Here is a close up shot of the data the DC electronic load captures when set to battery Ah testing mode. (click the image to make it larger) I set the capacity tester to 30A so as not to over heat it by running at full bore for 10+/- hours. The unit is rated at 40A but like anything electronic it likes to be run at less and will last longer doing so.


It should be noted that both my charge source and DC Electronic Load tester both utilize dedicated voltage sensing leads that do not carry any current. This means accurate charging voltages physically measured at the battery terminals, and also accurate cut-off voltages, measured at the battery terminals.


The cut off voltage for this capacity test was set to 11.2V or 2.8VPC. A Cell Log 8 was used to trigger alarms if any cell dropped below 2.78V.


The Process:


#1 Charging = 13.8V and current allowed to taper

#2 Cell Temps = 76F - 77F

#3 DC Load = 30A constant

#4 Voltage Cut Off = 11.2V / 2.8VPC

#5 Capacity Measurements = Ampere Hours & Time At Load


Results:


Cycle Number = 550

DC Load = 30A

Ah's Delivered = 419.2 Ah's

Time @ 30A = 13:58:55


Do your self a favor and create a baseline capacity figure that is both repeatable and useful to you!



CHECK BACK SOON, MORE TO COME!!