Johnson Controls unveils new start-stop battery system

  • 12-Jan-2015 08:49 EST
12 Volt Li-ion Battery-1.jpg

Johnson Controls' next-generation start-stop battery system will use a lithium-titanate battery as well as a lead acid battery. (Image shows the supplier's current 12-volt lithium-ion battery.)

An advanced start-stop system using two different battery chemistries is now in the prototype phase, Johnson Controls officials announced during media days at the 2015 North American International Auto Show.

Most conventional start-stop systems use a single lead-acid battery, typically a 12-volt absorbent glass mat (AGM) battery or an enhanced flooded battery (EFB). But a dual-battery design can provide a bigger performance payback for micro-hybrid electric vehicles.

The breakthrough with Johnson Controls’ two battery system is the combination of reliable start-stop performance from an existing technology, like AGM or EFB, and a significant increase in charging performance from a lithium-titanate battery, according to Craig Rigby, Advanced Market Technology Strategist for Johnson Controls Power Solutions.

“This dual battery start-stop system enables both an increase in fuel economy and a reduction in greenhouse gas creation because capturing energy from braking events will allow the engine to stay off for longer periods.

“We believe this will lead to an additional fuel efficiency gain of 3 to 5% when compared to existing start-stop systems. This is the same as an up to 8% gain over baseline non-start-stop vehicles,” Rigby said in an Automotive Engineering interview.

Johnson Controls and Toshiba are collaborating on the lithium-titanate cell design. “Lithium titanate is used in production automotive applications today, including 12-volt start-stop applications in Japan,” said Rigby, adding that the lithium-titanate chemistry is effective for fast recharging under a wide range of temperatures.  

The specific roles of the lithium-titanate and lead-acid batteries in the Johnson Controls’ advanced start-stop system will depend on an automaker’s vehicle implementation strategy.

“Generally, the lead-acid EFB or AGM battery will be responsible for starting the engine and supporting electrical loads (such as headlamps, navigation, and audio) after the key has been turned off. The lithium-titanate battery, on the other hand, will perform functions that require high power, like capturing electrical energy from vehicle deceleration (i.e., brake regeneration), something that is challenging for traditional battery technologies,” said Rigby.

The lithium-titanate battery will be in a hard case, prismatic shape. Overall package size for the dual battery configuration is approximately 7.4 in (190 mm) high, 9.4 in (240 mm) long, and 3.5 in (90 mm) wide. 

Start of production for Johnson Controls’ next-generation advanced start-stop system is expected in 2018. 

“We are in the prototype phase right now and are evaluating the design against several sets of customer requirements,” said Rigby, “We are also testing the battery system in our own test vehicles that we’ve modified to include the advanced start-stop function.”

HTML for Linking to Page
Page URL
Rate It
4.64 Avg. Rating

Read More Articles On

Chinese planners are focusing on NEVs to become a mainstay of its future automotive production and consumption. Although there’s overcapacity throughout China’s automotive supply chain as the economy slows down, a number of new companies are expected to enter the NEV market.
As President and CEO of the Center for Automotive Research (CAR) in Ann Arbor, Dr. Baron and his research teams are engaged with technology issues across a broad front, but even a brief conversation with him reveals his deep passion for plants, advanced processes and materials. Get him talking about Lightweighting and he won’t stop.
What does it cost to replace an EV battery at the retail level? For a BMW i3 a new battery will set owners back about $16,000, according to Dr. Christian Cozzarini, BMW Department Head, Environmental Engineering, who spoke at the 2016 CAR Management Briefing Seminars.
Raising the octane level of pump gasoline in the U.S. is integral to optimizing advanced combustion engines now in development, said GM and Honda executives at the 2016 CAR Management Briefing Seminars in Traverse City, MI. Their comments prompted positive but non-committal comments from Chris Grundler, Director of the Office of Transportation and Air Quality for the U.S. EPA.

Related Items

Training / Education