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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: December 07, 2017 02:04 PM

Circuits Designed by Dave Johnson, P.E.

Solar 1w Cob LED Light   -  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. . . . Circuit by David Johnson P.E.-May 23, 2017

Solar Fireflies In Jar Light   -  When I was a kid, growing up in Illinois, I remember catching fireflies and putting them into a jar.  I loved watching them flashing away at night.  Later, I would let them out to live another day. . . . Circuit by David Johnson P.E.-September 21, 2017

Solar Lithium Ion Battery Charger using LT1129   -  I have been designing a number of solar powered devices lately.  Many of them use just a single 3.6v lithium ion battery.  These batteries like to be charged from a fixed 4.2v source with a charging current limited to about C/8, where C is the milliamp-hour rating of the part . . . Circuit by David Johnson P.E.-December 24, 2012

Solar Path Light Improvement   -  Use the circuit below was designed to replace the guts of an existing path light assembly with one which has a much better performance.  I suggest using a quality 10 cell solar panel with at least a 4 square inch area.  Buy a panel with solar panels that . . . Circuit by David A. Johnson P.E.-March 13, 2011

Solar Powered Cell Phone Charger   -  The simple circuit below regulates the voltage from a 6v solar panel to a fixed +5v.  That voltage can be fed to any cell phone or USB connected portable device, to charge its battery.  The circuit uses a Reg113-5 voltage regulator from Texas instruments . . . Circuit by Dave Johnson P.E.-January 02, 2011

Solar-Powered_LED_Light_for_Tool_Shed  -  I have a lean-to 8ft by 12ft shed next to my house.  It is full of lawn chemicals and garden supplies.  There were times when I needed to get something from inside the shed during the dead of night.  Early on I had to use a flashlight.  But later, I installed a series of five 12v LED light strips on the ceiling.  Each strip contained 15 3v white LEDs.  The strip had 5 strings of three LEDs, wired in series, with a 150 ohm current limiting resistor. . . . Hobby Circuit by David Johnson P.E.-July 14, 2017

Solar Powered Lighthouse   -  While at a discount store one day, I spotted an interesting tall lighthouse.  It had a tiny solar panel and an equally tiny LED light.  The LED was pointing downward, at the center of a rotating light reflector.  I thought it might be turned into an interesting addition to my wife’s garden. . . . Circuit by David Johnson P.E.-September 21, 2017

Solar Powered Lithium Ion Battery Charger   -  The circuit below feeds a controlled current and voltage to a 3.6v lithium ion battery.  The current is limited to 300ma and the voltage is limited to 4.2 volts.  The circuit uses a LTC1734 IC from Linear Technology.  No diode is needed between the circuit a . . . Hobby Circuit designed by Dave Johnson P.E.-May 15, 2007

Solar Powered Mason Jar Light   -  I have modified several commercial solar garden lights over the years.  I switch out the LED, solar panel, battery pack and control circuit.  The result is a much better overall light.  One of my disappointments in using store-bought garden light assemblies is their construction.  They are built so cheaply that over time, water and insects get inside, killing the light operation. . . . Circuit by David Johnson P.E.-September 21, 2017

Solar Powered Quartz Clock   -  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. . . . Circuit by David Johnson P.E.-September 21, 2017

 


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

Safely Deep-discharges NiCd battery      -  04/29/99  EDN-Design ideas –  NOTE:  Scroll to find this circuit.   Also available at - http://m.eet.com/media/1150682/25098-42999dI     Nickel-cadmium (NIC d) batteries can possess an undesirable memory effect due to partial discharges.  The remedy is a complete discharge before charging again. Figure 1a shows a simple circuit that performs this feat.  __ Circuit Design by Jim Hagerman, Science & Technology International, Honolulu, HI

Salt Water Battery           -  About 13 years ago, I made a salt water battery to operate a single AA battery quartz clock.  It ran for several months until I got tired of adding water to compensate for evaporation.  The batttery consisted of 5 cells each producing about 300 millivolts.  As I remember, I used 5 small olive jars filled with about a cup of water and a tablespoon of salt to create 5 cells in series each producing about 300 millivolts for a total of around 1.5 volts.  The positive electrode was made from a strip of double sided copper circuit board (about 1 inch by 4 inch) and the negative electrode was a similar sized strip of aluminum. __ Designed by Bill Bowden

Sanyo's USB Powered NiMH
Charger
      -  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 __ Designed by Stefan Vorketter

Scheme provides automatic power-off for batteries       -  05/13/04  EDN Design Ideas:  The circuit in Figure 1 provide as 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 __ Circuit Design by Miguel Gimenez, Altair-Equipos Europeos Electronicos, Madrid, Spain

Shrink Battery-Powered Products with a Combination Battery Charger & DC/DC Converter          -  DN1002 Design Notes__ Linear Technology/Analog Devices

Shunt battery charger provides 1A continuous current   -  11/20/97 EDN Design Ideas:    A shunt method is Preferable than series regulation in Solar Powered Systems.    __ Circuit Design by Mitchell Lee, Linear Technology Corp, Milpitas, CA

Simple Circuit 12 Volt Battery Charger     -  Schematic only, no circuit description included.   __ Designed by G.L. Chemelec

Simple Circuit Battery Extends Power over Ethernet Poe Peak Current   -  DN361 Design Notes__ Linear Technology/Analog Devices

Simple Circuit capacitor charge Controller             -  Here's a basic cap switch that will connect capacitor to ground only when it's charged to within 0.4-0.7V from battery voltage (otherwise, it's charging through a 22 Ohm resistor, which can be a low-power 12V lightbulb, too)  __ Contact klausmobile @ yahoo.Com

Simple Circuit car battery charger             -  Automotive, car and motorcycle electronic circuit diagrams / circuit schematics__ 

Simple Circuit 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 Circuit Charges Lead Acid Batteries            -  02/03/97 EDN Design Ideas:  The circuit in Figure 1 charges lead-acid batteries in the conventional way.   A current-limited power supply maintains a constant voltage across the battery (2.4V/cell or so, as specified by the battery manufacturer until __ Circuit Design by Dana Davis, Maxim Integrated Products, Sunnyvale, CA

Simple Circuit Indicates Health of Lithium-Ion Batteries  -  05/14/09  EDN Design Ideas:  A simple inexpensive circuit quickly indicates a battery pack's health __ Circuit Design by Fritz Weld, Friedberg, Germany

Simple Circuit Li-ION Charge Termination using the LT1505            -  DN244 Design Notes __ Linear Technology/Analog Devices

Simple Circuit Lithium-Ion/ Lipo Battery Charger                -  This is a Lithium-ion charger for lipo batteries.  Circuit schematic shows configuration for charging single 3.7V lipo battery but voltage can be set to charge several batteries in series.  Lipo charger sets a current limit with the LM317, and 1 resistor, and the voltage limit with the TL431, and 2 resistors.1K resistor is needed to let the TL431 decrease the LM317 current, and to provide the necessary current to the TL431.  The optional Schottky diode at the output will prevent current flowing back from battery to the charger circuit when power is disconnected, and reverse biasing of the LM317.  Power supply with more than 3V above output voltage is required.  __ 

Simple Circuit safely Deep-discharges NiCd battery          -  04/29/99  EDN-Design ideas –  NOTE:  Scroll to find this circuit.   Also available at - http://m.eet.com/media/1150682/25098-42999dI     Nickel-cadmium (NIC d) batteries can possess an undesirable memory effect due to partial discharges.  The remedy is a complete discharge before charging again. Figure 1a shows a simple circuit that performs this feat.  __ Circuit Design by Jim Hagerman, Science & Technology International, Honolulu, HI

Simple Circuit Switchmode Lead-Acid Battery Charger    -  U-131 APPLIC ATiON   NOTE.  The charger circuit implements a two loop control.  system with the current loop operating inside the.  voltage loop.  During trickle-charge, bulk-charge and__ 

Simple Circuit Test Setup Performs Functional Testing Of Linear, Single-Cell Lithium Chargers       -  10-May-07 EDN Design Ideas:  A handful of off-the-shelf components makes a test setup that allows you to test the operation of a linear single-cell lithium charger __ Circuit Design by Marián Štofka, Slovak University of Technology, Bratislava, Slovakia

Simple Rx/Tx Battery Charger     -  Make You Own Simple Rx/Tx Battery Charger with Peak Detect.  This circuit is designed to peak charge Rx and Tx Batteries.  It is programed for a C/2 charge rate of 250mAh and 500m Ah batteries (charge currents of 125 mA or 250mA).  It will charge Rx from 12V at the field, TX from a 15V supply (like a care w/ engine running). __ Designed by C. Blaurock

Single Cell Sealed Lead Acid Charger        -  This charger is only meant for single cells of the lead/acid variety.  It can be used for cells with a capacity of up to around 10Ah if R1 is changed accordingly.  SLAs should be charged with a current of from 10% to 30% of their rated capacity (in Ah or mAh)  __ Designed by Soren

Single Cell Sealed Lead Acid Charger        -  This charger is only meant for single cells of the lead/acid variety.  It can be used for cells with a capacity of up to around 10Ah if R1 is changed accordingly.  SLAs should be charged with a current of from 10% to 30% of their rated capacity.   __ Designed by Tony van Roon  VA3AVR

Smart Battery Charger   -  This unit was constructed in the shell of a Radio Shack battery charger.  The original unit charged only one type of battery at a time and only in pairs.  This unit allows for mix and match for AAA, AA, C, and D cells.  Each battery is individually monitored and charged.  An LED for each one flashes to show the current charging condition as follows[list:68e9b49a6d]Dim with bright flash: No battery detected Solid on: Battery charging Blinking on: Battery charged[/list:u:68e9b49a6d] When a battery is first inserted, a small charge is pulsed to it.  In between the pulses, the battery is __ Designed by © 2006 Luhan Monat

Smart Battery Charger Reduces Size        -  DN1005 Design Notes__ Linear Technology/Analog Devices

Smart NiMH
battery charger based on Attiny85
  -  After seeing various online projects, especially based on the PIC  microcontroller, I decided to make a charger for NiMH
batteries driven by an ATtiny85.  Why we need a microcontroller to manage charging a battery? The answer is very simple … The most economic charger that on the market, regulate the charge based on a timer, that is if I charge a 2500mAh battery for example, they provide a charging current of 250mAh, keeping the charge for eg 14 hours (a part of the energy will be lost, so 10 hours would not be enough).__ 

Solar 1w Cob LED Light   -  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. . . . Circuit by David Johnson P.E.-May, 2017

Solar AA Battery Charger              -  This almost trivial circuit may be used to charge a pair of AA or AAA sized cells insun __ Designed by G. Forrest Cook

Solar Battery Charger     -  Schematic + info + pictures __ Designed by Lennie Zink

Solar Battery Charging   -  This instructable will show you how to make your own solar battery charger from very simple components.  It is taken from my documentation provided with a kit I supply, you should easily be able to source the same components yourself of course.  __ 

Solar Cell Battery Charger/Monitor          -    NOTE: Must register on this site __ Designed by Published in Elecktor July/Aug, 2010

Solar Cell Charger             -  These Circuits will allow for Voltage Regulation and isolation when Charging Lead Acid Batteries with a Solar Cell. __ Designed by G.L. Chemelec

Solar Cell NiCad Charger                -  Schematic & notes only, there is not a circuit description.   __ Designed by Tony van Roon  VA3AVR

Solar Cell Phone Charger              -  This little gadget uses a small 3 volt solar cell to charge a 6 volt NIC ad battery pack which, in turn, may be used to charge many models of cell phones and other portable devices with the addition of a suitable low-dropout voltage regulator.  The circuit "scavenges" energy from the solar cell by keeping it loaded near 1.5 volts (maximum energy transfer value) and trickle charges the internal battery pack with current pulses.  The simple circuit isn't the most efficient possible but it manages a respectable 70% at 100 mA from the cell and 30% when the cell is providing only 25 mA which is actually pretty good without going to a lot more trouble or using more exotic components. __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Solar Charger for Lead Acid Batteries      -  Solar lead acid charger, with battery voltage monitor, for12V battery __ Designed by Jan Hammer

Solar charger for lead-acid batteries.       -  This circuit is still under development, but works well as shown.  This circuit is intended for charging lead-acid batteries with a solar panel.  The customary diode that prevents the battery from discharging through the solar panel has been replaced by a FET-comparator combination.  The charger will stop charging once a pre-set voltage (temperature compensated) has been reached, and recommence charging when the voltage has dropped off sufficiently.  The load is disconnected when the baterry voltage drops below 11V and reconnected when it gets back to 12.5V. __ Contact IQ Technologies

Solar Fireflies In Jar Light               -  When I was a kid, growing up in Illinois, I remember catching fireflies and putting them into a jar.  I loved watching them flashing away at night.  Later, I would let them out to live another day. . . . Circuit by David Johnson P.E.-September, 2017

Solar Lithium Ion Battery Charger using LT1129   -  I have been designing a number of solar powered devices lately.  Many of them use just a single 3.6v lithium ion battery.  These batteries like to be charged from a fixed 4.2v source with a charging current limited to about C/8, where C is the milliamp-hour rating of the part . . . Circuit by David Johnson P.E.-December, 2012

Solar Panel Charge Controller/Low Voltage Disconnect   -  The SPC3 is a solar power center, it can handle all of the power functions for a solar charged 12 Volt DC system. The SPC3 contains a 9 amp photovoltaic charge controller, a 10 amp low voltage load disconnect circuit and a pair of built-in white LEDs for area illumination. The low voltage disconnect circuit has a load on-off switch and a battery low voltage indicator. By using the SPC3 as the center of a solar powered device, long battery life is assured. The SPC3 can be used for a stand-alone solar lighting system, it can also be used for making solar powered audio and radio devices. __ Designed by G. Forrest Cook

Solar Path Light Improvement    -  Use the circuit below was designed to replace the guts of an existing path light assembly with one which has a much better performance.  I suggest using a quality 10 cell solar panel with at least a 4 square inch area.  Buy a panel with solar panels that . . . Circuit by David A. Johnson P.E.-March, 2011

Solar Powered Cell Phone Charger           -  The simple circuit below regulates the voltage from a 6v solar panel to a fixed +5v.  That voltage can be fed to any cell phone or USB connected portable device, to charge its battery.  The circuit uses a Reg113-5 voltage regulator from Texas instruments . . . Circuit by Dave Johnson P.E.-January, 2011

Solar-Powered_LED_Light_for_Tool_Shed  -  I have a lean-to 8ft by 12ft shed next to my house.  It is full of lawn chemicals and garden supplies.  There were times when I needed to get something from inside the shed during the dead of night.  Early on I had to use a flashlight.  But later, I installed a series of five 12v LED light strips on the ceiling.  Each strip contained 15 3v white LEDs.  The strip had 5 strings of three LEDs, wired in series, with a 150 ohm current limiting resistor. . . . Hobby Circuit by David Johnson P.E.-July 14, 2017

Solar Powered Lighthouse           -  While at a discount store one day, I spotted an interesting tall lighthouse.  It had a tiny solar panel and an equally tiny LED light.  The LED was pointing downward, at the center of a rotating light reflector.  I thought it might be turned into an interesting addition to my wife’s garden. . . . Circuit by David Johnson P.E.-September, 2017

Solar Powered Lithium Ion Battery Charger          -  The circuit below feeds a controlled current and voltage to a 3.6v lithium ion battery.  The current is limited to 300ma and the voltage is limited to 4.2 volts.  The circuit uses a LTC1734 IC from Linear Technology.  No diode is needed between the circuit a . . . Hobby Circuit designed by Dave Johnson P.E.-May, 2007

Solar Powered Mason Jar Light  -  I have modified several commercial solar garden lights over the years.  I switch out the LED, solar panel, battery pack and control circuit.  The result is a much better overall light.  One of my disappointments in using store-bought garden light assemblies is their construction.  They are built so cheaply that over time, water and insects get inside, killing the light operation. . . . Circuit by David Johnson P.E.-September, 2017

Solar Powered Quartz Clock        -  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. . . . Circuit by David Johnson P.E.-September, 2017

Standalone Linear NiMH
/NiCd
   -  This charger requires no microcontroller or firmware__  

Step-Up Supply Charges Battery While Serving Load        -  06/08/95 EDN Design Ideas:  The circuit in Fig 1 supports portable applications in which a microprocessor controls battery charging.  Step-up switching regulator IC 1 boosts ViN (5V]to supply a combination of charging and load current. (Note that the 5V source  __ Circuit Design by Dana Davis, Maxim Integrated Products, Sunnyvale, CA

Supply Derives 5 & 3.3V from USB port  -  20-Dec-01 EDN Design Ideas:  The circuit in Figure 1 derives its power from a USB port and produces 5 and 3.3V supply rails for portable devices, such as digital cameras, MP3 players, and PDAs.  The circuit allows the port to maintain communications while, for example, charging a lithium-ion battery.  IC 2 boosts the battery voltage, VBATT, to 5V, and IC 3 buck-regulates that 5V output down to 3 __ Circuit Design by Chad Olson, Maxim Integrated Products, Sunnyvale, CA

Switcher IC hikes Battery Charger's Efficiency     -  06/23/94 EDN Design Ideas:  The adjustable switching-regulator LM2575T-ADJ, IC 1, in Fig 1 replaces a power-wasting pnp transistor in the data-book design for the NIC d battery charger IC 2, a MAX713. (its sister device, the MAX712, handles NiMH
cells.   ]IC 2 "fast-charges" cells by monitoring the cell's voltage and charging current __ Circuit Design by Huw Jones, Gyrus Medical Ltd, Cardiff, Wales, UK

Switching regulator charges NiMH
batteries
        -  12/21/00 EDN Design Ideas:  Many NiMH
(nickel-metal-hydride) fast chargers use linear regulators, such as the LM317, in a current-source configuration with a charge-monitor IC .  This arrangement dissipates much heat and requires considerable heat sinking, ad __ Circuit Design by Jason Hansen and Jim Hill, On Semiconductor, Phoenix, AZ

      >>>

Battery Charger Circuits:  #'s - B       C - K      L - R       S - Z
 


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