So, supposedly smartphone Li-On batteries are only meant to be recharged 730 times - in other words, once a day, for two years.
What if someone takes it to 1,200, or 2,000, or even more recharges? What happens to the battery (other than it getting weaker and weaker?) Does it become more hazardous?
Not really.
They tend to swell up, and that may damage your phone, but the end-of-life failure mode is not “catch on fire."
From personal experience (not rigorous analysis), the capacity slowly fades away and the battery becomes increasingly unreliable, but I haven’t had one explode on me and there is no reason not to use them for a couple of thousands of cycles if you can handle the moderate decrease in capacity.
Also, “A 2015 study by Andreas Gutsch of the Karlsruhe Institute of Technology found that lithium-ion battery lifespan could vary by a factor of five, with some Li-ion cells losing 30% of their capacity after 1,000 cycles, and others having better capacity after 5,000 cycles” which suggests that a slightly worn-out high-quality battery beats a fresher but crappy battery.
What does a “cycle” mean? From 0% to 100%? How often does that happen, really? I mean, my phone is almost always on its wireless charger, so most of the time it’s charging from 99% to 100%. Does that count as a full cycle, or just as 1% of a cycle?
Why is this a question at all? I see something like “Smartphone batteries only meant to be recharged 730 times” and I immediately know it’s woo.
The specfic number. No way is anything factual in this context that specific. Maybe a range like 500-1000 or some such. But 730? Come on, that’s clearly bull crap.
There isn’t a single, magic, one model of cell phone batteries. They come in all sorts of sizes, capacities, quality control. There’s a lot of variation in the nuanced technology in putting these together.
It’s like saying “All gas powered vehicles get 27mpg.”
Ergo, it is so obviously total nonsense no rational person would buy it for a second.
Yes, rechargeable batteries don’t last forever. There are a large number of factors that go into how long they last. Number of rechargings is one component of this. But even for that part how deep of a discharge, etc. factors in significantly.
The older a battery gets, the more likely it is to fail. Once in a while the failure mode is not good. So a hazard ensues. And that is quite uncommon. But, again, there is no magic number.
I also noticed that it’s exactly equal to one charging per day for two years, which is awfully convenient.
The most common symptom I’ve seen with old batteries is not just that they hold their charge less well, but they also report their charge less well. Ie, the phone (or laptop, whatever) will happily report 30%, and then die 10 seconds later. Once the charge percentage starts behaving erratically, it’s time to replace the battery (or phone.) Not because it’s dangerous, but because it’s irritating.
Cycle life is a old industry standard for a different type of battery chemistry, that of NiCd or Ni-mh. It does not directly apply to Li-ion, but it is s standard, and why it is still used.
The main factors that affect life are:
1 The temperature the battery is at at all times and all state of discharge it’s at that time.
2 The date of manufacture (it starts to self destruct from the time it’s made, slowly eating itself away)
3 The time it spends at any particular state of discharge (near 0% is the worst of the worst, Full charge is also not the greatest, 40% is optimal)
4 Artificial limits, almost all Li-ion rechargeable batteries have software limits 100% is not true 100%, 0% is not true 0%, the battery could be pushed more in either direction but at the expense of life.
From the above it can be estimated how long a phone battery can last as how people will use it, and consider one recharge per day, so cycle life is estimated at 730 cycles for a battery that should last 2 years.
For quite some time devices have extended life in devices that are often run at 100%, that will let it drift the charge down to 90% or so (laptops commonly do this), Smartphones if they know the charging habit will recharge to 80% then wait at 80% till it’s time to bring it to 100% which is when it thinks you will get up in the morning.
Are rechargeable batteries expensive?
I don’t consider high-quality automotive/marine or lithium-metal-phosphate batteries particularly cheap, but with smartphone batteries you have the additional problem of potential DRM as well as needing precise dimensions and a specific connector, preventing you from simply putting in any old rechargeable battery.
Like the responses to the OP, it also depends.
The phones I’ve had all have easily replaceable batteries and the models were produced in enough numbers that quite reasonably priced replacements are easily available.
But we’re moving into a “completely sealed up” world for smartphones. Apple was one of the first to make replacing batteries hard, and then even harder. For most people once the battery in the latest iPhones dies, it’s a dead phone.
DRM has been mentioned as one aspect of enforcing premature phone death used by some makers. Although DRM isn’t the term I’d use. There’s an encoded chip in the battery that the phone checks to verify a “legitimate” battery is installed. And if no such batteries are availble to the public outside of things like warranty replacement at manufacturer facilities, that’s not so good. Esp. for tinkerers like me.
So: the answer is from cheap to basically not for any price.
I should point out that pretty much every mall in the country has a kiosk that will replace any iPhone battery for $75 or less…
I’ve replaced mine, in a Samsung phone, twice in 4 years, once just recently. So I’m right on track for a 2 year life span. Batteries are under $25, and at least in a Samsung, take about 10 minutes, if you have to read the instructions.
I replace my battery when I have to charge it so frequently that I actually have to occasionally close down the data functions of the phone, so that it can act as a phone in case I need one (phone functions take WAY less power than anything involving data transfer).
To the best of my understanding, comparing batteries of equal quality, charging lifetime depends on the amount of time actually spent charging – i.e.- charging from 99% to 100% every night is very roughly equivalent to charging from 1% to 100% nearly 99 times. My wonderful old “dumb” Motorola flip phone had a battery that lasted for many weeks before needing to be recharged. Since these aren’t available any more I now have a low-end Samsung smartphone whose battery expires much more quickly because of all the stupid things it does that I don’t need. No, Samsung/Google/Android, I don’t want to watch the current NHL game live, I don’t want to play Angry Birds, and I don’t want to update 37 apps that I never use, but I MAY want to call 911 because I just fell down the stairs and can’t get up!
Good to hear. I’m about to replace the battery in my Kindle, which has been good for many years (it was one of the very first Paperwhite models). As an aside, be careful about getting the exact model number of your Kindle and make sure the battery matches. For the Paperwhite, for instance, there are at least two different batteries depending on the generation, which look almost alike but have a different number of connectors offset from the original configuration – either 3 or 4 connector tabs. They are NOT compatible!
Exactly my point above, although in a smartphone many of those power-consuming functions cannot be turned off.
One cycle is charging 100% of the battery capacity, but it doesn’t have to happen in one continuous charge. So if you use 25% of your battery for four days straight and charge it back up to 100% every night, that’s one charge cycle.
Still, I’m using a Samsung lollipop device over three years and still, it’s battery remains fine. Btw, the battery becomes swollen when the expected charging cycles end and may explode which means dangerous to use. Technically, Lithium-ion batteries use chemical processes to generate power and the process may not perform properly when the battery gets old. The improper process releases gas and causes a swollen battery. So, it’s better to change battery when you see bad symptoms on your battery
True of almost every device that goes by the name of battery.
Given that cell phone batteries are in a sealed case that you can’t easily look inside, what symptoms should I be looking for?