TORKEL900 series battery discharge test systems

There are two main causes:

• Temperature compensation is enabled and you have not entered a battery/ambient temperature. 
• The TORKEL is not detecting the battery.

What you can do:

First check to see if the temperature is set on the TORKEL; if not, make sure to enter the temperature. Otherwise, verify that all battery cables are firmly connected.

Check to make sure that nothing is blocking the fans. The fans also rev up to maximum speed when the “Emergency Stop” button is pressed; check and release the “Emergency Stop” button if needed.

The maximum power consumption that the TORKEL can provide is 15 kW, so the maximum current draw depends on the battery voltage. Check to make sure the current value you set is not too high, given the battery voltage. You can confirm the maximum possible current by checking the data sheet, user guide, or the “TorkelCalc” tab in the Torkel Viewer software. If this message appears when using multiple units together, you can ignore it if it does not appear on the primary unit controlling the test.

Under the “Settings” tab in the TORKEL, verify that you have set "Current measurement" to "External" and that the ratio is set correctly for your CT. The mV/A ratio must match the ratio on the DC clamp-on current probe itself. If you are using the optional 1000 A DC clamp-on probe from Megger, enter 1 mV/A. 

If you are still not getting any readings, check to verify the CT is turned on or cycle the on/off switch. Additionally, you can swap out the battery or check all connections if you have the power supply option. If you are getting faulty readings, perform a zero adjustment on the CT.

F1 is a voltage-controlled circuit breaker connecting the TXL Extra Load resistors to the battery. If F1 does not latch or remain at its upper (On) position, verify that power is connected to the TXL and that the unit’s mains switch is turned on. Ensure that you have correctly connected the control leads from the “CONTROL IN” input on the TXL to the “TXL STOP” output on the TORKEL.

Verify that the Data output port of the Power and Signal connector is connected to the BVM1 connection on the TORKEL. Verify the DC IN port and power supply are connected properly. Unplug and reconnect all connections to verify. If you have multiple BVM kits, swap out the Power and Signal connector to verify functionality.

Check the cables of the BVM units and the power supply to the BVM units. If you have multiple BVM kits, swap out the Power and Signal connector to verify functionality. If you have connected more than 61 BVM units, then you need to connect an extra ethernet cable from the last BVM (red alligator connector) to the “To last BVM unit” plug on the Power and Signal connector. Check the BVM connection diagram for reference.

Check the connections from the BVM to the battery cell to make sure they are tight. If a single BVM or only a few BVMs are not displayed, the problem is probably in the connection from the BVM to the battery. If a string of BVMs is not displayed, then it could be a fault in the connections between BVMs. To verify that a BVM is working correctly, switch it with a BVM on another cell that works properly. If the error follows the BVM, i.e., the missing cell now appears while the cell that you moved the suspect BVM to disappears, there is most likely a fault with the BVM, and you will need to replace it. If the error does not follow the BVM and the original missing cell is still not appearing, the fault is most likely in the interconnecting cable, and you will need to replace it. The same swap-out procedure can be performed with the cables to verify their integrity.

A capacity test is the only way to obtain a quantitative assessment of a battery’s actual capacity. When used regularly, capacity testing can track the battery’s health and actual capacity and facilitate estimations of the battery’s remaining life. The battery’s capacity might be slightly lower than specified when it is new. This behaviour is normal.

Rated capacity values are available from the manufacturer.  All batteries have tables telling the discharge current for a specified time, down to a specific end of discharge voltage. The table below is an example from a battery manufacturer:

Capacity is represented by current x time (Ah). A capacity test measures how much capacity a battery can deliver before its terminal voltage drops to a value equal to the end of discharge voltage x number of cells. A constant current is maintained throughout the test. You should select a test time that is approximately the same as the battery’s duty cycle, and use the same testing time for future capacity tests throughout the battery’s lifetime. This consistency improves accuracy in trending how the battery’s capacity changes.

Common test times are 3, 4, 5, or 8 hours and the typical end-of-discharge voltage for a lead acid cell is 1.75 or 1.80 V.

If the battery reaches the end of discharge voltage at the same time as the specified test time ends, the battery’s measured capacity is 100 % of its rated capacity. If it reaches the end of discharge at 80 % of the specified test time or sooner (e.g., at 8 hours of a 10-hour test time), you should replace the battery. If the battery reaches the end of discharge voltage after the specified time limit, the battery’s actual capacity is higher than its rated capacity. In these cases, even though the battery has not reached the voltage limit in the specified time, you should continue the test until the voltage limit is reached. Quantifying this extended time is necessary to discover the battery's actual capacity, which is important for trending. Batteries are designed to provide specified capacity until their end of life. Consequently, a battery will generally have a higher-than-rated capacity after it has been in operation for a while and one closer to its capacity at the end of its life. Note: All capacity calculations should be temperature corrected.