Curtis 1226 - Step 6: Set Discharge Time; Step 7: Set Charge Time and Start Charge Voltage; Step 8: Test and Tune

7 — CALIBRATING THE BATTERY DISCHARGE INDICATOR (BDI) OUTPUT
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Return to TOC Curtis Model 1226 – September 2019
Step 6: Set Discharge Time
Set the Discharge Time parameter by taking the following steps:
1. Drive the vehicle with a heavy load.
2. Pay attention to the battery voltage, BDI percentage, and time.
3. Stop driving when the vehicle becomes sluggish and the battery voltage drops signicantly. When
that happens, you have reached the fully discharged point of the battery.
4. If the BDI percentage did not reach 0% before you stopped driving, decrease the Discharge Time
parameter. Use the following formula to calculate the new Discharge Time value:
New Discharge Time = Present Discharge Time * (100% – BDI%)
Step 7: Set Charge Time and Start Charge Voltage
How you set the Charge Time and Start Charge Voltage parameters depends upon whether the
vehicle’s BDI gauge is required to support partial charging.
e typical method is to require a full recharge, which means the BDI percentage is reset only aer
the battery is fully charged. However, the 1226 controller can be congured to allow the operator to
stop charging in mid-cycle and then view a partial charge reading.
To congure these parameters, perform one of the following steps:
• To require full charging:
1. Set Charge Time to 600 minutes.
2. Set Start Charge Voltage equal to the Full Charge Voltage parameter’s value.
• To allow partial charging:
1. Set Charge Time to the product of the following equation, which uses the battery’s amp
hour rating and the charger’s average amp output:
1.5 * (Battery amp hours / Charger amps)
2. Starting with the dead battery that resulted when you set the Discharge Time parameter,
plug in the charger.
3. Charge for 10 minutes.
4. Measure the battery voltage with a voltmeter.
5. Set the Start Charge Voltage parameter to the measured voltage divided by the number of
battery cells.
Step 8: Test and Tune
Once you have calibrated BDI as described in this chapter, you’ll have a good initial BDI
conguration. However, for optimal BDI accuracy you should test the BDI conguration for the
vehicle’s expected usage. Factors such as battery age, hilliness, driving surface, and user weight all
impact the BDI percentage’s accuracy. If testing indicates you need to ne-tune the BDI accuracy,
repeat the procedures in this chapter.