When your deep-cycle battery nears end-of-life, it’s normal to want to squeeze as much out of it as possible before spending money on a new one. Numerous online videos show a variety of ways to revive a dead or dying battery using various substances and hacks. The truth is, there are many factors that contribute to poor battery performance and failure, and it is important to diagnose the symptoms of poor battery performance before determining a cure.  It is also important to understand that many of the supposed “cures” can damage the battery, while others can be dangerous and do nothing to improve battery performance.

Fred Wehmeyer, Senior VP of Engineering at U.S. Battery, has more than 50 years of experience in rechargeable battery design and development.  He says that many of these hacks claim to show some type of improvement, but the gains shown may simply be artificial. One of the more common ones is adding Epsom salt to the battery cells.  According to Wehmeyer, adding Epsom salt (magnesium sulfate) to a lead-acid battery will ‘artificially’ increase the specific gravity reading (SG), but because it does not increase the sulfuric acid concentration, it does nothing to improve battery performance.

“This is because the sulfates in the Epsom salt are tied up as magnesium sulfate and are not available for discharge to lead sulfate as the sulfates in sulfuric acid are,” said Wehmeyer. “If you filled a new lead battery with a magnesium sulfate solution instead of sulfuric acid electrolyte, it would have no capacity at all.”  Simply put, adding Epsom salt will not recover the battery capacity but does “artificially” increase the SG.

According to Wehmeyer, the result would be similar if you remove the dilute electrolyte from a discharged and/or sulfated battery and refill it with the electrolyte for a fully charged battery (usually 1.270). The specific gravity will be higher, but the battery plates are still discharged and/or sulfated. Doing this will probably kill a potentially recoverable battery (see below).

Baking Soda and Aspirin

Other popular hacks include adding baking soda to recover a dead battery. Baking soda mixed with water is often used to clean the tops of batteries and battery terminals because it neutralizes the sulfuric acid and acidic corrosion products. Wehmeyer says that pouring baking soda into the battery cells will neutralize the sulfuric acid in the electrolyte to sodium sulfate that cannot discharge to lead sulfate in the normal discharge reaction.  This will also permanently reduce the capacity of the battery, which was most likely already low.

Adding aspirin to the battery is another hack that is often seen in videos claiming to revive dead batteries. Wehmeyer says aspirin is acetylsalicylic acid, which eventually breaks down into acetic acid. Acetic acid attacks the positive lead dioxide plates in the battery and permanently damages them, leading to short battery life.  This may show a small, temporary increase in capacity but will quickly kill the battery.

Pulse Charging 

If your battery is sulfated, which results in low power and difficulty in recharging to full capacity, it can sometimes be recovered using proper pulse charging techniques. Wehmeyer warns, however, that there are an infinite variety of pulse charging techniques used by a wide variety of equipment sold for this purpose.  These techniques include DC (direct current) pulses using various voltages and currents, as well as AC (alternating current) pulses with a wide range of AC frequencies. “The problem is that if not done properly, it can do more damage than good,” says Wehmeyer. “Having said that, I have tested some very complex and very expensive pulse chargers that appeared to recover sulfated batteries more quickly than traditional methods.  Most pulse chargers use an external power source (wall AC) to power the device. Some, however, use the battery’s voltage to power the charge pulses. This can kill the battery if left connected for long periods of time without a separate charger.”

Ultimately the best recommendation for potentially recovering a sulfated battery is to save your money and try using a long, slow charge.  If you have a battery charger that has a reconditioning or equalizing charge mode on it, that may be your best bet. “Use the equalization charge mode regularly, about once a month, on deep-cycle lead-acid batteries to extend the life of the battery,” says Wehmeyer. “Regular equalization charges prevent sulfation and stratification by balancing the individual cells and properly mixing the electrolyte.  In addition, a long slow charge could help recover already sulfated batteries to make them last a little longer.  If your charger does not have an equalization charge mode, simply wait until the charger completes a normal charge and then restart it by unplugging AC power and reconnecting.  The charger should continue charging for an additional 1 – 3 hours.  If the battery is dead from poor maintenance, worn-out from too many deep cycles, overcharging, or excessive deep discharging; it probably can’t be recovered.”

Following manufacturer-recommended care and maintenance procedures will get you the longest life and best performance from any battery. For more information on how to care for your lead-acid batteries, check out the U.S. Battery User Manual.


Maximize Battery Charger


In the same way, that different deep-cycle battery designs vary in capacity and overall performance, charging the battery can be as unique as the battery itself. Because deep-cycle batteries in various vehicles and machinery can differ in their work environment, the battery’s capacity and performance are susceptible to how they are charged and maintained. Battery manufacturers like U.S. Battery work with charger manufacturers such as Delta-Q to develop various charging profiles for particular battery sizes and designs to maximize your lift’s battery performance. Ultimately, the overall performance of any work platform comes down to how well the batteries are maintained, the depth of discharge, and the “charge quality” during each recharging session.

According to Delta-Q, the manufacturer has more than 50 charge algorithms on hand for a variety of batteries. To determine how to give your equipment’s battery the best charge, you need to understand what charge algorithms are. There are different charge algorithms available on many battery chargers, but to understand this, you first need to know that there are basically three stages of battery charging. The first is a Bulk Stage, where the charger uses constant current at full charger output to bring the battery to approximately 80% state of charge. The second stage is Absorption Charge using constant voltage where the charge current tapers from full charger output to a lower level that depends on battery conditions. The charger allows the battery to control the charge rate at which it can accept a charge until 100% of the amp-hours removed on the previous discharge are returned. At this point, the battery is not quite fully charged and requires a controlled overcharge. The third stage is the Finish Charge, where the charger gives the battery a lower constant current charge at a charge rate that is proportional to the design capacity of the battery. Assuring the battery is fully charged and provides enough gassing to mix the electrolyte to prevent electrolyte stratification.

During these three charge stages, charge algorithms can differ in current, voltage, time, and amount of overcharge. Charge algorithms are adapted to optimize charging for specific battery models and chemistries. To begin with, there are three primary types of algorithms. SPECIFIC charge algorithms that are custom designed in collaboration between the charger manufacturer and the battery manufacturer and are used by most Original Equipment Manufacturers (OEM) of access lifts and machinery. For performance and warranty reasons, lift OEM’s use a specific battery and therefore require a particular charge algorithm to maximize the battery life for the performance and use environment of the equipment. Depending on the battery chemistry and its use, the charge time and current applied during these three stages can vary to provide the best possible balance between cycle life, runtime, and overall battery life.

Some charger manufacturers use GENERIC charge algorithms designed for particular battery chemistries (such as flooded lead-acid, AGM or Gel) and a wide range of amp-hour capacities. Each chemistry requires a different charge algorithm and amount of overcharge. According to charger manufacturer Delta-Q, a generic charge algorithm will provide a reasonable compromise between battery life and performance. Generic algorithms provide greater flexibility between battery makes and models, especially if the owner decides to change to a different battery when it’s time for the battery to be replaced.

Some charger manufacturers offer UNIVERSAL charge algorithms that can be used for all types of batteries, and most battery manufacturers do not recommend the use of these algorithms. If used, battery state of charge and temperature should be carefully monitored to prevent undercharge or overcharge that could severely decrease battery performance and life.

Ultimately, the best way to get the most out of your batteries, and your lift equipment, is to consult with the manufacturer and/or look up the charge algorithm they have for the specific battery in your equipment. The battery charger should use that specific charge algorithm; allowing you to get the most out of your batteries and ultimately your equipment. For more information on batteries and charging profiles, visit

User Manual Cover

U.S. Battery Manufacturing’s New User Manual Provides Complete Information On Battery Data, Maintenance, Safety, Optimization, And More…

U.S. Battery Manufacturing now provides customers with a User Manual that includes everything you need to know to get the most out of your deep-cycle batteries. “Our User Manual is like placing the entire knowledge base of our engineers and battery industry experts at our customers’ fingertips,” says Mike Wallace, U.S. Battery Director of Marketing. “We compiled all of this information into an easy-to-understand manual that is designed to help customers properly use and maintain their batteries from purchase to end of cycle life and beyond.”

U.S. Battery’s User Manual will be updated regularly and covers a variety of topics, including safety, installation, and storage tips, as well as proper maintenance procedures and performance optimization. Customers can also learn how to address frequently encountered scenarios and find links on how to properly compare battery features and capacities before making their next purchase.

To view or download the free interactive digital U.S. Battery User Manual, Click Here

Specific Gravity


Most electric golf cars utilize a battery pack of four or more deep-cycle batteries that can last a long time if you’ve performed the proper maintenance. Periodically, however, the vehicle may not seem to have the range it used to, and replacing all of the batteries may be cost-prohibitive at the moment. In most cases, it’s not the entire battery pack that is going bad, but instead, one battery is not keeping up with the rest of the pack and hurting performance.

Identifying A Bad Battery In Your Pack

1: Fully Charge Your Battery Pack And Take Readings

Perform a full charge to all the batteries and check the specific gravity readings on each battery with a hydrometer and multi-meter. Use the battery manufacturer’s data to see if the readings show the battery pack is undercharged. (Here’s an example of a typical deep-cycle battery data). Repeat the charge cycle to bring the state of charge of the pack up. If, after repeated charges, the batteries begin to increase in specific gravity readings, the problem is not the batteries, and further investigation is required.

2: Perform A Discharge Test At 50% DOD

If the specific gravities indicate charged batteries (1.260 or higher in all cells) and the voltage readings are good on each battery, discharge the battery pack on the vehicle in question. If one cell is significantly lower than the rest of the cells in the pack, mark that battery as suspect. Use a load tester or run the golf car through its typical routine. Battery packs that give less than 50-percent of the rated runtime are usually considered bad.

3: Test And Find The Bad Battery

Measure the voltage at the end of your discharge test to locate the bad battery. The one with a significantly lower voltage than the rest of the pack at the end of discharge is usually the culprit.

4: What If All The Batteries Show Low Voltage?

If all the batteries have a low voltage, and your hydrometer readings on all the batteries do not show a single defective cell, then the entire battery pack may be at the end of its service life.

Replacing Defective Batteries

Once you’ve found a bad battery in your golf car’s battery pack, it is okay to replace the single battery with a new one if it’s under six months old.  If the battery is over six months old, it’s best to replace it with another battery from your fleet that has a date within six months of the rest of the pack or replace the entire pack.

When replacing a single battery or battery pack, it’s important to keep these facts in mind:

1) Cycle life comparisons should be made at the same depth of discharge (DOD).

2) Amp-hour ratings should be compared using the same discharge time and/or discharge current that will be used in the application.

3) Run-time ratings may be the most accurate comparison when selecting a battery for a given application.

Battery Watering fill line

Take the Worry Out of Watering Deep-Cycle Batteries While Making Them Last Longer

The switch to battery-powered aerial platforms, scissor lifts, and boom lifts allowed these vehicles to be smaller, more maneuverable, and safer. Most use deep-cycle FLA batteries because they offer the lowest operation cost if you maintain and replenish water in the battery cells. That’s where the difficulty often lies. Busy schedules and long work hours often leave batteries improperly maintained in this critical area resulting in a loss of performance and life.

Addressing this issue results in two options:  replace your vehicle(s) batteries with more expensive lithium or maintenance-free lead batteries, or make watering simpler to assure your batteries are watered properly so they can last longer and provide optimum performance.  With the availability of a variety of battery watering monitors and single-point watering systems, there’s no reason that your batteries’ maintenance should be neglected.

A battery watering monitor replaces one vent cap on a single battery of a battery pack and indicates the battery pack’s water level. Since batteries are usually connected in series in a pack and charge and discharge together as a pack, you typically only need one monitor per vehicle to indicate the condition of the battery pack. Vehicles with multiple packs in parallel will need one for each series pack.  Watering monitors use a built-in probe and processor that triggers an LED indicator light to signal when the pack needs water. The indicator light can be mounted in the battery compartment for easy access by maintenance personnel or in a more convenient location that the operator can easily monitor.

Combined with one of several types of single-point watering systems on the market, watering batteries can be made very simple.  Watering systems are designed to work on just about any battery model. Most are very simple to install with many kits available pre-assembled for your specific vehicle, battery manufacture, and battery configuration. When batteries need watering, attach the inlet connection of the watering system to the kit’s siphon valve and a hand pump that supplies water from an appropriate source (most often a large container of distilled water). After a few pumps to start the siphon, all of the batteries in your pack are filled to the correct level without the fear of overfilling.

The advantages of maintaining the electrolyte levels more frequently and reliably results in battery packs lasting much longer – as much as 7 – 10 years in many instances, especially when battery packs are not discharged more than 50% as recommended by most manufacturers. Combine this with charging your batteries at every opportunity and performing an equalizing charge at least once per month. You’ll see a dramatic increase in the life and overall performance of your batteries.

In addition to saving money over the long run and making your batteries last longer, the drudgery of battery watering can be reduced to a quick and simple procedure.

Testing Battery Specific Gravity with Hydrometer

Temperature’s Impact on Charging Deep-Cycle Batteries

The chemistry of flooded lead-acid deep-cycle batteries makes them one of the most cost-effective methods of energy storage. The composition of the battery’s design, however, makes it sensitive to temperature, which can affect its charging and discharging rate, something that should be addressed in regular maintenance routines.

Cold temperatures slow the rate of charging and discharge, while warmer temperatures increase the rates. This means that it may take longer for your batteries to fully charge in the winter than they will in the summer. Additionally, in the warmer summer months, batteries may discharge more quickly. Battery manufacturers use 80-degrees F (27 C) as the baseline temperature for optimum operation and calculating charge and discharge rates. Obviously that doesn’t work for everyone, so it’s important to take specific gravity readings with a hydrometer to know if and when your batteries are properly charged in all temperature conditions.

Specific gravity is the ratio of the weight of a solution to the weight of an equal volume of water at a specified temperature. A hydrometer can give you an indication of the state of charge of the battery’s electrolyte. A higher number indicates a higher concentration of acid in the electrolyte, indicating the battery is charged. A lower number indicates that the concentration of acid in the battery is less, showing the amount of discharge of the battery.

Battery manufacturers recommend using a simple correction factor to your hydrometer’s readings. Using 80-degrees as your baseline, subtract (.004) from your hydrometer reading for every 10-degrees below 80 °F (5.6-degrees below 27 °C). For example, if the temperature of the electrolyte is 50 °F and your battery specific gravity reading is 1.200, you must subtract .012 from your reading. In this case .004 for every 10-degrees equals .012. Subtract this from 1.200 and your corrected specific gravity reading is 1.188.

Specific gravity readings must be done on every cell of each battery in the pack. Compare the readings to the battery manufacturer’s specifications to indicate the state of charge of your batteries. While it’s not necessary to calculate your hydrometer’s readings for slight variations above or below 80 °F, it should be done in extreme weather conditions or seasonally to ensure that your battery-powered vehicles or equipment are performing at their best.

Diagnosing A Bad Deep-Cycle Battery

Finding The Weak Deep-Cycle Battery In Your Pack

There’s a time in the lifespan of a deep-cycle, flooded lead-acid battery where it will begin to fail and not hold a full charge.  Typically there’s no indication when this happens, other than when your battery-powered golf cart, aerial platform, forklift or floor cleaning machine slows down and stops operating. While deep-cycle batteries do often go beyond their advertised lifespan, they will eventually lose performance. A single tired battery in a battery pack can bring down the overall performance, so finding which battery is the culprit is vital to restoring the full potential of your vehicle.

Fully Charge the Battery Pack

Begin your diagnosis by completely charging the battery pack and checking each battery’s specific gravity readings with a hydrometer. Healthy batteries should have similar specific gravity readings in all cells.  If a battery has one or more cells with low specific gravity readings, it may be getting weak and nearing failure.  If all the batteries have low specific gravity readings, try performing an equalization charge.  If the specific gravity readings continue to increase with equalization charging, the problem may be the charger or the charging methods and not the batteries.  Equalization charging should be performed monthly on healthy batteries and more frequently if continuous undercharging is detected.

Perform a Full Discharge

After charging the batteries and the specific gravity readings indicate that all the batteries are fully charged, perform a discharge as the car would normally be used over the course of a day.  If the runtime is significantly shorter than normal, there may still be a weak battery in the pack.  Check the battery voltages and specific gravity readings and confirm that all connections are clean and tight.  If one battery is significantly lower than the rest, mark that battery as a suspect. If no low battery is found, use a load tester to perform a timed load test.  Battery packs that give less than 50% of the rated runtime are usually considered to be no longer serviceable.

Measure Voltage

Using a multimeter, measure the voltage at the end of the discharge test to locate a potentially bad battery. The one with a significantly lower voltage than the rest of the pack at the end of discharge is usually the culprit.  If all the batteries have low voltage and low runtime and your hydrometer readings on all the batteries don’t single out a bad battery or cell, then the entire battery pack may be at the end of its service life.

Replacing One Or More Batteries

If a bad battery is identified, it may not be necessary to replace the entire pack.  Battery manufacturers suggest that it is acceptable to replace one battery in the pack with a new one if it is under six months old.  If the battery is over six months old, it’s usually best to replace it with another battery from your fleet that has a date within six months of the rest of the pack or replace the entire pack.

For more information on deep-cycle batteries, run-time ratings, and maintenance tips to keep golf car batteries running longer, visit

BWT install photo-12

Why Only Distilled Water Should Go Into Your Deep-Cycle Battery

Electric vehicles that run on one or more deep-cycle batteries require watering after the batteries have undergone a full charge. According to engineers at U.S. Battery Manufacturing, a global leader in deep-cycle batteries, water is lost from battery cells by evaporation. This happens during various instances such as, the heat that occurs during the charging process, heat from weather conditions, and during equalization charging, where the electrolyte in the battery bubbles to mix the electrolyte and prevent stratification (sulphuric acid settling at the bottom of the cells) which can diminish performance. 

Checking water levels periodically maintains the health of the battery cells and according to battery manufacturers, adding the right kind of water will aid in that process. Battery manufacturers such as U.S. Battery recommend using distilled water. 

Using ordinary tap water or softened water is bad for your deep-cycle batteries, as the minerals found in the water can react with the electrolyte and minimize performance and increase sediments 

Battery manufacturers recommend checking water levels frequently, usually after charging. When filling, it’s important to use proper safety gear such as latex gloves and eye protection. Manufacturers also emphasize that it’s important to fill battery cells only with enough water to cover the cell plates, but not to overfill, as the electrolyte expands with heat and overflow. To avoid splashing or overfilling, it’s recommended to use a hand pump or battery pitcher to fill each battery cell.

Adding the right kind and amount of water in your deep-cycle battery’s cells, will ultimately keep them in top shape and extend the life and performance. For more information, visit

Consistent Battery Maintenance Is Key To Longevity And Performance

There’s something to be said about due diligence, especially when it comes to your golf car’s batteries. While many individuals and golf courses are content with simply charging batteries overnight, and checking water levels whenever they get around to it, others conform to a strict maintenance schedule that ultimately prevents numerous conditions that can lead to poor performance and ultimately, battery failure.

Run It Till It Dies

The downtime while your batteries are charging is often inconvenient and some golf car owners run the car until it’s nearly out of power or dead altogether. Batteries that experience frequent deep discharges (discharges of more than 50-percent of a battery’s rated capacity) will have dramatically shorter life than batteries with lower depth of discharge (DOD). The use of ‘opportunity charging’ or charging at every opportunity instead of waiting to recharge until batteries are fully discharged will dramatically increase battery life. (This should not take the place of fully charging regularly.)  If you need longer runtime between charges, consider switching to batteries with higher amp-hour capacity.  This may require switching to a different type of battery with a lower voltage per monoblock but higher capacity.

For example, a golf car with a 48-volt battery pack can use four 12-volt batteries, six 8-volt batteries or eight 6-volt batteries (if space is available).  While all provide the same 48-volt pack voltage, the eight 6-volt batteries provide the highest capacity and runtime. According to Fred Wehmeyer, Senior VP of Engineering at U.S. Battery Manufacturing, a battery that is routinely discharged to 40% DOD will last about 2.2 times longer than a battery that is discharged to 80% DOD. The initial cost for eight 6-volt batteries is higher than four 12-volt batteries; but considering how much longer they will last, the return on investment is much greater.

Water Whenever

Failing to consistently check water levels and add water to your batteries can also result in low capacity and eventual battery failure if left unchecked. Watering flooded lead-acid batteries is one of the most basic and important maintenance procedures. During battery charging, gases evolved from the decomposition of water results in water loss. This lost water must be replaced by regular water addition.  The rate of water loss can be even higher at elevated temperature and water levels must be checked more frequently. If water is not replaced regularly, the tops of the battery plates in each cell can become exposed to air and damaged to the point that capacity is reduced and battery life is shortened.  Electrolyte levels should always be maintained above the top of the plates by adding water before charging and after charging to about 1/8-inch below the bottom of the vent wells.  Final watering should be done after charging to prevent electrolyte overflow.

If you really hate watering batteries, consider a Single Point Watering System and a battery watering monitor. These often come in kits that are pre-made for specific golf cars and/or battery packs. Monitors such as U.S. Battery’s Sense Smart Valve works with SPWS systems and indicates via a dash or battery mounted LED when the batteries need water.

Summer’s Over; Park It Till Next Year

Improper battery storage is, unfortunately,  a common practice with resorts and RV owners. Storing your golf car with the battery pack in a discharged condition for a long period of time can lead to sulfation (a condition that leads to the development of large lead sulfate crystals that reduce the battery’s available capacity). Over time, this sulfation can reduce both the full charge capacity and overall life of the battery.

The battery pack should always be fully charged before the vehicle is put into long-term storage. In winter months, this also prevents the batteries from freezing. Maintaining the batteries at full charge will keep your batteries in good condition until the next time you use them.

The Electric Golf Car Market Expected To Expand

Market Researchers See Continued Growth On Electric, Battery Powered Golf Cars Through 2026

According to a market analysis by consulting and marketing research firm, Future Market Insights, the golf car market is expected to be positive for the long-term, with electric golf cars having the highest anticipated compound annual growth rate of 6.4 percent through 2026. (Global Industry Analysis and Opportunity Assessment 2016-2026 ).

According to the research, the growth is due to the electric golf car as internal transportation for developing countries, as well as private clubs, golf-centric real estate developments, the travel tourism industry which is expected to include new construction of resorts and golf courses.

Golf Car Options Magazine also published the research, but they suspect that this expected growth of the global golf car market will be challenged with the maintenance of lead-acid batteries, claiming that they are also less efficient and require frequent charging. While battery maintenance is essential for optimum performance in electric golf cars, items such as single point watering systems, Sense Smart Valves and proper charging techniques, can dramatically reduce maintenance and extend battery life. In addition, flooded lead-acid batteries have the benefit of being recycled at a rate of 99 percent, with the recycled lead going back into new golf car batteries in a closed-loop system.

The report goes on to say that electric powered golf cars are expected to continue to dominate the market in terms of value over the forecast period.