Notes

Three winters of rooftop humidity

The first enclosure was rated for outdoor use and was not. Water entered through the cable gland, not the lid, which is the part everyone photographs.

The replacement used a gland one size down with the cable jacket intact, and a drip loop below the box. Two winters later the desiccant pack is still blue.

Battery budgets that actually held

Sleep current dominates everything. A radio that wakes twice a minute at 40 mA for eight milliseconds costs less over a week than one that idles at 90 µA.

Measure with a shunt and a scope, not with the datasheet.