2002 DS IQ 48v power/battery problems

[nudder12]

Hi. Brand new here, sorry for what is probably a very basic question.
I bought a house and the prior owner left their golf cart here for me. It was running ok as far as I could tell (I've never had anything at all to do with golf carts before).
It's a 2002 Club Car DS IQ. 48v (6 x 8v).
However it was some time before we could move in, and when I tried the cart it wouldn't go at all and wouldn't charge either. The prior owner is no longer contactable. I got the local auto elec guy out, he said the batteries had been neglected and were stuffed.
Not knowing anything about golf carts or batteries, I bought a 2nd hand set of 6 batteries - 5 tested at 8v, 1 was about 7v.
So I put them on the charger and let them charge until it stopped.
Turned on the cart to give it a test run - it barely moved. If I was very gentle on the pedal it slowly got going then picked up some speed but clearly something wasn't 100%.
But, I'm on a very sloping block, and I found that as soon as there was any incline at all, the cart struggled badly to go uphill. It started juddering and shaking.
So I can only drive it back & forwards across the front of the house because I'm pretty sure if I go down our very steep driveway, it won't make it back up.
I've re-charged the batteries several times now. Nothing has changed.
I've checked the batteries water levels, all OK, and when they're not charging the pack reads about 48.5V.
Being a novice I assumed that should mean the cart runs fine - it's a 48v cart and there's 48v power available.
Am I wrong? Does it need more voltage? Is 48v enough that it should run at least half-decent?
Almost forgot - once the charger is removed, the battery light on the cart's dash blinks - it stays on for 5 seconds, goes off for 5 seconds, then on for 25 seconds, then off for 5 seconds, and this cycle repeats. It's not a cycle that is described anywhere that I've seen.
Sorry for the long story, just trying to offer as much information as I can to assist the reader to understand the problem.
Any and all advice welcomed
Thank you

[cjpenny89]

It sure sounds like you have bad batteries. Each battery should be around 8.3 volts and your total pack battery voltage should be around 51v fully charged.
when the pack reads as low as 48.5 volts that means your batteries are around 50%. I would do a load test on each battery you may have one battery reading good voltage but if you load test it will be junk.
good luck and I would consider new batteries as the cart came with the house its still a cheap investment.
What year is your cart?

[Cartmaster]

As already said, the cart cost you nothing so install new batteries, dont even bother testing the old ones, they are undoubted shot if left a long time with no charge. and if not completely shot, will not last long before they are. It will be a good investment with the value of running carts these days.

[nudder12]

Originally Posted by cjpenny89

It sure sounds like you have bad batteries. Each battery should be around 8.3 volts and your total pack battery voltage should be around 51v fully charged.
when the pack reads as low as 48.5 volts that means your batteries are around 50%. I would do a load test on each battery you may have one battery reading good voltage but if you load test it will be junk.
good luck and I would consider new batteries as the cart came with the house its still a cheap investment.
What year is your cart?

It's 2002.
How does one do a load test on the batteries??

[CP241]

I agree with cartmaster. Don’t bother even trying to load test the batteries. If they’re 48.5v after being charged they’re garbage. You’ve paid nothing for the cart so you’re way ahead of the game already. Just buy new batteries and be done with it for another 5-8 years.

Read through some of the posts here about battery maintenance… how and when to charge, keep water levels, etc. and a new set of batteries should last you for many years to come if properly maintained.