charging problem on a 2004 Gem

I really know little more about this e-car than it’s a 2004 Gem 2 seat long bed. It has always been difficult to charge (had to wiggle the extension cord to make a connection). now i can’t get it to charge at all, it only beeps and the red light flashes. Is it time to replace the batteries or is it the charger.

Thanks

The flashes are a code.