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Step 17.  Repeat the above steps on String B, String C, String D, String E, etc.  
    

 

 

Parallel Connection of individual strings of batteries 

C&D recommends each of the individual battery strings be cabled separately to a common junction 
point or box. Each string should also contain a separate fuse or disconnect switch to facilitate 
maintenance, see Figure 2 & 5. The parallel connections should be completed only when the charger 
and load are not connected to the battery output circuit. The battery strings should not be ''daisy 
chained'' in parallel. 

 

Vl. Freshening Charge 

When the batteries have been in storage or transit for an extended period, over 6 months or if OCV’s 
are below 12.48 volts or when the number of cells in series is greater than 24, it is recommended the 
battery system be given a freshening charge at 2.4 volts average per cell for 24 hours. This will 
assure higher initial performance and will reduce the time period required for the cells to achieve 
proper voltage balance between the individual units. Normally freshening charges are only necessary at 
installation.  

 

Vll. Float Charging  

Following the freshening charge (if necessary) the battery system should be placed on “float“ charge 
at between 2.25 v/c and 2.30 v/c average (approximately 13.5 to 13.8 volts/unit average for 12 volt 
units at 77°F).  

 

Vlll. Periodic Maintenance 

These VRLA batteries are maintenance free with respect to the electrolyte. However, the charging 
voltage, temperature, performance and connection resistances must be periodically monitored and any 
necessary corrective actions taken if irregular values are observed to assure reliable standby power 
when required.  

 

Quarterly Inspection 

 

Measure and record the system total float charging voltage at the battery terminals  

 

Record the charger on charge output current and voltage  

 

Record the ambient temperature and condition of ventilation equipment 

 

Visually inspect the batteries and rack for; general appearance, cleanliness or any irregularity. 

 

Semiannual Inspection  

 

Repeat the quarterly checks  

 

Record the on charge voltage of each unit 

 

Optionally perform and record Ohmic checks for trending purposes 

 

Yearly and Initial Inspection  

 

Repeat the semiannual checks 

 

Inspect all connections to ensure integrity.  

 
 
 

Item 

Bolt Size 

Wrench Size 

Initial Torque 

TEL12-105FS 

¼-20 ¾ inch long 

7/16 

110 inch pounds 

TEL12-160FW 

¼-20 ½ inch long 

7/16 

110 inch pounds 

TEL12-160F 

¼-20 ½ inch long 

7/16 

110 inch pounds 

TEL12-180F 

¼-20 ½ inch long 

7/16 

110 inch pounds 

Table 1 

 

 
 

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