I'm working on a wearable with haptic feedback using the following ERM vibration motors:
https://www.digikey.com/product-det...ronics-inc/Z7AL2B1692082/1670-1023-ND/6009928

I'm powering my project with lithium ion cells, and as everyone reading this knows, those can go anywhere from 3.2-4.2V. To keep the motors within their rated voltage, I'm running these motors in series, but they're just not quite powerful enough. So, I'm looking for suggestions:

• If I run these motors above their rated voltage directly from the batteries, how much damage could that cause? They tend to get a tad warm if I do this, and since this is intended to be a wearable . . . that worries me a little.
• I'd be willing to consider an LDO regulator, but every time I go looking, I just get lost in all the available options. Note that I'm trying to use four of these motors in total, so it's got to be a regulator with enough available current.
• I've been digging through other vibration motors, as well. I need the vibration to be pretty powerful, but I'm also trying to keep things relatively compact as a wearable. Most of these smaller motors have the same rated voltages, though.

So . . . thoughts? Suggestions?

 

Their specified operating voltage is up to 3.6V so just put a diode or even two in series, a 1N4004 or similar.

 

Wow. I just looked under "related posts" and remembered that I asked this before. D'oh! It's been awhile - sorry about that . . .