Those small batteries are short-lived so if it is several years old - get new one and don't waste time on recharging.
Checking brake-away operation if one of the thing where DOT cops make easy money and on west coast when you have to drive via scales, you have 50-50 chances to get pulled over.
I keep lot of equipment with batteries in it. Even when there nothing turn on, the wires leak the current and will drain battery in longer storage.
Disconnecting battery clamp will keep the charge for a year.
Solar panel without controller can kill the battery.