How to use the charger
- Set Mode and Current switches to desired positions.
- Insert Battery/Batteries.
- LED(s) will light up white to indicate that batteries are detected and waiting for a button press.
- As soon as the button is pressed, the LED will go out.
- Depending on the duration of the button press, the charger will work in different sub modes:
Mode switch position:
- Short: Normal Charge.
- Medium: Attempt to revive a dead battery then normal charge.
- Long: Charge a battery even if it fails the internal resistance check - at a slower rate (400 mA)
- Short: Discharge Only.
- Medium: Discharge, then Charge.
- Long: Discharge, Charge, Discharge, Charge.
- Short: Charge, Discharge, Charge.
- Medium: Charge, Discharge, Charge, Discharge, Charge.
- Long: Charge, Discharge, Charge, Discharge, Charge, Discharge, Charge. (Charge, then 3 full cycles)
A short press is one that is less than 1/4 of a second.
A medium press is one that is for about 1 second.
A long press is one that is for 3 seconds or longer.
If after inserting a battery, the button isn't pressed within 10 seconds, the charge will default to the same mode as if there was a short button press. After the button is released, the LED will flash white a number of times to indicate which duration button press it detected: 1 = Short, 2 = Medium, 3 = Long.
You can set separate modes for each cell - e.g. you can set 1 battery charging, change the mode switch and set another one discharging or analyzing at the same time.
Meanings of the LED colors:
White (Solid): Shown at startup for about 1 second - turns off if no batteries are currently inserted. If you come back to the charge and the LEDs are white, it's most likely an indication that the charger has reset for some reason. LEDs will also show white for 10 seconds after batteries are inserted whilst waiting for a button press.
White (Blinking): Indicates detected duration of button press (see above)
White (Flashing): Shown at startup whilst reading program from SD card into EEPROM.
Red (Solid): Charging.
Red (Flashing SOS): Indicates that an error has occurred - probably a bug in the code!
Red/Blue Alternating: Waiting to charge. (Previously flashing Red, then alternating Red/White)
Red/Purple Alternating: Charging a cell with very high internal resistance at reduced current.
Red/Green Alternating: Doing top off charge.
Green (Solid): Finished Charging.
Green (Blinking off): Already Full.
Purple: Aborted Charging - probably because internal resistance is too high.
Aqua: Finished Discharging.
Blue (Solid): Resting (between charges and discharges)
Blue (Fast Flash): If there was a problem with initializing the logging code, both LEDs will fast flash blue for 5 seconds before the charger continues starting up as normal. If you get this, check to make sure that the SD card is properly inserted and not corrupted. (If the card is corrupted, you may not see this flash though, so it's a good idea to check the card regularly)
Data file format columns:
- Milliseconds since startup.
- Channel Number
- Comment, or time in seconds with decimal to milliseconds for duration of current task.
- Requested current - in milliamps.
- Measured Voltage
- Actual current in milliamps.
- Calculated power in milliwatts - calculated from measured voltage and calculated current.
- Accumulated capacity in milliamp hours.
- Accumulated energy in milliwatt hours.
- Measured Temperature.
- PWM Value
- Internal Resistance
Effective Charging Rates:
High: 950 mA
Medium: 475 mA
Low: 190 mA
High mode will only charge one cell at a time. If 2 cells are inserted, the first cell will be fully charged while the other waits. Once the first one is fully charged, it will automatically start charging the second cell. With the Medium and Low rates, the actual charge rate will be double the effective rate with an off period half the time. If 2 cells are inserted at the same time, the charger will alternate between them so that they're both effectively charged at the same time.
Before each charge, the code will test the internal resistance of the cell to try to prevent charging of non rechargeable cells. This is done by doing a brief charge and then a brief discharge - this will be observed as a red, off, yellow, off sequence on the LED. If the internal resistance is too high, the cell will be rejected and the LED will light up purple. If the cell voltage is above 1.40V, the cell will be rejected as already fully charged and the LED will flash green.
Let me know if anyone has any questions!