You don't have to get exotic in this, just do what everyone in the area of my old shop did (SoCal)
-Chain link fence (tall) around your truck parking area with roll-open gate section.
-Really bright lighting -permanent streetlight-grade stuff on roof or high on building -not motion detector either, just always on. (And stupid-bright -don't be conservative in this)
-Obvious (real) security camera (large all-weather enclosures) with red LED and warning notices.
-parking truck in a way to minimize accessibility to the battery-box -such as hard-up against a short concrete wall -make it really difficult to squeeze a person in there
-worst-case scenario -wire them with a forklift type connector and build a tray with handles to just remove them and lock inside if necessary. Having a custom height cart to slide them onto and wheel into shop makes this even more easier.
Alarms are a waste of time, everyone is so tuned to ignore them now. Don't bother with booby-traps, (in blue-states that will just get you sued)
A properly-welded belly-box type enclosure will make them give-up when coupled with the other difficulties listed above. Make it so they'll have to do real damage to get anything (-or just make them want to steal the whole truck and then your insurance takes care of the rest. :razz