Lithium 12v accessory battery

[benjylafond]

Question for you electrical gurus. Looking at options for replacing my 12v accessory battery (since I don't have room for it now). Lots of 12v lithium batteries that have a small footprint (wheelchair batteries that are 12 - 26 amp hours and many other lithium batteries that are 10 amp hours or less). I only use my accessory battery to power my headlights on the drive home from the golf course (1.5 miles) and to charge my cell phone and Bluetooth speaker. Any idea how many amp hours a battery would need for this application?

Thanks.