I’m doing some power testing of MPPT charger devices hooked directly to the Ace power terminals. Nothing too special. One certain MPPT charger / 5V boost board immediately reboots the Ace when I enable power to it in the app. I hear it click off immediately, the light goes off, then it reboots back into standby mode (blue LED) a moment later.
I am able to get it to work if I limit to 500mA and then enable power. After enabling power I could set the limit to 1A while it is enabled. I suspected maybe a large inrush current on this specific board causing it to reboot. But my understanding is that the Ace would just limit that.
Any idea why it might reboot like that for a certain device? Is that how the current limit works when it hits the limit?
Hi and welcome to the forum.
Most likely, what you are experiencing is a VBUS drop during the inrush current pulse.
There are several parts here, one is how quickly the computer USB port can deliver an inrush current pulse without dropping the USB voltage, and another is how quickly the Otii Ace Pro can limit the current to the current limit setting.
Also your connection between the computer and the Ace will affect this, best is to use the USB C-C cable supplied with the Otii Ace Pro, then typically the computer will be able to supply roughly 15W, from which 3.6W is consumed by the Otii Ace Pro.
You could test to use a DC adaptor, connecting on the DC plug on the backside of the Otii Ace Pro.
In most cases, this solves problems like this.
Best regards,
Björn