# Why does software upgrade need battery?
**URL:** https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058
**Category:** Factual Questions
**Created:** [July 14, 2019, 6:40am UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058 "2019-07-14T06:40:23Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@Velocity](https://boards.straightdope.com/u/Velocity)
#### Post date: [July 14, 2019, 6:40am UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/1 "2019-07-14T06:40:23Z")
My laptop says it cannot do software updates without the battery (I removed the battery last year) - does it need some momentary electrical power that cable cannot provide? It’s always plugged into wall power.
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### Author:  [@SkyRangerRich](https://boards.straightdope.com/u/SkyRangerRich)
#### Post date: [July 14, 2019, 7:32am UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/2 "2019-07-14T07:32:01Z")
To help guarantee uninterrupted power.
There are parts of the upgrade process which COULD be very difficult to recover from, should the process be interrupted.
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### Author:  [@FinsToTheLeft](https://boards.straightdope.com/u/FinsToTheLeft)
#### Post date: [July 14, 2019, 7:36am UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/3 "2019-07-14T07:36:08Z")
It’s done to ensure that the process can complete without a risk of interruption through the battery going dead. They figure since it’s a laptop, there must be a battery and it must have sufficient charge. They don’t bother with the same code on a desktop.
I chalk it up to lazy coding or they figure if your battery is missing or bad and won’t hold a charge it must be out of warranty anyway and not their problem.
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### Author:  [@Asuka](https://boards.straightdope.com/u/Asuka)
#### Post date: [July 14, 2019, 8:16am UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/4 "2019-07-14T08:16:51Z")
I have a phone that literally will not download updates unless connected to wifi even if it’s under 100MB despite the fact my current provider has unlimited data. Very annoying when I’m at work and am constantly getting pester updates urging me to connect to wifi every 5 minutes. Similarly it refuses to install patches unless I’m connected to a power source even if it’s at 100% power. Chalk it up to manufacturers afraid of the 1% of idiots who attempt the updates at 10% power and then brick their phones/go over their data limits.
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### Author:  [@joema](https://boards.straightdope.com/u/joema)
#### Post date: [July 14, 2019, 10:58am UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/5 "2019-07-14T10:58:19Z")
The laptop should be able to do true software updates (ie operating system updates) without a battery. Those are transactional updates from which rollback should be possible in the event of an interruption. But as mentioned maybe whoever coded this for your laptop used a lazy method and hard-coded the battery requirement.
By contrast a _firmware_ update involves much lower level changes to specialized hardware storage, e.g, microcode store. Those changes are not transactional since that would require 2x the microcode store to hold the old and new versions. That storage is expensive and would only be useful for updates. Thus many devices (including laptops) try to mitigate this by requiring constant power during the update.
In theory a failed firmware update could revert to a small, primitive boot loader which could re-try the update. In some devices this is available but not always.
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### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [July 14, 2019, 12:56pm UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/6 "2019-07-14T12:56:26Z")
What kind of laptop do you have? What kind of updates are these–Windows, or the laptop manufacturer’s, or third-party software? I have devices that recommend that you plug it into wall power to do OS upgrades but none of them require it. It seems like running down the battery is much higher risk than the wall current stopping. I have never run a laptop with no battery so I don’t know if what you are seeing is normal.
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### Author:  [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)
#### Post date: [July 14, 2019, 2:54pm UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/7 "2019-07-14T14:54:36Z")
Some laptops nowadays don’t even work without a battery. At peak performance they need both the battery and AC adapter plugged in to provide full power to the CPU. Thus, running it at full tilt for a long period of time (such as transcoding video files) can actually drain the battery even if it’s plugged in. Your laptop appears not to be one like this, but the software updater probably has no way to know for sure so it just checks if it’s a laptop, and if it is, then it must have battery installed with a sufficient charge to reduce the risk of interruption.
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### Author:  [@Cleophus](https://boards.straightdope.com/u/Cleophus)
#### Post date: [July 14, 2019, 3:15pm UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/8 "2019-07-14T15:15:06Z")
> [@jjakucyk](#):
>
> Some laptops nowadays don’t even work without a battery. At peak performance they need both the battery and AC adapter plugged in to provide full power to the CPU.
Most laptops are like this, in fact. Removing the battery causes the processor to clock down even under low to moderate load. You can see this with a tool like CPU-Z or HWiNFO. Why is the battery removed at all? Even if it’s worn out and doesn’t hold a significant charge, there’s no reason to remove it.
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### Author:  [@ftg](https://boards.straightdope.com/u/ftg)
#### Post date: [July 14, 2019, 9:01pm UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/9 "2019-07-14T21:01:24Z")
> [@jjakucyk](#):
>
> Some laptops nowadays don’t even work without a battery.
Nowadays? Years ago I started buying junker “laptops” at garage sales and such just to see what’s involved in repairing them. (Ones with like 8086 processors and such.) A lot of the times a working battery was a must. Lots of fun faking the thing into thinking there was a real battery attached.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [July 14, 2019, 10:22pm UTC](https://boards.straightdope.com/t/why-does-software-upgrade-need-battery/837058/10 "2019-07-14T22:22:14Z")
On the other end of the scale, years back I remember seeing a laptop that had a single bay for both the battery and the floppy drive. If you wanted to copy anything to or from a floppy, you had to plug the machine in.