- 1 Module LDO RTC
- 2 Type of Battery
- 3 Common Lithium Battery Charge Method
- 4 Battery Protection
- 5 Schematic
- 6 Battery Charge Management - "Smart Charge" IC
- 7 Mutil-Cells Battery Charge Mangement
- 8 Selection Guide (Writing, reference only)
- 9 Datasheet
Module LDO RTC
- MT2503 ED20 -> 1.1V RTC LDO
- SIM800 -> 2.8V RTC LDO
Type of Battery
|Core||Diameter x Thickness||Voltage, Charge current||Package, Volume||Application|
|CR2032/2025/2016, LIR2032||dia. 20mm, 3.2~1.6mm||3V (3.6V, charge 0.2C)||225 mAh (40mAh)|
|CR1220, LIR1220||dia. 12mm, 2mm||3V (3.6V, charge 0.2C)||8-12mAh|
|AG3||dia. 8mm, 3.6mm||1.5V||35 mAh|
|AG13||dia. 11.6mm, 5.4mm||1.5V||LR44, L1154, SR44, SG13, 128 mAh|
|Li+ = lithium battery (Lithium-ion, lithium-polymer)||3.7V-4.2V||18650, polymer, LIR2032|
|LA = Lead–acid battery, Lead-Sealed||2.1V||normally e-bike use 2.1V x 6 = 12V|
|Ni-MH, NiCd battery||1.2V||AA, AAA|
|Li+ Titante||Low voltage||E-Bus|
Common Lithium Battery Charge Method
- 5V High-voltage charging: This charging method does not have a dedicated control circuit, directly with a 5V power head (or a series of diode buck) on the battery with a protective plate charge, completely dependent on the protection board high voltage limit. Is the beginning of the current is very large, and then gradually reduced, at any time float; this type of board mostly will explode, commonly used in low-grade card MP3, etc.
- Constant voltage charging: This method to keep up with a constant voltage is actually "limit voltage", set a relatively accurate maximum voltage, and then go to that voltage dead charge, less than 4.2V oath endlessly, common called "silly charge" , if the end voltage 4.2 can reach probably will be fine, if not then the charge still rely on protection board.
Common in the current mobile phone universal charge and flashlight direct charge, the cost of this charger less than a dollar, all made by inferior parts.
- Constant current charge: This method is derived from the last and on a circuit, but the maximum charge current is limited, constant-current constant-voltage is actually "limit current and limit voltage".
The charge will not stop, now that a long time a small current charge is one of the causes of battery flatulence;
|Battery voltage < 3V||Recovery state||Pre-charge||charge with a small current, normally 0.1C|
|Battery voltage > 3V||Can support large current chartge now||Constant-Current Charge||0.2-1C|
|Battery voltage = 4.2V||reach battery maximum voltage||Constant-Voltage Charge||charge current gradually decreases untill 0.01C and end|
|-||End of Charge||detect minimum charge rate 0.02C-0.07C (sensor) or two hours later after constant-voltage charge (by timer)|
Battery Charge Management - "Smart Charge" IC
- R4 Prog value setting table, see right table
- Charging Status LEDs
- Module will generate many heat, because when run on high current, module need to step down the votalge from 5V-4.2V, so it is about 0.8V * 1A heat dissipation.
|Error (battery temperature is too high, too low and other fault conditions, with or without battery access (TEMP use))||OFF||OFF|
|No battery detected||Blink||ON|
- 1. The test current ammeter can only be connected in series with the 5V input of the charging board.
- 2. Charging current is the best battery capacity of 0.37C, which is 0.37 times the capacity, such as 1000mAH battery charging current 400 This is enough. Too large charge speed effect is poor, washed out of the battery voltage off more!
- 3. Charging connection wire can not be too thin. This connection resistance. Too thin then washed out the battery voltage dropped more.
- 4. The best connection with the battery contact. Otherwise, the battery voltage off more finished.
- 5. If the 5V input voltage is high, such as 5.2 or even 5.5, will cause the charging current less than 1000mA, this is normal. High voltage chip heat will automatically reduce the charging current, not to the chip burned. It is normal for the chip to generate heat at about 60 degrees at work. After all, charging current.
- 6. Input reverse has no effect on the chip, but the output (battery side) reverse will burn the chip, please note the buyer.
- Charge rate: 2K for 500mA, 10K for 100mA. 67K for 14.5mA
Mutil-Cells Battery Charge Mangement
Features and Use Guide of CN3722
- datasheet please see datasheet section below
- Support multi-cells, 5A max.
- Photovotaic MPPT Function
- Trickle-current charge, CC and CV charging Mode
- Trickle - on board backside R9 resitor to pin8, can be used to enlarge the trickle-current charge current.
- All following information from datasheet
- Detect constant-current charge current = Ics, according to datasheet Ics = 200mV/Rcs, board example:
Ics = 200mV / ( 2 x parallel 0.33R = 0.17R ) = 1.17A
- Detect Fb voltage = 2.416 * (1 + R7/R6) + (Ib x R7), in case (Ib x R7) is difference, Ib normally 50nA, we simply igore it first here, board example:
Vfb (Vbat) = 2.416 * (1 + R8/R9) = 2.416 * (1 + 13.7K/28K) = 3.589V, around 3.6V
- MPPT voltage setup, board example
Vmppt = 1.04 x ( 1 + 220K / 13.7K)
- Charge voltage VCC should be always 2V higher than stop voltage of battery, for example, if you have 3x 4.2V = 12.6, please supply 15V.
- Parts selection guide, refer from datasheet
|Header text||Header text||Header text|
|Diode D1 D2||30BQ015||50WQ03FN。|
- Rcs, 1A -> 2ohm, 2A -> 1ohm, 3A -> 0.067ohm, 4A -> 0.05ohm, 5A -> 0.04ohm,
Selection Guide (Writing, reference only)
|TP5000||Li-MnO2, LiFePO4(LFP) charger IC, 1/2A||Example|
|MCP73831||0.5 A charge current, LED indicator||Example|
|TP4056||Linear charging, 1A||Example|
All-in-one IC power management
|Type||Feature||Charge / Vout||Package|
|TP5400 / TP5410||-||1A/1A||SOP8|
|TPower TP4213||Volume display, battery protection||1A/1A||SOP8|
|IP5303 / IP5305 / IP5306||-||1A/1A, 1.2A/1A, 2.1A / 2.4A||SOP8|
|File:LDR5108 Spec CH V2.3.pdf||-||2A / 2A(2.5A double output)||SOP14|
|File:IP5108 brief.pdf, IP5206||-||2A / 2A, 1.5A/2.1A||SOP16|
|HB6266||为同步开关型高效锂离子/锂聚合物电池充电和升压放电控制芯片||?||TSSOP-24 或 QFN-24|
|TP5602||低成本同步型, display, internal battery protection||3A / 3A||QFN24|
|IP5209||-||3A / 2.4A||QFN24|
|IP5318||QC2.0/QC3.0||4.8A / 3.1A||QFN24|
- The rest: BL8579, JW5000, AD6606
- FP6719 / FP6717 / FP6291 DC-DC Boost
- Solution - FP6601 + TPS61088
QC Protocol Identify:
- LI4001 - LI4001是一款面向5V交流适配器的2A锂离子电池充电芯片。采用700KHz开关降压型转换器拓扑结构工作。LI4001包括完整的涓流充电、恒流充电、恒压充电、充电自动终止电路、自动再充电以及过流保护、短路保护电路。最大2A的可编程充电电流与简单的外围电路造就了一种能被嵌入在各种手持式应用中的小型化充电器。由于集成了温度保护、输入欠压闭锁，提高了芯片的应用可靠性。
- TP5100 - 2A开关降压 8.4V/4.2V锂电池充电器芯片
Lithium Battery Protection
- 8205S + DW01
|Solution and link||Header text||Current||Type|
|Charge:HB2055 (2DLF) + Boost: CE8301/BL8530(E50D) + Protective: S-8205A/B + DW01||-|