If you are having ongoing difficulty with this cart, or others have a similar difficulty you carry out the same test as the stationary test previously performed but this time put the cart under load .,this is a laymans discharge test.
Safety first. raise the rear wheels and/or remove any persons from the area/ clear a path in front of you just in case you do take off unexpectedly! With voltmeter connected to the battery pack, attempt to drive the cart forward (normally easier with the seat off) whilst looking at your multi-meter.
Test total Battery pack voltage first,(you should notice voltage drops under load of attempting to drive vehicle, then test each individual battery voltage (again under load)to locate any failing battery(s). If the batteries are all even but low i.e all around 7.2V DC, try charging again. If one battery is failing i.e 5.9 vdc and its voltage reading just keeps falling on the test, this usually means the battery has reached retirement.
Wearing safety glasses and no smoking or naked flames!!!!
Remove the battery cap you may notice a mist rising from one of the cells(hole in top of battery). The shuddering is either low battery voltage or a bad connection, the Club Cars dont use a drive belt on the electric carts, the clicking is most likely the main power solenoid/relay.
To check age of batteries
A date code is usually stamped on the negative terminal of each battery ,i.e B9, the letter is the month , the number the year. So B9 would be...(B)February (9)2009 D7= DApril 2007 etc
The onboard computer controls the charge cycle ,that is its primary function.
Batteries that have remained in a discharged ( FLAT) state too long are sometimes unable to be successfully charged the conventional way,due to sulfate covering the internal plates of the batteries preventing charging.
To overcome this some technicians bypass the charge computer in an attempt to force more charge into the batteries and disintegrate the sulfate , sometimes this action is successful.
You can also buy a Hydrometer from an auto parts store which tests a battery acid level (Technically called Specific gravity level) which is generally more accurate in locating less detectable battery problems.