Another battery question....

[anziosaint]

I just picked up a 48v 2004 Club Car DS with Interstate batteries.... I know, I know many of you guys have nothing good to say about Interstate.... They would not be my first choice either but they were in it and the price was right. Anyways, they are date stamped "J8" which I am assuming is Oct. 2018. They are pretty clean and not bulging. All have plenty of water as well. Here's the issue. When I went to pick this thing up the I took my DMM and got a reading of only 47.8V !!!! I rode the cart around and took it to a hill where, as you can imagine, it slowed to a crawl. I asked him what was up and he told me that it was plugged in last about a week ago and he thought maybe his kids ran it hard and put it away without him knowing. So I get it home and put it on the factory powerdrive charger. The volts start coming up and after awhile the pack starts bubbling. During the charge, i check the voltage and the highest the pack got was just over 57 volts. It charged for about 14-15 hrs and the charger shut down. I checked the battery level 12 hrs. later and the pack read 50.9v. I ran the cart a bit around the yard and up a 300 yard 2-3% incline and it felt weak on the hill. Not crawling, but it didnt have the giddy-up my personal cart has with 2018 US batteries. (same make/model of cart)
So i parked it in the garage and used a stand alone smart charger that has clips and i attached them to the pack instead of using the factory charger. I monitored the pack with my DMM and after 45min the batteries were charging at 58.5v. (higher than the factory charger ever took them) The charger itself was showing just over 59v but I trust the DMM as a true reading. As I write this they are charging and I am not sure what the end result will be but I got to ask..... Does it sound like these batteries were neglected to the point they cant be brought back to a strong running pack? I just don't understand how after 12 hours to settle and a reading of 50.9v they are don"t seem to have any pep. I thought that was a good reading for pack after a charge? These batteries are only about a year old? *NOTE* Individually all batteries tested the exact same with a single battery being one/tenth of a volt higher than the other 5 so that rules out a individual battery being bad right?

Even if the batteries are bad, the price was worth it for the cart so i am OK with the purchase. If the sale was dependent on batteries I would have ran the other way.

What are your thoughts?