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A similar question has been asked before but it doesn't answer my specific problem.

I got the HP Star Wars Special Edition Laptop (HP Pavilion series) when they were promoting The Force Awakens about three years ago. I'm looking to replace my battery since it has a maximum lifetime of 20 minutes without being plugged in.

The specific battery model is 800049-001 with 14.6V and 41Wh. I've looked everywhere and only found one result but it doesn't ship to my location. However there are plenty of batteries that are the same model that are either 14.4V and 14.8V.

When researching I found that a difference in amps or watts isn't a terribly big deal, but a difference in voltage is dangerous to the computer and the user due to the difference in chemistry.

How dangerous would using a battery with a 0.2V difference to my current battery be?

Zach
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2 Answers2

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It'll be fine.

14.6, 14.4, 14.8... All of these are well within the variations expected for the "nominal" voltage for Lithium-ion batteries. These are clearly four-cell batteries (nominal 3.6 V/cell, 3.7 for some slight variations in chemistry), but when freshly charged they'll be at more like 4.2 or 4.3 V/cell.

Concerns for "won't be fully charged" are not justified. The charging circuit must apply higher than the fully charged terminal voltage to get the battery charged. You can get an idea of how high that is by looking at the output voltage of the AC adapter. The worst that could happen here is that the higher-voltage battery might take just slightly longer to reach full charge.

As for powering the rest of the laptop, there's no issue there either. Every voltage applied to the laptop's internal circuits (from fans to CPU) comes not directly from the battery or AC adapter, but through voltage regulators. (Note, these are not inside the battery! They're inside the laptop.) When running on AC, these must cope with the power adapter's output - which as already noted, must be considerably higher than the battery's fully-charged voltage, let alone the nominal voltage. If the voltage regulators can handle that, certainly they can handle a battery voltage variation of a few tenths of a volt.

The notion that these circuits will fail, or fail prematurely, from battery voltage not two percent higher than the original is completely unsupportable.

Heck, even incandescent lamps aren't that fussy, and they probably have the steepest voltage-to-lifetime curve of anything we usually deal with.

Jamie Hanrahan
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In general terms - If the battery is 14.8 volts (and in the unlikely event it fits) it should be safe to use and will probably work OK, but not get fully charged (so less runtime). That is actually good for the battery. On the other hand a 14.4 volt battery is not a great idea as you are providing to much voltage to the battery, which could cause issues and early failure.

In practice I suspect (but cant know) that the batteries are all OK and will work fine due to voltage control and regulation on the battery itself, and because the difference is small. (Assuming the connectors fit - which in itself is likely to strongly imply compatibility)

In other words, no one outside HP can guarantee you it will work OK, but if you want to take a punt, go with the 14.8 volt one after ensuring the physical characteristics - and particularly the connector - fit.

davidgo
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