US consumers want accuracy above all in their wearables devices, according to Valencell and trade association MEMS & Sensors Industry Group. The organization stake their claim on a recent online survey they conducted, which polled 706 Americans between the ages of 18 and 65.

A majority of 63 percent of survey respondents ranked accuracy as the critical feature of wearables, beating comfort (at 57 percent) and battery life (at 47 percent). Seventy-three percent of respondents said they expect more accurate wearables to eventually directly impact users’ health, and 74 percent of those who don’t currently own wearable devices said they would consider buying such a device if better accuracy could help them improve their health.

It’s good news for Valencell, which prides itself on the sophistication and accuracy of its wearable biometric devices. Its PerformTek cardiac biometrics technology proved even more accurate than the Apple Watch in internal testing last year, and has gone on to prove increasingly popular with companies licensing it for their devices.

But even with a high level of accuracy assured, Valencell—and other companies offering biometric wearables technologies—will need to focus on another important area: Device recharging. The survey found that 37 percent of wearables owners reported that they had stopped using their devices, and in most cases (40 percent) they said it was because they just couldn’t be bothered to continually recharge them. Developers who can solve this problem could help to substantially boost the popularity of wearable devices and their biometric technologies.