Help buying laptop for a friend

[Firecroll]

Hi everyone, well as the title says i need some help trying to buy a laptop for a friend.
He asked me for help but i told him i dont know sh... about laptops. Im a desktop guy, and even with that i asked for helped here before (shoutout to ComputerGuy and SupaKomputa really nice ppl), so im here again to ask for your wisdom if possible.
He is in Spain cause he got a studentship of some kind (nvm the story) and he needs a laptop to do lab work etc (he studies Biology), he doesnt play games.
I read somewhere that there are CPUs that use less energy at the expense of performance but i dont how it works or if its worth.

Budget from 300 to 400 euros

Basically the preference here is something with 

• good batery life (around 7hrs i dont know if thats a lot or not)
• low weight as he will carry that thing in his backpack almost all day
• I dont know about RAM, maybe 8 if not 4 gbs maybe thats enough (im used to have 16gb or more in my desktop xD)
• storage is the same for him as he doesnt use much, ssd with 128 or 256 would be good but again, maybe too expensive for his budget, then a hdd with 500(i dont know if there are laptops with less storage than this nowadays).

I know its hard to look with euros but maybe you can give me some examples or guide me with what specs should i look for.

I saw one that seems to be good enough Lenovo Ideapad 320 15ISK but i dont know about the batery life, 4 hours would be really low and it has only 4gbs, seems like really low end (again maybe its ok for daily use, i dont have laptops XD) Link
Also Lenovo Ideapad 320 14AST link

 

Thanks in advance.

[Fasauceome]

links seem to be broken, idk. 

regardless, I picked up an asus transformer mini for school last year, extremely long batter life (a whole day or more off a single charge, continuous use) and they have more powerful machines too if the 2 core atom isn't up to snuff. it's a very cheap machine, more akin to a tablet than a laptop, but it has great features.

[Firecroll]

2 minutes ago, fasauceome said:

links seem to be broken, idk. 

regardless, I picked up an asus transformer mini for school last year, extremely long batter life (a whole day or more off a single charge, continuous use) and they have more powerful machines too if the 2 core atom isn't up to snuff. it's a very cheap machine, more akin to a tablet than a laptop, but it has great features.

LOL i did it the other way round, links fixed XD

Ill search that asus, thx

[genexis_x]

3 hours ago, Firecroll said:

300 to 400 euros

Go used. Older Thinkpads

[Firecroll]

22 hours ago, GeneXiS_X said:

Go used. Older Thinkpads

He needs a new one, he doenst know a thing about computers, not even installing windows and im not with him to see the laptop when he goes to buy it. Thats the whole problem
I'll keep searching, thx anyways.

[genexis_x]

12 minutes ago, Firecroll said:

He needs a new one

The problem is, new ones in this budget are mostly suck