Stryten Energy is developing a solution for military use that will have 42% more energy, 10x the cycle life, and 1/3 the weight of other options. That still does not take into account engine starting reserve capacity. For lead batteries, there may or may not be enough charge left to start an engine, especially if it is an older battery or starting at cold temps.
The Smart Battery System
As discussed earlier in this series, the lithium-ion battery system is a smart system due to the electronics required to make it safe. This intelligence has the advantage of being able to interrogate the battery to determine the state of charge (SOC) and allows the battery to communicate to the vehicle regarding charging requirements. It also allows the operator to know when the battery is running low and needs a recharge, or if there is a potential problem with the battery.
The United States military aims to enhance Silent Watch capabilities by increasing the number of lithium 6T batteries used by each vehicle. This approach would also standardize to a common battery across vehicles, which would increase efficiency with regard to supply and cost.
On a larger vehicle, four lithium batteries would provide 220 to 300 Ah, which is significantly more than lead. Using a Silent Watch load of 60A would drain those batteries in 100 minutes. Using a system of lithium 6T batteries may be fine for many vehicle variants, but longer Silent Watch time or higher current loads would require more 6T batteries, which could be impractical in the field.
The Stryten Energy Solution
The Stryten integrated battery solution for military vehicles includes use of a dual system, with a set of batteries to start the vehicle and provide higher power loads and a second set of batteries to provide the lower power Silent Watch. With this method, optimal technology can be used and a deeper depth of discharge can be attained. Most lithium 6T batteries are optimized for starting, meaning they use a power cell. Silent Watch is not a power requirement, but an energy requirement. Using energy cells that have higher energy but less instantaneous power improves the energy density and therefore gives longer Silent Watch time in the same space and with less weight.
Following is a comparison of the amount of battery charge remaining while running a moderate 60A load with standard lead batteries (two 12V in series), Stryten Energy’s Symbasys i6T and a Stryten Energy Symbasys SwatPack which is an optimized “Silent Watch only” battery.
Discharging below 50 percent is not recommended for a lead battery, as doing so can significantly reduce its lifespan. Longer Silent Watch times can be attained with less weight and space using the Symbasys SwatPack, which can also be expanded to deliver as much time as a mission requires.
Energy requirements are constantly changing for military vehicles, and battery solutions must be able to keep up with this very specialized market. Program managers are considering newer technologies such as lithium-ion batteries to solve multiple problems at once. A true Silent Watch solution must provide increased run time, improved survivability, reduced fuel consumption, and lower maintenance, at a lighter weight. In short, smart batteries help make smarter vehicles, and Stryten Energy stands ready to equip tomorrow’s military vehicles with the best possible solutions.
Read more about power solutions for military applications: