Support for the BITE3 battery impedance tester

This means that the battery system has internal noise. 

What you can do:

The system can still be tested with the BITE3 using the optional CT. In the BITE3 settings menu, set the CT for “Impedance” mode. Connect the CT to the BITE3 and around any suitable location within the string being tested. The BITE3 will use the measured current through the CT and the voltage drop caused by the system noise, measured via the BITE3 probes, to calculate the correct impedance.

This is what is expected. This message indicates the ripple current is low and the batteries are in float mode. If this is the case, click YES to proceed with the impedance testing.  

Note: If the ripple current exceeds 5 A per 100 Ah battery capacity, then you have found a problem that needs to be corrected.

Note: If the float current reads high then stop the testing; the batteries are not fully charged and the readings you get will be misleading.

The BITE3 can automatically detect the difference between a cell and a strap. If the unit displays “Confirm Strap”, this means the unit does not recognise a cell or a strap. If you are measuring a strap then just pull the trigger. If you are measuring a cell, you do not have a good connection.

This can be an indication of a fundamental current on the battery string. The BITE3 automatically detects cells and straps by measuring the floating voltage on the BITE probes. If the voltage goes high, this indicates the probes are across a cell. If the voltage goes low, this indicates the probes are across a strap. If enough noise or fundamental current is on the string, then the unit may not be able to identify if the probes are across anything.

What you can do:

Place the unit in the “spectrum analyser” mode and place the probes across a strap (you may need to place the probes close to one another on very noisy systems). If the spectrum analyser indicates fundamental current is present on the string, stop. Turn the charger off and see if the problem clears up. If it does, then the charger has an open rectifier and needs repair. If it does not, there is a short that is allowing fundamental current to get on the string. This must be corrected as it will lead to overheating of the batteries.  
 

The unit automatically detects the type of lead set connected. If this message appears, first check the lead connection to the unit. If this is good, then try a different set of leads, if available. If this does not work, contact customer service.

The Reverse Polarity message indicates that the probes are backwards.

What you must do:

Reverse the probes! DO NOT PULL THE TRIGGER until you have reversed the probes. Pulling the trigger will blow the fuse in the unit.

This is usually the result of a blown 1 A (Slo Blo) fuse in the side panel. To test for a blown fuse, place both BITE probes on the same terminal of a battery.  This will act as close as possible as a zero ohm connection and should yield a very low impedance measurement.  If the measurement indicates out of range impedance values, it is very likely that the protective fuse has been blown.  

There could be two causes for this: 

1. the leads got across >19 V
2. the two field-effect transistors (FETs) on the power board have shorted. 

What you can do:

It may be possible to replace the fuse, but if the FETs are shorted, the unit will need to come in for repair. If FETs are shorted, it’s more likely that you just won’t be able to read battery impedance.
 

There may be several reasons why you’re not receiving a reading or the reading is erratic:

• the impedance value you are trying to measure is too high
• the fuse in the unit is blown
• there is damage to the lead tips

What you can do:

• Check the fuse and replace it if it is blown
• If the fuse is ok, clip the leads of the unit together and take a measurement. If the “out of range” error is displayed, there is a problem with the BITE3 and you will need to contact the authorised repair centre. If the unit does take a measurement, the impedance of the cell you were originally trying to measure is too high.  
• Finally, lead tips can break off inside shafts on the 36616 lead set, and often remain stuck in the shaft and not visible as damage. If this is suspected, please return the instrument to the Megger Repair Department.

If you see a “system error” when powering up, it’s likely that there is damage to the processor. 

What you can do:

The PC104 module, where the firmware is located, has probably been damaged, likely by heat. The unit must be sent to an authorised repair centre for repair.

The real value in battery testing lies in the trending of data to determine if problems are imminent or farther out. The following table offers general guidelines to evaluate impedance and strap resistance measurements. Over time, BITE3 users will establish their own percentage deviation warning and alarm values. It’s strongly recommended to use the software provided with your equipment to keep all the historical data for each of the strings under test. The software includes several charts - including warning and alarm criteria - that will facilitate the trending and analysis of the data.