Arduino for kids toy with Battery (safe), Can Arduino overheat the Battery with long running code I am making a learning toy which kids can play with and learn basics of programming. But i am tired of keep replacing the AA batteries as they run out in few days. So i am thinking of using rechargeable battery. But i am very worried to use it considering it is kids toy and people says lipo and li ion battery can explode. There are dangers or over charge and heat etc.

Is it safe to use them? Which one to use? 

I am using Arduino pro mini 3.3v and some times 5v. 

I was planning to use: XCSOURCE 5 pcs 1A 5V Micro USB TP4056 Lithium Battery Power Charger Board Module TE420

I think some users have misunderstood the question and have voted this question to be closed. This questions is very much to deal with programming also apologies if i have not made it clear.


We can get the battery level in the code, but is there any way in code we can some how turn off the charging when the battery has been fully charged.
I am under impression (might be wrong, you can correct me), normal
battery single AA cell dies after some time on heavy use (using dc motor etc). But
rechargeable batteries are bigger with multiple cells in it they will
last longer. So if i am running some code in a loop for long time
will the battery get over heated will it be a problem.
Probably the easiest/cheapest and safest option is to buy a original USB Power Bank and there you have it. Power banks for cellphones/tablets have overvoltage/overcharge/undercharge protection on them and they are also completely sealed, so it should be perfectly safe to handle one of those to your kids (Of couse not some cheap chinese crap). 

They can then charge the power bank over USB on any PC or Wall charger and then use it for hours/days.

If I'm allowed to give you a tip, you could eventually pick one of these here, they are pretty good in my opinion.

Of course there are a ton of others around, so you can just pick one which fit your needs.

On your case you just cut a USB cable and plug the ends on the Pro Mini. If a short is detected, Power banks often just shut off and only turn on when they are charged again (You might try this first). If you use a 3.3V Pro Mini, just put a voltage limiter between it. You might also write "3.3V" on the voltage limitor and "3.3V" on the 3.3V version of the Arduino and teach your kids that if the Arduino has "3.3V" written on it, they should put that "3.3V" voltage limitor before it (or just not use 3.3V variants for ease of use).