XPS 15 battery and difference home/work

Hi,

I am interested in buying a new dell laptop(XPS 15). However when browsing the website I found it very confusing what the difference would be between laptops seemingly having the same characteristics and the same reference code BUT different prices between home and office tabs.

Also where can I find information on the battery (composition)? I would like to be able to compare laptops based on the performance of battery’s, considering I find to be working (I am a scientis) or use my laptop outside office hours for a long time without charging important.

Customer support isn't answering my questions unfortunately,

Thank you for the information, MargjeLova