1995 Medalist battery and charger questions

[Rangerdaniel]

I have a question regarding my 95 medalist and EZGO Total Charger III charger. Sorry to be long winded, but want everything to be clear.

Bought cart about 5 years ago. Ran brand new Trojan T605 batteries. They worked well, no problems.

Yesterday, I purchased a brand new set of Interstate GC2-ECL-UTL batteries. The are rated at 115 min @ 75 amps and 225 Ah @ 20 hr.

Just the other day before replacing Trojan batteries, I ran the EZGO Total Charger III until (old) batteries reached 45 volts on Scotty Bs meter. They died fairly quickly after, so i replaced them with the Interstate.

After replacing batteries, I followed Scotty Bs recommendations regarding breaking in new batteries.

Before attaching batteries, all brand new batteries measured btn 6.20-6:30 or so. I don't recall exactly, i want to say they were all near 6.25.

After installing, Scotty Bs gauge said new batteries read around 37.5-37.7 or so.

After installing new batteries, I plugged in Total Charger III. It ran at 20 AMPS up to about 40 volts on meter and then shut off. Knowing the old batteries ran to 45, I plugged it back in and it immediately cut off.

I ran cart 3 or so short trips last night, plugging it up every time. After running cart, the charger cut off around 40 - 41.

Last night i made a quick run to a friends house. less than a mile. Upon returning, Scotty Bs gauge read about 38.1. I fell asleep without plugging back up (wanted to allow batteries to rest a bit). This morning before leaving the cart read about 37.7

When i arrived home today around 8:00 PM (22 hours or so after last running cart), Scotty B gauge read 37.3.

I plugged it up, charger ran for about 10 minutes to about 41 on the meter and cut off.

I then ran cart for maybe a mile. Put it on charge. Again, charged till gauge read 40-41 (it immediately dropped to below 40 on Scotty B gauge).

After allowing cart to sit tonight for about 2 hours it reads 38.4.

I know 38.2 is a full charge.

I have a few questions:
1. Why would new batteries stop at 40-41 on gauge when old batteries would charge to 45 on gauge?
2. After sitting for less than 24 hours, why would new batteries drop from 38.1 (at 10:00 pm) to 37.7 (at 7:00 am next day)?
3. Why is battery charger charging so fast? It used to run for hours, now it seems less than 10-15 minutes.