Charging using the truck would require running the truck all day -- probably not an acceptable alternative. Consuming 2-10 Kw from a 200 Kw engine would be so inefficient that it'd be too expensive anyways. Instead you'd need to run a generator all day charging batteries.
A fast charging, high capacity tool battery takes at least 60 minutes to charge. In high power applications (lawn mower, leaf blower, chainsaw, etc) those batteries might be emptied in a little as 15 minutes.
A better alternative might be corded 240v tools running directly off the generator for high-power applications. 120v tools are limited to 2-3HP which doesn't compare well to gas engines.
Instead buy 120-volt and 240-volt leaf blowers. BTW 2-3 horsepower is plenty (probably too much) for one man.
We use water hoses w/o bitching too much. We could used corded leafblowers tomorrow. Or butch up, get rakes and get in shape: cleaner air, more exercise and longer hours for the lawn laborers.
If you had a serial plug-in hybrid with a 20+Kwh battery which also supported exporting 120vac, that would work. AFAIK such a vehicle doesn't exist in North America yet and might not exist anywhere globally.
You start stacking energy efficiency losses (engine -> charger -> battery -> inverter -> charger -> battery -> motor) and economic losses (expensive serial hybrid, higher than expected vehicle battery cycles, still need a large number of tool batteries which wear out in about a year, etc.) though.
A fast charging, high capacity tool battery takes at least 60 minutes to charge. In high power applications (lawn mower, leaf blower, chainsaw, etc) those batteries might be emptied in a little as 15 minutes.
A better alternative might be corded 240v tools running directly off the generator for high-power applications. 120v tools are limited to 2-3HP which doesn't compare well to gas engines.