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Battery Testers
Last Updated on: Thursday, June 25, 2015 06:20 AM

Circuits Designed by Dave Johnson, P.E. :

  • 6v NMH/NiCd Battery Tester -  I designed this circuit to test rechargeable six volt battery packs under constant current conditions. As designed, the circuit applies a 10 amp load to the battery pack. A heat sink must be used on the main power transistor . . . [Circuit by David A. Johnson P.E.,  12/12/04] 

  • 9v Battery Voltage Monitor -  This circuit turns on a LED whenever the voltage of a standard 9v battery connected to the circuit drops below 7. 2 volts. It uses a LTC1440 comparator, which also contains a 1. 18v reference diode. In standby mode, the circuit draws only 4uA . . . [Circuit by David Johnson P.E.,  07/09/06] 

  • Ground Resistance Tester -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0. 1 ohms.   This resistance must be tested with actual line current in excess or 10 amps.   The circuit shown uses a couple of LEDs to indicat . . . [Hobby Circuit designed by Dave Johnson P.E.,  04/28/01]

  • Small Battery Capacity Tester -  I have a client who uses a lot of batteries. His sells a device which is powered by a 3v lithium coin cell and he sells thousands of them. It seems that many of the batteries he has been importing from China have a milliamp-hour capacity which is much . . . [Hobby Circuit designed by Dave Johnson P.E.,  09/07/08] 

  • UL Ground Resistance Tester -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0. 1 ohms. This resistance must be tested with actual line current in excess or 10 amps. The circuit shown uses a couple of LEDs to indicate if in fact the resistance is less than 0. 1 ohms - modified on July 10, 2006 . . . [Circuit by Dave Johnson P.E.,  04/28/01] 

  • Voltage Monitor for a 9v Battery -  Nine voltage batteries are used in a wide variety of electronic devices. But, you often donít know when it is time to change the battery until the device stops operating. The hobby circuit below provides a visual indication when the battery needs to be . . . [Hobby Circuit designed by Dave Johnson P.E.,  07/09/06]


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

6v NMH/NiCd Battery Tester -  I designed this circuit to test rechargeable six volt battery packs under constant current conditions. As designed, the circuit applies a 10 amp load to the battery pack. A heat sink must be used on the main power transistor . . . [Circuit by David A. Johnson P.E.,  12/12/04]

 

9v Battery Voltage Monitor -  This circuit turns on a LED whenever the voltage of a standard 9v battery connected to the circuit drops below 7. 2 volts. It uses a LTC1440 comparator, which also contains a 1. 18v reference diode. In standby mode, the circuit draws only 4uA . . . [Circuit by David Johnson P.E.,  07/09/06]

 

Battery Characterizer -  . . .  [Circuit designed by Jon Fick]

 

Battery simulator provides current limiting -  08/01/97  EDN Design Idea   A constant-voltage active load can perform as a battery during the charge cycle. You can set the load voltage from 5 to 35V by using potentiometer PV and thus can simulate batteries ranging from 6 to 32V. . . .  [by Hern√°n Tacca, University of Buenos Aires, Argentina]

 

Button Battery Cell Internal Resistance Measurement Circuit -  The open cell voltage of a small silver oxide button cell battery remains very close to 1. 5 volts over most of the life of the cell. However, there is a relationship between battery health and the internal resistance of the cell.  This circuit when used . . . [Circuit by David A. Johnson P.E.,  07/11/06]

 

Constant Voltage Load Tests Battery Chargers -  04/11/96 EDN Design Idea   Testing battery-charging circuits on an actual battery can be difficult, because battery voltage changes during the charging cycle. The constant-voltage "load box" circuit in Figure 1 provides a constant-voltage load for a batter. . .  [by Jon Dutra, Linear Technology Corp, Milpitas, CA]

 

Discharger for Receiver Battery Packs -  You may have read about cycling NiCad batteries. If not, read a little here ( Red's R/C Battery Clinic) for an excellent overview. Overcharging apparently leads to voltage depression, which can be corrected by one or two complete discharges (to 1 to 1. 1 volts per cell). On the other hand, over discharging the batteries to a low or zero voltage can damage them, and if the batteries have not been overcharged and have no voltage depression, cycling just uses up regular battery life. I designed and use this discharger occasionally to remove voltage depression and insure battery capacity is still ok for those planes that have no low voltage alarm. . . .  [designed by Rob Crockett 8/3/98]

 

Ground Resistance Tester -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0. 1 ohms.   This resistance must be tested with actual line current in excess or 10 amps.   The circuit shown uses a couple of LEDs to indicat . . . [Hobby Circuit designed by Dave Johnson P.E.,  04/28/01]

 

LED Battery Condition Indicator -  In the circuit below, a quad voltage comparator (LM339) is used as a simple bar graph meter to indicate the charge condition of a 12 volt, lead acid battery. A 5 volt reference voltage is connected to each of the (+) inputs of the four comparators and the (-) inputs are connected to successive points along a voltage divider. The LEDs. . .  [Bill Bowden's circuit]

 

Measure Button Battery Cell's Internal Resistance  -  The open cell voltage of a small silver oxide button cell battery remains very close to 1. 5 volts over most of the life of the cell. However, there is a relationship between battery health and the internal resistance of the cell.  This circuit when used . . . [Hobby Circuit designed by David A. Johnson P.E.,  07/11/06]

 

My New Battery Desulfation/Tester -  This circuit helps to Desulfate Lead Acid batteries. Added Bonus: This Circuit also gives a good indication of the Internal Resistance of the battery. . . .  [G.L. Chemelec, designer]

 

NiCad Discharges for Tx & Rx Pack -  The reason I designed this discharger are many, however I will list a typical example. A modeler charges his batteies for 14 hrs, then goes to the field for a fly. He then rests for a week, then charges his batteries again for 14 hrs and flies again. The third time, he repeats the procedure, then wonders why his aircraft has a major argument with the runway. The problem with this method is that he is rechargeing a battey pack which after the first week, is in an unknown state of charge. . .  [by John Nooyen]

 

Nine-Volt Battery Voltage Monitor -  This circuit turns on a LED whenever the voltage of a standard 9v battery connected to the circuit drops below 7. 2 volts. It uses a LTC1440 comparator, which also contains a 1. 18v reference diode. In standby mode, the circuit draws only 4uA . . . [Circuit by David A. Johnson P.E.,  07/09/06]

 

NMH/NiCd 6v Battery Tester -  I designed this circuit to test rechargeable six volt battery packs under constant current conditions. As designed, the circuit applies a 10 amp load to the battery pack. A heat sink must be used on the main power transistor . . . [Hobby Circuit designed by Dave Johnson P.E.,  12/12/04]

 

Phantom Power Battery Test Circuit -  LED will light when battery is over42 volts. . .  [Jenson Transformers]

 

Resistance Tester got UL Ground Requirement -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0. 1 ohms.  This resistance must be tested with actual line current in excess or 10 amps.   The circuit shown uses a couple of LEDs to indicate . . . [Circuit by David Johnson P.E.,  04/28/01]

 

Self-powered Fast Battery-Tester -  Tests 1. 5 to 15 Volt cells; Two-LED display, no power supply required. . .  [Flavio Dellepiane's web site]

 

Simple but reliable car battery tester -  This circuit uses the popular and easy to find LM3914 IC. This IC is very simple to drive, needs no voltage regulators (it has a built in voltage regulator) and can be powered from almost every source. . . .  [by  Jonathan Filippi]

 

Simple Car Battery Charger psimages -  This very simple circuit uses a transformer , two diodes , a capacitor and an ammeter. To charge a battery just connect+ and terminals of circuit to corresponding terminals of battery. When battery is not charged, ammeter reading shows 1-3 amps. . . 

 

Simple car battery Tester -  This circuit uses the popular and easy to find LM3914 IC. This IC is very simple to drive, needs no voltage regulators (it has a built in voltage regulator) and can be powered from almost every source. . .  [author: Jonathan Filippi]

 

Small Battery Capacity Tester -  I have a client who uses a lot of batteries. His sells a device which is powered by a 3v lithium coin cell and he sells thousands of them. It seems that many of the batteries he has been importing from China have a milliamp-hour capacity which is much . . . [Hobby Circuit designed by Dave Johnson P.E.,  09/07/08]

 

Solid-state relays simplify monitoring electric car battery-voltage -  02/19/04  EDN Design Idea   Figure 1 shows the propulsion system of an electric vehicle. It includes an electric motor, drive electronics, a mechanical transmission, vehicle control/power management, a charging system, and a battery. The long-term performance. . .  [by Robert Krause, Fairchild Semiconductor, San Jose, CA]

 

Test batteries without a voltmeter -  11/09/00 EDN Design Idea   The circuit in Figure 1 is an easy approach to testing batteries without exiting the voltmeter. The battery holders in sizes AAA, AA, C, and D make this tester so much faster than a voltmeterPDF contains multiple circuits, scroll. . .  [by Nam Phan, Pasadena, CA]

 

Test batteries without a voltmeter, part 2 -  03/03/01   EDN Design Idea   From a high-volume-production point of view of the Design Idea   "Test batteries without a voltmeter " ( EDN , Nov 9, 2000, pg 167) , it is a time-consuming and laborious task to tweak the large number of potentiometers on each of the comparator input refere. . .  [by Nam Phan, Pasadena, CA]

 

Testing Sanyo's Eneloop Low Self-Discharge Rechargeable Battery -  Late in 2006, I found out about Sanyo's new Eneloop Nickel Metal Hydride (NiMH) rechargeable batteries, available in AA and AAA cell sizes. Unlike regular NiMH offerings from other vendors (e. g. Duracell, Energizer, Gold Peak) , Sanyo claimed the following benefits for their Eneloops. . .  [Stefan Vorketter's web site]

 

Tests UL Ground Resistance -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0. 1 ohms. This resistance must be tested with actual line current in excess or 10 amps. The circuit shown uses a couple of LEDs to indicate if in fact the resistance is less than 0. 1 ohms - modified on july 10, 2006 . . . [Hobby Circuit designed by David Johnson P.E.,  04/28/01]

 

UL Ground Resistance Tester -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0. 1 ohms. This resistance must be tested with actual line current in excess or 10 amps. The circuit shown uses a couple of LEDs to indicate if in fact the resistance is less than 0. 1 ohms - modified on July 10, 2006 . . . [Circuit by Dave Johnson P.E.,  04/28/01]

 

Virtual 9 V Battery -  PP3-size 9 V batteries (IEC: 6LR22) have a considerably poorer price/energy ratio than 1. 5 V AA (IEC: LR6) cells. This makes it all the more unfortunate when you accidentally leave a device switched on! The author uses a number of such devices and so started looking for a solution to this problemmust register on this site. . .  [Published in Elecktor July/Augu, 2010]

 

Voltage Monitor for a 9v Battery -  Nine voltage batteries are used in a wide variety of electronic devices. But, you often donít know when it is time to change the battery until the device stops operating. The hobby circuit below provides a visual indication when the battery needs to be . . . [Hobby Circuit designed by Dave Johnson P.E.,  07/09/06]

 

Battery Testers


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