Battery Tester Electronic Circuits

Battery Testers
Last Updated on: Monday, October 03, 2011 06:07 PM

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. (added 12/04)
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 in conjunction with an oscilloscope will measure the internal resistance. You will have to use a known good cell as a reference.
Small Battery Capacity Tester
The only truly accurate way to measure the current capacity of a battery is by connecting the battery to a constant current load and measure how long the battery can sustain that current before its voltage drops below a recommended “cutoff” point. The circuit below is designed to do this type of test.....

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.... [Designed by David A. Johnson]

Battery Characterizer - (electronic circuit added 4/05)

Battery simulator provides current limiting - 1-Aug-97 Issue of EDN 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.… [Design Idea by HernÃ¡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..... [Designed by David A. Johnson]

Constant Voltage Load Tests Battery Chargers - 04/11/96 EDN-Design Ideas [Design Idea added 6/06] EDN migrating links. This link is not verified. Search the "title" EDN for new link.

Discharger - 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....(added 6/07)

Discharger for Receiver Battery Packs - ….(Circuit design added 08/08) [Site is under construction right now]

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]

Phantom Power Battery Test Circuit - LED will light when battery is over42 volts (added 3/03)

Self-powered Fast Battery-Tester - Tests 1.5 to 15 Volt cells. Two-LED display, no power supply required. (electronic circuit added 06/07/08)

Simple but reliable car battery Tester - ….(Circuit design added 03/08)

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....(added 10/05)

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 - The only truly accurate way to measure the current capacity of a battery is by connecting the battery to a constant current load and measure how long the battery can sustain that current before its voltage drops below a recommended “cutoff” point. The circuit below is designed to do this type of test.... [Hobby Corner Circuit by Dave Johnson]

Solid-state relays simplify monitoring electric car battery-voltage - 19-Feb-04 Issue of EDN 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 of the electric vehicle depends on ensuring the electrical health of the battery and its charging system.... [Design Idea by Robert Krause, Fairchild Semiconductor, San Jose, CA]

Test batteries without a voltmeter - 11/09/00 EDN-Design Ideas 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 voltmeter....PDF contains multiple circuits, scroll to find the one of interest.... [Design Idea 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]

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 problem.….must register on this site... [Published in Elecktor July/August 2010]