How to reliably stop NUT from setting biweekly UPS calibration?

[MrPete]

I've got an admittedly older Smart UPS 1000 (SU1000). It works just fine.

What is NOT fine: it's now configured to do an auto-recalibrate (ie run the battery down to 25%) every two weeks. Pretty horrible for battery life.

I worked out how to use upsrw to set the recal time to zero... but a day or two later, it was back to two weeks.

a) Anybody have an idea where such a setting is stored, or how this reversion from my setting could happen?

b) In reality, these UPS's support a setting of "OFF" for ups.test.interval -- but upsrw believes this is a numeric enum supporting three number quantities. Any idea where such configuration is (incorrectly) stored?

THANKS!