Winter Battery Maintenance
Inspection
There are many tools that may help in properly caring for and maintaining batteries. Below is a list of basic items that Trojan recommends for this task:
Recommended Equipment:
CAUTION: Always wear protective clothing, gloves, and goggles when handling batteries, electrolyte, and charging your battery.
Batteries should be carefully inspected on a regular basis in order to detect and correct potential problems before they can do harm. It is a great idea to start this routine when the batteries are first received.
Inspection Guildlines:1. Examine the outside appearance of the battery.
- Look for cracks in the container.
- The top of the battery, posts, and connections should be clean, free of dirt, fluids, and corrosion. If batteries are dirty, refer to the Cleaning section for the proper cleaning procedure.
- Repair or replace any damaged batteries.
- Leaking batteries must be repaired or replaced.
- Look closely for loose or damaged parts.
- Battery cables should be intact; broken or frayed cables can be extremely hazardous.
- Replace any cable that looks suspicious.
Proper Torque Values for Connection Hardware:
Testing
Visual inspection alone is not sufficient to determine the overall health of the battery. Both open-circuit voltage and specific gravity readings can give a good indication of the battery's charge level, age, and health. Routine voltage and gravity checks will not only show the state of charge but also help spot signs of improper care, such as undercharging and over-watering, and possibly even locate a bad or weak battery. The following steps outline how to properly perform routine voltage and specific gravity testing on batteries.
I. Specific Gravity Test(Flooded batteries only)1. Do not add water at this time.2. Fill and drain the hydrometer 2 to 4 times before pulling out a sample.3. There should be enough sample electrolyte in the hydrometer to completely support the float.4. Take a reading, record it, and return the electrolyte back to the cell.5. To check another cell, repeat the 3 steps above.6. Check all cells in the battery.7. Replace the vent caps and wipe off any electrolyte that might have been spilled.8. Correct the readings to 80o F:
- Add .004 to readings for every 10o above 80o F
- Subtract .004 for every 10o below 80o F.
The readings should be at or above the factory specification of 1.277 ± .007. If any specific gravity readings register low, then follow the steps below. 1. Check and record voltage level(s).2. Put battery(s) on a complete charge.3. Take specific gravity readings again.
If any specific gravity readings still register low then follow the steps below.1. Check voltage level(s).2. Perform equalization charge. Refer to the Equalizing section for the proper procedure.3. Take specific gravity readings again.
If any specific gravity reading still registers lower than the factory specification of 1.277 ± .007 then one or more of the following conditions may exist:1. The battery is old and approaching the end of its life.2. The battery was left in a state of discharge too long.3. Electrolyte was lost due to spillage or overflow.4. A weak or bad cell is developing.5. Battery was watered excessively previous to testing.Batteries in conditions 1 - 4 should be taken to a specialist for further evaluation or retired from service.
II. Open-Circuit Voltage TestFor accurate voltage readings, batteries must remain idle (no charging, no discharging) for at least 6 hrs, preferably 24 hrs.1. Disconnect all loads from the batteries.2. Measure the voltage using a DC voltmeter.3. Check the state of charge with Table 1.4. Charge the battery if it registers 0% to 70% charged.If battery registers below the Table 1 values, the following conditions may exist: 1. The battery was left in a state of discharge too long.2. The battery has a bad cell.Batteries in these conditions should be taken to a specialist for further evaluation or retired from service.
TABLE 1. State of charge as related to specific gravity and open circuit voltage
Storage
Periods of inactivity can be extremely harmful to lead acid batteries. When placing a battery into storage, follow the recommendations below to insure that the battery remains healthy and ready for use.
NOTE: Storing, charging or operating batteries on concrete is perfectly OK.
The most important things to avoid:1. Freezing. Avoid locations where freezing temperature is expected. Keeping a battery at a high state of charge will also prevent freezing. Freezing results in irreparable damage to a battery's plates and container. 2. Heat. Avoid direct exposure to heat sources, such as radiators or space heaters. Temperatures above 80° F accelerate the battery's self-discharge characteristics.
Step by step storage procedure:1. Completely charge the battery before storing.2. Store the battery in a cool, dry location, protected from the elements. 3. During storage, monitor the specific gravity (flooded) or voltage. Batteries in storage should be given a boost charge when they show a 70% charge or less. See Table 1 in the Testing Section. 4. Completely charge the battery before re-activating. 5. For optimum performance, equalize the batteries (flooded) before putting them back into service. Refer to the Equalizing section for this procedure.
