Parallax Power Supply 7345

Battery temperature is measured on the posts of the battery.
That is the only place on a battery to get a true battery temperature reading and thus adjust the charge voltage.

I can add that with the Prosine 2.0 Xantrex says that mounting the sensor on the negative post "provides the most accurate results", and stuck to the side of the battery "also provides good results in most situations". The Outback temperature sensor has no provision for post mounting, just adhesive to stick it to the battery case, and of course the adhesive tends to fail in pretty short order.