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schematic

simulate this circuit – Schematic created using CircuitLab

Hey guys it's my first post here and i'm a bit unsure with this circuit, will it work or will there be some problems?

My suspicion is that the charging won't work correctly and there could be some under or over charging / balance issues but I'm not sure.

Also the current draw from the transformers will range from 500 mili amp to 4A depending on peripherals attached so on dead batteries im unsure if the transformers will get enough power as two tp4056's can only provide 2A, maybe a way of fixing it would be to add extra wires going from the tp4056 'in' pins to the 'in' pins of the transformers? (provided the micro usb 'in' supplies atleast 6A i would presume it could power the device while still charging the batteries?)

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YH11062B boost converter data sheet

  • Input voltage: 2.6-5.5V
    Input Current: 0-3A
    Output voltage: 5V
    Output current: 0-2A
    Short circuit protection: Yes

TP4056 DATASHEET: https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/TP4056.pdf

Help would be much appreciated!

(EDIT: Datasheet + Circuit Diagram, hope this one is better //i'm new to circuit schematics)

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  • 1
    \$\begingroup\$ Instead of posting a messy diagram how about making it not messy? \$\endgroup\$ Commented Aug 25, 2017 at 6:59
  • \$\begingroup\$ Welcome to EE.SE. There is a built-in schematic tool with a button on the editor toolbar. There are battery symbols, switches, etc., and a generic multi-pin component that will enable you to draw a meaningful schematic. You should also post links to datasheets for any devices used. \$\endgroup\$
    – Transistor
    Commented Aug 25, 2017 at 7:03
  • \$\begingroup\$ No, it will not work. They will fight each other. \$\endgroup\$ Commented Aug 25, 2017 at 9:12
  • \$\begingroup\$ Why? And how can i fix it? \$\endgroup\$
    – Matty
    Commented Aug 25, 2017 at 9:20
  • \$\begingroup\$ The TP4056 is designed for one thing and one thing only - charging a battery. It's not designed to power other things at the same time as it will have no idea what current is going into the battery and what is going elsewhere. \$\endgroup\$
    – Finbarr
    Commented Aug 25, 2017 at 10:45

1 Answer 1

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Your new and improved schematic shows that you have parallel connected the batteries and charger outputs. There is no way for each charger to know which battery is being charged.

enter image description here

Figure 1. The only circuit given in the TP4056 datasheet.

With only one example application that datasheet doesn't give a lot of help. I'd look around for a similar chip with more sample applications.

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  • \$\begingroup\$ Thanks, I will do just that. Just to clarify one thing, if i were to remove the 2nd tp4056 and battery would my circuit function correctly? \$\endgroup\$
    – Matty
    Commented Aug 25, 2017 at 9:26
  • \$\begingroup\$ If you configure as per the datasheet I don't see why not. I don't know about the YH devices. \$\endgroup\$
    – Transistor
    Commented Aug 25, 2017 at 9:29
  • \$\begingroup\$ Say for example the battery is charged but i still supply power to the tp4056, won't the tp4056 supply power to the rest of the circuit but also overcharge the battery? \$\endgroup\$
    – Matty
    Commented Aug 25, 2017 at 11:38
  • \$\begingroup\$ I can't answer this at the moment. I suggest you read up on battery management solutions and application notes. There must be thousands of articles on this as most USB powered devices can run while the batteries are charged. \$\endgroup\$
    – Transistor
    Commented Aug 25, 2017 at 11:44
  • \$\begingroup\$ I found this - ebay.com/itm/… would it do the trick and charge the batteries and also allow current for the rest of the circuit if i use a 2S setup and supply 8.4v? (Using buck converter instead) Sorry i couldn't find the datasheet for it \$\endgroup\$
    – Matty
    Commented Aug 25, 2017 at 12:57

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