Reasonable Battery Life Question

Simple thing:

How long should a motorcycle battery be expected to last between rides? Last rode Tuesday and didn’t want to start cold this morning at like 50+degrees in my garage.

Long version:

My friend bought a 2018 XSR700 in April 2019. Battery always faded quick, like no good riding weekends (busy life) only. Buy trickle charger (still need to install quick connect- Oye) and eventually am riding more and charging less.

But eventually he miss a week. Battery won’t charge. Ok- he’d been expecting this day for months. Figure cost of buying bike that’s been sitting unsold for too long.

Replace battery. Ride every couple days or more- no issues noticed. Go camp the family, miss a weekend, bike goes Wednesday-to-Monday between rides and my recently new battery is now behaving like departed original.

This can’t be right.

Anyone have any thoughts?