Pod Edamame v3

Nithya Menon
November 23, 2021


UX, Manufacturing, and Reliability Optimization

The Pod Edamame v2 was first deployed in the field almost 1 year ago exactly. It fixed an issue that we saw in earlier releases which prevented continuous usage of higher power/voltage systems, which is necessary for growing load demands and interest in productive appliances, particularly when paired with inverters.

Unfortunately, despite Edamame v2 passing high power tests in the lab, the addition of inverters introduced new transient stress conditions that resulted in unacceptable field failure rates. The hunt to find the root cause was arduous, and ultimately revealed that two lines of copper on the circuit board were a few millimeters too close together, causing transient feedback loops to spin out of control.

This debugging led to a revamped focus on rigorous stress and field testing prior to confirming the next design release for manufacturing. A significant outcome was a newly built accelerated life cycle test machine that can continually trigger all the key known failure modes in a controlled environment. We’ve seen that where v2s failed in 2-3 hours of stress cycling, the v3 design withstands 100+ hours without any problems, and we are yet to see any failures at all.

With more lab confidence than ever before, and very successful field trials of v3 prototypes, we manufactured and deployed new v3 Pod Edamames which have been in the field for almost two months now. We are monitoring closely, but so far we are proud to confirm that all the biggest appliances and inverters have been running without any issues.

In addition to electronics design improvements, Pod Edamame v3 includes several improvements to the enclosure and screw UX, assembly process, as well as many “DFM” (design for manufacturing) and QA/QC optimizations that reduce assembly labour. We’re so proud of everyone who made the Pod Edamame v3 as successful as it has been so far!

Nithya Menon is an engineering graduate from Harvey Mudd College who has spent her career developing technology targeted towards empowering marginalized and developing communities worldwide. She has been pivotal in designing Okra's key power-sharing algorithms, IoT firmware, and grid management software - and now drives the direction and strategy of Okra's technology as Product Development Lead.