Bad Batteries, Bad Charger Or both? 48v TXT

[bronsonj]

What voltage should my 48V pack be while on float charge?

I have a 2011 EZGO Txt with a 48v pack. The batteries are 8V Trojans that are also 2011... My range is about 2 miles before the cart feels dead, feels about half speed and showing 42.3v while floored on level pavement. So I need new batteries, but..... Do I also need a charger?

I ran the cart for one mile 2 days ago, ran fine. Plugged in the powerwise QE charger as soon as I got back. I checked it just now, the green LED is on solid, indicating a full charge. I measured the pack (with the charger still plugged in) and it is 50.3v I measured the batteries and the lowest was 8.30v and the highest 8.43v. Most of the batteries were at/around 8.39v. Individual batteries measured with handheld voltmeter. Pack measured with same and also with ScottyB in dash voltmeter.

This is consistent with how the cart has been behaving. If it charges a day, 2 days, a week, etc, the starting voltage is 50.3 or 50.4.

Stock sepex TXT drivetrain with lift kit and 23" OD tires and a ScottyB voltmeter in the dash. Otherwise stock.

Thoughts?...

PS. ScottyB in dash voltmeter probably the best thing I bought for my golf cart yet!

[JohnnieB]

Trojan suggests float charging a 48V pack of their brand batteries at 52.8V, but a Powerwise QE charger doesn't float charge.

When the green LED comes on steady, charging ceases. It monitors the pack voltage and initiates a new charge cycle if the pack voltage drop below some preset voltage, or after a preset number of days have elapsed, but other than that, it might as well be unplugged from the cart.

The batteries start self-discharging the instant the LED turns to steady green and the time window for getting a reasonably accurate SoC estimate from the attached chart is in about the 12 to 24 hour range. Based on the 50.4V reading, you batteries appear to only be charging to about 90% SoC.

Which of the 5 Trojan 8V cart battery models do you have?
I suspect it is the T-875 (170AH) since that is the one most commonly used.

The batteries are going on 4 years old, which is the typical lifespan, so they may at or near the end of their useable life. Florida's hot climate, reduces battery life.

Also, the storage capacity of FLA batteries decreases by about 10% for every 15° the temperature is below 80°F, so you are seeing a reduction in run-time from the cooler weather as well as the aging.

Sounds like the cart sits for days occasionally, so float charging is needed for maximum battery lifespan. The DPI Accusense I use is the best bang for the buck. http://www.cartsunlimited.net/48v_Battery_Charger.html