Johnson Controls Forecasts Enormous Stop-Start Growth

John Petersen

On June 27th Johnson Controls (JCI) hosted their 2011 Power Solutions Analyst Day and unveiled their expectations for the future of stop-start idle elimination systems. After noting that all automakers are developing a range of powertrains, JCI used this graph to emphasize their view that the overwhelming bulk of alternative powertrain vehicles over the next five years will have simple, cost effective and fuel efficient stop-start systems.

You don’t see much about stop-start systems in the mainstream media because politicians and reporters are too enchanted with plug-in vehicles and other exotica to deal with mundane issues like purchase prices and payback periods, but JCI has made it crystal clear that its meat and potatos business over the next five years will be cheap, not cool.

JCI’s estimates for market growth over the next ten years were equally impressive, particularly when you realize that the advanced energy storage systems required for stop-start generate twice the per unit revenue and three times the per unit margins of flooded lead-acid batteries. It’s a manufacturer’s dream come true, stable unit volumes with rapidly increasing revenues and margins.

In their presentation JCI explained that the three key attributes of energy storage systems for stop-start are:

• Cycling – reliable system charge/recharge cycles over time;
• Useable energy – range of stored energy that can be used to optimize the system; and
• Charge acceptance – rate of recharge to maximize opportunity capture.

It ties perfectly to a joint presentation from BMW and Ford at last fall’s European Lead Battery Conference where the two automakers explained why the stop-start duty cycle is so hard on conventional batteries. In a normal vehicle, you start the engine at the beginning of the trip and turn it off at the end. In a car equipped with stop-start, the engine turns itself off automatically every time the car is stopped and restarts automatically when the driver takes his foot off the brake. While the difference between one start per trip and one start per mile is enormous, a more critical problem arises from the fact that stop-start systems require the battery to carry all accessory loads during frequent engine off intervals.

In the segment of the BMW-Ford presentation that quantified a typical stop-start duty cycle, the accessory load was 50 amps for 60 seconds, or about 3,000 amp seconds while the starter load was 300 amps for one second. In other words, the accessories accounted for a whopping 91% of total load. Their graph of AGM battery performance over time shows that charge acceptance (the downward curving blue line) plummets as the battery ages while the time required to recover from an engine off event (the upward curving red line) soars from 30 seconds to three minutes or more.

Since all systems are designed to disable the stop-start functionality until the battery has recovered an acceptable state of charge, system efficiency falls off rapidly as the battery ages. The automakers want and need something better than AGM batteries, the principal solution that old line auto battery manufacturers like JCI want to provide.

The first advanced technology introduced for stop-start systems was developed by Continental AG in cooperation with Maxwell Technologies (MXWL) for use in diesel stop-start systems from Peugeot. In this dual device configuration an AGM battery carries the accessory load and a supercapacitor module carries most of the starter load. It insures a reliable engine restart, but can’t do much about the bigger problem of accessory loads. Contiental and Maxwell expect that their system will be installed in up to a million Peugeot vehicles in the next three years. If the system works well for Peugeot and stop-start vehicle sales ramp as rapidly as JCI expects them to, implementation rates will probably be higher.

A second advanced technology solution for stop-start systems is a third generation lead-acid-carbon hybrid that’s being developed by Axion Power International (AXPW.OB), which hopes to begin a commercial roll-out of its PbC battery later this year. In a joint presentation by BMW and Axion at last fall’s ELBC, the performance differences were obvious. The graph that tracked PbC’s performance over time using the BMW-Ford test protocol showed that charge acceptance (the flat blue line) stayed stable at 100 amps, or twice the charge acceptance of a new AGM battery, while recovery times (the flat black line) remained stable at 30 seconds.

The BMW-Ford graph shows that AGM batteries fade very rapidly over the first 5,000 miles of use in a stop-start equipped vehicle. The BMW-Axion graph shows that the PbC offers optimal performance through 40,000 miles. In a recent presentation at the 2011 Advanced Automotive Battery Conference in Mainz, Germany, Axion unveiled an updated graph of follow-on testing through 80,000 cycles, or approximately eight years of use, with only modest degradation.

I’ve been bullish about the future of stop-start idle elimination technology for a couple years. If the JCI forecasts are even close to accurate, I’ve been seriously understating the potential. Since JCI is the largest lead-acid battery manufacturer in the world and has a 36% share of the global automotive OEM and battery replacement markets, it will undoubtedly be the biggest beneficiary of the rapid worldwide implementation of stop-start idle elimination systems. The second biggest beneficiary will probably be Exide Technologies (XIDE), which is emerging from several years of tough restructuring and trades at a significant discount to JCI on a forward looking earnings basis. Emerging technology developers like Maxwell and Axion also have significant opportunities to grab a sizeable share of what’s shaping up as $6 to $12 billion market niche. Their respective market capitalizations are summarized below:

As former Axion director, I’m all too aware that it’s a very little fish in a very big pond. I also understand why the PbC’s extreme cycling performance and charge acceptance can be crucial to the future development of stop-start, a world-class fuel efficiency technology that’s already being produced at scale and will become dominant in this decade. It’s easy to dismiss my ramblings because I have a large stake in Axion. It’s harder to dismiss BMW, a first tier automaker that joined Axion as a co-presenter at last year’s ELBC. It will be darned near impossible to dismiss a big three US automaker that’s apparently signed on as an Axion subcontractor in a pending DOE grant application.

Disclosure: Author is a former director of Axion Power International (AXPW.OB) and holds a substantial long position in its common stock.