2014 BBB 72v Recoil IS battery charging problem
 

Hello Everyone!

I recently purchased a really clean BBB Recoil IS 72v, brought it home and first thing i did is read the Owners manual to get familiar with it. I threw the charger on it before driving and let it sit over 24 hr time to bring the batteries to a full charge. Disconnected charger, removed caps from the installed Trojan t-875 8 volt batteries that are 10 months old, topped them off with distilled water and capped them. I performed a Voltage test with a multimeter and all batteries were in the 8.46+ with charger not plugged in. I ran it for one week and noticed that i was getting less and less of a charge on the battery that is underneath the driver seat furthest to the rear left corner (if sitting in vehicle), It's also the battery that is connected to controller B- (Picture Attached). Assuming that it was a bad battery i ordered a hydrometer and performed a test on all batteries before purchasing new. After i got my hydrometer i performed the test and All were good except the battery that i ran off that specific location.I am currently on my second NEW Trojan T-875 that has replaced the exact spot with all measuring tests being performed after each ride and after each full charge and it still continues to deteriorate the performance of that specific battery. When i Installed the batteries New on a full first charge, they ran great and after recharges battery life slowly dropped measuring fully Charged 7.9V and not passing hydrometer test, all other batteries are between 8.4-8.5V. Is it possible that the controller is not allowing a full charge on that specific battery? Is there a Service manual with schematics available for these units? Any advise greatly appreciated, Thanks!