When our customers approach us about battery reliability, the most pressing question is always, “How do we prevent catastrophic battery failures?” While the rate of field failures is statistically low at only 1 to 10 ppm, the impact of battery failures has often been severe in recent years. Higher energy densities, and the use of lithium ion batteries closer to the human body are to blame for the severity of impact.
In my conversations with product engineers and designers, I often come across people who feel confident that their lithium-ion batteries are safe because they passed standards-based safety tests. If that is indeed the case, then why did major global companies experience thermal events even after having passed compliance tests? And that brings up a bigger question – are standards-based tests such as UL safety tests sufficient to guarantee lithium-ion battery safety?
The race to improve the performance and reliability of batteries is on, from electric vehicles to advances in wearables and mobile devices. In the pursuit of performance and the desire to outpace competitors, manufacturers may be tempted to overlook potential shortfalls. Most notably, Samsung made news when the company halted production of its Galaxy Note 7 and eventually scrapped the entire product after devices caught fire.
In part 1 of this 3-part blog series, we discussed the most important metrics for battery selection. One thing to remember about battery selection is that it is essentially about managing tradeoffs. You trade off some battery metrics in order to gain in others – for example in order to gain power density, you may have to trade off energy density.