Pod Firmware v1.9

Nithya Menon
December 14, 2020



Each Okra pod can individually be configured for daily limits, limiting the daily available capacity for households and maintaining network reliability. But now, boost allows a household to opt to consume more than their daily limit, as long as there is more power available in the network. Households get to use more power and utility partners increase utilization and revenues.

Households simply click a button on the screen to consume and be billed, for excess power. They automatically go back to normal mode at midnight.

Support for AC Output

The Okra pod distributes and outputs DC power (due to lower transmission costs and higher efficiency) but most big, productive appliances are only available in AC. So we worked to ensure our pod could power AC inverters. One technical challenge is that inverters have high inrush current, meaning that there is a large spike of current on startup, which mimicked short-circuit behavior and tripped our protection. In this release, we removed the short circuit protection on this specific load port, and added an enable/disable protection switch within a hidden screen menu. In the upcoming versions of the hardware, we have re-tuned our hardware protection circuit to better distinguish between true short circuits and inverter current spikes.

Support for more battery chemistries

Previously, the pod supported lead acid and lithium batteries as 2 generic types. But there are small, but important, charging and setpoint differences even within either family of battery chemistry. This release expanded our battery configuration support to allow the installer to specify between AGM lead acid and gel lead acid. This also set up the architecture to support more battery variants in the future.

Households simply click a button on the screen to consume and be billed, for excess power. They automatically go back to normal mode at midnight.

Improved daily usage display

Especially for homes using more appliances, it’s highly valuable and required that they can easily monitor their daily usage. The pod’s screen displays the daily usage and shows it as a percent of their daily limit. This value was resetting when the pod turned on and off, which was leading to confusion, so the usage is now stored in memory, making the pod more resilient to an unexpected reset.

Households can easily see the percentage of their daily limit remaining.

Data optimizations

Initially, to improve stability of the communications protocol, each snapshot of data from the pod was being sent to the cloud individually. Now, with greater confidence in the protocol’s reliability, we send multiple packets of data in the same message, which reduces the overhead.

Stability improvements

Bug fixes in this release included:

  • Dramatically reducing the occurrence of pod resets
  • Solved occasional corrupt data packets

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.