You can see the frequency at which they buy and hold properties by examining the sale history of the property (you could also do this on the register of deeds site).When you have the funds invest in a good CRM/database and have a module or app to keep track of your cash buyers.

Solar has come a long way now, especially with generator and battery back up systems.

There are numerous examples none of which they have the man power, batteries, or factories to produce. 

Most management software made for those with that number of units and up will have document creation/signing modules built in. 

It is usually the Landlord's responsibility to repair/replace anything that belongs to the rental, except for consumables (e.g. light bulbs or smoke detector batteries).

I assume you asked them if the batteries are dead? 

The only Schumacher I know is a battery charger.

Battery powered cameras are good for about 6 hours, less if they are using night vision. plus the picture will be quite choppy with wireless.

(Battery operated electronics in water tank = bad idea).  

I also wrapped in some basic analytics like rental days/goal days, average booked rental rate, average rented days, etc.And I included some very simple reminders to let me know when to change air filters, smoke detector batteries, things like that.I couldn't rely on syncing Airbnb and VRBO/Homeaway calendars using the tools that either company provided so I just rolled my own.