93 SL2 1.9 DOHC 115K W/auto tr issue

The car has had the alternator and battery replaced within the last year, but the car has sat about six months unused. I obviouslty had to jump the battery to get the car to start right up. I tried to take the car down the street to charge the battery and every time at the first gear change(30mph), the car bucks and all the indicator lights on the dashboard blink. The engine did not stall. Is this just be a case of the battery being dead? Or do you think it is more serious?
any suggestions- hopefully this car will be given to my kid to drive.