Refurbishment
So what does it mean for a battery to be reconditioned? Great question. And an important one, because every company seems to have a different definition. We break down our process, step-by-step, and also highlight some of the practices in the industry to beware of.
We generally have two categories of reconditioned batteries – garage sale, and reconditioned. Garage sale means the battery is intended for the truck that runs no more than three to four hours per day, cumulatively. Garage sale batteries are significantly discounted, but they also do not come with a warranty. Reconditioned batteries come with a 6-month warranty, and generally render at a minimum 75% of original capacity.
Triage
What we do:
When a used battery hits our docks, we evaluate the battery and make a decision about how to proceed. Some batteries are just too old or have problems that cannot be reversed. Since there is no “cure-all” for refurbishing batteries, we eliminate batteries that have no chance of being reliable power. Furthermore, we use this opportunity to determine our plan of action specific to the battery. From there, we spend days working on each battery!
Benefit:
The supplier benefits because we pay for the best test the battery produces, not just how it performs when we receive it.
The benefit to the customer is that batteries that are too old or show signs of permanent damage are never resold. You don’t have to worry about buying batteries with cells that are extremely old or are close to failure.
What to watch out for:
We call it the “Frankenstein” battery. You are told it is a specific year from a specific manufacturer, but in reality, the battery has cells from a wide range of years and from numerous manufacturers.
Desulfation
What we do:
One of the most common causes of loss of battery power is sulfation. This is a naturally occurring process in which, over time, the liquid sulfuric acid crystalizes into a solid form on the lead plates. This diminishes battery performance by reducing the amount of liquid sulfuric acid in the battery and also by creating a barrier between the acid and the plates. We use a series of electronic pulses and continuous low-amperage charges to slowly break down that built-up sulfation in the battery.
We identify the presence of sulfation through a combination of visual inspection and evaluation of voltages and specific gravity. Once we determine that sulfation may be present in the battery, we follow a progression of continuous low amperage charging and high frequency electronic pulses that help break the sulfation apart.
Benefit:
Removing sulfation restores the battery’s ability to receive a charge and deliver power. There may be other problems with the battery, but sulfation is the most common cause of battery failure. This is also a more long-term fix than simply adding acid. The presence of more acid does not remove the crystals that prevent the battery from performing well.
What to watch out for:
Some companies will put additives into the battery and claim that battery life is extended. Others will simply put more acid in the battery to help it perform better. Both of these are proven to help in the short term (a few months), but they also cause the battery to deteriorate. Additives make the plates more brittle and cause additional shedding of the lead. Adding acid also destroys the inside of the battery much faster. You can see the increased acid by looking at the final specific gravity readings. They should be in the ballpark of 1.285 up to 1.330 depending on manufacturer.
Acid Adjustment
What we do:
Over time, if a battery has been over watered, the acid will have spilled over and onto the shop floor. This is usually caused by watering when the battery is not charged, and then placing it on charge. We see evidence of spillage when looking at the sides of the battery. In instances of repeat spillage there are streaks down the side of the tray, and often corrosion on the top of the cells. In these instances, we remove some of the old electrolyte and add higher concentrated acid to get the electrolyte up to the specified ratio. We also adjust the specific gravity readings back to a baseline of 77°F. As a battery gets hotter, the specific gravity readings and voltages drop. Conversely, as the battery gets colder, the readings increase.
Benefit:
Because our acid adjustments are performed in a controlled manner including temperature adjustments, we are careful to not add too much acid to the battery. This means our test results are reliable and are not over-stated.
What to watch out for:
If you see specific gravity readings that are above 1.315, you should be skeptical. While there are some manufacturers that require a specific gravity of up to 1.330, the most common is 1.285. As acid is added, specific gravity increases. Higher levels of acid will help a battery test well, but they also destroy the battery. Be careful if you do not see temperature adjustments for acid readings!
Cell Replacement
What we do:
A bad cell in a battery will cause newer forklifts to generate a fault code, and will cause older forklifts to die in the middle of a shift. Not only is a bad cell an inconvenience, but a weak battery will cause greater internal resistance in the forklift and cause failure of the forklift’s electrical componentry.
It is not always a good idea to replace a cell. Before doing so, we evaluate the health of the rest of the cells in the battery. If it is likely that more cells will fail soon, it is not worth the money to replace the cell. When we decide to replace cells, we use an overhead crane so that it provides smooth, even pulling power. Our team is well-trained in the burning process of reconnecting cells. This is critical! Bad burns on the intercell connectors will reduce battery performance and cause additional cell replacement! Anytime you order cell replacement done, always perform a visual check of the intercell connector after completion. Not all companies are skilled in this highly technical task, and it can cause future cell failure if not done properly.
Benefit:
We only replace cells if we believe that it will add value to the battery for another one to two years at minimum. We will tell you if we think replacement is a waste of money. We don’t want to charge you for a cell replacement job and then have you be upset because another cell failed two months later.
What to watch out for:
When performing a visual check on the burn of a reconnected intercell connector, you want to see that the top is smooth and even. If you can still see the defining edges of either the center post or the edge of the intercell connector, that means the burn didn’t make a good connection. If the melted surface is wavy, that means the job was rushed and the operator didn’t make a good connection. Grab the intercell connector in your hand and give it a good pull. If it is a good burn, it won’t go anywhere.
Detailed Testing
What we do:
All of our testing is conducted at the manufacturer-specified 6-hour rating. This means that the battery’s rated capacity is drawn down continuously over 6 hours (1/6th drawn out each hour). We begin with initial starting voltages, and record the temperature of the battery. This is important because a hot battery will test better than a cold battery. Running a battery hot destroys it, so performance when hot should not be considered a good indicator of future performance. We then measure the voltage of each cell, every hour, until any cell drops below 1.70 volts. At which point, the battery is considered to have failed. We are adjusting the amperage draw of the load banks frequently, and measure the amp draw of the load banks twice a month to verify that the machines are actually drawing what the meters say they are drawing.
Benefit:
This full level of testing, performed in a detailed manner, is the only way to know how the battery will test when you put it in your operation. When you see a load test from Evergreen Industrial Batteries, it is the most accurate picture possible of battery performance.
What to watch out for:
There are some companies that will do an “accelerated test.” Instead of running for 6 hours, they will test for 3 hours at an increased draw. We have seen some companies shrink the test time down to 15 minutes! Accelerated testing is based on a theory called Peukert’s law. However, it is only an estimate and it does not translate into reliable information in the warehouse. If you want to know if your battery will hold up in a forklift, the only way to know is with a full test.
Additionally, every battery should have the original manufacturer’s serial number still on the battery. This is crucial because the serial number tells you when the battery was made. Some companies remove these serial numbers, leaving you to guess when the battery was manufactured.
Lastly, be aware of the temperature and specific gravity at which the test is performed. As was stated earlier, batteries that are hot or are filled with too much acid test better. However, these are just temporary gains, and the battery will not perform that way for long.