DIY Manual

32 | P a g e 10-543-1 REV A
DIY Manual
Ending Amps
The red arrow above indicates the point during the Absorb cycle at which the current has
decreased to its lowest level; that is ending amps, which means the batt bank is full. That is the
point that you want the charge controller to transition to Float.
As stated, ending amps for most batteries is 1 – 3% of the bank’s 20-Hr, Ah rating. If you want to
precisely determine the ending amps for your batteries, then perform the following steps:
1. Set Ending Amps (Charge/Advanced menu) to 1A.
2. Monitor the WBJr Status page during the Absorb cycle
3. Watch for the amps reading below “Whizbang” to stop decrementing. This value is the
actual ending amps for your batts. This is the amount of current that cannot flow any
more into your batts at the fixed Absorb voltage setting relative to the batt’s internal
resistance. It’s the point that your batts are in balance or harmony internally.
4. Change ending amps from 1A to this observed amp setting. Depress Enter to save the
change.
If you chose to terminate the Absorb cycle using ending amps, then set the Absorb timer in your
charge controller to a value higher than normal; add another 60 minutes to it. This ensures the
ending amps are reached first before the timer expires. The Classic and KID will change to Float
based on whichever occurs first – ending amps or timer expiration.
Both the Classic and the KID allow for either its internal shunt to be used to calculate ending amps
or an external shunt (with the MidNite current-sensing device called the Whiz bang Jr). If you
use the internal shunt, the controller will only know the current going into the battery bank; it
will not know the amount of current leaving the bank. Why is this important?