Low Maintenance Battery - Revised
83jaguar01Date 11-01-83
ITEM: J83/66
MODEL: XJ-S HE
SUBJECT: NEW BATTERY SPECIFICATION
From vehicle identification number, 112450, all Jaguar XJ-S HE models are equipped with a new Lucas low maintenance battery known as the "Lucas MF.3".
Interchangeability with the previous Lucas battery is not affected.
GENERAL INFORMATION
Battery Type Part Number - 0CP 13/118
Plate Capacity - 13
AMP Hour Rating - 68 Amp.
TOPPING UP INTERVALS
For the "Lucas MF.3" are 3 years or 50,000 miles.
Distilled water should be used to maintain the electrolyte level between the max/min level markings on the battery container.
CHARGING PROCEDURES
A. Temperature
i. Charging should only be carried out if the electrolyte temperature is between 37~F and 105~F. During charging the temperature should not be allowed to rise too high; if it reaches 115~F
the charge rate should be halved, and if it reaches 122~F, the charge must be interrupted until the temperature has dropped to below 105~F. If the temperature is below 37~F, it should be warmed to at least 37~F before commencing charging. ii. Should "topping up" be required, this should be carried out during the latter stages of charging. However, in cases where the tops of the plates are exposed, distilled water should be added to just cover the plates before commencing charging.
B. Charging of Low Maintenance Batteries
Charging should be continued until the battery gases freely for at least two hours. The fully charged condition can be detected when the electrolyte density remains stable over three consecutive hourly readings at the end of the charge. If any cells fail to gas after prolonged charging, then it is likely that these cells are faulty.
C. Monitoring of Battery Condition
The state of charge of a battery can be determined in a number of ways and the two most convenient ways are by measuring accurately, the open circuit voltage or by measuring the density of the electrolyte.
i. Open Circuit Voltage
This only gives a REASONABLE INDICATION of state of charge provided:
1. The battery has stood open circuit for at least 12 hours since it was last charged or discharged.
2. The measuring instrument (voltmeter) is itself accurate and has a sensitivity of at least 10,000 ohms per volt.
The following table gives approximate state of charge v/s voltage:
Open Circuit Volts State of Charge %
12.60 95
12.50 85
12.40 75
12.30 65
12.20 55
12.10 45
Open Circuit Volts State of Charge%
12.00 35
11.90 25
11.80 15
11.70 5
ii. Electrolyte Density
This measurement is potentially more accurate but less convenient than open circuit voltage; it will give good indication of state of charge provided:
1. The battery has not been topped up with distilled water since it was recharged.
2. The density measuring device (usually a hydrometer) is itself accurate.
The following table gives state of charge v/s electrolyte density:
Density kg/m State of Charge%
1280 100
1260 90
1240 80
1220 70
1200 60
1180 50
1140 30
1100 10
1080 0 (flat)