Tear down TOMO V8-4 to check if it’s the best portable power bank of yours 2

Someone, like you and me, always tends to seek perfection, such as a perfect guy, a perfect phone, or perfect experience. Even a perfect portable power bank is no exception. Both of Xiaomi and OnePlus advocated that their power banks are the best. But actually as we all know what’s the most suitable is the best. So your best portable power bank is the one that is able to fit for you.

Today we will tear down a TOMO V8-4 to check if it’s the best portable power bank for you.

It is not very hard to disassemble TOMO V8-4. Even a screwdriver is not needed. Finished tear-down, you may be impressed by its elegant case design and solid feel. The whole PCB looks totally new. The layout of the PCB is elegant and straightforward.

The PCB of TOMO V8-4 has 7 distinguished features as followed.


A. SS32 Schottkey diodes from MIC: Level dissimilar voltage and avoid reverse polarity – protect battery cells.

Four SS32 Schottkey diodes from MIC are designed to be respectively associated with the negative contact for one of the battery cells. This design contributes to ensure that the battery cells keep approximately similar voltage during discharge, so it will prevent the cells to be damaged by low currents among them caused by dissimilar voltage. On the other hand these Schottkey diodes play a switch role in the PCB. When an incorrect insertion was made, it will turn off the switch. Again the cells are protected to be damaged.

B. High-efficiency tantalum filter capacitors: smoother and more stable output Direct currents – protect your phone, Ipad, and MP4, etc..

High-efficiency tantalum filter capacitors are applied in the PCB. It can filter the Direct currents very efficiently, which leads to smoother and more stable output Direct currents to sure the USB devices to be well protected.

C. High-efficiency inductors.

Combination of high-efficiency inductors and high-efficiency tantalum filter capacitors is a perfect filter circuit.

D. TP4057 charge management IC: independent charging system guarantees charging safety.

Four identical TP4057 charge management IC are each associated with an individual battery cell, so that each battery cell can be charged independently. It is safer.

E. 9926A MOS: make sure a stable output of 5V/3A.

The purpose of the design is to regulate the output current and manage the power distribution when USB devices are connected.

F. PIC16F1933 micro-controller from Microchip: manage and detect the whole power bank

The LCD display is driven by the micro-controller. All the information you can see from the display is detected by this magic micro-controller. It provides information about the charging level of each cell,  powering on automatically when insert a battery, which USB port is drawing currents, and so on.

G. MT5032A Synchronous Step-up Converter: convert 3V-4.2V to 5V.

The converter plays a role in converting the voltage 3V-4.2V of cells to the regulated voltage 5V catered to USB devices.

That’s all for today. Is TOMO V8-4 the best portable power bank for you?

2 thoughts on “Tear down TOMO V8-4 to check if it’s the best portable power bank of yours

  • Guy Fallon

    Thank you. Yes this is the power supply/ charging dock I need.
    The fact you have explained the unit to me was impressive. I will look to our company first for future purchases and tell my friends and colleges about you.

  • AcE Krystal

    Really nice to explain the inner workings. I like it when people get excited about there own product and like to share it with the world. Some find showing some transparency of there own product a dangerous thing they keep far from, but for me it shows people have trust and love for there own product.

    Also great job explaining it for different experience levels. nice low level explanation + the actual component names for the more experienced people.

    I’m curious though, will there be an version coming out that not only shows if something is draining, but also show how much current it is draining, maybe with a estimate time of battery live the the current drain (maybe estimate battery live by avarage drain of last x minutes for a more consistent number?).

    I guess I will place some orders in the future for all my personall and business DIY/IOT projects.

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