1. D

    Connecting 2P2S battery pack to BMS

    Hi All, I have four identical 18650 Li-ion batteries 3.7v \ 2500mAh and a BMS 2S. My goal is to get 5v (with step down) and more current capacity. so I though of connecting the batteries as 2P2S as battery university suggested. 2P because the Li-ion will balance themselves and for more...
  2. Cyirxrc6vec

    Charging Li-ion circuit

    Hi, I made a circuit that charge Li-ion battery. When I simulated it, I found something strange; the time for charging was too short. I made it with 'LTspiceXVII' and here's my circuit's diagram and the graph, also I uploaded the 'Li-ion bat file'. So, would you like to help me if you don't...
  3. G

    Li-ion cell charging module resistor selection?

    Greetings. A vendor selling TP4056-based 5 V charging modules for Li-ion cells specified the following resistance values and resulting current for selecting the current-programming resistor: R (kΩ) I (mA) 30 50 20 70 10 130 5 250 4...
  4. P

    Li-ion battery charging termination current

    Hi all, I have a question about Li-ion rechargable batteries. I have almost no experience with it. Documentation to battery is very poor, but there is an info about charging profile: Stage 1: Constant Current 0.82 Ampere (0.2C) until Voltage reach 4.2V Stage 2: Constant Voltage (4.2V) with...
  5. eliasklk_04


    Good night. I bought this flashlight for my bike: https://www.ebay.es/itm/Luces-Bicicleta-Luz-10000LM-Impermeable-3XT6-LED/292872854958?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 But the light that comes out seems very little to me. I think it has more potential. Could I modify...
  6. Tamás Fegyvári

    Non inverting DC-DC converter that makes fix 4V from a decreasing voltage from 4,2V to 2,8V?

    Hi! Is it possible to make a a non inverting DC-DC converter that makes a fix 4V from a Li-ion battery's voltage. I need about 1,5A. The input voltage starts from 4,2V and decreasing to 2,8V as the battery discharging.
  7. Carlosonline

    Li-Ion Battery Managment IC Issue

    Hi, I would appreciate if someone would be able to comment/advice on the following matter. I have been looking around for an IC that would charge and balance Li-Ion cells 2-3 of them in series. It seems that the balance feature is absent in most cases. MCP73841 appears to provide most of the...
  8. N

    Battery protection board needs to have voltage applied to output before turning on.

    Hello I have a Lithium ion battery pack that uses a small protection board that protects the battery pack from short circuits and under voltage. I am using 2 lithium ion cells in series for a nominal 7.4 volt output. The wierd thing is the protection board has to be first initialized by...