howto minimise Lopy deep sleep current?

[achalmers68]

I have a 2xLoPy and 3x FiPy. I trying to minimise the current consumption during deep sleep. I can get the Fipy down to ~35uA easily, however I can only get the LoPys down to about 380uA.
I've seen reports of people getting as low as 16uA for some boards.
As yet I haven't found a definitive reference for the lowest current for a LoPy and how to achieve it.

Here is my setup:

• LoPy dev module with deep sleep shield; no expansion board.
• 3.6V battery. Nothing else connected.
• 1.20.1.r1 firmware.
• Wifi_on_boot(False)
• rgbled(0) to turn LED off.
• using go_to_sleep() from DeepSleep module to sleep for 10 minutes.

Does anyone know what other steps can I take to minimise the LoPy current in deep sleep?

Cheers,
Andrew.