tell me if this would work

[krazy_texan]

i have the idea of putting a second battery on my truck on an isolator switch to seperate it from the cranking battery then putting a power inverter on it to run my block heater while i am at work then once the truck is cranked flip the isolator switch to recharge the second battery. I started to do this on my another truck but never got to test it in the winter. I am just wondering if anyone thinks that i could make this work as i drive my truck daily and i get off work at 3am so it is usually butt cold at that time.