You know how it goes, something will go wrong when you least expect, so
Keep on of those small clip on torches under the seat and check on the battery from time to time.
In case you break down you might need some light to investigate.
Also buy of those blinking cyclist LED lights, in case you have an electric failure in a dark road and have to pull to the side.
You want to be seeing by other road users.
Clip on your arm or your bike....
It might save your live..........
Safe Riding