Charge controller

A charge controller, charge regulator or battery regulator limits the rate at which electric current is added to or drawn from electric batteries to protect against electrical overload, overcharging, and may protect against overvoltage.[1] This prevents conditions that reduce battery performance or lifespan and may pose a safety risk. It may also prevent completely draining ("deep discharging") a battery, or perform controlled discharges, depending on the battery technology, to protect battery life.[2][3] The terms "charge controller" or "charge regulator" may refer to either a stand-alone device, or to control circuitry integrated within a battery pack, battery-powered device, or battery charger.[4]

Charging controller of a Selectec HYT-Q3 Quick Charge-enabled power bank with both USB-C and USB-B micro input for compatibility, heat sink, and status indicator LEDs.

Stand-alone charge controllersEdit

Charge controllers are sold to consumers as separate devices, often in conjunction with solar or wind power generators, for uses such as RV, boat, and off-the-grid home battery storage systems.[1] In solar applications, charge controllers may also be called solar regulators or solar charge controllers. Some charge controllers / solar regulators have additional features, such as a low voltage disconnect (LVD), a separate circuit which powers down the load when the batteries become overly discharged (some battery chemistries are such that over-discharge can ruin the battery).[5]

A series charge controller or series regulator disables further current flow into batteries when they are full. A shunt charge controller or shunt regulator diverts excess electricity to an auxiliary or "shunt" load, such as an electric water heater, when batteries are full.[6]

Simple charge controllers stop charging a battery when they exceed a set high voltage level, and re-enable charging when battery voltage drops back below that level. Pulse-width modulation (PWM) and maximum power point tracker (MPPT) technologies are more electronically sophisticated, adjusting charging rates depending on the battery's level, to allow charging closer to its maximum capacity.[citation needed]

A charge controller with MPPT capability frees the system designer from closely matching available PV voltage to battery voltage. Considerable efficiency gains can be achieved, particularly when the PV array is located at some distance from the battery. By way of example, a 150 volt PV array connected to an MPPT charge controller can be used to charge a 24 or 48 volt battery. Higher array voltage means lower array current, so the savings in wiring costs can more than pay for the controller.[citation needed]

Charge controllers may also monitor battery temperature to prevent overheating. Some charge controller systems also display data, transmit data to remote displays, and data logging to track electric flow over time.

Integrated charge controller circuitryEdit

Circuitry that functions as a charge regulator controller may consist of several electrical components, or may be encapsulated in a single microchip, an integrated circuit (IC) usually called a charge controller IC or charge control IC.[2][7]

Charge controller circuits are used for rechargeable electronic devices such as cell phones, laptop computers, portable audio players, and uninterruptible power supplies, as well as for larger battery systems found in electric vehicles and orbiting space satellites[8]

Charging protocolsEdit

Due to limitations in currents that copper wires could safely handle, charging protocols have been developed to allow the end device to request elevated voltages for increasing the power throughput without increasing heat in the wires. The arriving voltage is then converted down to the battery's optimum charging voltage inside the end device.[9]

Quick Charge and Pump ExpressEdit

The two most widely used standards are Quick Charge by Qualcomm and Pump Express by MediaTek.

The 2014 and 2015 versions of Pump Express, Pump Express Plus and Pump Express Plus 2.0, differ from by communicating voltage requests to the charger using current modulation signals through the main USB power lanes (VBUS) rather than negotiating through the USB 2.0 data lanes.[10]

Pump Express Plus supports elevated voltage levels of 7, 9 and 12 volts, whereas the specification for Quick Charge 2.0 lacks the 7-volt level. A 20-volt level was added in a revision named "class B" of the specification.[11][12]

The voltage range of the successor Pump Express Plus 2.0 is between 5 volts and 20 volts, with half a volt between each step (5.0 V, 5.5 V, 6.0 V, ..., 19.5 V, 20.0 V). The Quick Charge 3.0 protocol supports finer-grain voltage levels and has a lower minimum voltage. According to PocketNow, Quick Charge 3.0 starts at 3.2 volts with 0.2 volts between each step and goes up to 20 V (3.2 V, 3.4 V, 4.6 V, ..., 19.8 V, 20 V).[13][14][15][16] The site "" claims that the protocol has a minimum voltage of 3.6 volts.[17]

Oppo VOOC and Huawei SuperChargeEdit

Oppo VOOC, also branded as "Dash Charge" for the subsidiary "OnePlus", as well as SuperCharge by Huawei, have taken the counter approach by increasing the charging current. Since the voltage that arrives at the end device matches the optimum battery charging voltage, no conversion inside the end device is necessary, which reduces heat there. However, unlike the charging protocols that only elevate voltage, the higher currents would produce more heat in cables' copper wires, making it incompatible with existing cables, and require special high-current cables with thicker copper wires.[18]

See alsoEdit


  1. ^ a b "Charge Controllers for Stand-Alone Systems" (Web page), part of A Consumer's Guide to Energy Efficiency and Renewable Energy, U.S. Department of Energy. Retrieved on 2007-08-20.
  2. ^ a b Webarchive backup: Brown, David. "Technical Article: Battery Charging Options for Portable Products." (Commercial website). Analogic Tech, 2006-07-01. Retrieved on 2007-08-21.
  3. ^ "United States Patent 5475294: Charge controller for battery charger." (Website) Retrieved on 2007-08-21.
  4. ^ Webarchive backup: "Remote Observation Station, Entry #F2040: Abstract."[dead link] Circuit Cellar Flash Innovation 2003 Design Contest, via 2003. Retrieved on 2007-08-21.
  5. ^ "Conergy Solar-Port available from Energy Matters" Archived 2007-09-27 at the Wayback Machine (Press release). 2007-07-23. Retrieved on 2007-08-21.
  6. ^ Dunlop, James P. "Batteries and Charge Control in Stand-Alone Photovoltaic Systems: Fundamentals and Application" Sandia National Laboratories, Photovoltaic Systems Applications Dept, 1997-01-15. Retrieved on 2007-08-21.
  7. ^ "MAX712, MAX713 NiCd/NiMH Battery Fast-Charge Controllers." (Data sheet). Maxim Integrated Products. 2002-06-21. Retrieved on 2007-08-21.
  8. ^ Glover, Daniel R. (Editor: Andrew J. Butrica) "SP-4217 Beyond The Ionosphere: Fifty Years of Satellite Communication, Chapter 6: NASA Experimental Communications Satellites, 1958-1995." National Aeronautics and Space Administration, NASA History Division, 1997. Retrieved on 2007-08-21.
  9. ^ "How Does Fast Charging Work? Every Standard Compared | Digital Trends". Digital Trends. 1 July 2021. Retrieved 26 April 2022.
  10. ^ Mediatek Pump Express Introduction (2016)
  11. ^ "What is Qualcomm Quick Charge?". Power Bank Expert. 18 January 2020. Retrieved 21 July 2020.
  12. ^ "Qualcomm Quick Charge FAQs | Qualcomm". Both Class A and Class B adapters are rated at 5, 9 and 12 volts. Class B adapters go one step further, up to 20 volts.
  13. ^[bare URL PDF]
  14. ^ Pump Express Plus — MediaTek Technology White Paper (April 2015)
  15. ^ "Quick Charge 3.0 specs". Qualcomm. Archived from the original on 2022-05-17. Retrieved 2022-05-17. Maximum Input Voltage: 22 V
  16. ^ "Qualcomm Quick Charge 3.0: the Good, the Bad, and the Ugly". voltage between 3.2V and 20V at 200mV increments
  17. ^ "What is Qualcomm Quick Charge?". Power Bank Expert. 18 January 2020. Retrieved 17 May 2022.
  18. ^ "Quick Charge, Dash Charge, VOOC und Co.: Schnellladetechniken im Vergleich -". Curved (in German). 23 June 2016. Retrieved 26 April 2022.