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Battery Chargers
All Battery Chargers:   #'s - B       C - K      L - R       S - Z

Also see:      Alkaline       Lead Acid        Lithium      Nickel

Last Updated: June 02, 2021 01:44 PM

Circuits Designed by Dave Johnson, P.E. :

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 David A. Johnson P.E.-December 12, 2004

Path_Light_Using_COB_LED_1w_Solar   -  Chip on board (COB) LEDs are all the rage.  These devices assemble multiple tiny LED chips onto a metal backed circuit board, then cover the assembly with a plastic cover.  The metal back allows the assembly to be mounted to heat sink to keep the device cool.  The multiple LED chips can be wired into any number of series/parallel configurations.  Some are wired for 12v operation while other COB LEDs in flashlights are all wired in parallel, with an operating voltage of about 3 volts. . . . Hobby Circuit by David Johnson P.E.-May 23, 2017

Quartz_Clock_Solar_Powered   -  Connect a solar panel to a quality AA size 1One of my homes in Colorado had a large battery powered quartz clock above the fireplace.  It was powered by an AA size 1.5v alkaline cell.  The battery would run the clock for about a year or so, then I would have to break out a tall step ladder and replace the battery for another year or so of operation. That gave me a great 10:1 energy margin. . . . Hobby Circuit by David Johnson P.E.-September 21, 2017



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

Never buy another 9V battery -  Don't buy expensive, short-lived 9V batteries.  This little DC-DC converter is adjustable and lets you use two AA, C or D-size cells instead.__ SiliconChip

New Battery Charger ICs Need No Heat Sinks -  DN124 Design Notes __ Linear Technology/Analog Devices

New Charger Topology Maximizes Battery Charging Speed -  DN194 Design Notes __ Linear Technology/Analog Devices

New ICs Simplify Battery Charging from the USB -  DN320 Design Notes __ Linear Technology/Analog Devices

NiCad Batteries Zap Adapter -  Don't throw away those seemingly un-chargeable, rechargeable batteries; they could very well be brought back to life with the aid of this simple circuit.    (Tony van Roon's Tony van Roon) __ Designed by Tony van Roon  VA3AVR

Ni-Cad Battery Charger with LM317 -  LM317 regulator is used to regulate the voltage and current for this circuit.  This battery charger should be used only for Ni-Cad cells.  Other type of batteries (li-ion, NiMH Lead and Li-ion polymer) needs special care so it cannot be used. __ Designed by Jose Pino

NiCad Battery Cycler -  For Rx/Tx NiCads   Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

NiCad Charger -  Sometimes its more convenient to recharge batteries 'in place' rather than removing them and putting them in an external charger.  This device is built around a PIC12F675 (a dandy little part from Microchip).  The number of cells (1 to 8) is programmed in using the one button __ Designed by Luhan MonatMesa Arizona

NiCd Battery Charger -  This simple charger uses a single transistor as a constant current source.  The voltage across the pair of 1N4148 diodes biases the base of the BD140 medium power transistor.  The base-emitter voltage of the transistor and the forward voltage drop across the diodes are relatively stable.  The charging current is approximately 15mA or 45mA with the switch closed.  This suits __ Designed by Andy Collison

NiCd Cell Charger -  The project of cell charger shown here uses IC (7808) and transistor (BC547B).  The transformer TR1 is a step down transformer, and steps down 230V AC voltage to 12V AC.  This 12V AC is fed to the rectifier bridge.

Ni-Cd Charger -  This is a NiCd/Ni-MH charger that can charge with constant current and automatic charge termination when the total voltage for all cells reach the setting voltage.

NiCd Charger with Thermal Peak Detection -  The electric model aircraft and car industries have produced a bewildering array of field chargers for NiCd motor battery packs.  These range from simple 6 or 7 cell chargers consisting of a resistor and mechanical timer, to more complex chargers with peak detection, cycling, and the ability to handle 36 cell packs __ Designed by Stefan Vorkoettert

NiCd or NiMH Battery Charger -  Rayovac NiMH Charger and Rechargeable BatteriesThe charger has already recharged my Rayovac 1600maH NiMH batteries countless times and has never left|

NiCd/NiMH charger, capasity measure & conditioner, with NO CPU -  The front pannel, Display to the right show number of condition (discharge followed by charge) the big segements to the right: houres, small: minutes charge time.  Left display: capacity in percent of nominal rating __ Designed by Thomas Scherrer OZ2CPU

NiCd-NiMH Charger -  The charger is build around a LM317 (click to download datasheet) adjustable regulator. The charge starts when a battery is connected between pins JP1-JP4 or JP2-JP4 or JP3-JP4. __ Designed by Ilias Iliadis

NiMH & Li-Ion fast battery chargers & controllers -  This power supply was designed and delivered in less than 4 weeks for a client that had discovered that his power supply solution would not work in his vehicular test and measurement application.  Leveraging the clients existing parts inventory and parts directly available from local distributors this supply was designed and sent out for fabrication in 7 days, thereby preserving their delivery schedule __ Designed by Steve Hageman

NiMH-Charger -  If you are using NiMH-Akkus for your GPS-Receiver, Digital Camera, etc.  then you may be interested in this little super-low-cost solution how to charge them. __ Designed by Herbert Dingfelder

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 David A. Johnson P.E.-December, 2004

Offline IGBT charges batteries -  12/03/98 EDN-Design Ideas (File has several circuit ideas.  Scroll to find this one.) Power supplies for portable equipment must be light, and they must provide international travelers with a convenient universal input.  Although switch-mode power supplies naturally benefit from a universal input, they are more expensive than standard linear supplies, which are based on a transformer.  Recent insulated-gate bipolar transistors (IGBTs) offer an inexpensive way to charge batteries from the ac line. Design by Christophe Basso, Motorola SPS, Toulouse, France

Optimizing High-Frequency Battery Charger Performance for Worldwide Applications -  07/06/00 EDN-Design Ideas Providing Power for electric vehicles for worldwide use requires knowledge of energy conserving and high efficiency technologies Design by Anuradha Rao and Jon Marshall, Curtis Instruments Inc

Path_Light_Using_COB_LED_1w_Solar -  Chip on board (COB) LEDs are all the rage.  These devices assemble multiple tiny LED chips onto a metal backed circuit board, then cover the assembly with a plastic cover.  The metal back allows the assembly to be mounted to heat sink to keep the device cool.  The multiple LED chips can be wired into any number of series/parallel configurations.  Some are wired for 12v operation while other COB LEDs in flashlights are all wired in parallel, with an operating voltage of about 3 volts. . . . Hobby Circuit by David Johnson P.E.-May, 2017

Photovoltaic Battery Charge Controller -  A charge controller is one of the main components of a solar battery charging system (Fig.1).  Its main function is to fully charge a battery without permitting overcharge or reverse __ Electronics Projects for You

PIC NiCad Battery Charger -  This cheap and easy to build NiCd/NiMH Battery Charger is suitable for automatically charging a wide range of batteries for many applications.  Proper chargers are usually expensive and cheap chargers supplied with the original equipment often incorrectly charge the cells and dramatically shorten their life __ Designed by Peter Hayles

Plus-minus 5V Supply From 9V Battery -  Op-amps require dual-polarity supply for proper operation.  When working with battery supply, it becomes difficult to get dual power supply for the op-amps.  Presented here is a simple circuit that provides ±5V from a 9V battery.  This is one of the interesting projects among Electrical Engineering Project Ideas.  Op-amps require dual-polarity supply for proper operation.  When working with battery supply, it becomes difficult to get dual power supply for the op-amps. __ Electronics Projects for You

Portable iPod charger -  After having to spend far too many bus rides home with an iPod that had a dead battery, I decided to make a portable charger for it.  (this will work with other USB devices too)It's different from the popular "Altoids box" designs because it charges the iPod through the USB, not firewire.  The advantage is that you use less batteries (5AA instead of 8AA or 2AA and 2 9v) and the voltage remains constant and does not start at 13.8v and then drops down to 10 to 11 volts.  (thats not the right way to charge a $400 mp3 player) __ Contact: nikosapi @ gmail . com

Portable Solar Battery Charger -  Here's a neat little project that uses both your ham and carpentry Homebrewing skills.  (No jokes about my woodworking, now) About a year ago, I bought a 5 Watt solar panel on sale at Harbor Freight.  It's an ICP Battery Saver Pro, and will supply about 15 Volts DC at 335 mA in full sunlight, which is about perfect for the 7 AH batteries I usually use for QRP portable __ Designed by Monty Northrup

Power Bank for Smartphones -  This power bank can be used for charging smartphones.  The circuit uses two integrated modules and a lithium-ion battery.  The first module is a lithium-ion battery charger and the second is __ Electronics Projects for You

Power Conditioning Techniques for Batteries -  Linear Technology AN8 __ Designed by Jim WilliamsMay 1st, 1985

Power inverter is bidirectional -  08/02/01  EDN-Design Ideas If you want to swap charge in either direction between unevenly loaded positive and negative battery buses, you need an inverting dc transformer.  One implementation is the symmetrical flyback converter shown in Figure 1.  The circuit Design by Tom Napier, North Wales, PA

Power Supply 5v Solar -  This project uses the 1.2v rechargeable battery and solar panel from a Solar Garden Light.  These lights can be bought for less than $5.00 in most $2.00 shops or similar shops that sell general household items. __ Contact: Collin Mitchell

Powered AA NiMH & NiCd Battery Charger -  The charger in this project is designed to charge two AA NiMH or NiCd cells of any capacity (as long as they are the same) at about 470mA.  It will charge 700mAh NiCds in about 1.5 hours, 1500mAh NiMH s. __ Designed by Stefan Vorketter

Pre-Charged (Low Self-Discharge) Rechargeable Battery Roundup -  It's been about two years since I first published my review of Sanyo's Eneloop low self-discharge rechargeable batteries.  Since that time, other manufacturers have jumped on the bandwagon. __ Designed by Stefan Vorketter

Prevent Deep Discharge of Battery -  09/26/96 EDN-Design Ideas NOTE : Page includes several designs, scroll to find this one.  mCs such as the 8051 and 8096 and UARTs such as the 82510 provide hardware support for a multiprocessor asynchronous serial-communication protocol (MicroLan].  This featu Design by Rolando Herrero, Instituto Tecnologico de Buenos Aires, Argentina

Provide Automatic Power-Off for Batteries -  05/13/04  EDN-Design Ideas The circuit in Figure 1 provIdeas a simple and inexpensive way to protect one of the most valuable components in portable applicationsthe battery.  Applications include all portable equipment that requires a limited time of operati Design by Miguel Gimenez, Altair-Equipos Europeos Electronicos, Madrid, Spain

Pulse Charger for reviving tired Lead Acid batteries -  The object is to get the cell voltage high enough for the sulphate to dissolve without boiling or melting the battery.  This is achieved by applying higher voltage for shorter periods and let the battery rest for a while. __ Contact: IQ Technologies

Quartz_Clock_Solar_Powered -  Connect a solar panel to a quality AA size 1One of my homes in Colorado had a large battery powered quartz clock above the fireplace.  It was powered by an AA size 1.5v alkaline cell.  The battery would run the clock for about a year or so, then I would have to break out a tall step ladder and replace the battery for another year or so of operation. That gave me a great 10:1 energy margin. . . . Hobby Circuit by David Johnson P.E.-September, 2017

Rechargeable CMOS Battery -  Occasionally we come across a computer motherboard that seems to eat those CR2032 batteries every 4 to 5 months.  This is particularly frustrating because the computer works perfectly once booted but all the important BIOS settings are lost when the CR2032 battery fails.  This is very irritating if the affected computer will not boot up with the default BIOS settings.  I recently had a computer motherboard with this same irritating phenomenon.  A test revealed that the current drain __ Designed by Radio Amateur Society of Norwich N1HFX

Rechargeable Flashlight Obsoletes Lantern Battery -  12/11/03 EDN-Design Ideas This design idea describes a high-intensity, rechargeable flashlight system that you can build from a 6V lantern-type flashlight.  The rechargeable battery comprises four 2V, 2.5-Ahr(ampere-hour] SLA(sealed lead-acid] cells, similar in size to a standard D-sized battery.  SLA cells are especially well-suited to powering flashlights because of their low self-discharge rate Design by Fran Huffart, Linear Technology, Milpitas, CA

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