I am working on an Arduino project with two Megas and was hoping to find a way to power it the way I want. One method of powering is a 600mAh 9volt battery which I can plug into the VIN and GND ports. It is a Lithium-ion Rechargeable battery and I have the charger that came with it. The second method is a dc wall socket power converter I have. It has a 2.1mm barrel plug, it emits 9 volts at 2.5A. I can get a breakout for and plug this into the VIN and GND Pins. I know how to do both of these. What I want to know is how to do both of them. I know I shouldn’t just plug the barrel breakout into the 9 volt battery, I know JUST doing this will cause the battery to burst because once it is fully charged the current won’t stop. (Is there an additional danger to charging a 9 volt 600mAh battery with a 9 volt 2.5A current.) What I want is a way to properly charge the battery and have it automatically stop charging once the battery is near full. Here is a basic Fritzing of what I know not what to do. Could you please detail a PCB board (or other solution) I will have to make to accomplish this.
I am going to the electronic parts store on Tuesday and would like a list of parts then.
More to the point though, 2 Megas off a 9V battery? That'll run out of juice in like 6 hours just powering those boards, forget about whatever they're connected to. Never use a development board for a battery powered project, the parts the make it easy to use also makes them suck way too much juice and you can't turn those parts off.
If you don't want to hook a pair of giant 6V lantern batteries to the project, low power usage requires a bit of a learning curve and stepping a bit outside of the Arduino's playpen to enable to full potential of the chips. Battery power is a legitimate hardware challenge in its own right.
What are you going to be running that needs two Megas? Those things are monsters. Would you be able to get away with Unos? Their chip (ATmega328P) comes in a DIP package and is much easier to prototype with.
Thank you for your concern about how quickly I would drain the battery. I will mostly be using with the wall plug or a car jack plug. The battery is so I don't have to reset it while switching between plugs.
I already own a smaller of what you linked. It charges two 9 volts at a time. I want to build a circuit to safely charge my 9 volt battery without taking it out of my project. Your solution doesn't solve this issue.
If what I want to accomplish is to ambitious please let me know directly.
Troymako:
I know how to do both of these. What I want to know is how to do both of them.
So you actually meant that you don't know how to do 'both of these'?
Also, do you mean to say that you would like to implement both charging methods at the same time? Or you just want to choose one of these charging methods?
Troymako:
I know JUST doing this will cause the battery to burst because once it is fully charged the current won't stop.(Is there an additional danger to charging a 9 volt 600mAh battery with a 9 volt 2.5A current.)
Li-ion + high charging current + no cut off = a disaster in the making
Your battery might burst even before it reaches full charge because of high charge current.
Troymako:
What I want is a way to properly charge the battery and have it automatically stop charging once the battery is near full
Looks like you need one of these modules m8. an LM2596 DC-DC Step-down Adjustable CC/CV. Costs just 1.5$
It will give CC/CV to any of your li ion battery. You can set the desired voltage out and the desired current out ( I would say a 600mAh battery needs CC of 150mA rate to be safe ).
The module will auto cut off when battery reaches full charge. It can take voltage input from 7 -35v so your wall wart could be used to input.
additionally when you don't need need your project anymore you can also use this module as an LED driver.
However, If I were you I would go for a beefy 11Whr 18650 cell and use a TP4056 v2 and a XL series boost module. Would give more than double the run time + the charger is a very efficient one with good safety and battery protection features.
I have decided I don't want my device to be able to function at 2.5 amps. This is too much for my components. I will get the LM2596 for the battery. What do I need to reduce the current entering my device from a 2.5 amp 9 volt wall jack and car plug. Another one of these; one for the battery and another for the power entering my device??
Troymako:
I have decided I don't want my device to be able to function at 2.5 amps. This is too much for my components. I will get the LM2596 for the battery. What do I need to reduce the current entering my device from a 2.5 amp 9 volt wall jack and car plug. Another one of these; one for the battery and another for the power entering my device??
