TyrePal Failures

I am interested in others experiences of this monitoring system. I originally purchased a TC215/B monitor and 6 sensors, in April 2016.  So far, of the original 6 four have failed. Two simply stopped working, the other two started draining batteries in a couple of days. One failed under warranty (12 months) the others since.

The six original sensors were a slightly different design than subsequent replacements, having a small locking screw tightened with an Allen key, rather than the locking nut of the replacements. So far none of the replacements have failed.

I do leave them on the car and caravan all the time. However, the caravan sits in storage a lot of the year and the tow car does not do a high mileage, so it is not as if they are getting a lot of use in harsh conditions.