Otii Ace Pro overview

An advanced look at the Otii Ace Pro - technical specifications

As shared on the Otii Ace Pro page, this version is the big brother of the Otii Arc Pro. Keeping the same portable and compact form with comprehensive technical features for energy optimization but with enhanced capabilities to boost battery-driven and energy-harvesting devices requiring high precision at higher voltage ranges, with a high sample rate and low step size.

It is an all-in-one tool with an isolated power supply unit, a constant voltage/current source and sink, and a high-precision multichannel multimeter. Making it a power analyzer/profiler that records and displays currents, voltages, and power measurements in real time. Enabling hardware, firmware, and software developers to optimize the energy consumption and battery life on any device under test.

With Otii Ace Pro and Otii 3 Desktop App, you can source the voltage of the device under test (DUT) up to 25V while simultaneously measuring and recording current, voltage, and power data in real-time for further analysis to optimize battery life throughout the development cycle.

To take Otii Ace Pro's capabilities to the next level, and make it the perfect addition for product development, test and verification, quality assurance, and maintenance, explore Otii Toolboxes for battery profiling and simulation or automation tools features.

Hardware overview

The front side of the Otii Ace Pro has the main connectors, additional ports to extend measurement capabilities, plus a status LED.

The back side of the Otii Ace Pro has the host USB connector and an input socket to power up the unit with an external DC adapter when required.

Main connections

The Otii Ace Pro has the voltage(+) and voltage(-) binding post (red and black connectors located on the right side of the instrument), which are used to source the DUT but also to measure the current, voltage, and power of the device. The DUT can be connected through its battery connectors or DC input; refer to the connection diagram below for better understanding.

To power up the Otii Ace Pro and enable the communication with the host computer, use the provided USB C to USB C cable to connect the unit to your computer.

Check out the Wiring up page to explore all possible connection configurations between the Otii Ace Pro and your DUT.

Expansion Port

The expansion port on the front of the Otii Ace Pro is designed to enhance the hardware's functionality, allowing users to measure additional voltages and currents or trigger external events. These additional pins feature multi-input and multi-output for analog and digital signals, serial communication, and additional power and ground points. Below is a general overview of the additional pins available:

ConnectorDescriptionMaximum rating


Adjustable output between 0V and 15V

600 mA


Digital ground (return current)


UART RX / Digital Input (Exclusively under Scripting)

0V - 5.5V


UART TX / Digital Output (Exclusively under Scripting)

0V - 5.5V


Digital input #1

0V - 5.5V


Digital input #2

0V - 5.5V


Digital Output #1

0V - 5.5V


Digital Output #2

0V - 5.5V


Digital ground (return current)


Analog ground (return current) | Analog measurements


Differential input for current measurement. It also measures single ended voltage with respect to AGND

-10V to 25V


Input for current measurement

-10V to 25V


Analog input with the AGND as reference/return

-10V to 25V


Analog input with the AGND as reference/return

-10V to 25V

In case of using the expansion port, checking out the entire technical specifications for all the details about each available pin is highly recommended.

Status LED

The table below explains the Otii Ace Pro's status LED behaviors and their meanings to help you quickly identify the device's state.

LED behaviorOtii Arc Pro Status

Solid blue

Otii Ace Pro is active

Solid green

Relay closed, sinking/sourcing power or in-line mode

Flashing white


Flashing red/blue

Upgrading firmware

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