http://uuhome.de/william.darden/dcfaq3.htm
which I found with Google with a search on 'lead acid battery'. You say 'batteries' so I'm guessing you have four 12-volt lead acid batteries in series (positive connected to negative, etc.). If that's true the cleanliness of the connections is very important. Start by cleaning all of the terminals and connectors and make sure they are all tight. If your fully charged voltage is still 48.5 you likely have one or more batteries that are degraded. When the batteries are fully charged and you have the batteries disconnected to clean the terminals measure the voltage of each battery individually. If you have a digital voltmeter you can probably trust the reading you get, but if it's analog it may have greater error than the charged to discharged voltage range of a 12-V lead acid battery. You can still measure the voltage across the individual batteries and look to see if there are significant differences between them. As Mr. Darden suggests a fully charged healthy battery should show about 12.65-Volts across the terminals (that's 50.6-Volts for your four batteries in series with good connections). Less, and your meter is inaccurate or the battery is partially discharged or it and/or the connections have problems.
Also, look to see what the service life on the batteries is. If these are original equipment they may only be 48-month batteries (manufacturers are cheap).
I hope this helps,
Alan Brooks
At 03:50 PM 10/23/2003 -0700, you wrote:
Hi Group:
My warning lite (low battery) comes on half way thru the round. These batteries are only four years old. The output volts are about 48.5, fully charged.
Any suggestions re desulphizing etc????????????
Thanks I enjoy the posts in the group
Joe
