Solar - will it last?

ELV1897

Hi all
First time poster, some time watch buyer here.
I'm no fan of planned obsolescence and when I buy a watch I want something that will last decades, not years. I'm thinking of purchasing a Solar Seiko but I wonder, will it last?
Does anybody have any insight into this -- what kind of lifespan would the solar cell be expected to have? I'm sure you can get a cell replaced today if you want to, but I'd wonder if in 20 years time it would be a case of "part no longer available" and the watch would have to be sold for parts.
Thanks in advance!

Thirdfox

I have heard (and it makes sense to me) that for ultimate long life you want to be going with mechanical movements rather than electronic. The problem with electronic circuits is that while they will last a long time without problems and require a lot less servicing than say a mechanical piece, if/when the circuit board goes out there is almost no way it can be repaired by a watchmaker - you'll need someone who can reprint a circuit board (or most likely, buy a working example of the watch in question and cannibalise it for parts). The benefit of a mechanical movement is that while in the short term it requires more servicing due to lubrication/replacement of moving parts etc a watchmaker potentially has the ability to create the screws/pivots/joints/gears needed if something goes wrong 50 years down the line (however they may still go the route of cannibalising parts as well - whatever is more economical).

It is easier to cnc a toothed gear than to reprint and programme a circuit board I think.

Having said that - I think most quartz watches should last a pretty long time - and specifically on the point of your question with regards to a solar powered watch irrespective of the condition of the circuitry the rechargeable battery will ultimately decay (because of battery chemistry) and need to be replaced. I don't know the rate of decay of a watch's (presumably lithium ion) battery however. It's anyone's guess if Seiko/Citizen etc. will still have that model of battery in 20-30 years time.

Though it is highly possible that if we are still wearing watches in 30-50 years time they could always insert the newest version of that module into the case of the watch that you have presently - depends on the complexity of the module of course.

jaxxx

I've a solar watch for 7 years and it was going great until recently. Stopped charging and would no longer work. But I put that down to my own stupidity because I threw it in a drawer one day and completely forgot about it for several months. Took it to a jewellers who had to send it to the manufacturer. As long as it gets daily exposure to a decent light source, it should last ages I reckon. If it wasn't for my own stupidity I'm 100% confident my own would still be going.

saccades

Related but not.

I have a quartz fashion watch I was given as a wedding present 15 years ago.

It's a bit of an odd design on a resin strap, but was relatively famous at the time and sold all over europe, not massively expensive at £150 or so.

However I love it and when it broke I learnt quite a bit about the expected watch lifetime.

There are no backup crystals but you can get them made.

There were 100 back up straps, I have bought the last three from the original manufacturer in China. Incredibly luckily in the odd colour of my watch.

The movement was superseded (it's an ISO Chinese built movement) but the new movement has moved the date window from 6 to 4 so the numbers are canted. I'm lucky that a lady in Switzerland sent me an original movement she had discovered FOC.

This was all five years after being for sale.

Seiko are very modular so I suspect you'll be able to get replacements for ages, 20 years... Well that's a lifetime for a non mechanical watch and then we get into trigger's broom/ship of Theseus territory.

dxhound2005

If frugality is the most important consideration, then I think the best approach would be to buy one watch and use it until it fails. Buy cheap and cheerful, and expect to replace it in a few years, or go a bit upmarket and expect to get 20 years upwards. I don't think planned obsolescence is part of watch makers business plan, but neither would I expect them to give a lifetime guarantee with their products (a lifetime being circa 80 years).

Very few people buy a phone or a TV and then wait until it fails before getting another one. And it seems to be the same with watches. If I get 20 years out of the €270 watch I bought recently, I think it will be decent value.

Wibbs

I have a few quartz watches that are nearly 50 years old made in the very early days of quartz. There is an element of survivor bias going on. My examples are the ones that for whatever reason are still going.

What Thirdfox notes has much truth in it; mechanicals are generally easier to keep going for a very long time. If nothing else because a whole industry exists to keep them going. I'm quite sure it would be easy to rebuild/remake new modules for older quartz watches, but the market isn't there as few quartz models would be collector pieces. Not yet anyway. I have seen examples were a watchmaker remade old movements with new circuitry and it was actually quite "easy" to do and cheaper than making new mechanical parts*.

Of my old quartz I have spare movements in antistatic bags for all but one type.





*analogue quartz watches have mechanical parts too, but these rarely wear out as the torque of a quartz motor and resultant stresses leading to wear are significantly lower than in mechanical. They also "tick" less.

Modern solar watches use rechargeable lithium button cells. They should last many years. How they are used determines to an extent how long they last - number of charge cycles subjected to, deep discharge etc. Of course they are like any product in that a percentage of units just fail prematurely.

I have seen cells go in 6-7 years. I have ones that are going strong I think 15 years after purchase. If they are allowed to fully discharge - to go below the minimum voltage - (as in example by jaxx above) they usually can't be recharged again.

I can't predict the future but I expect official replacements will be available for many years to come because a given replacement is usually the same part for many modules. And if official replacements are no longer available I would expect third parties - particularly in China - to offer them.

ELV1897

Thanks for all the replies. It makes sense that well made mechanical watches have better longevity than quartz. Though interesting to note that the pressure on the mechanism of quartz is less, I hadn't thought of that. I'm surprised that the solar watches can't be allowed to run down and then pick up charge again, that seems like a bit of a flaw really, not much of a problem for people who buy one watch and wear it every day but not great for somebody with a collection who rotates them.

ELV1897

ELV1897 wrote: »

I'm surprised that the solar watches can't be allowed to run down and then pick up charge again, that seems like a bit of a flaw really, not much of a problem for people who buy one watch and wear it every day but not great for somebody with a collection who rotates them.

It's the case with most rechargeable lithium batteries. Even the ones in your phone, tablet etc. They have a minimum cell voltage which they're not supposed to go below. The cell gets damaged if it goes too low and there is usually circuitry which refuses to charge it once that happens (for safety reasons).

In normal use it shouldn't happen. It will only happen if you left the watch in total darkness for months/years.

unkel

A rechargeable lithium-ion watch battery consists of a single cell. A reasonable life expectation is between 10 and 20 years, but you could be unlucky. A phone has several cells and if one goes, the phone is still fully usable, but battery life has gone sour. An electric car has thousands of cells and over time, the battery life (range) will go down gradually as cells die, but even after 20 years there should still be substantial battery life (range) left in it

art

I had a Casio solar (protek type) that did die within a few years, battery wise - it was about four or five I think, unexpected and really disappointing! Never replaced the batteries; on googling, it seems relatively common enough that these batteries fail unfortunately [edit: just to clarify that, on Casio Proteks I mean]

Trigger Happy

My own Citizen ecodrive was a present from Santy in 1996. It is still going strong. But I do avoid letting the battery/power cell fully run down.

Alanstrainor

I've had my Citizen Eco Drive for about 12 years, so far the battery life is still amazing. Or in other words, I never even think about it. I've left it in a drawer for 6 months and when I took it out it was still ticking away nicely.

https://www.ifixit.com/Guide/Citizen+Ecodrive+Watch+Battery+Replacement/85046

The Eco Drives seem to use a lithium capacitor which can be replaced:

https://www.ifixit.com/Guide/Citizen+Ecodrive+Watch+Battery+Replacement/85046

The process doesn't even look that bad! I'm not sure where best to buy batteries, but ebay has some at 30->40eur.

They often wrongly them capacitors but nowadays the ones used by Seiko & Citizen are fairly straightforward lithium rechargeable cells.

The earliest generation of Seiko kinetic/solar watches indeed used actual capacitors but they proved unreliable and were eventually replaced with lithium cells.

The lithium cells have higher capacity than the original capacitors but fewer rated charge cycles (the commonly used ones are typically rated for 50-100 cycles). However that rating implies ~80% original capacity after the rated cycles so in reality they can tolerate many hundred cycles before you would notice anything amiss. 80% capacity still gives you several months power reserve.

Any lithium cell will go eventually and this can be hastened in some well understood ways (eg deep discharge). Most users will get at least 10-20 years from a fresh cell before they notice any issues. A small percentage will experience failure sooner, either due to they way they use it or just an unlucky dud cell.

Solar watches with high-drain features (eg radio sync, temperature sensors etc) will burn through a battery quicker for simple reason that they are going through more/deeper charge cycles per year.

unkel

Deleted User wrote: »

The earliest generation of Seiko kinetic/solar watches indeed used actual capacitors but they proved unreliable and were eventually replaced with lithium cells.

That's very interesting. The general concensus about the future of EV batteries is that they will use supercapacitors instead of the current cells!

unkel wrote: »

A reasonable life expectation is between 10 and 20 years, but you could be unlucky.

Deleted User wrote: »

Most users will get at least 10-20 years from a fresh cell before they notice any issues. A small percentage will experience failure sooner