Battery Bank
Ver-Mac 2018
PCMS Operations, Safety & Maintenance V3.0
43
NOTE
Hydrometer readings should not vary more than 0.05 between cells.
State of Charge
Specific Gravity
100% Charged
1.265
75% Charged
1.239
50% Charged
1.200
25% Charged
1.170
Fully Discharged
1.110
These readings are correct at 25°C (75°F)
NOTE
Sulphation of batteries starts when specific gravity falls below 1.225 or voltage
measures less than 12.4 for a 12V battery, or 6.2 for a 6V battery. Sulphation
hardens on the battery plates. It reduces and eventually destroys the power
generating ability of the battery.
12.3
Sealed Battery Maintenance
12.3.1
Validating Battery State of Charge (SOC)
To check battery level:
1. Bring the trailer inside.
2. Put the trailer in full operation mode, at the highest brightness, and let it in operation for at least
five (5) minutes, but no more than 15 minutes.
3. From the terminal strip inside the plastic battery box, measure the voltage:
a. Put the positive lead on any of the screws that has a cable identified 12 V.
b. Put the negative lead on any of the screws that has a cable identified GND.
4. Use Table 1 to find out if the batteries are fully charged.
Note that gravity measurement is not possible with sealed batteries. See next section for the battery
charging procedure.
Percentage of Charge
Open Circuit Voltage (V)
100
12.73
90
12.62
80
12.50
70
12.37
60
12.24
50
12.10
40
11.96
30
11.81
20
11.66
10
11.51
Table 1 - State of charge for a 12 V sealed battery
12.4
Suggested Recharging Times
Ver-Mac units use two models of IOTA chargers. The recharge time guidelines
suggested below apply to IOTA 30 and IOTA 55 chargers only.
