The world’s energy diet is changing. Significant government investments and policies focused on green energy solutions has seen the global battery market increase significantly in recent years. In fact, it’s expected to continue growing at an annual rate of 14 per cent between 2020 and 2027. The safety of lithium batteries has always raised concerns amongst end-users. Unfortunately, we are hearing of more and more cases of accidents caused by exploding lithium batteries, which suddenly set on fire while they were being used or during charging.
Using a lithium-ion battery to power a lift truck has many advantages in the right application, We're also getting more and more inquiries about lithium-ion replacement lead-acid battery options, and for good reason. Lithium-ion batteries allow opportunistic charging, require less maintenance, and provide longer runtime between charges, so they have proven popular in many industries.
The Boeing case, which happened in 2013, (Focus wrote about it here and also CNN) , is one of the most famous ones, what must the cost have been to Boeing in terms of its image and the expense of grounding the 50 incriminated Boeing 787s???
You have probably also heard about many other cases of lithium batteries exploding and setting on fire, from Tesla cars to electric coaches, and even electric scooters that resulted in entire homes burning down, unfortunately leading to several deaths.
Why did this happen?
Who is responsible for these disasters?
Do you want to avoid the possibility of your machinery and your brand image being marred by these accidents?
In this article, we reveal the 3 key factors for the safety of lithium batteries:
● Choosing the right chemical structure of lithium batteries
● The type of assembly of lithium accumulators
● The electronics controlling a lithium battery
Lithium accumulators come with hundreds of different chemical structures, but there are 3 main ones:
● Lithium NMC – Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)
● Lithium NCA – Lithium Nickel Cobalt Aluminium Oxide (LiNiCoAIO2)
● Lithium LFP – Lithium Iron Phosphate (LiFePO4)
Our aim is to identify the safest lithium chemical structure for your vehicle in order to prevent unnecessary hazards when using lithium batteries.
Today’s market for industrial batteries has grown dramatically through innovation and the adoption of new technologies, such as multiple types of new-generation lithium batteries, hydrogen fuel cells, and new variations of the older lead-acid batteries. It is increasingly hard to make the right choice, given the variety of equipment types, makes, and models designed for a specific application and a specific work environment and operation pace.
The BSLBATT Battery engineering team zeroed in on lithium LFP cells as the best choice for industrial lithium batteries powering material-handling equipment and off-highway EVs (Class I, II, and III electric lift trucks; tugs; personnel and burden carriers; sweepers; scrubbers; and aerial platforms). We use LFP lithium cells in BSLBATT batteries, which
● Provide the best equipment performance;
● Satisfy the requirements of high-power, demanding applications;
● Exhibit the longest cycle life of a battery;
● Ensure the top safety level of operation and reduce operation maintenance costs.
As stated above, LFP chemistry is the optimal choice for material handling equipment batteries, and here’s why.
Of all the various types of lithium-ion batteries, three cell chemistry types emerge as widely used in on- and off-highway electric vehicles: lithium ferrophosphate, or lithium iron phosphate (LFP), lithium nickel manganese cobalt oxide (NMC), and lithium nickel cobalt aluminum oxide (NCA).
All batteries degrade with usage, decreasing their Ah capacity with each charge/discharge cycle. In material handling, batteries usually become unusable when they drop below 80% of their nominal capacity.
A battery’s longevity, or its cycle life, depends on three main factors:
● Chemical composition of cathode materials;
● Ambient temperature of operation;
● Depth of discharge.
The graph below shows the results of recent independent degradation tests of the three types of cells with different chemistry, under equal conditions of temperature and depth of discharge.
One “equivalent full cycle” is the sum of charge/discharge events that add up to one full (zero to 100%) charge and one full (to zero) discharge of a battery.
LFP lithium batteries exhibit superior performance compared to NMC—they offer a longer lifespan and are generally less expensive.
“The LFP cells exhibit substantially longer cycle life spans under the examined conditions.”（Source onecharge battery, if there is any objection, please contact in time）
Lithium nickel cobalt aluminum oxide (NCA) batteries performed similarly to or worse than NMC.
The tests were performed at Sandia National Laboratories as “part of a broader effort to determine and characterize the safety and reliability of commercial Li-ion cells.”
Apart from longer cycle life, LFP wins on safety, with better stability and a higher thermal run-away temperature threshold (roughly 420°F for NMC and 520°F for LFP).
NMC chemistry is higher on specific energy, which means NMC cells have higher energy density than LFP. This is important for electronics and electric vehicles, where battery weight is a decisive factor (the lighter the better). On the other hand, industrial batteries for material handling applications are often engineered as a counter-weight (the heavier the better).
The assembly is another fundamental issue for ensuring the intrinsic safety of the battery, and more specifically, the number of parallel cells inside the pack is a key element. We already looked at this concept in our article describing the different types of lithium cells.
Staying in the world of lithium batteries for electric vehicles and industrial machinery , the demand here is for generally high capacities ranging from 100Ah to in excess of 2000Ah.
Earlier, in the video, we saw how a single lithium-LFP battery cell remains safe even in case of an internal short circuit.
Many manufacturers of lithium batteries assemble battery packs consisting of small cells and as a result they have to fit a larger number of cells in parallel.
Take a 600Ah battery, for example.
If this is made up of 3Ah cylindrical cells, you will need 200 cells in parallel, but if it is made up of 100Ah prismatic cells, you will need 8 cells in parallel.
What happens if one of these 8 or 200 cells short-circuits?
The lithium cell that short-circuits will have to absorb all the energy for the entire parallel string, i.e. 8 or 200 times its capacity.
As a result, the cell temperature will increase exponentially, endangering the safety of the entire battery or the entire vehicle.
Our laboratories have simulated and tested these safety issues and came to one conclusion: BSLBATT Battery consist of maximum 8 cells in parallel in order to guarantee their safety in any situation.
The third and last aspect for guaranteeing the safety of the internal lithium battery pack concerns the electronics controlling the battery: the battery’s brain. Over the coming months, we will publish an article about the BMS, its features and its functions. For now, we are simply going to describe its safety features.
The main job of the electronics is to monitor the voltage and temperature of the individual cells.
It also has to interact with the vehicle and battery charger in order to stop it charging and discharging if a critical situation occurs, tripping the general remote contactors, if necessary.
The difference between manufacturers of lithium batteries lies in how the control electronics work in hazardous situations.
Traditional systems monitor the temperature every 3-4 cells and not always at the right point.
For batteries used in cars, there are regular reports of malfunctions and even fires. Different rules apply to industrial trucks. Even in everyday operation without accidents, the possible mechanical strain is considerably higher than in the car. The batteries in BSLBATT are therefore designed in such a way that the batteries are not destroyed or damaged even in the event of an accident. Thanks to a multi-stage safety system, BSLBATT lithium-ion batteries protect cells and modules as well as the entire battery. For example, BSLBATT uses a different cathode and anode material than the manufacturers of automotive batteries. This material is thermally much more stable. A solid steel trough also protects the battery body in the event of an accident.
Now let’s discuss safety and hazard issues with lead acid batteries in your forklift. Li-ion batteries will not corrode battery trays and other nearby parts of your equipment that can lead to voided manufacturer warranties and malfunctioning electrical equipment. And since there is NO GASSING during the charging process with a Li-ion battery, the release of toxic gases and spilling acid are eliminated!
Finally, multi-shift operations that use lead acid batteries typically involve multiple batteries for each lift. The constant changing of batteries leads to extra wear and tear on the battery and the lift, as well as a greater risk of harm to employees. Once a Li-Ion battery is installed, the days of changing batteries to get through shifts are completely eliminated.
Choose a BSLBATT Li-ion battery and rest assured knowing that safety is built-in!
With more than 100.000 batteries around the world, BSLBATT Battery is setting important records and has never reported any safety issues with its products. This is why they are chosen by multinationals where avoiding fire risks is vital, such as paper mills.
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