Question Battery replacement w/ one with lower voltage: Does it really cause problems?

[KS_]

I bought a used dell latitude 5290 2-in-1, and after a while I discovered that battery health is low. So I decided to get a new replacement battery.

There were two options available for latitude 5290 2-in-1. 31.5Wh one and 42Wh one. And my laptop had a 31.5Wh battery.
Larger capacity would be definitely better. So I want to go for larger one. I discovered, however, that the voltage was different between each other. 11.4V for the former and 7.6V for the latter.
I searched throughout the internet to check if different voltage causes any problem, and found out that replacing battery with a lower voltage one would make laptop not work properly.
Several other documents also said that 7.6V battery would be not compatible.

If that's true, I have no other choices but to go for smaller one, but here's one thing I don't understand.
There are some model in the market with the exact same motherboard configuration and part number as mine, but equipped with 42Wh battery.
So it would be logical to think if 42Wh battery can be fitted with the motherboard which is same as mine, then that battery would be compatible with my model as well.
But documents I searched told me the opposite, which made me really confused.

Bottom line is, can I use 42Wh battery with replacement, or should I just buy the 31.5Wh one?
If 42Wh battery is incompatible with my model, why? Can the same motherboard be configured different to match for different battery voltage?
Just curious about what I've discovered.

My motherboard is the one with i7-8650U CPU, 16GB ram and part number is 3VWJK FYI.

 

[thx1138v2]

Yes, the battery must be the same voltage as the one you are replacing. And your laptop must recognize the battery as a Dell battery or it probably won't work. Buying an off brand battery usually doesn't work.

 

[jay32267]

"Bottom line is, can I use 42Wh battery with replacement, or should I just buy the 31.5Wh one? "
No...buy the 31.5Wh one.

"If 42Wh battery is incompatible with my model, why? "
Wrong voltage.

"Can the same motherboard be configured different to match for different battery voltage? "
Yes

It all depends on the power delivery circuit of the laptop.

although I am surprised it has the same part #. That doesn't seem right.

"There are some model in the market with the exact same motherboard configuration and part number as mine, but equipped with 42Wh battery. "

^^^This is hard to believe.

 

[sizzling]

My experience on non OEM batteries is they are a waste of money. At worst they don’t actually work/charge and at best they work for a short time and then die. I’d only consider a genuine Dell battery.

 

[TommyTwoTone66]

I’ve never heard of. 7.5V laptop battery, could you post a link to it please?

 

[punkncat]

It seemed a little confusing at first, in that most batteries I am aware of are rated by voltage, and then amp hours. Wh is another way to express that and is not an indicator of the voltage.

You MUST use the same voltage. You MUST use at least as much Ah (Wh) as it is spec'ed for, or more (typically). Going to a lower Wh (sometimes also referred to as "cell") will result in less on battery run time.

I would look more closely at the batteries you are considering and make SURE it is actually the same battery/compatible model number. A battery spec'ed for a specific machine should not be available in different voltages.

 

[geofelt]

Some laptops require a battery with a embedded chip to manage charging.
"compatible" batteries do not always work.
To be certain, buy only an exact original replacement.
There should be a part number on the battery.
Yes, original batteries will cost more.

 

[KS_]

Thanks for lots of reply in such a short time! I'm going to buy an original 31.5Wh one then.

 

[alceryes]

It seemed a little confusing at first, in that most batteries I am aware of are rated by voltage, and then amp hours. Wh is another way to express that and is not an indicator of the voltage.

You MUST use the same voltage. You MUST use at least as much Ah (Wh) as it is spec'ed for, or more (typically). Going to a lower Wh (sometimes also referred to as "cell") will result in less on battery run time.

I would look more closely at the batteries you are considering and make SURE it is actually the same battery/compatible model number. A battery spec'ed for a specific machine should not be available in different voltages.

THIS.

Going with a higher 'Wh' may work fine and give you slightly longer battery runtime as long as the battery is compatible and runs the same voltage. These 'extended run' batteries were more popular in the early 2000s. You don't see them much anymore.
HOWEVER, non-OEM batteries are usually crap quality. Personally, I'm 1 for 4 with getting non-OEM replacement batteries that meet or exceed the original run time. The other 3 either had bad cells right out of the box or only managed 70-80% of original battery run time.