Car Battery Charger

This Charger Can't be used as a Power Supply, Without having a battery in place. The Battery MUST be Connected to get power out. Note: This Charger Features a Reverse polarity Indicator. Instructions: Before plugging this charger into the 110 volt line (or turning it on if you use a Switch), FIRST Connect this Charger to the Battery. In doing so, No Damage will occur if the battery is accidently connected in reverse, but the Reverse Polarity LED will light up. If that LED Does light, Reconnect the battery Correctly, than apply the 110 line voltage. Connecting the Line voltage, With a reversed battery connection, WILL Result in Damage. Especially if you don't use the fuse on the output, as shown in the schematic. Although Not Shown in the schematic, A suitable Line fuse would also be advisable.
Car Battery Charger - schematic

There is No Amp-Meter shown, But I would Definately recommend including one in either the positive or negative line, going to the battery. The Transformer, Diodes and SCR, Must be caplable of handling the output current. And Don't use a 10 amp transformer. If you expect to charge battery's at 10 amps, Allow youself a Safety margin! Use a 15 Amp transformer. Also the Diodes and SCR will Definately require a Suitable, LARGE Heat Sink! The 100 ohm trimpot on the PCB sets the Maximum Charge Voltage. To set this Correctly, attach a Fully charged battery to the output. Than using a meter to monitor the output,Set the trimpot to give an output of 14.5 volts at Very Near ZERO CURRENT. I Show a Center Tapped Transformer and two Diodes, But a Single output, 16 Volt transformer could be use with a full wave bridge rectifier. Some manufacturers recommend Charges with a Low Output, AC Ripple content. If this concerns you, You can add a large Filter Cap across the output. However this Capacitor will NOT be Protected by a reversed battery, unless it is connect before the fuse in that line.

Recommended videos

  • How to make a 12 Volt car battery charger
    Duration: 7:23.
  • Hack a USB car charger into a variable voltage power supply
    Duration: 6:46.
  • How To Make A 12 Volt 5 Amp Battery Charger - DIY Technology Tutorial - Guidecentral
    Duration: 1:52.


  • Expanding 60W AC/DC power supply range now offers battery backup units
    Electropages (blog)
    Electropages (blog) range now offers battery backup unitsStadium Stontronics has announced today that its SA60 AC/DC open frame family has been extended to include two new 13.8VDC and 27.6VDC standard output units, and two new 13.8VDC a
     26 September 2016
  • Electronics EETimes (registration)
    Electronics EETimes (registration) Fairchild Semiconductor, now part of ON Semiconductor, has added the SuperFET III family of 650V N-channel MOSFETs, citing performance advances in ...Third generation 650V MOSFETs cut resistance by 44%
     22 September 2016
  • Business Wire (press release)
    Business Wire (press release) Fairchild's new SuperFET III 650V N-channel MOSFETs meet the higher power density, system efficiency and reliability requirements of the latest teleco.
     20 September 2016
  • ThomasNet News (press release) (blog)
    ThomasNet News (press release) (blog) The VR6 Voltage Regulator reduces the cost of adding another power supply and snaps together with the PDS8 Dual Input Power Distribution Module via common standoffs saving valuable enclosure space to prov
     15 September 2016
  • ThomasNet News (press release) (blog)
    Altronix Showcases Outdoor NetWayTM Managed PoE Switches at ASIS 2016 - September 14, 2016 - Altronix Corp.
     14 September 2016
  • Semiconductor Today
    Semiconductor Today The launch in late August by Dialog Semiconductor plc - a fabless provider of highly integrated power management, AC/DC power conversion, solid-state ...Consumer chargers to represent 30 percent of GaN power market
     8 September 2016
  • Business Wire (press release)
    Diodes Incorporated (Nasdaq: DIOD), a leading global manufacturer and supplier of high-quality application specific standard products within the oad.
     8 September 2016
  • Compound ...
    Compound Semiconductor
    Compound Semiconductor VisIC Technologies has launched a new bottom-side cooled 650V GaN power switch. A member of the ALL-Switch family, the device is designed for idge ...VisIC launches low-RDS(ON) 650V GaN switch product line in ...
     7 September 2016
  • American Journal of Transportation
    American Journal of Transportation Market to Surpass $20 Billion by 2017Commodity AC-DC include all high-volume, consumer-based , for example, for desktop PCs, notebooks, tablet PCs and mobile phones. The category also includes all pow
     31 August 2016