Quote Originally Posted by tasmod View Post
Regarding the 0.47 ohm resistor.

As it's in the ground leg am I not correct in thinking the power rating is different, as it's current is say, 1amp, but it's the voltage drop across the resistor that counts which is in mV.

Put it this way with real world on the board. On the positive output it ran quite warm at 1amp. In the ground leg it is still cold at 1amp.
It doesn't matter whether the resistor is 'in line' with the 12V supply wire ....or inline with return to ground wire....the same current will be present (the current leaves the charger, goes through the battery & returns to the charger's negative reference .....one current path if you like)

If it was hot before & it isn't now, then that can only mean one of three things...

1. You had more than 1A running through the resistor in its original position.

2. You've not got 1A running through the resistor in it present/new position (what does a DVM say the voltage drop is) ....at 1A through a 0.47R resistor, should see a voltage drop across the resistor of 470mV. You've got 470mW being disppated across the resistor...which I reckon should be warm to touch.

3. You somehow connected the resistor in situ wrong....it should sit between the negative return wire from the battery & the circuit's 0V reference.