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Topic: Parallel tp 4056 for powering Wemos (Read 512 times) previous topic - next topic

mat_ko

Hello,

i would like to power Wemos D1 mini with solar panel and two 18650 batteries. I was thinking to wire two TP4056 parallel (each charge their own battery) and with OUT pins powering Wemos. I'm also attaching diagram for better understanding. Would this wiring be OK ?

This is for my hobby project (weather station:), and since I'm more in SW development I would really appreciate for any advice from you HW gurus.. :)

Thank you in advance!
Regards,
Matko

Mikeb1970

Hello,

Have you considered you are trying to power 29.6W with a solar cell rated at 2W, and I'm certain your gonna have losses in your circuits. I'm not sure if this is possible with this solar cell, but I don't have much experience with them.

MarkT

#2
Dec 06, 2017, 11:33 pm Last Edit: Dec 06, 2017, 11:35 pm by MarkT
I think that chip does one charge cycle only, then cuts out(*) until it is power cycled - its a phone
charger chip, not a solar panel charger chip.

It wouldn't work well in overcast conditions, its assumes the supply can provide full charge
current.

A dedicated chip that knows about the behaviour of PV panels would likely be much more
satisfactory.

And you definitely can't just parallel outputs from two such devices, they will probably get
completely confused as each one switches in and out of trickle mode...

(*) I think it will trickle-charge only once the charge cycle is only, which isn't useful for this application.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

mat_ko

Thank you for your answer!

What dedicated chip would you advice instead of this two TP4056 ?


For reference for my wiring, i was having this project:
http://www.instructables.com/id/Solar-Powered-WiFi-Weather-Station/

 

MarkT

The place to search for components is at electronics stockists websites and major semiconductor manufacturers websites - they want to sell the parts, so they provide tools to find them...
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

Mikeb1970

Hello mat_ko,

In all honesty I do think that all the replies you have gotten sofar have not been very helpful.
I have been taught that it is sometimes very helpful to look at you problem very modular, and I think in this day and age were single purpose PCB have become so cheap this would be an ideal way to solve your problem. The end solution is that you want a solar powered voltage supply for you Wemos D1 mini, so you want 3.3V. Have a look at this, and scroll down to see the specs and look at the pics they posted.

https://www.ebay.com/itm/2in1-Buck-Boost-0-8-6V-to-3-3V-DC-DC-Converter-Module-for-esp8266-Wifi-Bluetooth/202035955278?hash=item2f0a48064e:g:xu8AAOSwhLJZoP7Q

This chip can be provided by either one or two 18650 batteries in parallel (not in series, because the max voltage input of the chip is 6.0V, I don't know why you need two batteries, but i'm assuming your doing this for power reasons. It is perfectly acceptable to put 2 18650 batteries in parallel, as described here.

http://batteryuniversity.com/learn/article/serial_and_parallel_battery_configurations

Have a look at this, if you can agree with what we have achieved sofar then we only need to add a charger PCB for your batteries and the solar panels. If there is something you don't agree with or don't like on what I suggested so far, then please let me know

With regards,

Mike

srnet

https://www.ebay.com/itm/2in1-Buck-Boost-0-8-6V-to-3-3V-DC-DC-Converter-Module-for-esp8266-Wifi-Bluetooth/202035955278?hash=item2f0a48064e:g:xu8AAOSwhLJZoP7Q
So assuming the Wemos is asleep and  in low current mode, what is the quiescent current consumption of the module you recommended ?
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
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mat_ko

#7
Dec 08, 2017, 04:12 pm Last Edit: Dec 08, 2017, 04:21 pm by mat_ko
Mike, thank you for your answer! I really appreciate and i'm grateful for any advice or direction...

I'm fresh in arduino development and i really like to do something useful. :) I already have wemos with sensors, but since it's located near house i would like to move it somewhere on open space, so I need alternative power supply.  I found similar projects with TP4056 (but they used only one battery) so this was my reference for thinking further. Since i was not sure about my wiring I asked here. Wemos D1 mini can be connected to 5V (5v pin), so there is no need to convert back to 3.3V.

The only reason for two batteries is because winters here can be really foggy so some times there is no sun for a week or two. So i put two of them to ensure enough power in such conditions. Or one would be enough? Wemos is reading from sensor every 5 minutes and then goes to sleep mode.

If I would take this chip u recommended, i still need charger. Could I use TP4056 as charger anyway ? Or some kind of solar regulation would be more appropriate (like this for example: https://www.aliexpress.com/item/Cool-Solar-Controller-10A-Solar-Regulator-12V-24V-LCD-Display-USB-5V-Solar-Panel-Charge-Regulator/32716946371.html )

I'm really open to any advice, so thank you again in advance!

Regards,
Matko









srnet

I think that chip does one charge cycle only, then cuts out(*) until it is power cycled - its a phone
charger chip, not a solar panel charger chip.
Correct.

Once a battery is fully charged you need to cycle the incoming power for the charger to start again.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

mat_ko

Correct.

Once a battery is fully charged you need to cycle the incoming power for the charger to start again.
I'm sorry, I don't understand totally, does this means that it will charge battery only first time? What means 'cycle incoming power' ?

Thank you!

srnet

What means 'cycle incoming power' ?
Removing the incoming power input to the charger.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

mat_ko

Can you please explain this a little bit more?

If it's used as phone charger for example, when battery is full, and I don't disconnect incoming power, it will start recharging again when phone battery voltage drops.. (i'm assuming phone chargers behave like this)?

Mikeb1970

mat_ko, hello again.

I don't know why some here keep saying that you tp4056 isn't suited for this job and claim its a phone charger. When looking at the datasheet of the tp4056 it is clearly mentioned that its suited for automatic recharge and even better it has 2.9V Trickle charge threshold. It is also clearly mentioned that it is used for allot more things then charging phones. In short I do believe your choice for this product was a very good choice, you can even use this to charge two 18650 in parallel, or, if you think the sun will not play along, use two in series and use  two solar panels. For being able to generate the max 1000mA the tp4056 can deliver, and witch I would recommend you will need a 5V 5W solar panel, do the math. This would be for two batteries in parallel. If you decide to go for the batteries in series I would go for 5V 2.5W or, since you prob have them use your 2W one's.

For the disbelievers of the tp4056 here is the datasheet.

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

good luck with your project mat_ko

mat_ko

Thank you Mike !
I will take more powerful solar panel 5V 5W and give it a try...

Regards,
Matko

Mikeb1970

You are welcome Matko,

I have just ordered 10 tp4056 boards myself. I would say if you want, keep me informed of your project, if you have the time.

Good luck,

Mike

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