Battery and Charger
11-10
Chapter 11
Inspection and test of the battery
Please refer to Chapter 1 “Protection for Electrical Safety”.
Carry out four inspections to find out the cause to the battery performance reduction. As these
inspections are more and more detail and time-consuming, please carry out the inspection from the
beginning before proceeding to other inspections until the problem is identified as shown in “battery
troubleshooting diagram” (see Fig 11-7).
Inspection and test of the battery charger
The easiest way to monitor the battery of the vehicle is to observe the reading on the ampere-meter of
the battery charger on completion of one charge cycle. When the battery is fully charged, unplug the DC
connector of the charger and wait for 20-30 seconds before reconnecting the DC connector of the
charger. The pointer of the ammeter will jump to over 15A, and then drop below 6A in 10 to 20 minutes,
which means the battery is normal and fully charged. In case the performance is still poor, the problem
may lie with the electrical system, braking system or the battery charger of the vehicle. In case no
problem is identified from the electric vehicle or the charging system, inspection of the additional voltage
should be made. The battery of over 6V should also go through charging voltage inspection.
Charging voltage inspection
When the battery is fully charged, unplug the DC connector of the charger. Wait for 20-30 seconds
before reconnecting the DC connector to restart the charger. Five minutes later, measure and record the
voltage of the battery pack and of each battery with the multimeter. Set the multimeter at 200V DC.
Attach the red (
＋
) probe to the positive (
＋
) terminal of No.1 battery, and attach the black (-) probe to
the negative (-) terminal of the battery pack
(see Fig 11-5).
Take down the reading. Then set the
multimeter at 20V DC. Attach the red (
＋
) probe to the positive (
＋
) terminals of all batteries, and attach
the black (-) probe to the negative (-) terminals of all batteries. Take down the reading. The charged
battery of the battery pack should have a voltage between 56.0-63.0V, which is subject to the years it is
used and the electric quantity of the inspected battery. In case the reading of a single battery is higher
than 7V, and the difference of readings do not exceed 0.7V, the ins pection by hydrometer should be
conducted. In case the reading of any single battery is lower than 7V, and its difference with the battery
that has a voltage of over 7V exceeds 0.7V, the ba ttery should be replaced. In case the reading of any
single battery is lower than 7V, but its difference with other reading does not exceed 0.7V, it means the
battery is too old. The capacity of the old battery may be able to sustain for a few months. Inspection with
the hydrometer shall be conducted.
Inspection with hydrometer
The specific gravity of the battery electrolyte can be measured by the hydrometer. The higher the
specific gravity is, the more electric quantity the battery has. When the temperature is 80
℉
(26.7
℃
),
the reading of the fully charged battery should range between 1.250 and 1.280. Never increase the
specific gravity by means of filling acidic fluid into the battery.