Accugraph, a NiCd/NiMh/LiPo discharger and data collector.

My brother builds electrical model aero planes driven by NiCd/NiMh/LiPo rechargeable batteries and he is therefore interested in keeping these rechargeable batteries in good shape, as they are quite expensive. He has therefore build the Accugraph, an rechargeable battery discharger and data collector. The apparatus can hold data from up to 250 discharge cycles (200.000 10bit samples) from up to 99 predefined rechargeable batteries. The discharge data can later be transferred to a PC through a RS232 serial port. The design is build around a 18F4620 PIC microcontroller, 8x24LC256 I2C serial eeprom, a DS1621 temperature measurer used to warn when the heat sink is hot. Below you can see some pictures of my brothers design (click on the picture to enlarge it):

A look inside the complete Accugraph apparatus.
New! The memory module schematic.
The memory module with 8x24LC256 I2C serial eeproms (256Kb)		Pcb files updated 2007.12.27
The backside of the front plate with LCD display, and the warning buzzer.
The 1 K/W heat sink used to deposit the discharge current, through 4 effect resistors.
The RS232 connector used to transfer discharge data to the PC.
New! The DS1621 schematic.
The DS1621 measures the heatsink temperature and turns on a warning LED, when temperature is above 50°C		Pcb files updated 2007.12.27
New! The main board schematic.
The main board containing the 18F4620 PIC, a 1Hz time reference, the MOS-FET's used to switch on the effect resistors. Updated to the newest firmware version 7! Note you will have to change the PIC to a 18F4620 to use the new firmware.		Pcb files updated 2009.09.09
The front of the Accugraph.
The Accugraph manual, and data files examples. Updated to comply with the newest firmware version 7!		Manual and datafiles updated 2009.09.03

This page was last updated 2010-02-20.