Time is perfect for testing the charging of a frozen cell. Morning temps are in the low 20's and remain in that zone for some time. Today it was 30 at 9am. I put the battery on the hood of my car that is sitting out in the open under the stars. It gets cold and with the metal of the car the battery is sure to get frozen through and through. Perfect for charging. The cell was sitting at 2.6 volts today. Considered discharged. The cell is a good cell.
I am going to charge at 15 amps or as close as possible until it reaches a voltage of 3.6 volts.
I will then hold that voltage until the amperage drops to about 2 amps.
I will monitor and log the volts and outside temps every 10 minutes until done.
I will then connect the cell to my starter/generator motor and let it discharge down to 2.6 volts.
I will monitor and log the discharge every 10 minutes until done.
I will try to monitor the discharge amperage the best I can.
When done I will graph the results on both the charge and discharge.
When done I will do it again the following morning.
We will then log and graph to see if there is any capacity loss.
Factory says not to charge frozen batteries. Damage will result. Some want to see this so I figured I'd do it with what I have. Might not be super accurate but I can duplicate the test and log what we get. Consistent is what we can do. Close enough anyway.
Gonna be coooooooooold in the morning.