MKR NB and running through Vin

Hi,

Has anyone solved the running using VIN issue for MKR NB? I have had this working on other MKR boards with utmost success and it saves a lot of power compared to the LiPo connection - it also allows the choice of finding the lowest voltage the board runs at, again to save battery power.

However the NB board seems to be the odd one out, and no matter how big the battery (in terms of mAh and I have gone up to 2800 mAh) it just does not behave - even with the simplest of codes (e.g. blink!).

Any ideas? An replicants? Is this a flaw in the board or is it that I am missing something obvious.

Thanks

What have you tried? I want to use the MKRNB1500 to monitor crude oil levels in tanks and am thinking a LiPo battery may to be a great idea as if it by chance burst into flames bad things might happen. Would like to power it from alkaline batteries. One thing I've been pondering is to use a buck/boost regulator to supply 5V to vin but that doesn't seem to be good for long battery life. My knowledge in this area is weak.

I'm using a Pololu 5V Step-Up/Step-Down module S18V20F5 on VIN and it seems to work fine using 3 or 4 (4.5 or 6 volts) input. The output is a solid 5.00V on the one I have. The quiescent current of the module is approximately 1 ma. I'm powering off the modem between sensor readings but haven't put the SAMD into deep sleep yet so don't know what the current draw will be then. The green USB led is on and the battery charging led is blinking which need to be disabled. I'm hoping that can keep the total drain with modem powered off and in deep sleep to very near the 1ma quiescent draw. There will only be 3 or 4 readings per day so if my arithmetic is close maybe can get 3 months on AA batteries. Space isn't critical so could use C or D cells.