Help with Rechargeable battery power for Arduino based bot

greenhorn

greenhorn

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Juggernaut
I am trying to build a OTTO DIY bot for my son to practice scratch
www.ottodiy.com

Otto DIY Academy

All in one online EdTech learning platform for robotics and design with Otto DIY. STEM-A curriculum , free guides articles and tutorial on how to program, build and design your own robot in the classroom. TinkerCAD, Fritzing, Arduino IDE, Blockly, Otto DIY, App inventor.
www.ottodiy.com www.ottodiy.com

I am not able to find a solution for the battery - the official build thread says to use this

But this is nowhere to be found. Can someone help me with finding a substitute battery + charger combo?

I was planning to use a TP4056 based module

TP4056 1A Li-ion lithium Battery Charging Module With Current Protection – Type C – RoboticsDNA

roboticsdna.in roboticsdna.in
which is commonly available with a 1250 mah battery
but it looks like this module puts too much current for such a small battery
It can be modified but SMD Soldering is beyond my comfort zone
What are my other options ? Can i go ahead with the above combo?
 
The battery shield that you linked, is of a rare type because it uses a rare sized cell which is 16340, now I think this is due to the size constraints of your bot.

The similar shield for widely popular 18650 cell is available here, it will be slightly bigger, check if the size of this works for you.

1744449821393.png
 
greenhorn said:
https://www.amazon.in/gp/aw/d/B0DLSJ3WVL?ref=ppx_pt2_mob_b_prod_image
Found this version which can fit a 18650
Click to expand...
That 2S battery holder does not have any charging and discharging support circuitry.

You have to charge them manually by other means, by removing the cells from the holder.

You don't want to discharge the cells completely, because when lithium cells goes into deep discharge, below 2.5v, it requires different charging strategy. This is where discharge support circuity helps, it never lets cell go below a certain voltage by disconnecting the load automatically.

If you charge a deep discharged cell manually by applying 4.2 volts, it can cause it go into thermal runaway, and cause fire and explosion. A good charger will detect that the cell is deeply discharged, it will charge it the right way.

Caution - a lithium cell and a kid is involved in a project, be careful. Make sure never plug the cells in reverse polarity, it happens very often because 18650 cells are not meant to be used barebones.

Reputable kids toy never come with 18650 cells in market for a reason. They prefer much safer Ni-CD Rechargeable Batteries.
 
greenhorn said:
I have ordered one of these

Type-C USB 2S BMS 15W 8.4V 12.6V 1.5A Lithium Battery Charging Boost Module With Balanced Support Fast Charge With Indicator – RoboticsDNA

roboticsdna.in roboticsdna.in
Once the bot is assembled it's all closed and he won't have access to it
Click to expand...
Can we use a 5v power adapter to charge this or do you need a specific voltage power adapter
Found this a little simpler to use
 
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