|
|
Lead-acid battery capacity analysers
11 July 2007, Test & Measurement
Dean Marcus, Aztec Electronics
Today, most UPS, aircraft, telecoms and other critical application batteries are of the lead-acid chemistry. The unfortunate truth about most of these batteries is that you will never know their true capacity until you actually perform a full capacity test.
In order to correctly determine the capacity of a given lead-acid battery, the battery must first be fully recharged before being allowed to 'cool down' for several hours. Once cool, the battery must be discharged at the manufacturer's determined rate, down to a set end voltage. For example, a 12 V 100 Ah battery could be discharged at 10 A for 10 hours down to 1,85 V per cell. If the battery is able to sustain the 10 A discharge for 10 hours then it has 100 A hours of capacity at the C/10 rate, where C is the capacity of the battery. However, if the same battery can only sustain the 10 A discharge for say 5 hours, then the battery only has approximately 50% capacity left.
One of the most advantageous features of lead-acid batteries with pure lead-tin alloy (from suppliers such as NorthStar and Hawker SBS) as opposed to the cheaper and lower performance lead-calcium is that their state of charge (SOC) can be estimated simply by measuring their open-circuit voltage, since the open-circuit voltage is a direct function of the concentration of electrolyte within the battery - even though the battery might be dry. As the concentration of electrolyte decreases so too does the % SOC. For NorthStar batteries, the relationship can be linearly approximated by the following equation: % SOC @ C/20 = OCV x 62,5-712,5 where C is the capacity of the battery in question.
Aztec Electronics stocks a wide range of lead-acid (and NiCad) battery analysers/dischargers. Aztec's Beta D-50 analyser is suitable for 12 V and 24 V batteries and can be adjusted for constant current discharges between 0 and 50 A. The end-point voltage and test time can be set prior to discharging. Once complete, the digital display will show elapsed time, voltage and current and a green lamp will illuminate when the battery capacity is above the preset requirement. Alternatively, a red lamp will illuminate if the battery fails to meet preset limits. |
|
|
|
| Share: |
 |
Via email client |
 |
 |
 |
 |
print |
|
|
|
|
|
Further reading:
- Passive intermodulation analyser
27 March 2019, Actum Electronics, Test & Measurement
Passive intermodulation (PIM) is one of the main causes of faults in modern networks. PIM can significantly reduce the network quality with regard to range and data transmission. PIM is caused by a number ...
- Arbitrary waveform generator
27 March 2019, Vepac Electronics, Test & Measurement
Tektronix launched the AWG70000B arbitrary waveform generator with new features that enable it to fully support the testing of complex electronic warfare and wireless communications systems that require ...
- Battery optimisation software for IoT devices
27 February 2019, Concilium Technologies, Power Electronics / Power Management, Test & Measurement
Keysight Technologies has introduced the X8712A IoT device battery life optimisation software solution, to ensure optimal battery life prior to device deployment to accelerate troubleshooting and device ...
- Calibration and the challenges of choice
27 February 2019, Concilium Technologies, Test & Measurement
A poor or incomplete calibration can lead to significant errors in your measurements. The time to develop a product may exceed your original schedules and production yields may be too low if the test ...
- Compact and rugged test fixture ranges
27 February 2019, Electronic Industry Supplies, Test & Measurement
In order to offer a compact test fixture solution, Ingun’s manual test fixtures MA 350/F, MA 360/F, MA 260/F and MA 160/F were designed for testing small PCB series. These compact units not only meet ...
- Coaxial components for high-frequency testing
27 February 2019, Coral-i Solutions , Test & Measurement
Anritsu has introduced W1 coaxial components that are metrology-grade designed and manufactured to deliver precision performance and repeatability for high-frequency measurements.
Comprised of a W1 ...
- EXFO tests terabit research network
27 February 2019, Lambda Test, Test & Measurement
EXFO, C Spire and Nokia Bell Labs have collaborated on a demonstration of a terabit-speed research network.
To put it into context, networks running at this speed would make it possible to download ...
- Arbitrary function generator
27 February 2019, Comtest, Test & Measurement
Despite their importance in electronics testing and their wide adoption, arbitrary function generators (AFGs) have lagged behind other test instrumentation in terms of usability, making do with small ...
- Vector signal generator
27 February 2019, RFiber Solutions, Test & Measurement
The G6 vector signal generator from Transcom Instruments can generate arbitrary wave, continuous wave, common vector, digital, standard wireless vector, standard radio and custom signals.
Covering ...
- MEMS-based environmental sensors
30 January 2019, Electrocomp, Test & Measurement
The BPS line from Bourns has been designed to provide high sensitivity/accuracy, long-term reliability, high temperature capability and harsh media compatibility.
The BPS110 and BPS120 pressure sensor ...
- Multi-channel data-logger
30 January 2019, Instrotech, Test & Measurement
In the world of instrumentation, an enormous amount of data can be produced by each measuring point, which must be logically and clearly displayed and processed. Kobold’s ZLS electronic multi-channel ...
- Keysight releases new DAQ system
30 January 2019, Concilium Technologies, Test & Measurement
The DAQ970A data acquisition system (DAQ) has been released by Keysight Technologies to speed test development times with rapid measurement and scan rates, expanded measurement types and ranges, as well ...
|
|
