BITE5 battery tester series
Test multiple battery types
The BITE5 and BITE5 Advanced will test lead-acid (VLA and VRLA), NiCd, and lithium-ion batteries.
Support for battery discharge testing
While performing a discharge test with a Torkel test set, you can use the BITE5 and BITE5 Advanced to measure individual cell voltage, impedance and temperature throughout the test. This will help you identify weaker cells in the string and determine unique impedance baseline values.
Touch screen setup and data trending
With the touch screen on the BITE5 and BITE Advanced you can review data immediately, evaluating individual cells or trending string data and cell performance. Get answers on the spot, make any repairs needed, and re-test to verify the repairs – all in a single trip to the site without transferring or printing data.
Measure impedance on modules up to 500 V
New chemistries and applications mean higher voltage battery modules are becoming more common. The BITE5 can test modules up to 200 V DC, and the BITE5 Advanced can test modules up to 500 V DC.
Measure inter-cell resistance
Using a higher test current, the BITE5 Advanced accurately measures inter-cell (strap) resistance, helping you identify poor or corroded connections.
Reduce testing time
The BITE5 Advanced lets you test parallel strings without spending time isolating segments. It also includes an RFID tag reader for rapid battery identification without manually entering data.
About the product
The BITE5 and BITE5 Advanced battery testers let you perform simple tests to quickly evaluate the state of health of lead-acid (VLA and VRLA), NiCd, and lithium-ion batteries. Both instruments have an easy-to-use touch-screen interface and support impedance testing and discharge testing when used in conjunction with a load bank. The BITE5 Advanced allows you to monitor batteries and cells during recharging and test parallel strings without segmenting. With the BITE5, you can perform tests on modules up to 200 V and, with the BITE5 Advanced, on modules up to 500 V.
Measurement options provided by the BITE5 include cell impedance, cell voltage, ripple voltage, AC ripple current and DC float current. The BITE5 Advanced supports all of these tests and also has provision for accurately measuring inter-cell (strap) resistance.
For impedance tests, you can set pass, warning, and fail limits for impedance and voltage. For discharge tests – and recharge tests with the BITE5 Advanced only – measurements are recorded throughout the full discharge or recharge period. Trends can be displayed on the instrument’s touch screen, and stored results can be downloaded via a USB cable or an SD card for further analysis and archiving. Wireless transfer of data to Megger’s PowerDB software suite is also supported.
Both the BITE5 and BITE5 Advanced support voltage measurement up to 1000 V DC and 600 V AC, which means you can use them to measure solar combiner boxes and check the input and output voltages of inverters used in renewable power systems. An additional feature of the BITE5 Advanced is an RFID tag reader, which allows the instrument to recognise assets without requiring manual data entry.
Technical specifications
- Data storage and communication
- SD card
- Data storage and communication
- USB
- Power source
- Battery
FAQ / Frequently Asked Questions
The frequency of impedance readings varies with battery type, site conditions, and previous maintenance practices. IEEE Recommended Practices suggest semi-annual tests. With that said, Megger recommends that VRLA batteries are measured quarterly due to their unpredictable nature and semi-annually for NiCd and flooded lead-acid.
Many manufacturers now publish impedance values to establish baselines. Several larger organisations who buy many batteries per year have written percent increases of impedance into their battery purchasing specifications for warranty and replacement purposes.
As a battery ages, its characteristics change. In lead-acid batteries, plates corrode and sulphate. In sealed batteries, electrolyte dries out. In Lithium-ion batteries, SEI builds up causing capacitive fading. As these batteries change chemically, their internal impedance changes as well. No ohmic test by any instrument will indicate the remaining capacity; only a discharge test can do that. However, a discharge test is long and expensive and, as such, they are only performed every few years. Batteries can fail within that time frame. Impedance testing provides quick, easy on-line tests that will flag any batteries that may be failing. This can save an entire string because a bad battery can act as a load on the string, damaging adjacent batteries.
The BITE5 can not only be used to test and troubleshoot lithium-ion cells, but it can measure and record the output of solar cells, inverters, and combiner boxes. Combining all these measurements in one device eliminates the need for several individual pieces of equipment.
The BITE5 is designed to measure lead-acid, NiCD, and lithium- ion batteries. These types of batteries can be found in substations, telecom, UPS, data centres, solar and wind applications.
The BITE5 is designed not only to measure lead-acid batteries, but NiCD, and lithium-ion batteries as well. With one connection, you can measure cell voltage, impedance, and temperature. The BITE5 also has the distinct advantage wherein it can be used in conjunction with the TORKEL battery discharge test set to measure the above parameters throughout a discharge test. With the touch screen interface, it is Megger’s easiest impedance tester to use. With touch screen trending, it is also the easiest instrument for making on-site decisions concerning the maintenance and replacement of individual cells. Moreover, it has a built-in voltmeter for basic troubleshooting.
Yes, the BITE 5 has two different concentric probe tips that allow you to access the terminals of the battery through the access hole.
It is the ripple current that generates heat, thus decreasing the life of the battery. A rise of 10 °C will cut the life of the battery in half. Some equipment manufactures, such as those who produce chargers and UPS, may list ripple limits in volts. Therefore, the BITE5 can measure both AC ripple voltage and current.
While performing a discharge test, IEEE requires you to measure the individual cell voltages multiple times throughout the test. Using the BITE5 to measure cell voltage gives you the advantage of measuring impedance at the same time. With the extra data gained from impedance testing, you will be able to see which cells are more susceptible to failure, even though they may not have reached their voltage limit during the test. Additionally, with the impedance data from fully charged cells and from cells throughout and at the end of the discharge test, you can develop baseline impedance data. With the baseline data, you will have pass/fail limits for future impedance tests on the tested battery bank, as well as its specific types of cells.
IEEE 1106-1995, “IEEE Recommended Practice for Installation, Maintenance, Testing and Replacement of Vented Nickel-Cadmium Batteries for Stationary Applications” has similar recommended practices as IEEE 450 for flooded lead-acid batteries.
IEEE 1188-1996, “IEEE Recommended Practice for Maintenance, Testing and Replacement of Valve-Regulated Lead-Acid Batteries for Stationary Applications” defines the recommended tests and frequency. VRLA cells have been classified into tiers of criticality of the installation. The frequency and type of tests vary based on the battery’s tier.
IEEE 450-2002, “IEEE Recommended Practice for Maintenance, Testing and Replacement of Vented Lead-acid Batteries for Stationary Applications” describes the frequency and type of measurements that need to be taken to validate the condition of the battery. The frequency of tests ranges from monthly to annually. Some of the monthly tests include string voltage, appearance, ambient temperature, float current, etc. Quarterly tests include specific gravity, cell voltage, and temperature (on a representative sample of ≥10 % of cells). Annual tests are performed on the entire string. Additionally, the resistance to ground of the battery rack and intercell connection resistance need to be measured. Other tests may need to be performed based on the values measured during periodic tests and battery usage (cycling history).
Dry-out is a phenomenon that occurs due to excessive heat (lack of proper ventilation), over charging (which can cause elevated internal temperatures), high ambient (room) temperatures, etc. At elevated internal temperatures, the sealed cells will vent through the pressure relief valve (PRV). When sufficient electrolyte is vented, the glass matte is no longer in contact with the plates, thus increasing the internal impedance and reducing battery capacity. In some cases, the PRV can be removed and distilled water added (but only in worst case scenarios and by an authorised service company since removing the PRV may void the warranty). This failure mode is easily detected by impedance testing and is one of the more common failure modes of VRLA batteries.
Further reading and webinars
Related products
Interpreting test results
The following table offers general guidelines to evaluate impedance and strap resistance measurements. A comparison to the average string results is a recommended analytic approach. As subsequent tests on a battery system yield additional data, trending becomes possible, which gives you the ability to determine whether a problem is imminent or further out. Over time, it is expected that you will establish your own percentage deviation warning and alarm values. It is strongly recommended that you 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.
Percent variation from string average | Percent variation from string average | Percent deviation from baseline | Percent deviation from baseline | |
---|---|---|---|---|
Warning | Alarm | Warning | Alarm | |
Lead-acid, Flooded | 15 | 30 | 30 | 50 |
Lead-acid, VRLA, AGM | 10 | 30 | 20 | 50 |
Lead-acid, VRLA, Gel | 20 | 30 | 30 | 50 |
NiCd, Flooded | 10 | 20 | 15 | 30 |
NiCd, Sealed | 10 | 20 | 15 | 30 |
Inter-cell Connections (Straps) | 15 | 20 | - | - |
User guides and documents
Software and firmware updates
BITE5 Fimware
BITE5 Firmware and Update Instructions
latest version
Released on 11-2024
Bug Fix:
Corrected limit error causing false measurement warning messages
Updated German Translation errors
Improved impedance measurement stability
Download zip file that contains firmware version and installation instructions
PowerDB Software
FAQ / Frequently Asked Questions
In reality, float voltage measurements are of limited value. They can be used to confirm that the charger is working, but they give no information at all about the battery's state of health. Measuring the float voltage of a cell will also show whether or not it is fully charged, but it is important to remember that, just because a cell is fully charged, this doesn’t mean that it will deliver full capacity. It is by no means unusual for a battery that is close to failure to have a float voltage that is within acceptable limits. A low float voltage may indicate that there is a short in the cell. In a lead-acid battery, this should be suspected if the float voltage is 2.06 V or less, assuming that the charger is set for 2.17 V per cell. In other cases, a cell may float at a considerably higher voltage than average. This may be because the high float voltage cell is compensating for another weaker cell that is floating low. It is also possible for one cell to float high to compensate for several cells that are floating a little low, because the total of all the cell float voltages must always equal the charger setting.
Momentarily press and release the “Power ON/OFF” button. The displayed screen will be saved to the SD card as a bitmap file. The bitmap will be located at the following path: \MEGGER\PQA\SNAPSHOT
You’re actually doing an overall discharge test of all the cells and it’s inevitable that some will reach the end voltage – let’s say this is 1.75 V – earlier than others. You shouldn’t stop the test when one cell reaches 1.75 V, you should stop it when the average cell voltage is 1.75 V. At this point, some cells could be at 1.8 V and others at 1.6 V. Monitor the overall battery voltage during the test and, if you have for example 60 cells, stop the test when the voltage reaches 60 x 1.75 V = 105 V.
The IEEE recommendations say that a 50 % to 100 % change from the baseline on a cell is serious and warrants further investigation, but it’s important to take into account the criticality of the application and battery type. VLA and VRLA batteries fail in different ways. The typical failure mode for a VLA cell is positive grid corrosion. When a VLA cell fails, it fails in shorted mode, which means that current can still pass through it. This means that series strings can be used even in critical applications. VRLA cells, however, most often fail due to drying out and they fail in open mode, which means that they may not be able to pass current. In critical applications therefore, they should be used in parallel. With these differences in mind, a 50 % to 100 % change from baseline is a good screening criterion for VLA batteries, but with VRLA batteries you may want to consider being a little more cautious and use 20 % to 30 %.
When performing an impedance test, or any ohmic test, the batteries must be fully charged. An impedance test is a relative test that compares a present measured value to past values. If the battery is not fully charged, then the measured value will not be the same as it would in the battery’s fully charged state. Therefore, you cannot compare such a value to past values because there is no common state of charge of the battery. Note: With the BITE5 there is a special impedance test that can be performed while the battery is undergoing a discharge test. This will allow the operator to trend the cell impedance values throughout the process and establish alarm limits for the string. See: “Performing an impedance and discharge test (special testing)” in the user guide for further details.
For accurate ohmic measurements, we recommend that you perform a zero adjustment when changing probes. A zero bar is included with the unit. Select the “Configuration” icon on the bottom of the left column main navigation. In the “Meter” screen, click on 0-Adj located at the bottom right to perform the procedure. For further details, refer to the “Configuration of BITE5” section of the BITE5 user guide.