Notebook battery maker gets charged up for cars

The lithium-ion battery maker has raised $45 million in a third round of funding. It also has signed its second contract manufacturing deal, an agreement with China's GP Batteries, which will give it the capacity to churn out a million batteries a month by the end of 2008. In all, Boston-Power has raised more than $68 million in funding.

Hewlett-Packard plans to release a notebook sporting one of Boston's Sonata batteries this year, and other large computer makers are currently in the final testing phases with the Sonata, Boston-Power CEO Christina Lampe-Onnerud said in an interview. (Last year, HP was still testing the battery.)

Boston-Power also has hatched plans to move into making large format lithium-ion batteries that could be used in plug-in hybrid cars. The current Sonata batteries for notebooks are based on small format cells, and each cell provides about 4.4 amp hours of power. Conventional notebook batteries provide about 2.6 amp hours. (Amp hours measure how much power a battery can store.)

Plug-in hybrids require batteries with cells that can provide 5 to 10 amp hours. Boston Power, in its labs, has come up with batteries that get into this range, but they are still in the experimental stage. (A battery for a plug-in will also contain far more cells than a typical six- to nine-cell notebook battery.)

"We have solved a fundamental problem for large cells," Lampe-Onnerud said. "We will take the same time to make sure it is fine-tuned for the appropriate market."

Boston-Power is one of a number of relatively new companies trying to improve the humble battery, particularly the now familiar lithium-ion ones. A favorite of notebook makers and consumer electronics manufacturers, lithium-ion batteries can hold more energy than competing types of batteries.

Unfortunately, they also come with a glaring side effect. They can short on occasion, resulting in a "runaway thermal reaction" in industry parlance. In layman's terms, that's a fire or an explosion. Recalls in 2006 cost Sony millions of dollars.

Some companies have tinkered with the internal chemistry of the batteries. Notebooks contain lithium cobalt batteries. Altair Nanotechnologies and EnerDel have devised lithium titanate batteries, while others have come up with lithium potassium batteries. The change in chemistry lowers the risk of explosions, but also lowers the energy density. Lower energy density directly leads to lower mileage or runtime on laptops. Others are looking at getting rid of lithium altogether and switching to a rechargeable zinc battery.

By contrast, Boston-Power has largely kept the internal chemistry the same and instead fine-tuned the other elements that make up a battery. (Lampe-Onnerud and other members of the Boston-Power executive team have worked in the lithium-ion industry for years.) The can, or outside casing around the battery cells, on the Sonata is made from a metal alloy that is stronger than the iron cans used with conventional notebook batteries and, thus, will remain intact in the case of a thermal reaction or fire, according to the company.

Boston-Power also spent a lot of time on the interrupt system, which prompts the battery to shut down permanently if there is danger of a thermal reaction. The company can't guarantee the batteries will never have problems, but it has added safety features not seen in ordinary batteries.

In addition, Boston-Power works closely with its contract manufacturers, Lampe-Onnerud said, and has developed a process monitoring system that collects more accurate data about each battery as it goes through manufacturing and assembly.

"Some factories still use very, very rudimental quality measures," she said.

At the same time, the Sonata will outperform conventional batteries, the company said. It will recharge from depleted to 80 percent capacity in about 30 minutes. The Sonata also will provide like-new performance for three years, according to the company. Most notebook batteries begin to degrade after three to six months.

And runtime? Lampe-Onnerud said she gets four hours out of the conventionally sized Sonata plugged into her notebook on a regular basis in ordinary conditions. The power meters on most notebooks say they get four hours, but in reality the runtime is shorter than that.

There is a catch, however. The Sonata will sell at a premium. Notebook makers always try to minimize component costs. Manufacturers also tend to be skittish when it comes to trying out products from start-ups.