To make the test and calibration of the chargers and harness proceed as quickly and accurately as possible, I built a test fixture. The 100W resistors allow full power test, which presents a stable voltage and current, as well as a temperature controlled oven for an elevated stable temperature reference.
This oven was made from a big aluminum heat sink.
The fins are curved so they make spring pressure mechanical contact with the part of the temperature probe that is the sensing chip.
This makes for reasonable warmup and settling times, which we use to test and calibrate the voltage and current analog signal conditioners, as well as being a 100% test of the charger harness and output connections.