Electric Forklift Batteries

Forklifts may use several different types of batteries. Electric forklifts require the battery to operate, while gas powered forklifts need a battery to start. Over time, these batteries will run down. Electric forklifts will need to be charged periodically, while other types of forklifts will need the battery completely replaced when it runs down. Replacing these batteries is done in much the same manner as a battery on an automobile, so we will focus more on maintaining batteries in electric forklifts.

What Makes Up the Battery?

An electric forklift battery is made up of five different parts. Those who work on an electrical forklift should know these parts to avoid getting shocked or, worse, causing the battery to explode.

1. 1.  The battery cells – the battery is divided into different cells, each of which contains a set of positive and negative plates. The plate at each end of the cell is negatively charged, and plates alternate throughout the cell. The number of cells determines how many volts the battery produces.
2. 2.  Separators – each of the positive and negative plates is separated by a separator, which provides the insulation.
3. 3.  The battery tray – this is the container that holds the battery cells. It’s usually made from steel.
4. 4.  Electrolyte solution – everything inside each cell is submerged in an electrolyte solution made of sulfuric acid.
5. 5.  Element – the top of each cell features an element made up of one positive and one negative terminal. The positive plates are all connected to the positive terminal, while the negative plates connect to the negative terminal.

How Can you Select the Best Battery for your Forklift?

One factor in deciding on the best battery for your forklift is to look at its size. Larger forklifts that are rated for lifting larger loads are going to need bigger batteries because they will require more power. Smaller forklifts won’t have as much weight to move because the frames are usually lighter, plus they’re not rated for lifting really heavy loads. Another very important factor when selecting proper battery size for your forklift is weight. In an effort to save money, it may be tempting to purchase a smaller battery. Minimum battery weight is listed on the data tag located on your forklift. It is very important to fit a battery that meets these weight requirements. The battery is factored into the counterweight and crucial to the lifting capacity and safety of the forklift. Make certain you get the correct size battery for your forklift.

Before purchasing a new battery it would be wise to have the battery inspected by a battery technician. Often these batteries can be repaired. It may be a matter of replacing a cell or two. It may just need an acid adjustment. These remedies to not make your battery new again but can in some cases extend the life by a few years.

Be careful when buying off-brand batteries. Yes, they may work in your forklift, but they may also be cheaper for a reason—many off-brand batteries are of a lesser quality and will not last as long as the more expensive brand names. Look for product reviews before you make a purchase.

Tips on Charging the Battery

Maintaining a proper charge on your forklift battery is important. If the battery isn’t properly charged, it will run down much more quickly, and then you’ll end up spending more money on replacement batteries than you should. Here are a few quick tips on charging your batteries to make certain you get the most out of them.

• •  Recharge your battery when it has about 20 percent power left, not before. Recharging a battery when it has more power may damage the battery and shorten its life.
• •  You don’t have to charge a battery daily—if it’s not run down, don’t charge it. Most forklift batteries are designed for a certain number of charge cycles (1,500 or more). If the battery doesn’t need to be charged, don’t waste one of these cycles.
• •  To make sure the battery is performing at its best, use the equalize, weekend, or weekly charge setting (the term varies from brand to brand) once every five to ten recharge cycles. This will help ensure longer battery life. However, don’t use this setting too often or you may damage the battery. You may want to keep a log of when these special charge cycles are done to help with this.
• •  You’ll also want to keep a log of when water was added to the battery. New batteries will need water added to them once every ten charges for the first couple of years in use. After that, or if you’re using a reconditioned battery, you may need to add water to it after every five charges.
• •  Add water after the charging cycle, never at the beginning of a cycle.
• •  Don’t interrupt a charge cycle. Doing so will waste one of your charge cycles, plus it can damage the battery.
• •  If a battery does run completely down, be sure to recharge it as soon as possible. Don’t let it sit for a long period of time.

Steps on Replacing the Battery

On average, a battery for an electric forklift will last around five years, less if it’s used and recharged a lot. Under ideal conditions a well maintained low usage battery can last as long as 10-12 years. Fortunately, these batteries are fairly easy to find, and most are reasonably priced.

There are a number of signs that your forklift battery is about to expire. Here are a few of the most common:

• •  It doesn’t hold a charge for long
• •  It needs recharged several times during the day
• •  The battery case starts to show corrosion buildup
• •  The battery begins to smell
• •  The battery begins to smoke while in use or when charging—replace this battery immediately!

Replacing a forklift battery is not as simple as replacing other batteries. The first issue is that the battery can weigh several thousand pounds. It’s going to take another forklift to move it. It can also be very dangerous as batteries carry high amperage that can be deadly if not handled correctly. In many cases, it’s easiest to simply have a battery technician do the installation. These professionals have been trained in forklift battery replacement and can handle everything.

However, if you’re going to do the replacement yourself, you should first make certain that you keep the top of the battery clear of all metal objects. Otherwise, the battery could short circuit and explode. You should remove any jewelry you’re wearing such as a wedding ring—even that small bit of metal can cause an arc. Even keep the connector cables away until you’re ready to connect it. Keep them out of the way, and make sure they’re not going to get caught under the battery.

Now move the new battery under the hoist using a second forklift. Make certain the hoist hooks are securely connected to the battery’s lifting hole. Lift the battery up, carefully move it into position, and then lower it into the forklift. Connect the connector cables and power up the forklift to make certain it works.

Post by Intella Parts Company, LLC

ELECTRIC FORKLIFT DIAGNOSTICS

So your forklift won’t move, where do you start?  Here are some basics in understanding electric forklift diagnostics.  Whether your forklift is electric powered or engine powered the problem could be your forklift electrical system. In this article I will explain the basics of electrical forklift diagnostics.

Because electricity is not visible, it is not easy to diagnose. Compounding the problem is that electrical schematics and diagrams can be confusing. I will try to equip you with the tools needed for proper diagnosis. A technician has to rely on those tools to show where electricity is, or where it isn’t, and then draw accurate conclusions from that knowledge.

If you can learn to “think” like electricity and skillfully use your multi-meter. With an understanding of some basic electrical principles you can then apply them to testing electrical systems.

Have you ever witnessed a technician spending time looking at wiring diagrams or drawing sketches on a piece of paper. He was actually diagnosing the problem at hand. A big part of electrical forklift diagnosis is done at the bench before ever lifting a wrench. A multi-meter (VOM) is the second most useful tool in your arsenal after your brain.

Computer controlled systems offer another complexity to the way electricity works. It is easy for technicians to replace a control board, often because they don’t understand what it does or how it works. This often results in unnecessary expense and can also cause the new part to be damaged because the original problem was not corrected.

By understanding what a control board needs in order to function properly and then ensuring that it has everything it needs to do its job, a technician can successfully determine whether the board needs to be replaced.

OK, so let’s get started. A simple understanding of electricity and basic terms is in order.

What is VOLTAGE?

Voltage can be thought of as electrical pressure. Voltage is the force that pushes electrons along an electrical conductor. The measurement for voltage is called the volt. There are two types of voltage: alternating current and direct current. In forklift circuits we are use both direct current and alternating current.

Direct current voltage (DC voltage) is voltage that is applied in one direction all of the time. Most forklifts use direct current to get their jobs done. Industrial forklift batteries or automotive type batteries supply direct current to the electrical circuits.

Alternating current voltage (AC voltage) is voltage that is applied in both directions in an alternating fashion. This is similar to the electricity found in the electrical outlet of your house wiring.

Some modern forklifts use AC powered motors as they require less maintenance and can be more efficient than their DC counterparts.

What is CURRENT?

Where voltage is the driving force in an electrical circuit, current or amperage is the measurement of how much electricity (electrons) is flowing in a circuit.

We measure current in amperes (amps). Current is the quantity of electrons passing a single point at any given time. Current can be measured in both AC and DC circuits.

What is RESISTANCE?

Resistance is the opposition of flow in an electrical system. This is sometimes built into the circuit for various functions. All loads create resistance that is normal in a forklift circuit. Resistance can also be caused by lose connections, faulty components and faulty wiring. Understanding resistance can be a key component in understanding how to diagnose electrical circuits.

Resistance is measured in OHMS Ω.

How can we see these different parts of electricity? Using a VOM we can measure the existence of voltage, amperage, and resistance.

To measure voltage; place the black lead of your meter in the com jack of your meter and place the red lead in the V jack. Now adjust the meter to AC or DC depending on the circuit you are testing. Set the meter on auto range. If your meter does not have this functionality, you should set the meter to the highest voltage that you expect to be reading.

There are two types of voltage measurements that are useful in forklift diagnosis: available voltage and voltage drop.

AVAILABLE VOLTAGE

Available voltage is voltage that is present at any given point in the circuit. You can measure available voltage by placing the red meter lead at some point in the circuit (switch contact, fuse, connector, etc.) and the black meter lead on a common terminal. This test will tell you how much voltage, or electrical pressure, is present to do some work at a given point in the circuit.

The available voltage test is good for determining if you have voltage present, but it does not do much in the way of diagnosing what is wrong with the circuit.

Available voltage is a good test to use when you want to see whether voltage is present at a point in the circuit or not. You can think of the available voltage test as a “go, no go” type of test.

Do not use the available voltage test to determine whether a circuit is functioning properly or not. There may be voltage present at a point in the circuit, but that does not mean that the circuit has what it needs to work.

VOLTAGE DROP

The second voltage test while performing electric forklift diagnostics, and by far the most useful, is called a voltage drop test.

We say that voltage is “dropped” when some form of load uses all, or a portion of, the voltage available.

Loads come in the form of motors, solenoids, contactors, lights, etc. Corrosion, open circuits and damaged contacts can also be considered loads on the system as they can cause voltage drop also. When a load of this type “uses up” or drops voltage, then it may not leave enough available voltage to the rest of the circuit for the circuit to work properly. A voltage drop test will help you to isolate where voltage is being dropped, or used up.

Unlike resistance measurements where the circuit is not turned on, a voltage drop test is performed with the circuit working or turned on.

To perform a voltage drop test you must place the meter leads at two points within the circuit. Remember, during the voltage available test we place the leads at one point in the circuit and the other to common. In the voltage drop test, both meter leads will be placed in the circuit.

With the meter leads placed in the circuit, you are now measuring how much electrical pressure, or voltage, is present between the meter leads. If you measure any voltage at all on the meter display, then there must be some sort of load between the meter leads.

Your next job is to determine whether the load that is represented on the meter display is a load that is supposed to be there, or whether it is a load that may be harmful to the circuit. Remembering a few simple rules will allow you to determine if the voltage drop you are measuring is “normal” or not.

A meter reading of less than 0.1 volts represents a wire, or switch that is operating normally.

A meter reading of full source voltage represents all of the available voltage being dropped. This could be due to an open wire, or it may be a “normal” load that happens to be the only load in the circuit.

CURRENT

The third measurement that can be useful in electric forklift diagnostics is the measurement of current, or of how many electrons are flowing. Current is measured in amperes, or amps for short. Like the voltage drop test, an advantage of measuring current is that the circuit will be performing its function, making this a “real world” test.

The technician must first determine what current or amperage draw is normal for the component or circuit he or she is working on. Current specifications for even common circuits can be hard to come by. If specifications are not known they can sometimes be found printed on the component as on a coil or motor. You can also compare to a known good component.

The second drawback to testing current during electric forklift diagnostics is in that the meter must be installed in series with the circuit you are testing. Since current measurements are actually measuring how many electrons are flowing in the circuit, all of the electrons in the circuit must pass through the meter. This means that the meter must become part of the circuit. An ammeter must be installed in series with the circuit, at a location where the maximum current within the circuit will flow through the meter. This involves opening the circuit up and connecting the meter leads in series with the circuit.

There are a number of good locations for opening up a circuit up to install the meter while performing electric forklift diagnostics, with the most popular, and often the easiest, being at a circuit fuse. This is done by removing the fuse and installing the meter leads on either side of the fuse connectors.

The third drawback to using current as a diagnostic tool is that you may not know how much current is flowing before you install your meter. The current flowing is often more than what your meter can handle. Although a quality meter is fused, often these fuses will blow when trying to measure current because the circuit being tested uses higher current than what your meter is designed for.

To get around these last two drawbacks, technicians will use an “amp clamp” or an inductive ammeter for electric forklift diagnostics. This device uses the electromagnetic field that forms when electricity flows through a conductor in order to determine how much current is flowing in a circuit.

Amp clamps have two significant advantages: firstly the circuit does not have to be opened up to install the ammeter, and secondly the amount of current flowing in the circuit cannot damage the meter. The disadvantage is that you must purchase an amp clamp that measures the range of current you expect to find. It is not possible to purchase a single clamp that will measure all current ranges.

With these basics, a good Multi-meter, and a wiring diagram or schematic the technician can navigate circuits to determine where voltages or currents exist in there correct specifications. Before replacing components a good mechanic will assure that all necessary wiring and circuitry is in place that could cause component to fail.

Post by Intella Parts Company, LLC