You said Batteries are DEAD Now what is the full model number of that Parallex? a 7345 can, in theory pump up to 45 amps into the batteries if they are that low.. But the fuse is only 30 amp.
The solution.. Partially charge the batteries via another method, such as a "Dumb" auto charger (odds are smart chargers will refuse the job) say a 10 amp for one hour.. Then see if the parallex will hold. Or drop one battery off, see if the parallex will charge the other, then tomorrow sway them and then hook them back together.. The parallex normally does not put full current into the batteries but if they are very dead,, It will try, and that can pop the fuse.
