The U.S. Army has developed a smart controller to charge car batteries with solar energy/extend the life of the battery by 3-5 times

According to foreign media reports, the US Army recently submitted a patent application. Researchers Ernest Luoto, Brian Frymiare and David Carrier have developed an intelligent controller that can control the distribution of power from solar panels to batteries, thereby preventing thousands of car batteries in parking lots from slowly failing. It is expected that this technology can save customers millions of dollars.

(Image credit: U.S. Army)

The U.S. Army has a large fleet of tens of thousands of wheeled combat vehicles deployed at military bases around the world. 75% of these multi-purpose wheeled vehicles (Humvees), mine-resistant ambush-protected vehicles (MRAPs), light medium tactical vehicles (LMTVs), and 5-ton trucks travel less than 3,000 miles per year. Since these trucks spend most of their time in parking lots, their lead-acid batteries slowly drain and degrade. In order to keep these trucks ready at all times, the U.S. Army needs to spend $26 million per year to replace the batteries.

The researchers said: "Data from the latest Army Sample Data Collection and Analysis (SDC&A) report shows that combat vehicle batteries need to be replaced on average every 13 months, but the minimum expected life of the battery is three years, and if properly maintained, the battery life can be expected to reach approximately 6 to 8 years." If solar energy is used to charge the battery, the life of the vehicle battery can be extended by 3 to 5 times, saving the Army $17 million each year.

However, modern military trucks are equipped with powerful radios and other electronic systems powered by 12V and 24V batteries connected in series and parallel. For example, some trucks require four large 120-amp batteries to output 12V and 24V power, but the battery packs on the vehicle have different loads, which will cause voltage imbalance.

Research has shown that a 1V difference between two 12V battery wires is not uncommon, but a 1V difference can make a huge difference between a battery being 100% charged or about 20% charged, which limits the use of solar chargers.

So the researchers developed a pulse-width modulation controller that can turn the solar panels on or off, moving the charge between the different batteries every hour while preventing the batteries from sulfating and overcharging.