Most readers know me as someone prepared to enter into debate on the subjects of form factor and smartphone design, but also having my own distinct preferences. You'll remember an in depth feature I did on the subject of sealed vs removeable batteries? It's fair to say that, personally, I come down on the 'removeable' side of the fence - yet I find myself, in December 2013, using a sealed design for my primary device. In this feature, hopefully of interest to both AAS and AAWP readers, I examine my objections to 'sealed' and ask which of them, if any, are still showstoppers.

Here's a slightly tweaked version of the original pros/cons table from the earlier feature:

The guts of the Lumia 1020 - this is the only way to get to the battery: complete disassembly!

Despite my own appreciation for all the advantages of replaceable batteries, it does feel like the tide is against me here - Samsung aside, almost all top smartphones now have 'sealed' batteries, with manufacturers opting for the technology which can provide the maximum mAh in the slimmest form factor and never mind the long term cost or inconvenience. Which, for flagship devices, bought by those who tend to swap phones every 18 months (or less), perhaps makes sense - the original owners are unlikely to experience much degradation in the sealed battery, after all.

In addition, and the reason for this feature, I find myself using the Nokia Lumia 1020 as my primary smartphone, despite it having a completely sealed battery. Yes, the reason I'm using the phone in the first place is because of the camera/flash combination, but my need for that (along with having a high resolution screen, modern OS and fast processor) is evidently greater than my dislike of the restrictions of the sealed battery design.

Here then are my thoughts on each of the four 'disadvantages' of a sealed battery design, lifted from the table above, in the context of having used the Lumia 1020 now for around three months. My musings will hopefully also be of interest to AAS readers (this article being cross-posted).

• "When the battery's flat, there's no alternative but to charge the phone directly, via mains, USB or a portable charger."
  
  There's no getting round this, of course. Portable USB chargers have gotten more varied in size and I still swear by keeping a Pocket Power in my wallet - this has got me home several times when my 1020 would otherwise have turned into an expensive brick. It may only give me an hour or two's extra capacity, but that's always been enough.
   
  However convenient a pocket charger is, of course, it's always going to be bigger and less efficient overall than the flexibility of a charged, spare battery - but I can live with the charger solution and it's only once a month that I'm in this sort of power emergency situation. 
    
• "When the battery's capacity has significantly decreased/degraded, you have to take the phone to an approved service centre and pay whatever the manufacturer demands to get the battery replaced."
   
  This is also set in stone, in that there's no practical way to take the Lumia 1020 apart. Other past smartphones with nominally 'sealed' batteries (e.g. the Nokia N8) have proved remarkably simple to get into, but the 1020 requires almost complete disassembly before access can be granted to its battery.
   
  However, the estimates in my previous article were perhaps a bit pessimistic. You'll remember this chart of tests on a Li-Ion battery system?
   
  
  ^{A typical chart from industry studies, in this case from the Department of Chemical Engineering, University of South Carolina, Columbia (PDF link).} 
   
  I talked originally about 500 cycles simulating a 'year of use' but in fairness a) there are only 365 days in a year and b) this is assuming 500 full charge/discharge cycles, i.e. the worst case for battery 'wear'. In a real world environment, with a user who's looking after his or her new smartphone, taking care not to discharge it fully except when there's no alternative, trying to top it up whenever possible (frequent top-ups are much less wearing) and taking care that the phone doesn't get too hot, actual battery degradation may be a lot less.
   
  I'd certainly hope so in my case. The chart shows 33% capacity loss after 800 full charge cycles, but I'd estimate that with more gentle use and nightly charging/top-up, 33% capacity loss wouldn't be reached for around at least 1200 partial charge cycles, or at least about three and a half years. 
   
  Even allowing for my smartphone to be sold on or handed to another family member in two years time, they'd still have a couple of years themselves with decent battery life before things started to get critical. Assuming Windows Phone and today's hardware and software was still useable in 2017/2018!
    
• "If the battery goes 'bad' and swells up or leaks, your device can be permanently damaged."
   
  This is still true, though such swelling does seem to be fairly rare in well treated devices. Anecdotally, such swelling occurs only when the battery is faulty or mistreated (e.g. charged improperly with a cheap charger or left discharged for a year and then an attempt made to charge). I have numerous smartphones from the last decade, some of which are now ten years old and fairly well looked after, and only once have I seen slight swelling, in a phone from 2010. And even then, it was after wider family use, I suspect a degree of abuse (don't tell my family I said that!) 
   
  This remains then, a risk, but a slight one. Plus, if the battery swells in the first couple of years and causes damage then a fix or replacement should be standard for a manufacturer like Nokia.
   

• "If there's a technical issue with the phone, you can't take the battery out for a minute and re-insert, to fix the problem."
   
  Although this is indeed true, every smartphone sold with a sealed battery these days has an override function baked into its electronics. In exactly the same way as holding down the power key on a troublesome PC or Mac for four seconds powers it down however badly the computer has frozen, holding down (usually) the power key for over ten or twelve seconds on a modern smartphone shuts everything electronic off inside. In theory, achieving the same effect as pulling the battery.
   
  In theory. And, to be fair, the system has worked whenever I've needed it, on Windows Phone, Symbian, Android and iOS. Yes, there's physical peace of mind in pulling the battery if things go pear-shaped, but in practice it's probably not strictly essential.

• "On a long, demanding day out, you can't take a 'spare' battery (just in case)."
   
  Which, of course, is where the aforementioned portable charger comes in - if you didn't fancy the wallet-sized version above, what about a larger monoblock USB charger, especially useful kept in a car glovebox? Just remember to charge it back up after any emergency use and to also top it up every couple of months.
   
  In fairness, even if one goes down the spare battery route with a phone which has a replaceable battery, there's just as much hassle involved in charging up one cell or another 'out of the phone' and remembering to keep the spare topped up. Either way it's a pain and at least with the USB charger system you don't have to shut the phone down in between batteries!  

The sealed Lumia 1020 and replaceable-battery 808 PureView - even leaving aside camera hump thickness differences, the 808's body is still a couple of mm thicker, arguably mainly due to the use of a battery bay and robust rear cover.

There's no one perfect design, of course, which is why the table above looks fairly even. Samsung has done fabulously well with its range of Galaxy Android-powered handsets, all of which have replaceable batteries - and I've maintained for a while that at least part of its success is the flexibility it gives consumers in terms of battery options (not forgetting extended batteries and replacement backs) and memory expansion.

Yet there's now a growing swell of rather excellent handsets with sealed battery designs. Right now, the Google Nexus 5 (or LG G2, very similar hardware, made by the same company) and Nokia Lumia 1020 are among the leading contenders here.

I use the 1020 each day and, if I'm honest, don't give the sealed battery much thought. If Nokia came out with a variant with replaceable battery, would I switch? Yes, of course. But the lack of such an option doesn't keep me up at night anymore.

Comments welcome. What's the oldest 'sealed' smartphone you own and what's its battery life like these days? Has it lasted the course of time or did the new owner head for the service centre to get a new power pack?