars
  • shills
I've written on this topic before where I argue that (in the main) reviewers are the problem. So if you wanted someone to stroke your genitals while you decide if you should buy these you've come to the wrong site.

What experience do I have?

Up front I don't like modern buds. The reasons are pretty simple, you have to squish them into your ear. When in your ear they change how you hear everything else. Because of the direct acoustic coupling to your ear canal they amplify any sounds you make with your voice or even if you just scratch your chin, In short they have all the disadvantages of Hearing Safety ear plugs but without anything like the level of protection that they provide in a noisy environment.

Worse they dull your situational awareness, as hearing is important to detecting threats like; cars, busses and other obstacles in a crowded environment (where kiddies often wear them and walk under a bus while engrossed in their little bubble). So be careful when using these things.

I do own buds and have used; heaphones, over ear clips, in ear buds and whatnot for most of my life. I had a Sony Walkman when they came out, and its fair to say I've used these things extensively in many environments. This is my previous bench mark in-ear bud style headphones:


They are Koss brand and, as you can tell from the marks and buffing that on little case, they've been around. I bought them in 1985 or so (when I was delivery driving for my dads business) to use with my walkman. I have used them in the office daily for years as well as when listening to music or language lessons. These things have been through much with me: Japan, India, Finland, Europe. 

The key thing here is not only are they comfortable, sound good and are compact and easy to carry, they still fucking work (although the trend away from 3.5mm sockets is killing this).

I did find however that another type I bought in the 2000's (in Japan) were these:



These little Sony's became my goto for a long time (yes, they still work too) as they were more comfortable to wear in the office, allowed the ear to breath better and (importantly and I'll come back to this) passed through everything (like conversation) as if they weren't there. This allowed me to listen to music privately while still remaining part of a team.

So basically I'm saying I've been in this space for decades. With respect to Active Noise Cancellation (ANC) I have had Bose headphones for over 10 years now starting with the QuietComfort QC-2 over ear headphones which were game changers for long haul flights and noisy open plan offices. I still use the QC-2's for field recording of ambient sounds and bird calls. 

I currently use QC35 II headphones pretty much daily; for office, for car phone calls, for general music listening (that isn't speakers). However knowing how "sweaty" things get in summer and starting a job where I will make a lot of support calls I wanted to have some alternative. Hence the QC buds.

So getting back to the Bose Quiet Comfort buds...

Having said all of the above and given that they are buds of the worst type (squished in / sealing the ear typethese things are simply amazing, they have exceeded my pre-purchase expectations in every way (except that annoying physical acoustic coupling which you get with ear plugs, where my deep breaths are heard, scratching my head is heard and anything touching them (like a hoodie) is amplified right into my ear hole). I think there is a solution to that, but as the marketing tail is currently wagging the engineering dog I don't expect (looking at the Bose web site) the solution will ever emerge.

My usage case...

I do an amount of driving, and my car is an old 4WD (lets leave my motorcycle out of this) and want to be able to make and take hands free calls when in my car. I've found that the ANC changes on incoming calls to act in some way towards making my environment less noisy for the listener, that's important to me. I first knew of this when I took a call (with my QC35 II's) in my 4WD on my way home from work on the highway and my friend say "oh, are you in the office, can you talk right now or should I get you on the way home".  I was impressed and said to him "no, I was in the car on the way home" and we discussed how good the audio of my voice in my environment was for him. Top points awarded. It was then that I noticed that when a call comes in I can hear more of my cabin noise in my own ears as well as some of my voice. This pass through was good and I reckon it contributes to me not unconsciously yelling (because I can't judge my own volume due to the cancellation). 

This experience forms the basis of my expectation with the buds, and as I said at the start they have exceeded my expectation (no easy feat).

Whats good?

That I can drive down a corrugated dirt road in my rattily 4WD and have a conversation is fantastic, that I can do it without over ear headphones is even better. In Winter I don't mind the over ear nature of the QC35 II's but they do making putting on and taking off sunglasses a bit more cumbersome and many sunglasses break the head seal of the cans and allow some background to bleed in. These buds of course get around that problem.

So by not sitting on my head I can get good air ciculation, put on / take off sunglasses and or optical glasses as needed.


When wearing them unlike the "bullet" shaped plugs these are a bit different, they are sort of a cone (or lamp shade shape) and a support to hold it more securely ...


without that "suction cup" effect when putting them in or taking them out and which fits in the ear nicely:


Putting them in is sort of an insert and twist backwards that slides in and tightens up.

In Summer it means that my ears won't get as sweaty but I'll still get the advantages of ANC. I happen to prefer a standing desk and when on the phone to a client like to be able to move a bit, pace, whatever. Wireless is good, and I'd hoped that these Buds would mean that my ears wouldn't be wearing ear-muffs for lengthy times. As a Developer at my desk beavering away on code in a noisy (but air conditioned office) the QC 35 II's did get a bit sweaty even in the AC in summer, in the car it was much more pronounced ... like a sauna for my ears when I faced a 2 hour drive.

The Aware mode is great for almost all situations. It also passes through so well I can hear conversations well enough (great for when my workmates are actually talking to me and saves me taking out the buds if I don't want to) with just a quick double tap.

There are three settings to cycle through (on the version of the firmware I have, I understood that earlier ones had only two) and customisation in the App (on my phone or tablet) allows me to have more. I've set my three up to be:

  1. Aware - almost no ANC
  2. Commute - about 4 out of 10 setting on ANC
  3. Quiet - full ANC
I could add more but really I'm quite ok with those three to cycle through.

To compare these for the intended purpose I've taken my 4WD for a drive along a rough dirt road while talking to a friend on the phone. I used the QCB and the QC35II's and he found that (from his perspective) both did a very good job of noise cancellation. This is in an environment where it is so noisy in the cabin you'd be yelling at each other to hear.

Next I have mowed the lawn while listening to quiet music playing through the QCB's ... I could still hear the music (without turning it up) and found the result was similar to putting in a pair of noise reducing safety ear plugs.



I call that set of results: Pass, with flying colours.

What's not to like

Simple: they are buds, and thus when wearing them; 

  • chewing,
  • coughing, 
  • swallowing and 
  • scratching my head 
now conducts through to my ears in a way I don't like (just like when you wear ear plugs). Not many reviewers mention that and act as if its not a feature.

As well touching them (to adjust volume, hang up, skip a track or change mode) is also acoustically annoying too.  In this way I much prefer the QC35II's to these.

If you forget to put them into the case to recharge (having taken them out for some reason) then by morning they'll be nearly flat (so the hibernation isn't as good as it could be). Lacking any sort of switch (as the QC35II's have) I of course need to put them into the case for charging when I'm not using them. So if I'm not using them for a few days (this happens) then they'll be at full charge most of the time. Anyone with knowledge of how Li-ION works knows that's a recipe for reduced battery life. Actually if I take them off and just put them down they won't even work after 24 hours. So you need to be returning them to the case.

In contrast, with my QC35II's I (can) turn them off as I take them off and so they can sit for days or even weeks at somewhere around 50% and I know that will give the maximum life of the battery. I've had them since 2019 and the battery is doing well. I doubt that this will be the case for these.

Because the case is also a battery charger that's yet another battery I need to pay attention to (if I don't want to be buying a new set every year or so because the battery isn't working).

Unlike my little Koss headphones the case won't fit in a pocket, so that means I really do need to keep my backpack with me for that.

Generally the feeling is "if you have to think about money then you can't afford it", but given the advertising on their WWW site Bose are aiming at kids who have no concept of fiscal responsibility (or are drug dealers).

The app ... aside from using it to make any configuration and customisation its just dead space on your phone. Mine silently failed on my (admittedly 4 year old) phone, but worked fine on another device (Android Tablet)

So the above negatives may seem inconsequential to you and if they do then that's good as there are even less downsides.

Where will this model go?

Well, as Yoda said "Hard to see, the future is" so with that said I'd say that the QCB will likely slip into being discontinued and the QCB2 will take over. I mean its possible that they'll keep the original QCB on cheaper than the QCB2 but I doubt it.

If you are bargain oriented keep an eye on the Bose outlet store for refurbished QCB's as these will likely be about half the price.

Personally I like the size of the QCB and (not having tried them) suspect that the QCB2's will be a bit fiddly to use.

What would I like to see?

Well given that these things are already so minature I'd love to see an ear clip type of over ear type similar to my Sony. We've already seen (quite some time ago) Bose QuietComfort 3 over ear headphones which had pretty good ANC. From the Bose site:


(link)


While it may not be possible to get over ear style being as totally isolating as squish plugs into your ear type buds, actually having such perfect ANC isolation may not be ideal. Perhaps the reality is  that when being out and about its is actually dangerous to be so isolated from sounds.



... as that idiot found out (which is better than got killed and didn't). Perhaps we shouldn't be aiming for 100% ANC?

So on point below is a quick and dirty of what my ideal over ear ANC system would look like without wires


Myself I'd gladly sacrifice a little perfection in isolation if the trade off is more comfort and not needing things squished into my ears (thus conducting the physical sounds of my body into my ears).

In Summary

I recommend the Bose QCB (generation 1) but reserve judgement on the QCB2's until I get them to compare.

HTH

PS: I've discovered how to make the case a holding stand (see this link).


Saturday 3 September 2022

(battery charging, and) Cells in a Battery

When I built my shed I knew I'd need power down there and so it immediately occurred to me that this was an excellent opportunity to conduct a practical (and beneficial) experiment in "Off Grid" solar. 

I knew that while I understood a lot of the theory, its often the case that some surprises occur in the actual operation. This blog post is about an expectation that was fulfilled: cell imbalance in flooded lead acid batteries.

This issue is important to anyone choosing lead acid chemistry in an off grid application because it leads to premature death of your (often expensive) investment in batteries. The reason for 24V is that I want to use the energy in the battery to power things which are made for AC, thus I need an inverter. The above mentioned blog post has a few more details.

the invisible (to most people) issue

People never think past words, like "battery".  A battery is not just an indivisible block, but basically a connected series of cells each depending on the other (check the word battery in a dictionary).

Charging a cell is straightforward, but charging batteries is more complex than people usually consider. This is because while each cell needs to be charged equally we apply a voltage across the entire battery and "magic happens"; where the battery magically stores the energy. 

If only it was this simple there wouldn't be any problems.


Above is a picture of my 24V battery system for my solar shed, the battery system was commissioned  (fancy word for the relatively simple process, sorry) in early March but as you see the battery dates are 4th of Feb (which is why dear American readers the rest of the world writes 4/2/22 and your Month Day Year format is frankly 0.o

As you can see I have two 12V batteries connected in series to make a 24V battery, and each 12V battery has a small volt meter on it. I did this as I wanted make voltage checking a simple matter (rather than kneel down on the floor with my volt meter). I wanted to check because I wanted this to be an experiement in exploring why batteries fail early. 

I believe batteries fail  early because of unaddressed issue in imbalances. Of course I'd like to improve on this situation, but that's pretty much impossible with the way modern batteries are made and (a big hint to off gridders to select batteries appropriately) how batteries are connected for charging.

Probably the first thing you can see there is that the voltages are different between each 12V lead acid battery. 

  • B1 is 13.3V
  • B2 is 13.6V
This wasn't always like this, as back in Feb they were both new and both within 0.01V of each other. Somehow that balance has changed. Leading me to my point about balance:

The Balancing Act

So we get to the thing I'd like to talk about here cell balance, and the word cell will need to be clarified here because I'd say more than 90% of readers have really never given this any thought. When the battery is made each cell is made pretty accurately to be identical, but unless this is a battery made for NASA some small variances in all the parts can mean that each cell has a slightly different reaction to charge and discharge. Over time these small variations can add up.

The nature of these differences usually is in the resistance each cell has (in the chain of cells in series) and perhaps in its actual capacity for charge and discharge. If left unchecked and unaccounted for inevitably at least one cell starts to get more stress.

The Cell

As you (should) know a 12V battery (as above) is actually a collection of 6 cells (or electro-chemical cells) each which contains some sulfuric acid and some lead plates. This cross section diagram (borrowed and altered from here)


Its tempting to just see this as a black box (well and its often in a black plastic box) but the reality is that each cell may well need individual attention.

In that above cutaway you can see that the battery is a series of  6 cells linked together inside connecting postive to negative to make a 12V battery. By joining two batteries you can make a bigger battery and double the voltage available. An off grider with much nouse would probably find themselves joining 4 12V batteries into a 48V battery, thus reducing the amount of amps that need to be carried to feed their inverter (which makes 240V AC which powers things that plug into the wall).

But returning to my more simple model (having 2 batteries or 12 cells) lets go back to that 0.3V voltage difference.

Once upon a time we had tools to measure the chemistry of each cell, this dates back to a time when (for various reasons) nobody had volt meters. The most common tool was a hydrometer and you can see how its used at this Wikipedia link. You'll notice that in that picture that each "cell" is by itself and has a hatch to allow you to suck up some of the chemistry (sulphuric acid) and measure how much is there.


You may even recall having seen batteries with 6 little caps along the top to allow you to make this measurement. Indeed more expensive and larger batteries usually still have them (see below)




But because less and less people have a clue what to do with these the makers target these to the applications where people should have a clue (and sadly this results in less and less people having a clue).

Lets get back to that 0.3V and work through this a bit more.

Because those little LED meters are cheapies ($2 each) I know they aren't perfect and I know there is about 0.1V difference on one of them (and perhaps something under 0.5V on the other meaning I can't actually see it easily). This means that when I use my Fluke digital volt meter (pretty accurate and provides 2 decimal places) I can see that the voltages are more like 13.18 and 13.38V so that's a bit better.but back on the 8th of the 3rd they were already drifting apart and were 12.91 and 12.89V (which the astute will observe is the other way around).

I noticed that differences were creeping in and so I wanted to observe these more carefully thus I bought those small LED's and fitted them.

  • 14/04/22 I noted 0.1V difference when the batteries were on trickle charge
  • 14/05/22 I noted 0.5V difference when the batteries were on trickle charge

I recently cycled them both down and individually (<<note that point) groomed them back up with a smart charger. Yes, this means I physically dis-connected them (so no more power coming from them if you're off grid) and charged and allowed to settle post removal from the charger. 

Both sat nicely at 13.36V when on the smart charger on "trickle". This is one measurement, but another is what's 'rested' voltage and this was 13.18 and 13.38 ... so this difference now seems to be permanent. 

While this may seem like a small small things may grow.

Is this a problem?

For me, in this situation, no not yet, because (importantly) when the batteries are under load (like when I'm running a vacuum cleaner which draws a lot of power) everything holds up ok and within expectation.

Why is this important?

well we know that the voltage of the battery is 13.18 or 13.38 depending on which we're looking at, what we don't know is what each cell is doing because on these batteries we can't measure that. If we imagine that we could only see the pair of batteries (which importantly is what the inverter or charger sees) we would see 26.56V - its only because we can measure each component we know something is amiss.

But where and by how much?

Lets say only one cell is down and that B1 has one cell that is 0.2V different. 6 of the cells are ideal at 2.23 and one cell is 2.03V ... that means that this cell will now become the weak link in the chain and will suffer more stress and eventually result in the early death of that battery because it is the weaker link.

Important note: a battery is a chain of cells ...

Worse, if I replace B1 then the new battery will be stronger than the then worn B2 (that didn't fail) so that will cause that link to fail sooner too. Meaning I'm minimising the returns on my power from what I spent on the battery.

As it happens (and partly because this is a learning exersize) I paid $90 each for these batteries (they were bought new), but they are, as you can see, small. But then so too is the load and so is the charging. Further I'd say that they are the perfect relationship between needs and cost.

However, f you were in an off-grid house and you were in this situation each battery could well be around $500 and you may have 4 or 8 of them (at least). For instance here is a freinds off grid house 48V system with each "battery" component being a 6V battery (of three 2V cells).


however you can see that each has an inspection cap so you can measure the state of charge and fix up any chemistry. Each of those boxes is nearly a $1000 now, so you can see that caring for and understanding this is crucial for your investment (unless you've got more money than sense).

So ... is there a better way to charge?

Yes, each cell needs to be monitored. However lead acid chemistry is more tolerant of over charging in terms of how it fails, Lithium ION on the other hand is not, and has a nature of catching on fire if over charged and dying (irreversibly) if discharged too deeply. Since Li-ION is expensive and fires inconvenient people have developed a management system for the battery (called a Battery Management System or BMS). This not only monitors the charge but monitors every cell being charged. This is the one out of my scooter still attached to the cells. It manages 13 cells.


As you can imagine with 13 cells in series (compared to just 6 in a regular car battery) the chances of anything getting out of balance is not just high, its practically inevitable (unless you are buying cells that are suitable for NASA). This  BMS not only governs the charge of each cell during charging it it also ensures that if any cell falls below the minimum safe voltage it shuts down the access to power from the pack.

Normally with just 6 cells there is less chance of an imbalance, which is why most small scale solar systems use 12V ... but it of course has inherent limitations in terms of the voltage and therefor the amount of Amps that are required to power much. As you should remember my system actually has 12 cells (6 in each "car" battery) because its 24V and this has no doubt created the situation where somewhere (and we know that its in B1) at least 1 cell is down. This is then going to place more stress on B2 in terms of over voltage charging because the charger only knows the entire voltage of the battery.

Is there something like this for Lead Acid batteries?

Myself I think there is, but its a bit of a fudge (and beyond the scope of this article) so the answer is basically no, and perhaps the "why we don't see things like this in Lead Acid is:

  • Lead Acid is an old technology most commonly used in 12V configurations
  • its perceived as less needed because there is no safety hazzard, and (probably) 
  • because lead acid batteries are very recyclable and rebuildable unlike Li-ION.

Further most companies don't warrant car batteries to be used in Solar Power Systems, so if you kill your battery early then its all on you.

Right now what I see is that its on me to basically prevent this by keeping an eye on the system (and turning off the panel and disconnecting the battery from the Solar Charge Controller) when I'm not in the shed and just let it sit there essentially in storage. Fortunately that's something that Lead Acid is pretty good at.

I'll put it into another blog post for what my solution is on another day (see here for that). Mean time its been a fun ride with my system. I hope you've found this interesting and helpful so far.

Until Next time