Keep Hackers’ Hands Off Your Battery Packs

March 5, 2020

Norberto Sanchez-Dichi  By: Norberto Sanchez-Dichi
 Member of the Technical Staff, Applications; Maxim Integrated 


In today's world of battery-powered electronics, one of the issues facing OEM manufacturers and customers alike is counterfeit products. Aside from lost revenue by manufacturers and disappointing product quality experienced by customers, counterfeit products—especially counterfeit batteries—can be a safety hazard when improperly recharged due to the array of unique cell chemistries in the market.

With battery authentication, you can avoid this scenario by verifying that your portable device connects to a proper battery. What's more, with battery fuel gauging that provides state-of-charge (SOC) information that compensates for cell aging, temperature, and discharge rate, an OEM manufacturer and their customers can always be sure to know that the right battery is powering their portable devices.

By using the MAX17211EVKIT, you can go through the process of setting up symmetric authentication using the SHA-256 engine. Watch my seven-minute video to learn how symmetric authentication works. I'll show you how to generate a 160-bit secret key using the MAX17211EVKIT software's random generator and how to provide a randomized challenge to verify the message authentication code (MAC) generated by the MAX17211 authenticator and the software. The MAX17211 provides a stand-alone ModelGauge m5 fuel gauge with SHA-256 authentication. The ModelGauge m5 algorithm brings together the short-term accuracy and linearity of a coulomb counter with the long-term stability of a voltage-based fuel gauge, plus temperature compensation. The result is industry-leading fuel gauge accuracy.

After watching this video, you'll have an understanding of how important and how easy it is to ensure that only an authentic battery can power a portable device.

P.S. In case you're interested, Maxim has newer fuel gauge ICs with authentication available. For example, the MAX17301MAX17303 and MAX17311MAX17313 are 24µA IQ stand-alone pack-side fuel gauge ICs with protector and optional SHA-256 authentication for 1-cell lithium-ion/polymer batteries. With their low quiescent current, these devices are ideal for small electronic devices like wearables and portables.

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