How do I make my battery last longer?

[GGJstudios]

yet batteries in cars which see a much heavier duty cycle, in a much wider range of temperatures, can last a decade or more despite seeing tens of thousands of cycles.

Again, we're talking about Mac notebook batteries, not car batteries.

If the battery controller in your laptop prevented it from ever being discharged below 20% or charged above 80%, barring normal defect rates, the battery would outlast the computer.

Not true. There are some who have followed such strict procedures with their notebook batteries and they died anyway. A Mac notebook can last 6-7 years or more. It is highly unlikely that any battery would retain enough health to be useful that long, regardless of how it is charged and discharged.

 

[zhenya]

Again, we're talking about Mac notebook batteries, not car batteries.

Not true. There are some who have followed such strict procedures with their notebook batteries and they died anyway. A Mac notebook can last 6-7 years or more. It is highly unlikely that any battery would retain enough health to be useful that long, regardless of how it is charged and discharged.

Which use, for all practical purposes, the same technology, and in some cases, even the same cells. Tesla, for example, famously uses the same 18650 battery used in many laptops and other consumer devices.

 

[GGJstudios]

Which use, for all practical purposes, the same technology, and in some cases, even the same cells. Tesla, for example, famously uses the same 18650 battery used in many laptops and other consumer devices.

That's the false assumption that so many make in battery threads. They quote text from sites like batteryuniversity and assume that the battery technology employed by Apple is simply to drop a generic lithium-polymer battery into a Mac notebook and they're done. That is simply not true. Apple battery technology is more advanced than that, involving the battery, the chip in the battery, the MagSafe adapter and the logic board, as well as software factors.

You can't intelligently compare Mac notebook batteries to Tesla batteries and draw any meaningful conclusions.

 

[zhenya]

That's the false assumption that so many make in battery threads. They quote text from sites like batteryuniversity and assume that the battery technology employed by Apple is simply to drop a generic lithium-polymer battery into a Mac notebook and they're done. That is simply not true. Apple battery technology is more advanced than that, involving the battery, the chip in the battery, the MagSafe adapter and the logic board, as well as software factors.

You can't intelligently compare Mac notebook batteries to Tesla batteries and draw any meaningful conclusions.

Yes, again, let's resort to Apple's 'magic' when logic fails.

Apple is doing NOTHING that would make the generic cells that are exactly the same as everyone else in the world uses behave differently when charged in a manner not recommended for longevity. A charge state at 96,97,98,99,100%, whatever, is not an ideal state for the battery to sit in for a long period of time.

In a practical manner, I would not, do not suggest worrying about how you treat your battery because most people will replace the computer before the battery fails catastrophically, and if it does, the incremental cost of replacing the battery is far lower than the bother of worrying about it daily as you use it. That doesn't change the technical facts, however.

 

[GGJstudios]

Yes, again, let's resort to Apple's 'magic' when logic fails.

It's not magic. It's technology. If you haven't read about it, including things like how it's designed to prevent shallow discharge/recharge cycles, you may find it helpful to learn about it.

In a practical manner, I would not, do not suggest worrying about how you treat your battery because most people will replace the computer before the battery fails catastrophically, and if it does, the incremental cost of replacing the battery is far lower than the bother of worrying about it daily as you use it.

On that we can agree.

 

[zhenya]

It's not magic. It's technology. If you haven't read about it, including things like how it's designed to prevent shallow discharge/recharge cycles, you may find it helpful to learn about it.

As someone who manages the development of industrial tools using these same batteries, which themselves see much higher duty cycles in a much wider range of temperatures, I understand what Apple is doing. As I said earlier, their methods are fairly standard and still prioritize battery life of the computer over the longevity of the cells. We do the same thing. So long as the battery lasts the user 3-5 years of regular use, they would rather advertise an extra 2 hours of battery life when new than take the more drastic steps that would extend the life of the battery out into the tail end of the usefulness of the computer. If Apple were forced to guarantee that the battery would retain most of its rated charge for a decade the way EV manufacturer's are, they would be taking these same steps.

 

[simonsi]

So how does one explain a one year old laptop just dying on you when it's taken off life support "AC power cord"? My company gives me a laptop every 2 years since they lease them that long. My dock has to be connected to AC power to obviously work. If I take my laptop home with me I'm lucky if I can get a little over 3 hours on a charge. I'm going to stick with my suspicions and say that by having the AC cord plugged into the laptop all the time it does kill the life of the battery.

Did the do a Mythbuster's on this? I'll take a look and see.

By the way the previous laptop that I had did the same thing. I'm due for a new laptop this Summer and I'm sure that will be the same thing. I've had a Dell, now HP, and will be getting a new Dell once this lease is up.

Crappy battery design/quality or faulty? But these were a Dell and an HP? Not all "laptop" batteries are built equal...

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yet batteries in cars which see a much heavier duty cycle, in a much wider range of temperatures, can last a decade or more despite seeing tens of thousands of cycles. Batteries are generally considered 'disposable' in consumer electronics because the electronics manufacturers prioritize battery life of the device when new over longevity of the battery. If the battery controller in your laptop prevented it from ever being discharged below 20% or charged above 80%, barring normal defect rates, the battery would outlast the computer.

Which vehicle batteries are you referring to here please?

 

[zhenya]

Which vehicle batteries are you referring to here please?

The Prius was the first vehicle to widely promote this kind of battery cycling for longevity. If you remember when the Prius was still new, there were all sorts of doomsday predictions about how quickly the batteries would fail and how expensive they would be to replace. Because of Toyota's extremely conservative management of the pack however, that has never materialized, an many examples go hundreds of thousands of miles and probably many tens, if not hundreds of thousands of cycles on the pack (as the pack in a traditional hybrid is quite small, so it is constantly being charged and discharged as you drive). The standard Prius does not use lithium-ion, but the pack in the Plug-In version such as I own does, and it uses the same method of battery control. The Chevy Volt has also been extremely successful using the same formula, again, with lithium ion.

Tesla is the one pure EV manufacturer right now that is being extremely conservative in how they handle the batteries. By default the car will not charge above 90%. You must tell it to do so each time, manually, by choosing the 'max range' charge. It will also not fully deep discharge, although they don't yet have the range to fully block off a large portion of the pack; most owners will have enough range in their daily use that they will generally cycle between ~40-90% SoC as the car is charged at night at home and then driven for only a portion of the available miles during the day. It would only be deep discharged on occasion when someone really needed the full range of the car (uncommon among the majority of owners).

Most of the ~80 mile EV's - the so-called 'compliance' cars built solely to meet California's CARB requirements don't take such precautions because they can't afford to cut into the already limited range of the vehicle. As a result, the replacement rate on cars like the LEAF have been much higher than on cars that are more conservative with their battery management.

 

[simonsi]

...although they don't yet have the range to fully block off a large portion of the pack;...

And that is the crux of the matter. Laptop generally are trying desperately to achieve the position of being able to run a full working day on a charge, using real-world usage, as such they are in exactly the position of the cars you quote, the range of the pack isn't enough to enable the overhead of max-life AND the required useful capacity.

Macbooks are closest I believe but not there yet, just as the Tesla isn't. The only way to currently fix that issue causes the same problem in both the Macbook and car, ie excessive weight caused by the overhead in capacity required to impose the 80% upper limit.

Not sure your 10yr experience stands up, Prius (early ones), may have that experience but tesla doesn't in operational volume, how the batteries actually age (just with time), under real world usage in cars is likely something they are still building data on.

And a Prius may do 100,000's of miles but due to the small battery pack that is likely still low battery usage..as most long-distance journeys will be primarily on (direct) carbon.

 

[zhenya]

Not sure your 10yr experience stands up, Prius (early ones), may have that experience but tesla doesn't in operational volume, how the batteries actually age (just with time), under real world usage in cars is likely something they are still building data on.

And a Prius may do 100,000's of miles but due to the small battery pack that is likely still low battery usage..as most long-distance journeys will be primarily on (direct) carbon.

Absolutely; this is one of Tesla's key advantages, IMO, that they are building a huge database of charging and usage data because all of their cars and Superchargers are networked. Keep in mind that the Roadster went into production in 2008, and there are a fair number of owners who are over 50k, I think a few even above 80k on the original packs. It remains to be seen how their management system works in large volume though. It may be that they aren't being conservative enough, but that may be a cost they have to bear until technology allows them to increase energy density further to allow that larger buffer.

The way the battery in the Prius works is that it is constantly in use. Every time you let off the gas, or step on the brakes, it regenerates some of that energy back into the pack, and then uses it up again when you accelerate. Except for pure highway driving when you go hours without braking or even coasting, the pack is pretty much being constantly discharged and recharged.

 

[simonsi]

Absolutely; this is one of Tesla's key advantages, IMO, that they are building a huge database of charging and usage data because all of their cars and Superchargers are networked. Keep in mind that the Roadster went into production in 2008, and there are a fair number of owners who are over 50k, I think a few even above 80k on the original packs. It remains to be seen how their management system works in large volume though. It may be that they aren't being conservative enough, but that may be a cost they have to bear until technology allows them to increase energy density further to allow that larger buffer.

The way the battery in the Prius works is that it is constantly in use. Every time you let off the gas, or step on the brakes, it regenerates some of that energy back into the pack, and then uses it up again when you accelerate. Except for pure highway driving when you go hours without braking or even coasting, the pack is pretty much being constantly discharged and recharged.

Interesting - of course Tesla and Prius have an almost entirely different set of issues to deal with, but I suspect there is no great breakthrough obtainable from optimising the charging regime for the Tesla, they are no doubt pushing for a breakthrough in cell technology to take us to the sources of the future.

Slightly off-topic but interesting to see what fiction thinks:

Oblivion - coke-can sized fuel cells
Edge of Tomorrow - fist sized battery packs
Star Trek - don't think anyone ever showed how the communicators are powered, must be huge ranks of charging docks down in engineering LOL

 

[Hieveryone]

How do I make my macbook pro battery last longer? Any tips or tricks I could try? thanks in advance!

Turn your screensaver off

 

[GGJstudios]

Turn your screensaver off

That depends on the screen saver. Some consume more resources than others.

 

[addictzz]

Battery life is an exception, they are a consumable item. Just as with tyres I wish they would last 500k but unfortunately physics gets in the way. No doubt they will continue to improve over time but with current tech 3-5yrs seems more normal. Wishful thinking will not add 2yrs to that I am afraid.

now this is what I think. If the battery will eventually give in, what's the point of Apple stating 1000 cycle count life? If we conserve the batt life, it doesn't do any difference anyway.

 

[steveyo]

Just use it then replace 3 years from now.

Threshold charging and tweaking isn't worth while

 

[simonsi]

now this is what I think. If the battery will eventually give in, what's the point of Apple stating 1000 cycle count life? If we conserve the batt life, it doesn't do any difference anyway.

That is their reasonably arbitrary cutoff for expected life for warranty vs user-cost replacement purposes. Its essentially a commercial decision and likely plays no real relation to designed life (no-one could specifically design it for 80%/1000 cycles), that is probably just a sensible cutoff point after testing and user experience.

And "eventually" could be 2yrs, could be 5yrs...