Restart after sitting 8 months

I'm putting a new engine in the gen 3 2013 transmission 2. I cannot believe that it's just going to start right up so I guess I need to come up with some kind of way to charge up the hybrid battery maybe I don't want to spend $500 on a grid charger I'd rather buy one homemade out of a computer power supply or such I'll probably only do this one time

 

The RC hobby charger is capable of charging the whole pack 240 some odd volts seriously I thought that was just for individual modules what I'm thinking I'm talking about is what they call a grid charger prolong is one of the big makers of these things it's a round green and white thing I would assume it has to be able to put out close to 300 volts to charge the whole battery as a whole not individual modules my battery was working fine when I shut the car down in the engine blew up it's been sitting 8 months for the last 4 months if I had a charged 12 volt battery and we go out and put it neutral it would tell me I had to check the hybrid system and blah blah blah yes because the engines blowed up and I've got stuff disconnected under the hood ready to take the motor out so of course I better check the hybrid system but now all I want to do is raise the voltage of the complete battery pack the 28 cells whatever's in the silly thing I'm staring at it it's right here in the trunk I just want to hook some leads up to something leave them permanently and be able to plug this little silly charger in whenever I desire apparently