Lithium ion batteries may be the technology of choice for electrified cars, but lead-acid batteries still have a big role to play.
Johnson Controls is betting that automakers will pair its absorbent glass mat batteries, which are more durable than conventional lead-acid batteries, with stop-start systems.
Many automakers plan to introduce 48-volt systems to optimize their stop-start systems, regenerative brakes and other fuel efficient technologies.
Tom Watson, JCI's vice president of powertrain systems, said Tuesday at the CAR Management Briefing Seminars that 13 to 18 percent of vehicles sold in 2025 will have 48-volt electrical systems.
"Forty-eight volts will be a pillar of our strategy," Watson said. "We see a big opportunity in that space."
Forty-eight-volt systems typically feature a 12-volt starter battery plus a small lithium ion battery to handle the demands of regenerative brakes and stop-start systems.
Watson expects automakers to adopt these technologies as they improve the efficiency of their internal combustion engines.
While absorbent glass mat batteries cost twice as much as conventional lead acid batteries, they are durable enough to restart a vehicle's engine many times a day as it idles at red lights.
They can also power a vehicle's accessories while the engine is off.
And because a 48-volt system typically costs $1,000 to $1,200 — significantly less than a full hybrid powertrain — it can be cheap enough for mass-market vehicles.
So there is a big potential market for absorbent glass mat batteries, and Johnson Controls is betting heavily on this scenario. Last year, the company announced plans to spend $780 million by 2020 to expand global production of absorbent glass mat batteries.
The company's plant in Holland, Mich., produces some lithium ion batteries, but JCI has avoided big investments in lithium ion at a time when the world's EV battery plants are operating at 50 to 60 percent of capacity.
Watson said Johnson Controls will decide whether to invest in lithium ion batteries when demand for electric vehicles picks up.