Scan the horizon of the battery technology market today. You'll see prominent technological landmarks familiar to everyone from the medical device designer to the commercial-off-the-shelf customer. Battery performance, as it relates to runtime and capacity, guides all of our journeys in search of market advantage. Such issues as weight, safety and cost -- though obviously standard factors in design and manufacture -- remain in a secondary position.
Numerous battery chemistries can be found on that horizon as well, from conventional lithium-ion to lithium-iron-phosphate to high-rate lithium-polymer. For a significant number of people in the industry, those many chemistries have created a sense of disorientation. Which chemistry will serve my product best? Which will help me gain market leadership? In a recent survey conducted by Nexergy, Inc., about a third of the design engineers and marketers interviewed were unable to identify their choice for their next portable power solution.
A desire for optimal battery performance and a knowledge gap regarding chemistries exist side by side in a market in which the majority of engineers consider battery pack performance as a key competitive advantage for products. Greater market education is an obvious long-term solution. Possibly less obvious is the design engineers' understanding that partnering with seasoned experts can help ensure competitive advantage today and in the future.
When the customer "walks through the door," the typical discussion begins with the topics of runtime, cycle life, and power. Engineers and designers are indeed confident that the better battery pack can create a competitive advantage for their products -- but they may not know how to create that pack. For those engineers and designers, application-specific information becomes critical. Many questions need to be answered, including:
How long must the device run between full charges?
How much space and weight can be allocated to the power source?
What is the load consumption of the device during operation or standby if typical applications include long periods of inactivity between uses?
What are the minimum and maximum values for supply voltage?
What is the pack output needed to meet the product's peak load or continuous current requirements?
What is the acceptable battery life in the typical usage scenario?
With applications requiring a smart battery, optimal performance will also depend on the selection of the most appropriate gas-gauging technology and protection circuitry as well as the designing of the correct charge circuit, regardless of whether it is internal or external to the pack. Feedback from our study confirmed that the industry is coming to appreciate these aspects of the design challenge. Ensuring that the gas gauge is accurate, or that the charge or discharge cycles don't terminate prematurely or that the pack is not abusively charged or over-discharged affects realized capacity, safety and cycle life.