I think I just wasted $1500 on Deka Gels

When I got my Think 2 years ago, it had 1 year old set of US Battery AGMs in it. The range was great. On it’s first long drive, I went ~16miles and only dropped 2 bars. It’s a factory Rev2 motor and controller.

Then 6 months ago, even with a short drive of 6 miles, I would lose 1 bar. Another month or two, 2 bars down. Eventually it got to 1 bar left and the cart goes into limp mode. I changed out the DPI charger because it was only floating the batteries at 79.5V. When I first got the cart, the pack would be at 81V even after a short drive, so I knew the charger wasn’t doing it’s job.

But even with a new charger(quick charge SCO7210), that only helped a little bit. So I thought these batteries were toast and time for some Dekas.

So I bought a brand new set that came fresh from the factory. Installed them and setup the charger for gels. Things are better but still not great. After 6 miles I’m still down 2 bars. No where near what I was getting originally when I bought the cart.

I checked the voltages during charge and after, they seem spot on. Batteries charge at 88.5V and float at 83.3V measured at the pack. In fact, my old AGMs that were sitting off the cart for 2 weeks are still 13-13.2V without being on the charger. I hate to say it but I think I spent $1500 on batteries and that wasn’t the issue. The cart seems to be OK, no odd mechanical sounds, no obvious electrical issues, and doesn’t seem sluggish with a fresh charge.

So here’s what I’m thinking.
#1 There’s some odd electrical drain somewhere or a bad electrical component. Do the contactors ever corrode, does the motor controller ever have issues that causes excess draining, motor issue, etc?

#2 Do the Deka gels require some sort of break-in period before they get to full capacity potential?

#3 Anyone ever had bad new Deka gels? I know these came direct from the manufacturer and were very fresh(born on month/year same as when I bought it). They were only sitting at 12.5V though when I picked them up.

Any help or insight would be greatly appreciated.

Are you sure you have the right algorithm on the charger. I had a problem with range on new Deka batteries and after 4 years of problems I changed out the Delta Q charger to a OBE72/10 Quick Charge 72 Volt 10 Amp Float charger. This was only for gel batteries. The Delta Q charger would seem to fully charge the batteries but would run down quickly. I was down to 1 mile for the first bar to disappear and fully out of juice in about 6 miles. I could not change the Delta Q algorithm even though I followed the proper procedure. Finally the charger quit working. I purchased the quick charge and I’m now getting about 9 miles before the second bar disappears. So it seems to me the Delta Q was using the wrong algorithm even though it indicated it was the correct one.

Does the cart roll free? No dragging brakes?