(ET) RE: Battery Testers

["Eric & Tracie Miller" <ewmiller erols com>]

     Lets continue with the Battery tester.  If you are looking over a pile
of used batteries,searching for a few good batteries, you are better off
using the automotive hand held type of battery tester.  This tester will
help you weed out the obvious weaker batteries from the batteries that show
potential.
     For a more indepth test of your 6 volt batteries, it is best to use a
battery tester similar to what is used in the golf car industry.  The golf
car battery tester will actually test all 6 of your batteries at one time.
Newer golf car battery testers are also capable of testing 48 volt battery
packs by applying a 56 amp draw on the batteries.
     The golf car battery tester will apply a 75 amp draw on your 36 volt
battery pack until the battery pack voltage drops to 31.5 volts (5.25 volts
per battery).  How many minutes it takes for the fully charged battery pack
voltage to drop to 31.5 volts is the battery pack's actual capacity (not
"reserve capacity").  The golf car battery tester will display for you
during the test:  the discharge time in minutes and seconds, the present
voltage of the pack (during the test), the lowest battery voltage reached
during the discharge test, which voltage system test being performed 36 or
48 volt, and finally the option of down loading the data on a computer so
you can receive a printout of the test data.
     Normally if the batteries test to at least 60 minutes (60% of their
capacity) they are considered still good, but anything less than 60 minutes
is considered weak.  So, 60 minutes is the dividing line for the 220 amp/hr
batteries.  If you are going with higher amp/hr batteries such as the T125
or the US 2300 batteries the dividing line of good and bad should be 
raised.
You are free to use the weaker batteries that test to maybe 50 minutes, if
you only need them to mow for 1/2 hour while pulling about 75 amps.  Using
these weaker batteries is inefficient because you are still charging them
for 8 hours or so as you always have, but they are only capable of 
producing
for 50 minutes instead of 105 minutes.
     You can purchase one of these testers from any golf car dealer or have
them perform the test on your battery pack for you.

                                      Eric & Tracie