• StandardProducts
• Lithiumate
• Service
• Testing
• Cell Board

Cell Board testing

Once you have determined that an individual cell board may be bad (using the troubleshooting procedures: missing or reporting wrong measurements), use these procedures to test it

There are 4 ways of testing an individual cell board (a cell board for a single cell in series):

• Observing its behavior in the system

  • Use the missing procedures

• Replacement with a known good cell board
• Testing with a test fixture
  • Elithion provides information on a cell board test fixture to large scale customers of its integrated circuits
• Testing without a test fixture

Testing cell boards for multiple cells in series is more complex, and is not covered in this guide.

Testing without a test fixture

Use these procedures to test an individual, unconnected cell board

Test the supply

For this test you need:

• A DVM (Digital Volt Meter / Multimeter) preferably with a DIODES range

Procedure:

• With the ohmneter in the 200 kohm range, measure the resistance between the B+ and B- pads
  • There should be infinite resistance in both directions
  • If you see any resistance, the cell board is bad
• With the ohmneter in the DIODE range, measure the resistance between the B- (red lead) and B+ (black lead) pads
  • There should be a voltage of about 0.48 V in that direction
  • If you see no voltage (infinite reading) or much lower voltage, the cell board is bad
• With the ohmneter in the DIODE range, measure the resistance between the B+ (red lead) and B- (black lead) pads
  • This reading depends on the meter used!
  • There should be open voltage (infinite reading) in that direction: if so, this test passes
  • If you see any voltage, either the cell board is bad, or your meter uses different parameters in the DIODE range:
    • Try the same test on a known good board, to see what your meter reads
    • If the board under test reads the same, this test passes
    • If the board under test reads noticeably lower, the board is bad
    • You can always to the "Test for current drain", below, to be sure

Test the functionality

For this test you need:

• A low voltage power supply (you could also use a LiIon / Lipo cell with at least 2 V, but that's a bit dangerous in case of a short circuit)=

Procedure:

• Set the supply for 3.0 V
• Connect the negative end of the cell board (B-) to the negative output of the supply
• Connect the positive and of the cell board (B+) to the positive output of the supply
• Check what the LED does once connected:
  • The LED comes on and stays on:
    • The cell board is bad: its load is permanently on
  • The LED doesn't come on:
    • The cell board is bad: its micro is not powered or dead, or the LED is bad
  • The LED blinks twice, and repeats that 3 times, then goes off; the cell board may be OK.
    • Continue with the tests below

Test for current drain

For this test you also need:

• A DVM with a DC Current range

Procedure:

• Set the supply for 3.0 V
• Place a current meter in the 200 mA range
• Connect the negative end of the cell board (B-) to the negative output of the supply
• Connect the positive and of the cell board (B+) to the positive output of the supply through the current meter
• Wait for the LED to stop blinking
  • If you see any current, the cell board was damaged by plugging it in backwards
• Place a current meter in the 2 mA range
  • If you see any current, the cell board was damaged by plugging it in backwards

Test the communication ports

Procedure:

• Disconnect the cell board from the supply
• With an ohmmeter, check for a short between the C+ and B+ pads
  • If so, that's a problem: look for a solder bridge between them
• Check for a short between the C+ and B- pads
  • If so, that's a problem: look for a solder bridge between them
• Check for a short between the C- and B- pads
  • If so, that's a problem: look for a solder bridge between them

Without a test fixture, this is as far as you can test a cell board.

Testing with a test fixture

* Test Fixture