2008 YDRE: charger error code "excessive discharge"

[CapnIndifferent]

Been working on this cart for a few months off and on, so I'll try to be as accurate and detailed as possible and keep things in order.

-The cart was working fine and over time, even though it showed it was charging fully, the cart ran slower and would die earlier and earlier in the day.
-It ended up that the batteries would not charge fully and died in under 2 hours of light use.
-We replaced all the batteries and cables, but it would not charge fully and additionally it would trip the fuse on our oldest charger.
-We then replaced the charging receptacle and are using a different charger. Currently, it still does not charge to full, but it will charge overnight and in the morning it shows a solid Error 1 and Error 2 on the charger. I looked up the code and it shows up as "Excessive Discharge." Also, the speed is still quite slow, it doesn't struggle to get over speed bumps or anything, but it's at maybe half or maybe a third of the speed I would expect from it. It does, however, run for the full length of my shift now.

I have tried looking through the forums and the only relevant suggestion I saw was possibly to use a 12v charger to top off the batteries individually, but with them being new batteries I wasn't sure that is the right play. Any help is appreciated, thanks.

[cgtech]

Verify that the battery pack voltage is the same as the voltage at the charger port pins. Maybe the charge port isn't hooked to all the batteries properly.

[DaveTM]

Can you check each individual battery with a Multimeter when the cart is at a full charge?

[CapnIndifferent]

So apparently whoever ordered/installed the new batteries installed four 8V batteries. It's my understanding that if a golf cart uses 4 batteries that it requires four 12V batteries. Is this accurate and likely the issue? All of our chargers are 48V and I believe the old batteries had that V orientation to the ports, which means they were 12V. Hopefully someone can confirm.

To answer the other questions: First off, thank you for replying. I have not been able to check the individual batteries, but the charger port reads 30.something volts. So it seems like the batteries are good, though the above issue is likely the overall problem.

[cgtech]

Need 4x 12v , or 6x 8v batteries.

[cgtech]

Originally Posted by CapnIndifferent

....
-We replaced all the batteries and cables.....

It seems "we" is the problem.