question

Solar current is the current coming from your PV solar panels, it's normally lower as it would be at a higher voltage.

Battery current is the MPPT output current & will conversely be higher, due to the lower output charge voltage.

(P=V×I)

Note: Even though it is called 'battery current', it may not be the exact current flowing to your battery, as the MPPT doesn't know abut any loads that may be on at the same time. Accordingly some or even all of the MPPT output charge current may go directly to the load.