I have a 36volt 800watt hub motor bike (3 12 volt 12Ah lead acid batteries). It was a kit from ebay. I put it all together and it ran great for about a month. I could get about 15 miles or 45 to 60 minutes of run time before the batteries started to die. Now I can only get about 5 miles or 10 minutes of ride time before the batteries start to die (motor temporarily shuts off and "chatters" when coming on again under load). I took the batteries to an auto parts store after they had been acting weak- dead. They said each battery (12v 12Ah) tested at about 12.5 volts, and between 125 - 140 cold cranking amps. They said the batteries tested good and showed charged, but they won't run the bike at full power unless I charge them again for about 6 hours. Any suggestions???????