Li-Ion Battery Charging Solutions:
Over the past year, I’ve replaced numerous conventional batteries in my household devices with lithium-ion batteries, significantly enhancing their performance. Various gadgets like lantern radios, LED lanterns, and handheld brooms received this upgrade. For instance, a radio lantern initially powered by a 6V battery and another device using a 1.5V pen cell were revamped. In both cases, a single li-ion battery sufficed. By connecting the li-ion battery in series with a stray wire and a 1N4007 diode, a voltage of approximately 0.7V was achieved.
Additionally, a LED flashlight operating on a 6V battery required just one li-ion battery. In contrast, for devices with three Ni-MH batteries (3.6V total), two lithium-ion cells connected in parallel provided adequate power.
To charge the lithium-ion batteries in the radios and LED lanterns, the MCP73831, a compact charging controller in a SOT-23-5 package capable of delivering up to 500mA, was employed. It features an LED indicator to display the battery status and requires minimal external circuitry. These circuits were powered using a 5V adapter as the energy source.
In the charging setups employing the MCP73831. I incorporated battery protection modules for some lithium-ion pins, ensuring safe charging. However, these modules were omitted for the vacuum cleaner application. To prevent overcharging, I integrated a bubble charge circuit into the adapter, which activates when the vacuum cleaner is in use. Depending on the desired charging current, I adjusted the MCP73831’s current setting resistor (R1) to values such as 2.2K for 500mA, 2K for 240mA, 4.2K for 160mA, 6.34K for 130mA, and 7.87K for 100mA. The input and output capacitors were also adjusted correspondingly.
MCP73831 LI-ION BATTERY CHARGING CIRCUIT DIAGRAM
Back then, I had discussed the TP4056 modules, but their prices were high for the required 1-ampere capacity. Consequently, I opted for various PCB sizes tailored for the MCP73831.
Recently, I employed TP4056 modules for charging my Li-ion batteries, a total of three. Each TP4056 module necessitated a dedicated power supply. Although I had some high-power SMPS cards available, none of them proved suitable. To resolve this, I repaired faulty 1.6A 5V SMPS adapters manually, utilizing them for my devices while waiting for their proper repair. For housing, I repurposed a defective SMPS adapter box.
In this setup, I mounted a 3-Li-ion battery socket inside the box and soldered the TP4056 modules securely. To monitor the charging status, I cut an opening on the box and added a red mica cover…
If you possess a high-power SMPS adapter, there’s no necessity for an additional power supply dedicated to the TP4056 modules.
Initially, I tailored the perforated panel to fit the box and then inserted the cards. To enhance the setup, I incorporated a passive EMI filter into the 220V input.
The charging current of the TP4056 charger module is adjustable. TP4056 modules typically come with “Prog” resistors to determine the maximum output current. By altering the resistor connected to pin 2, the TP4056 can be configured to provide a charging current ranging from 130mA to 1000mA.
If your available power supply slightly exceeds the charging current requirement – for instance. If you’re using a 5V 1A adapter – it’s crucial to set the TP4056 module’s current to 800mA or less. Failure to do so might lead to the adapter malfunctioning or entering a protective mode.
WHAT SHOULD BE THE BATTERY CHARGE CURRENT?
Charging current to be used when charging the battery varies according to the power of the battery. Below table shows charging current information of LG, SONY, PANASONIC, SANYO, SAMSUNG batteries.
The optimal charging current for ensuring extended battery life is represented by the green zone. Battery brands vary, ranging from 0.3A to 1.5A.
In the yellow zone, the standard charge current specified by the battery manufacturer is indicated.
The orange region denotes current values provided by the generator for rapid charging. However, it’s important to note that fast charging significantly reduces battery life and can be hazardous. Additional precautions need to be taken in such cases.
To preserve your battery life, it’s essential to consult the manufacturer’s information specific to the brand and model of your battery. Adjust the charging module or device according to these specifications.
Update: I will be addressing a question in a different article that might be beneficial to the concerned individual, along with a few additional points…
@ Basri Acar 2018/04/21
Mr. Gevv, I made a battery of 80 volts at 4.7 volts from 18650 lithium batteries. Kismetse, in the coming months I will travel on a long route for cancer susceptibility with a 5-meter cannon. That’s why I keep amperes high. But I can not find the circuit I want because I will charge it with the solar panel. I am very happy if you can help with this.
If your solar panel is 6v, your job is easier, but can you connect the high current panel to the kanoya? the size becomes bigger in the base.
The TP4056 modules are connected in parallel (as mentioned in some forums) and try to connect and try as in the following diagram, the current rises as the number of modules increases (usually 2 modules are used ..)
The parallel connection status of TP4056 modules was examined in a more detailed application, and a specific module with 3A power was available for purchase on eBay. In this setup, all modules utilized a 1.5k plug-in current regulator resistor and a 780mA current-resistance plot. Consequently, the total charging current reached 3.1A. Although a charge current of 1A was feasible, I opted to keep it lower due to concerns about the larger PCB size needed for efficient cooling.
In the parallel connection configuration, only one set of display LEDs was connected among the modules, leaving the LED connection legs of the remaining modules empty. Additionally, the +2 inputs of the modules were connected to +2 SS54 shock diodes in parallel, supporting a power of 5A and a voltage of 40V.
TP4056 4X PARALLEL CONNECTION SCHEMATIC
When utilizing a complex module, you can connect diodes to each module’s + input. Similar to the 6V solar panel connection described earlier. For TP4056 modules, the recommended input voltage ranges from a minimum of 4V to a maximum of 8V, with an ideal voltage of 5V according to the upper schematic. When connecting diodes in parallel, there is minimal voltage loss.
In cases where the input voltage is 5V, it is advisable to employ a shock diode. While a 0.7V loss on a 6V input is generally acceptable, the 5V input voltage might pose integration issues if not handled properly.