is their any possible way to make the psp battery last longer(plugins or programs etc...)?

yeah just keep the volume switched off and have the screen brightness at the lowest other than that their are probably no other ways.

There's one other way through CFW or LCFW at the cost of speed. With Pro-B LCFW you can change the speed the processor runs at when you launch a game. I did this with Megaman X MH to get slow motion and used only the default blaster for the fun of it.