Buggies Gone Wild Golf Cart Forum

I have a 1991 ez go marathon, controller cart, with a total charge charger (LR-69689). The problem is if the cart hasn't been charged for a couple hours (or after a round of golf), I can plug in the charger and it will charge for 10 to 20 minutes, then click off. So then I'll take the plug out, then put it back in (because it definitely takes longer than 20 minutes to recharge the batteries after 18 holes) and it will click back on for may 5 to 10 seconds then off. I basically have to let it sit for a while, then I can come back in 30 minutes or so and plug it back in and start the whole process over again. The cord between the charger and receptacle plug gets mildly warm during the 20 minute charge. I'm not really sure what's going on with it because this just started recently. If anyone has any ideas what the problem might be I would greatly appreciate any info.

I also measured all the battery voltages and they measure between 6.27 to 6.33, and the voltage across the entire pack is 37.69V. Also all the batteries are less than a year old, so I don't think it's anything with the cart. But I may be wrong about that. Any help is appreciated.