Datasheet

MCP1631HV Multi-Chemistry Battery Charger Reference Design
DS51791A-page 42 © 2009 Microchip Technology Inc.
C.6.2 NiMH Lab Exercise (3 Cell, 700 mAh pack, with thermistor)
1. In the mikroC
™
“Project Summary” frame, click on the “H files” branch to expand
the ‘.H’ file list.
2. Double click on the
“MULTICHEMISTRY_REF_DESIGN_BOARD_102_00232.H” file to open it.
3. Scroll through the header file and locate “#define LION_SUPPORT”.
Set it to “DISABLED”.
4. Scroll through the header file and locate “#define NIMH_SUPPORT”.
Set it to “ENABLED”.
5. Scroll through the header file and locate “#define LED_DRIVER_SUPPORT”.
Set it to “DISABLED”.
6. Scroll down to the “#IF (NIMH_SUPPORT == ENABLED) section of the header
file. The section contains Nickel Metal Hydride and NiCd specific parameters.
7. Set the NIMH_NICD_CONDITION_CURRENT to 140 mAh. (0.2C Conditioning
mode current)
8. Set the NIMH_NICD_CONDITION_VOLTAGE to 900 mV. (Transition point from
Conditioning to CC mode)
9. Set the NIMH_NICD_CHARGE_CURRENT to 700 mAh. (1.0C Constant Current
Charge)
10. Set the NIMH_NICD_CHARGE_TERMINATION_CURRENT to 84 mAh. (0.07C
– Termination Current for CV mode)
11. Set the DVDT_MV_PER_CELL to 6.0. (Termination Voltage change per cell per
minute in millivolts)
12. Set the NIMH_NICD_CHARGE_DTDT_60SEC_THRESHOLD to 0.3. (Termina-
tion Temperature change per minute in degrees Celsius)
13. Set the NIMH_NICD_CHARGE_OVTEMP_SETPOINT to
THERMISTOR_OHMS_45C. (Termination temperature for safety)
14. Save the file (File | Save).
15. Compile (Project | Build).
16. Open MPLAB and load the workspace if it is not already loaded. (File | Open
Workspace) MCP1631HVBuckBoostBatteryChargerReferenceDesign.mcw
17. Import the new “MCP1631HVBuckBoostBatteryChargerReferenceDesign.hex”
file. (File | Import)
18. Download the file (Debugger | Program) and reset the processor (Debugger |
Reset | Processor Reset).
19. Run the new program (Debugger | Run).
20. Turn on the power supply and set the output voltage to 8V. Turn off the power
supply.
21. Connect the variable 8V supply (+) lead to the input connector (+) pin J1-1.
22. Connect the variable 8V supply (-) lead to the input connector (-) pin J1-2.
23. Connect the NiMH battery pack to the charger board J2 connector.
24. Turn on the variable 8V supply.
25. Press and hold the “ON/OFF” button on the charger board until the LED’s flash
(about 5 seconds). The board is now in Configuration Mode.
26. Press and release the “CHEM” button until the “NiMH” LED is on.