When deploying automated guided vehicles (AGVs), autonomous mobile robots (AMRs) and forklifts in warehouses and factories, the choice of battery has a major impact on your return on investment. One factor that is easily overlooked is charging time. This article explains why short charging times translate directly into higher uptime, and why a lithium titanate (LTO) battery is the ideal power source for an AGV fleet.
To put the conclusion first: a lithium titanate (LTO) battery combines fast charging, long cycle life, a wide usable state of charge, strong low-temperature performance and high safety. Together, these properties make effortless opportunity charging possible — exactly what an AGV needs. The value of an AGV deployment is decided not only by the performance of a single vehicle, but by how continuously the entire fleet keeps moving. Short charging times raise uptime directly, and an operation built around opportunity charging lowers the total cost of ownership of your warehouse or factory by reducing the number of robots and chargers and the floor space they occupy.
1. Fast charging determines AGV uptime
An AGV creates value only while it is moving. Every minute it stands still to charge is a direct loss of productivity, which makes the ratio between charging time and operating time critically important.
Let’s look at concrete numbers. With a conventional lithium-ion battery that runs for 15 hours after a 3-hour charge, 15 hours of every 18-hour cycle are productive — an uptime of about 83%. With a fast-charging battery that runs for 3 hours after only a 5-minute charge, 3 hours of every 3-hour-and-5-minute cycle are productive — an uptime of about 97%. For the very same number of vehicles, charging speed alone creates a gap of roughly 14 percentage points.
| Conventional battery | Fast-charging battery | |
| Charging time | 3 hours | 5 minutes |
| Operating time | 15 hours | 3 hours |
| Uptime | 83% | 97% |
Table 1: How fast-charging performance affects uptime
This difference goes far beyond per-vehicle efficiency. Higher uptime means the same transport volume can be handled by fewer vehicles, letting you cut back on waiting robots, chargers and charging space all at once. Charging time is a factor that shapes the design of the entire fleet.
2. Opportunity charging: topping up in the gaps
The operating model that makes the most of short charging times is opportunity charging (German: Gelegenheitsladen). Instead of waiting until a battery is empty and then charging it for a long time, opportunity charging tops the battery up frequently during natural pauses — between tasks, during breaks and at shift changes. Whether or not you can rely on opportunity charging changes the entire operational design. Once charging shifts from “a dedicated task that needs a reserved block of time” to “something that happens naturally in the gaps,” you can minimise both the robots queuing to charge and the dedicated charging area. In fact, operations built around opportunity charging have become a standard approach in European logistics, including Germany.
Figure 1: The concept of opportunity charging
Conventional batteries, however, were poorly suited to this model. Lead-acid batteries take a long time to charge fully, require a cool-down period afterwards and a dedicated charging room, and tend to spend long periods out of service. They also have a weakness: repeated partial charging in a partial state of charge accelerates their degradation. Ordinary lithium-ion batteries handle opportunity charging better than lead-acid, but repeated high-rate fast charging still raises concerns about heat generation and wear.
3. Why lithium titanate (LTO) batteries are ideal for opportunity charging
Industrial lithium-ion batteries with a lithium titanate (LTO) anode offer many characteristics that lead-acid and ordinary lithium batteries lack.
As an example of an LTO battery, let’s now look at the specific cell characteristics of the Toshiba SCiB™ and why it makes effortless opportunity charging possible.
Fast charging: over 80% in 6 minutes
The SCiB™ charges to more than 80% in just 6 minutes [1]. Even the brief moments between tasks or during breaks are enough to secure a practical amount of charge, delivering both high uptime and an operating model ideally suited to opportunity charging.
Long cycle life: more than 20,000 cycles
Its cycle life exceeds 20,000 charge/discharge cycles [1]. Opportunity charging means topping up many times a day, yet the SCiB™ shows little degradation even under frequent partial charging and retains its capacity over the long term.
Wide usable state of charge (SOC): 0–100%
The SCiB™ can use the full state-of-charge (SOC) range from 0 to 100% [1]. Whereas ordinary lithium-ion batteries reserve part of their capacity as a safety margin, the SCiB™ lets you use the installed capacity to the fullest — so the same capacity can be packaged in a smaller, lighter, more energy-dense design.
Low-temperature performance and battery safety
The SCiB™ can charge and discharge even at temperatures as low as −30 °C [1], staying stable in freezer and cold-storage warehouses. In addition, if an internal short circuit occurs, the LTO material itself undergoes a phase transition to an insulator, suppressing sudden short-circuit currents and heat — so there is essentially no risk of fire or thermal runaway [3]. In 24/7 operations with frequent charge/discharge cycles, this level of battery safety brings real peace of mind.
For full SCiB™ specifications, see the, see the Toshiba SCiB™ LTO battery product page.
4. Fleet-level benefits: fewer robots, fewer chargers, more space
The benefits of shorter charging times and opportunity charging are not limited to higher uptime. Across the whole fleet, you can achieve three reductions at once:
- Higher uptime lets you handle the same transport volume with fewer vehicles — reducing both the number of robots you need and the queues waiting to charge.
- When each vehicle charges in less time, a single charger can be shared among more vehicles, reducing the number of chargers required.
- With dedicated charging space and waiting queues no longer needed, that floor area can be redirected to storage and transport.
Figure 2: The benefits of adopting an LTO battery
5. Conclusion
The value of an AGV deployment is decided not only by the performance of a single vehicle, but by how continuously the entire fleet keeps moving. With fast charging, long cycle life, a wide usable SOC, strong low-temperature performance and high safety, a lithium titanate (LTO) battery effortlessly supports opportunity charging — making it the ideal battery for AGVs. If you want to maximise the value of your AGV deployment, choosing the right battery is a decisive first step.
You can see product details about Toshiba SCiB™ specifications here. If you have any questions about specifications or deployment, please feel free to contact us.
Contact
Please feel free to contact us about LTO Battery (SCiB).
Product information
Further specifications and product information are available on the product page.