Replace XPS 13 9370 Battery

It is possible, but if there's a 2.5" drive in the system, installing the larger battery requires removing it permanently.  You can't have both a 2.5" drive and the 97 WHr battery in the system together.

If the system has only a 2.5" drive now, you'll need to buy an M.2 SSD in order to use the larger battery.

Wouldn't Dell make the 4 and 6 cell battery different sizes though? Been waiting for an answer from Dell Support but nothing has been happening.

I myself have no idea what to do with technology - we would do it ourselves if we could but we honestly would mess up the laptop if there wasn't like a guide to follow.

I'm willing to pay whatever the cost (except a new laptop) to improve the battery life - such a waste of a good laptop.

They honestly shouldn't sell such a good laptop with ridiculously low battery life!

Yes, that's the point - the 97 WHr battery is physically larger than the 56 WHr version.  That's why you can't have both a 2.5" drive AND the 97 WHr battery together - the larger battery takes the space of the 2.5" drive.

You can call Dell to buy a battery (ask for spare parts).  You'll need a Torx and a Phillips screwdriver to replace the battery.

As for why it's sold with a smaller battery - in some cases it's price, and in others it's because some are willing to sacrifice battery life for a 2.5" drive.

The service manual details the way the battery is removed and installed.

https://topics-cdn.dell.com/pdf/xps-13-9370-laptop_service-manual_en-us.pdf

What's the 2.5" drive for? Is it important for the laptop?

Would I have to specify I would like a 6 cell battery? They might ask for the Service Tag and give me back a 4 cell battery instead.

Would I also have to get a different charger for the laptop since it's a different WHr? 

Thanks for the info, feeling a bit more confident about doing it.

The 2.5" bay is for a hard drive -- if your system now has a 2.5" drive, in addition to a battery you'll need to buy an M.2 solid state drive to replace it -- as above, you can't have a 2.5" hard drive and the larger battery in the system.

Tell Spare Parts you want the 6-cell battery.

Buy her a USB-C Dell Power companion. The internal battery has 52 Wh, the external battery has 65 Wh. It is not possible to replace the internal battery for a larger one. BTW: There is no 2.5" drive inside DELL XPS 13, only m.2 drive.

Anyway, the latest older DELL XPS 13 9360 with Kaby Lake refresh has the same parameters, but only has QHD display and larger 60 Wh battery, so it will last significantly longer.

You won't need different charger in any case. The difference in capacity would only affect how long the battery charges, what is important for the charger is the votage and at least 45Wh of power = 2.25 A @ 20V. Also the USB-C power companion is compatible with both 9360 and 9370 as they both can be charged via USB-C. 9360 also has 4.5mm barrel connector, 9370 only comes with USB-C for charging.

PS: If your daughter's notebook only lasts for 3-4 hours, then she might be doing something wrong - meaning using very demanding applications. It of course depends on what she really needs.
Text editors + simple websites (University's IS, wiki, learning, etc.) = low demanding
Image processing + games + heavy websites (facebook, youtube, etc.) = high demanding

My laptop usualy draws 7-9 W with many applications running, which translates to (52 Wh / 9 W) 5-8 hours. When I am doing heavy development, then it indeed lasts for 3-4 hours. Just opening a facebook switches to high performance mode and the notebook suddenly draws up to 15 W and that indeed is 3-4 hours (52 Wh / 15 W = 3.46 h).

Get her a Battery Bar from https://batterybarpro.com/ . When set properly, it shows current power usage so that she can monitor what apps should she close when at school.

batterybarpro
Note: I am a software developer, and still my battery life is 4:46 hours on a typical work day.