2009 Stealth Patriot - New batteries but won’t drive

[Dodnof]

I recently purchased a used 2009 Stealth Patriot in great condition except that it needed batteries. Purchased 8 new Trojan T-105’s and got everything installed. It worked great for about a month. Drove it probably 20 miles total and charged it a couple times in that distance. The last time I went out to drive it, the batteries were dead, and appeared to be all the way dead. My wife thought maybe she’d left the lights on when she last parked it. So I plugged the charger back in, and it immediately started charging (which I didn’t expect it to do if it truly was fully discharged). I let it reach full charge, then took it out to drive. It made it just up my street when I noticed the battery indicator had dropped all the way down. I turned around and headed back, putting it right back on the charger. I tried it again after letting it completely charge and what happens is confusing me! It shows full charge on the battery charger. It shows full charge on the Quick Charge battery level indicator. But as soon as I switch the FNR switch over to F and try to drive, the battery level indicator immediately flips all the way to the bottom and starts flashing as if the batteries are about to die. I checked voltage with a voltmeter and I’m getting 48 volts across the battery bank.

Any ideas on what is going on???

[Cobra,1]

Believe 48 volt pack voltage is a dead battery pack.
Did you try Back to back charges? What is each batteries voltage Hydrometer reading of each cell. Water level full.
Couple things to check till others chime in.😊

[Dodnof]

I’ve tried back to back charges. Each battery individually reads approximately 6 volts. I haven’t don’t a hydrometer test of the water in each battery but the water is full in them. They were brand new a month ago.

[Bama Brad]

I would try 12 hour charge, let sit for 12 hours and do another 12 hour charge and let sit for a few hours. Then test each battery with volt meter. I think each battery should be somewhere around 6.25 volts fully charged. Hydrometer is about $8 at auto parts store, get one and test each battery. If one of the batteries doesn't charge up to the 6.25 volts, charge it alone (using a battery charger) up to a full charge (6.25 volts like others). Always leave cart rested a few hours after charging for batteries to cool and condition down. I am not an expert, but I also have a 2009 Patriot and have been told that. I assume you have double checked all your connections and they are solid.....nothing corroded or loose.