Prefer AC adapter over USB-C power source possible?

Product Discussion Pepwave MAX
1

I can power my MAX Transit Duo Pro using the included 4-pin AC adapter when my vehicle is on or a USB-C-connected portable battery when the vehicle is off. I want the battery to act as a backup power supply when the AC is unavailable.

Problem: Even when the 4-pin AC adapter has power, the Transit continues to draw power from the USB-C battery until I disconnect it or the battery is drained.

Is there any way I can change this behavior so that I can keep the battery plugged in to USB-C ready to act as standby / backup power?

Supplying AC adapter power does not decrease the number of watts drawn from USB-C. It seems to have full preference for USB-C over 4-pin, only switching over when USB-C is disconnected. Connecting multiple USB-C sources causes it to draw half the wattage from each, but this doesn’t help me.

My best plan now is to place a UPS in between the AC source and the AC adapter, and not use USB-C battery at all.

2

Resolved. Now I have AC power adapter as primary and USB-C battery as fallback/backup power.

Peplink support informed me that the Max Transit Duo Pro prefers the power source with the highest voltage.

My power bank supplies up to 28V DC, so I resolved the issue by switching to a 29V 2A DC power supply with AC adapter.

I cut off the barrel connector for the AC adapter and wired the leads directly into the VCC and GND pins of the green 6-pin power input, which conveniently screwed down tightly onto my bare wires. Success!

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