Allmand Brothers MB 6200 - Manual (Page 53)

53
Caring for Stored Batteries
The self-discharge rate of the batteries used in the system varies as a function of temperature. The dis-
charge rate is rated in terms of a reduction in the specific gravity of the batteries. The chart below shows
the relationship between temperature and reduction of specific gravity.
Care for batteries that are stored during winter months or slow periods is as follows:
1. Fill battery as required with distilled water. See Batteries under weekly maintenance for additional
information.
2. Fully charge to a specific gravity of 1.290 to 1.300 (15.60 Vdc on charge, 12.6 Vdc terminal off charge).
3. Place in a cool place between the temperatures of 32° (0°C) and 80°F (38°C)—cooler is better.
If one battery’s voltage differs from the rest of the bank by 5 percent, check its specific gravity.
Example: Voltage for all batteries measures between 5.99 and 6.12 volts, except one pair measuring 5.68 to
6.43 volts. This represents a greater than 5 percent difference and indicates a problem.
System Wiring
Maintain the wiring as follows:
Battery Wiring
Loose or corroded connections cause high resistance. Any battery connection that moves when five to ten
pounds of force is applied is considered loose. This could cause the battery pack to overcharge or under-
charge, with possible damage to the PV array system and/or battery bank. Clean and lightly grease (using
Lubriplate No. 630-AA or equal) all battery connections and tighten as required. Commercially available
corrosion inhibitors are available at most automotive supply stores.
System Wiring
Check wiring for cracked or frayed insulation and moisture damage. Inspect entry and exit points from all
junction boxes, and look for breaks or cracks in the insulation. Tighten or replace as necessary.
One year
BRICK/Rail Assembly
Check the BRICK and Rail Assembly for contamination and debris. Clean and remove as necessary.
Temperature Specific Gravity
100°F (38°C) 3 points per day
80°F (27°C) 2 points per day
50°F (10°C) 1.50 points per day
30°F (-1°C) 0.10 points per day