Monday, March 16, 2015

Mailbag arrival! New Battery solution for ESP8266 Modules!

================== W A R N I N G ! ! =================
Li-Ion batteries are very dangerous if not handled properly.
Use them only with proper protection circuits and chargers.
     Using any of the informations available on
 is on your own risk !!

   Finally Arrived! This was a long awaited one. Postal service at it's best :)

   I was asked for a more compact and easy to recharge battery pack solution for the ESP8266 Modules and with the new items arrived in the MailBox, here it is:

ESP8266 Battery Module

What we will need:
  • LGDB318650 - Rechargeable 3,7V/2600mAh Li-ion Cell 
  • 18650 Cell holder
  • Li-ion Charger/Monitor with protection
  • Asorted wires - choose your desired color but red/black, blue/white standard coding with be better :)

Li-ion Cell and holder
   As the LGDS318650 Li-ion Cells does not have any internal protection been bare ones - usual find in laptops battery packs - we will need to use a charger/monitor with some sort of protection mechanism.

Forget the Ni-Mh abuse if you want to run your Li-ion cells properly and safely for a long lifespan.  Li-ion Cells shouldn't be charged/discharged/drained more than the recommended values to prolong its life and even to avoid a nasty explosion or fire!

The module from the picture below it's covering decently all the required needs:
  • USB compatible constant-current/constant-voltage charger - linear
  • Monitor for overcharge/overdischarge and/or overcurrent
  • High speed MOSFET Switching protection mechanism
Li-ion Cell Charger/Monitor with protection

   It is based on TP4056 1A Standalone Linear Li-lon Battery Charger with Thermal Regulation chip

   The TP4056 is a complete constant-current/constant-voltage linear charger for single cell
lithium-ion batteries. Its SOP package and low external component count make the TP4056
ideally suited for portable applications. Furthermore, the TP4056 can work within USB and wall

   No blocking diode is required due to the internal PMOSFET architecture and have prevent to
negative Charge Current Circuit. Thermal feedback regulates the charge current to limit the die
temperature during high power operation or high ambient temperature. The charge voltage is
fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The
TP4056 automatically terminates the charge cycle when the charge current drops to 1/10th the
programmed value after the final float voltage is reached.

    TP4056 Other features include current monitor, under voltage lockout, automatic recharge and
two status pin to indicate charge termination and the presence of an input voltage.
TP4056 - SO8 package


  •  Programmable Charge Current Up to  1000mA 
  • No MOSFET, Sense Resistor or Blocking  Diode Required
  • Complete Linear Charger in SOP-8 Package for Single Cell Lithium-Ion Batteries
  • Constant-Current/Constant-Voltage
  • Charges Single Cell Li-Ion Batteries Directly from USB Port
  • Preset 4.2V Charge Voltage with 1.5% Accuracy
  • Automatic Recharge
  • Two Charge Status Output Pins
  • C/10 Charge Termination
  • 2.9V Trickle Charge Threshold (TP4056) 
  • Soft-Start Limits Inrush Current
   For more details please see TP4056 Datasheet

   TP4056 is accompanied with DW01-G battery protection IC.

   DW01-G is designed to protect lithium-ion/polymer battery from damage or degrading the lifetime due to overcharge,overdischarge, and/or overcurrent for one-cell lithium-ion/polymer battery powered systems, such as cellular phones.

Protection circuit - DW01-G + Mosfet switch
   DW01-G has an accuracy of ±50mV overcharging detection voltage that ensures safe and full utilization charging. Also the very low standby current drains little current from the cell while in storage.

  • Reduction in Board Size due to Miniature SOT-23-6 Package
  • Ultra-Low Quiescent Current at 3μA (Vcc=3.9V)
  • Ultra-Low Power-Down Current at 0.1μA (Vcc=2.0V)
  • Precision Overcharge Protection Voltage 4.25V ± 50mV
  • Load Detection Function during Overcharge Mode
  • Two Detection Levels for Overcurrent Protection
  • Delay times are generated by internal circuits. No external capacitors required
  Battery Protection Swithing is done with 8205A Mosfet. The ML8205A uses advanced trench technology to provide excellent RDS(ON), low gate charge and operation with gate voltages as low as 2.5V. This device is suitable for use as a Battery protection or in other Switching application.

We will use this battery solution setup in the future for our battery powered projects.

Stay tuned for more about soon!


Plamen Todorov said...


Any chance that you will publish the PCB files and BOM? Do you have any PCBs for sale? Thank you!

Tracker J said...


I don't have any Li-Ion charger modules available now. If you want to quick put one together just use the datasheets examples. Also similar modules are available online to different sellers, including Ebay but beware of quality.

For any other questions please contact me directly at tech at Will be more than happy to help you.

gregwareblog said...

I was wondering if the 5V output can be used while the unit is charging?
i.e. use the battery as a 'buffer' in case 5v supply drops out?

Tracker J said...

Hi Greg,

It's working also in that way, not recommended, apparently it will not charge 100% and close the process gracefully (means blue light on) but I have one running like that for weeks already, combined with a solar panel, and is not complaining to much :).
Will go back to that one later, been busy this days with MPSM v2 story and the new CBDB DevBoard tests.

James T. Heires, PMP said...

A similar product based on the TP4056 was seen on for just $2.99 ( but it seems to have fewer parts. I suppose it's missing the MOSFET switching and battery protection circuit and a few other goodies, but maybe good enough?

Tracker J said...

You have right James, looks like a bare one, no protection, no nothing. Probably to make it more cost effective.

Might work OK but be sure that you are using Li-Ion cells with inside protection ONLY!.

The LGDB318650 ones from above are without any protection and I will not recommend you such a combination.

James T. Heires, PMP said...

Thanks, Tracker J. How about this model? Looks like it has the components onboard...

Tracker J said...

James, that one looks way better :). Cannot say anything about quality just from a picture but looks OK.

Unknown said...

Hi Tracker J, i have a question. The Charger circuit provides the output from 4.2 - 3.7 volts depending on the battery present capacity. How to get a regulated 3.3v which can power ESP8266? Also can i use this setup like a UPS for the ESP, like if I disconnect the power to the charger circuit, it should switch to battery for power. Sorry for noob question, as I am new to this field. Thanks :)

Tracker J said...

you need a 3V-3.3V LDO regulator to be able to run properly your ESP module. The usual LD1117 is not good as it has a voltage dropout around 1V. Look at the new CBDB nEXT EVO Board Schematic, it has a LDO (MCP1825S) suitable for battery run:

Pranesh Kumar.R said...

Thank you Tracker J

crazypiazza said...

don't follow this tutorial ,he inverted the polarity of the battery and i burned my project thanks to it

Tracker J said...

crazypiazza, do you have any idea what are you talking about? Must be some kind of joke. The polarity of the Voltage Output AND Battery connections are clearly written on the Battery Charger board.

Ralphes Bushman said...

Check this article on Flexispy hacking app, to get the latest update on the topic.

Sergio Ariel Fernandez said...

Hi, hello and thaks you for this information. Can I ask you a question? One person ask this to, without answer. "" can i use this setup like a UPS for the ESP, like if I disconnect the power to the charger circuit, it should switch to battery for power. ""
Thank you very much!

Tracker J said...

Hi Sergio,

It will work somehow but is a catch: to have a load all the time connected the power consumtion should be less that available input power - charging power needs to be able also to charge the battery.
I would suggest a separate very simple power failure detector + switch that can be something like some shottky diodes to a mosfet.

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