12v Battery Service!

Recently had the 1st service on my DS4 E Tense and was looking up on what is changed at each service interval, I was surprised to see that the 12v Service Battery is classed as a serviceable part to be changed at service 4.

Its the first car I’ve owned to have the 12v battery included as a serviceable part !
By “Service Battery” I guess they mean the smaller 12v battery ?

Also noticed the cost of “Premium Filter” was £52 !!!
I’m guessing this is the pollen filter ?
The part number is P9837470680.
£52 for a pollen filter is in my opinion expensive, when they’ve only charged £38 for oil and £14 for the oil filter ?
I’ve actually priced the pollen filter online and I found genuine DS for less than £15 so how can the dealer be charging £52 ???