18350 three-in-one power column

This project has no separate use, it is mainly used as a front part, it can be said to be a whole family bucket of Injoinic.
 
 
1. The circuit scheme
uses 3 4.2V 900mAh 18350 batteries. The 18350 is used for compactness, after all, it is not designed as a power bank.
6P typc-c input, but there is no cc1 cc2 pull-down, the dual c-port fast charging cable should not be able to power.
Lithium battery protection: IP3005A, built-in power mos, simple periphery, integrated voltage and current overcharge and over-discharge protection, IP30xx has multiple types corresponding to different protection parameters, see Battery Management Protection | Product Center | Shenzhen Injoinic Technology Co., Ltd. (injoinic.com) for details, but some retailers seem to be unable to buy it.
Charge and discharge management: IP5306, built-in 5V synchronous boost, power path management, LED power indication, and also has certain overcharge and short circuit protection functions. A frequent visitor of DIY power bank.
 
2. Explanation:
Three 18350 lithium batteries are connected in parallel through nickel sheets. The nickel sheets are placed like the Mercedes-Benz logo (three lines from the center to the vertex of the regular triangle) to connect the three lithium batteries. First, it should be noted that lithium batteries of different manufacturers/different capacities/different voltages cannot be connected in parallel. It is recommended to buy three in the same store and charge each to the same voltage (a difference of 0.01V is allowed) before connecting. Second, it should be noted that the welding temperature must not be too high and the time must not be too long, otherwise there is a risk of fire and explosion. The dangers of lithium batteries should also be known. The best way is to use a spot welder. It is recommended to use low-temperature solder paste (139 degrees) and a soldering iron within 250 degrees for 3-5 seconds. It can be welded in multiple times, but the soldering iron must not be pressed on the battery for too long. In addition, it is recommended to polish the battery poles in advance, otherwise it is not easy to tin.
The large bottom pads of IP5306 and IP3005A need to be grounded. Since I only have a soldering iron, I lead out a section of the bottom pad for easy welding. The former's unreliable grounding will result in a synchronous boost output of only 2-3V, and the latter's bottom will have too much current, so you need to be careful when welding.
The power control board and the bottom plate share a common ground through a copper column (this ground is actually the GND of the battery rather than the output P-), so be careful of short circuits between pads.
The 5V output is brought out through two flange pads, as shown in the figure. This design is because the subsequent load parts can be placed on the same PCB and conduct electricity through the copper column (such as a lighting board or a board with a USB-A interface, etc.), and can be stacked layer by layer without exceeding the load current, which is more beautiful.
 
 
3. Actual picture