Cub Cadet RZT-S Zero Electric - Manual (Page 118)

RZT-S Zero
114
Capacity/discharge test
Standard lead acid batteries (starter batteries) are designed to deliver short burst of high current draws. Deep
cycle batteries are designed to supply a steady current flow over a long period of time. The batteries capacity is its
ability to deliver a fixed current draw over a period of time, measured in amp-hours. An example of this is if a battery
supplies 10 amps for 15 hours, the battery would have 150 amp-hours (10 x 15 = 150).
A capacity test is performed by applying a fixed current draw and measuring the amount of time it takes for the
battery pack to reach a voltage of 1.75 volts per cell (42 volts). There are automated capacity testers available com-
mercially, popular in the golf cart market, that will maintain a fixed current draw and measure the time in minutes until
the battery pack reaches 1.75 volts per cell. Cub Cadet recommends the Lester #17770 36/48 volt battery discharge
tester.
To perform a capacity/discharge test:
1. Make sure the battery pack is fully charged. Re-
charge if necessary.
2. Remove the left pod by following the procedures
described in Chapter 2: Body.
3. Disconnect the negative cable from the master
ground bus.
4. Disconnect the positive cable from the contactor
assembly.
5. Connect the tester to the positive and negative
cables coming from the battery pack.
6. Start the tester by following the recommendations of
the tester manufacturer.
NOTE: The Lester #17770 will test the batteries at their 1 hour rate, which is 59 AH for the RZT-S zero.
NOTE: The tester must be for a 48 volt system and apply a 54 amp load.
NOTE: The tester is automated. Warranty will not cover labor costs while the tester is running.
7. When the test is complete, document the results before turning the tester off.
NOTE: A battery pack is considered failed if it has less than 50% of its rated Amp Hour capacity.
NOTE: This test should take over an hour to perform. The stronger the battery pack the longer the test will
take.
IMPORTANT: If the battery pack fails the test, replace all four batteries at the same time.
8. Turn off the tester.
9. Disconnect the tester.
10. Reassemble the mower by following step 2 through 4 in reverse order.
11. Re-charge the battery pack.
Figure 6.4
Capacity/discharge tester
! CAUTION ! CAUTION
The battery pack’s leads are live.
Take measures to prevent the
cable ends and the tester clamps
from making contact with any metal surface on
the mower. See Figure 6.7.