Hanfried Sievers is the Training Manager at Cutting Edge Training and, in this article, he discusses the importance of battery maintenance and the problems that will arise if they are not kept in optimum condition
Anyone who has an understanding of electric golf buggies will know that they are a great money-spinner for the Pro Shop, but at a lot of clubs, nobody takes overall responsibility for them. Over time, their performance will diminish and, at worse, leave a valuable customer stranded at the furthest edge of the golf course. The reason … "batteries are not what they used to be!"
In fact, the contrary is true: nowadays, batteries are designed and built to give a long and trouble-free life. Battery life can be greatly extended by giving them a little 'tender loving care' and this article will cover basic battery maintenance by adhering to the following steps:
- Keep the batteries clean
- Keep the elecrolyte (water) at the correct level
- Keep the batteries charged correctly
- Keep the battery and cables secure (tight)
Although this article specifically addresses deep-cycle flooded lead acid batteries, the general principles also apply to valve regulated lead acid batteries. In addition to the above points, the following two topics are discussed:
- Storage of Vehicles
- Testing of Batteries
Storage Facility for the Golf Carts and Utility Vehicles
The first step in good maintenance practice is to have a suitable storage facility for the vehicles. This facility has to be laid out in such a way that the rotation of the golf buggy fleet can be ensured; meaning that all of the buggies will be used equally and so will their battery packs.
Hydrogen is released during the charging process of the batteries and we all know how volatile this little gas is. Therefore, good ventilation of the storage area has to be ensured. It is recommended the volume of air is circulated five times an hour. The ventilation system has to be installed in such a way that there is no chance of hydrogen build-up in pockets of the ceiling. Also, keep any flames or sparks away from the charging area at all times and do not smoke in the vicinity.
It is strongly recommended that one charger is dedicated to one particular vehicle, i.e. the chargers are numbered according to the numbers of the buggies and buggy number 15, for example, is only charged by charger number 15. This way a possibly faulty charger will only affect one particular buggy. The electric power supply to the chargers has to be stable during the complete charging cycle and a maximum of two chargers are protected by a single fuse.
During prolonged storage of the vehicles the battery packs have to be charged and watered monthly.
Before getting started, be sure to wear the correct protective clothing when handling batteries or electrolyte; as a minimum, rubber gloves and goggles. The following tools will be required:
- Sodium Bicarbonate (Baking Soda)
- Distilled or De-ionised Water
- Insulated Spanner(s)
- Post Cleaner or Wire Brush
Batteries should be inspected on a regular basis (preferably weekly, but as a minimum monthly) in order to detect and correct potential problems before they can do harm.
- Examine the case of the battery. Look for cracks in the case or for discoloration, warping or raising of the case. Inspect the top of the battery. The posts (terminals) and connections should be clean, free of dirt, fluids and corrosion. Repair or replace any damaged batteries.
- Any fluids on or around the battery may be an indication that electrolyte is spilling, leaching or leaking out. Follow the instructions under 'Cleanliness' below in order to clean the batteries. Leaking batteries must be repaired or replaced
- Check all battery cables and their connections; look for loose or damaged parts. Battery cables must be intact; broken or frayed cables can be extremely dangerous. Replace any cable that looks suspicious. Cable connections need to be cleaned and tightened as battery problems are often caused by dirty and loose connections. Follow instructions in 'Everything Secure' below for correct torque settings.
Cleaning batteries is an important issue. Battery tops should be clean and dry, as dirt and moisture actually provide a conductor to allow a discharge across the grime on top of the case. This discharge may cause the terminal clamps and nearby metalwork to corrode, which will cause a high resistance at the connections, resulting in power consumption due to heat generation. The heat can lead to cables melting or battery terminals distorting or melting which, in turn, will slacken the battery terminals and connections, thereby increasing the problem.
Therefore, there will be a reduction in the performance of the battery pack and voltage drop during use.
It is recommended that the battery tops be cleaned monthly. However, if the batteries are cleaned with a water hose (without first neutralising any acid) the acid from the top of the batteries will just be moved to another area of the vehicle or storage facility, where it will attack the metal structure or the concrete/asphalt floor. Also, after hosing down the batteries, a residue will be left on the battery, which is conductive and will again contribute to the discharge of the batteries.
The correct cleaning technique is to spray the top and sides of the batteries with a solution of sodium bicarbonate (baking soda) and water. This solution is best applied with a litre-sized hand sprayer. The solution should consist of two teaspoons (10 ml) of sodium bicarbonate (baking soda) mixed with one litre of clear water. In addition to the batteries, special attention should be paid to metallic components adjacent to the batteries which should also be sprayed with the sodium bicarbonate solution.
- Ensure that all the vent caps are securely in place to prevent any contamination from entering the battery
- Spray the battery tops, sides and nearby metalwork with the above solution of baking soda and water
- Allow the solution to sit for at least three minutes to allow the neutralisation to take place
- Use a soft bristle brush or cloth to wipe the tops of the batteries in order to remove any residue that could cause the self discharge of the battery
- Rinse the entire area with low pressure clear water. Do not wash electrical components with a direct stream of high pressure water
- If any evidence of corrosion is still evident (green powered foam), spray again with the baking soda and let the solution stand for at least five minutes before rinsing; repeat if required
- Dry all the battery tops and sides with a clean cloth
- Clean battery terminals and the inside of cable clamps using a post and clamp cleaner. Clean terminals will have a bright metallic shine
- Reconnect the clamps to the terminals as described in 'Everything Secure' below
- Keep the area around batteries clean and dry
Maintaining the electrolyte level is extremely important since any portion of the plates exposed to air will be ruined (corroded) beyond repair. Of equal importance is to prevent too much water, which will result in electrolyte being forced out of the battery due to gassing and the increase in volume of the electrolyte that results from the charging cycle.
It is recommended that the electrolyte level in every cell be checked monthly and filled to the correct level, as required. The plates must be covered by at least 13mm when fully charged, but the level must still be 6-10mm below the vents to allow hydrogen to escape during the charging cycle.
The use of a battery-watering gun or a single point watering system (SPWS) will assist in accurately completing this task. Water should be added, if needed, after the charging has been completed, unless the tops of the internal plates are exposed. In that case, water should be added before charging.
Be sure that the water is suitable for watering batteries. Use distilled or de-ionised water only. Be aware that the electrolyte in the battery is a solution of acid and water, so skin contact must be avoided. Never add acid to a battery.
If an SPWS is not fitted, follow this procedure during watering:
- Open the vent caps and look inside the fill wells to check electrolyte level; the minimum level is at the top of the plates
- If necessary add just enough distilled water to cover the plates at this time
- Put batteries on a complete charge before adding any additional water
- Once charging is completed, open the vent caps and look inside to check electrolyte level
- Add water until the electrolyte level is 6-10mm below the bottom of the fill well
- A piece of rubber or plastic can be used safely as a dipstick to help determine this level
- Clean, replace and tighten all vent caps
Batteries should be charged after each day's use. Lead acid batteries do not develop a memory and do not need to be fully discharged before recharging. The charging must take place in an area that is well ventilated and capable of removing the hydrogen gas that is generated by the charging process. A minimum of five air exchanges per hour is recommended. Keep sparks or flames away from a charging battery.
The battery charger is designed to fully charge the battery set. Automatic chargers will determine the correct duration of charge to the battery set and will shut off when the battery set is fully charged. This may take up to twelve hours. Always refer to the instructions of the specific charger used. If the batteries are severely deep cycled, some automatic battery chargers contain an electronic module that may not activate and the battery charger will not function. In this case, a second battery pack may be used to "jump start" the first battery pack or the batteries have to be charged individually for a while.
- Before charging, check the electrolyte level (see 'Electrolyte Level' above)
- Ensure all vent caps are securely tightened before charging
- Ensure the charging connector components are in good condition and free from dirt or debris
- Ensure the charger connector is fully inserted into the vehicle receptacle
- See that the charger connector/cord set is protected from damage and is located in an area to prevent injury that may result from personnel running over or tripping over the cord set. It is recommended that the cord is fed through the steering wheel, to prevent accidental drive-away
- Prevent overcharging the batteries. Overcharging causes excessive gassing (water breakdown), heat build-up, and battery aging by corrosion of the positive grids. Buckling of the plates may also occur. This can result in perforation of the separators and internal short circuits.
Never leave a charger connected for more than twenty-four hours
- Prevent undercharging the batteries. Undercharging causes permanent stratification (because the temporary sulphate is not completely removed from the plates during recharge, allowing the remainder to convert to permanent sulphate) which can lead to premature battery failure
Flooded batteries benefit from periodic equalising charges. Many experts recommend that batteries be equalised periodically, ranging anywhere from once a month to once or twice per year. However, i would only recommend equalising when low or wide ranging specific gravity (+/- .015) is detected after fully charging a battery.
Equalising is an overcharge performed on flooded lead acid batteries after they have been fully charged. It reverses the build-up of negative chemical effects like stratification, a condition where acid concentration is greater at the bottom of the battery than at the top. Equalising also helps to remove sulphate crystals that might have built up on the plates. If left unchecked, this condition, called sulphation, will reduce the overall capacity of the battery.
- Conduct a normal overnight charging cycle of the battery pack, until the charger completes its cycle and switches itself off
- Set charger for the equalising voltage. If your charger doesn't have an equalisation mode, you can unplug the charger from the vehicle and plug it back in to restart the charger. This will also conduct an equalisation charge
- Start charging batteries. Allow the charger to run until it completes its cycles
- Batteries will begin gassing and bubbling vigorously
- Unplug the charger and re-plug immediately after the previous charging cycle was finished
- Repeat for a third consecutive charge cycle
- Allow the batteries to cool down and inspect the electrolyte level in each battery cell and top up if necessary
Batteries that are not held securely in position will suffer excessive vibration, which can dislodge active material from the grid or break the straps, grids and inter-cell welds. This could lead to an internal short and possible explosion. On the other hand, excessive tightening of hold-down clamps can cause the battery container to crack, resulting in leakage of electrolyte.
Cable connections need to be clean and tightened. Many battery problems are caused by dirty and/or loose connections. Clean cable terminals before connecting them to the battery and remember to connect the negative or earth cable to the battery last. Make certain there is good contact between the terminals and the battery posts.
Using force when fitting connections to the battery can damage the battery internally or the poles. Tighten all cable connections to 7-9 N·m (95-105 in·lbs). Do not overtighten terminals. Doing so can result in post breakage, post meltdown, or fire.
To prevent corrosion of cables and posts of batteries, apply a thin coating of high temperature non-oxide grease or anti-corrosive battery post spray to the connections.
Testing of Batteries
Before any testing is done, charge the battery pack so that the water and electrolyte mixes. Record all test results on a test sheet, including the battery make, type and date code, the total amp-hours of the vehicle, as well as the vehicle model (type) and serial number.
The following tests are available for testing deep cycle batteries:
On-Charge Voltage Test
This test is a quick-reference test to see if there are any obviously faulty batteries in the pack.
After the charging cycle was completed, unplug and immediately re-plug the DC Cord of the charger. Just before the charging cycle is completed again (the light on the charger reaches solid green during the fast-blinking mode), take the on-charge voltage reading of each individual battery and of the full set.
Batteries that meet the following criteria could be suspicious:
- For 6 Volt Batteries - Any battery that shows less than 7 Volt, and is more than 0.50 Volt below any of the others
- For 8 Volt Batteries - Any battery that shows less than 9.5 Volt, and is more than 0.75 Volt below any of the others
- For 12 Volt Batteries - Any battery that shows less than 14 Volt, and is more than 1.0 Volt below any of the others
This test is a quick-reference test to see if the battery pack and the individual cells are fully charged and can give an indication of any obviously faulty batteries in the pack. Be aware that the vent caps of the batteries have to be opened: there will be a danger of coming into contact with the acidic electrolyte.
- Before proceeding with this test, take a temperature reading of the centre cell of the centre battery
- With a hydrometer, test each battery cell in order and record the readings to 3 decimal places
- Correct all readings to 27°C (80°F):
- For every 6°C (10°F) the electrolyte temperature is above 27°C (80°F): add 0.004 to the measured reading.
- For every 6°C (10°F) the electrolyte temperature is below 27°C (80°F): subtract 0.004 from the measured reading.
- Any cell that shows a difference of more than 0.050 below any of the others could give an indication of a faulty cell or battery.
- If all the cells of the batteries are below 1.250 then the battery set is not fully charged. A fully charged battery set should read between 1.275 and 1.280.
This test places the battery under a load and discharges the pack at a constant rate to a pre-determined voltage. The time it takes to reach this voltage will indicate whether there is a problem with the battery pack. Consult the vehicle OEM's instructions on this time for the specific batteries in the pack.
Ensure that the on-board charger is disconnected from the mains supply, or the off-board charger is unplugged from the vehicle. Carry out a discharge test, if the discharger is still discharging after the time indicated by the OEM, there are no faulty batteries. Stop the test, disconnect the discharger and fully charge the battery pack.
If the discharger completes the discharge below these times, switch the discharger on again and measure the individual battery voltages. Record the voltage readings for each battery and replace batteries as indicated by the test, compared to the instructions of the vehicles OEM.
(As an example: For T105 batteries, if the set discharges <60 minutes, replace any battery which measures >4.5 Volt.)
After replacing any faulty battery, fully charge the battery pack before using the vehicle.
Cadex Spectro Battery Test
Using a Cadex Spectro Battery Rapid-tester greatly reduces the time taken to test a battery pack. It is essential that the surface voltage of a freshly charged battery pack is removed, by either driving the vehicle for ten minutes or by connecting a discharger for five minutes.
The test only takes about ten minutes per vehicles and has the advantage that it also indicates the remaining capacity of each battery. The results are immediately available on-screen and can also be downloaded onto a PC at a later stage. This is a brilliant tool for fleet owners, as similar capacity batteries can be grouped, in order to get the best power results out of each battery.
Look after the batteries. There really is not much to battery maintenance, but monthly checks, cleaning, watering and testing is a must!
When the batteries are kept clean and free of grime, checked that the electrolyte level is correct, charged after each use, checked for clean and secure cable connections and tested and grouped regularly, they should last and give a satisfactory result and power supply to the vehicle.