How to Make Mobile Charger With AA, 9V Battery (Regulated Voltage)

There are hundreds of guides on the web on how to make mobile charger with AA, 9V battery. But none of them tell you how to easily get regulated power supply in easy cheap, easy way. Here is Easy Guide On How to Make Mobile Charger With AA, 9V Battery Which Will Supply Regulated Voltage Ensuring Recommended Stable Voltage Supply.

In recent long tour, when I connected my Samsung mobile to new car, it started an odd problem – once connecting, in next moment getting disconnected. As if there is some loose connection. I tried all possible ways and usual end – slapping, praying to God etc. Suddenly I tried with my iPhone. Astonishingly, it nicely started to take charge. After a brief Google search, it returned that most mobile phones has some issues with car’s USB port intended for charging or charger used with cigarette lighter charger. It is not about the manufacturer, phones manufactured by Apple to Samsung all suffer from this odd effect. Basically, car’s battery optimized for running operations of the car. These days, car’s battery not limited to supply power for honking, headlight, tail lamp. Those power outlets of cars use a relay, which somehow can not suck higher current from battery when another source drawing more current.

I understood that I need some kind of portable charge. That is starting of discovering this new DIY way.

We can forget about car. Charging mobile phone on the go is a headache. A somewhat fix is buying a power bank. But power bank usually costly and ultimately after a time face the same fate – it need to be charged. Most convenient, easily available DC power is common batteries – AA, D size, 9V battery. Of course, D size battery is great but it is difficult to get a holder for four D size batteries. We had an article on choosing batteries for electronic projects. You’ll commonly get AA size batteries all over the earth, even in remote village. Availability of 9V battery is slightly limited but our way will not bother you much.

Materials and Steps to Make Mobile Charger With AA, 9V Battery

As list, you need :

1. One Ywrobot MB-102 Breadboard power supply
2. Your mobile phone’s USB to micro USB cable or multi-plug sold for car cigarette lighter charger  to charge mobiles
3. A plastic box to keep the things

If you use 9V battery as power source (it is neat) :

1. One 9V battery
2. One 9V DC battery connector (5.5mm x 2.1mm plug)

Optional parts if you need to build mobile charger with AA batteries (it is practical) :

1. Plastic Battery Holder Case for AA batteries which can hold 6 batteries
2. One male DC connector plug (5.5mm x 2.1mm plug) for that battery casing to connect with battery holder case

Plastic battery holder case for four AA batteries will also work but not exactly good for our work. Basically, it is better to supply MB-102 Breadboard power supply unit. We discussed about cheap Made in China breadboard power supply. Actually, one 7805 IC works as voltage regulator but cost of MB-102 Breadboard Supply is around hardly $2 dollar. It has big advantage of being a complete circuit with LED indicator, a pushbutton OFF-ON switch. Needless to say, it avoids soldering works making it usable to anyone. So you need to buy one MB-102 Breadboard Supply from somewhere – local shop, Ebay, Amazon – whatever is cheap to you.

In our graphical illustration we have shown charging Samsung J7 Max with 9V battery and MB-102 Breadboard power supply. I understand you have questions. China stuffs has no manual or Chinglish manual.

How Much This Charger Will Cost?

MB-102 Breadboard power supply – hardly $2
One 9V battery with DC connector – hardly $2
Mobile phone’s USB to micro USB – free, supplied with your mobile phone charger (not truth for older iBad phone)
A plastic box – free if you can steal from your mother or wife’s collection. Cost minimum to buy, 3D print etc.

Later you can buy cheap 9V batteries without DC connector. Online shops sell 9V battery with DC connector at very high price for the beginners in electronics. Low end 9V DC battery cost 30 cents/battery all over the earth. Charging your mobile using household electricity is not free. Probably charging with household electricity costs 10 cents for 0 to 100%. Batteries are just chemicals.

How to Use Your This Charger?

For 9V battery system :

1. Plug 9V battery with DC connector
2. Plug 9V battery’s DC connector with MB-102 Breadboard power supply
3. Plug mobile phone’s USB to micro USB cable to MB-102 Breadboard power supply’s USB port
4. Optionally, change jumper of MB-102 Breadboard power supply to 5V at least at one side
5. Plug mobile phone’s USB to micro USB cable to mobile phone’s charging port
6. Switch ON MB-102 Breadboard power supply
7. Switch OFF MB-102 Breadboard power supply when not needed

For AA battery system :

1. Connect loaded plastic battery holder case for AA batteries with DC connector
2. Plug DC connector with MB-102 Breadboard power supply
3. Plug mobile phone’s USB to micro USB cable to MB-102 Breadboard power supply’s USB port
4. Optionally, change the jumper of MB-102 Breadboard power supply to 5V at least at one side
5. Plug mobile phone’s USB to micro USB cable to mobile phone’s charging port
6. Switch ON MB-102 Breadboard power supply
7. Switch OFF MB-102 Breadboard power supply when not needed

How Many Mobiles a 9V Battery Can Charge?

One 9V battery can charge hardly one newer mobile with big screen. It is for emergency purpose, not everyday solution. If you use smartphone as car GPS, starting with 100% charge, a 9V battery is enough to keep charge to 80% for 6 hours continuous use in power saving mode of Android phones. Of course if mobile’s battery is closer to need of replacement then 2-3 9V battery may be needed.

How Much Current We Are Getting?

Input : 6.5V to 12V
Output : 5V (we are not using 3.3V in this case)
Output current: 700 mA

How Much Time it Will Take to Charge a Mobile?

Rate of charging for Android mobiles will be half than wall socket power supply. Most of the Android phones rated for 5V 1500 mA input. We are supplying less than half current (700 mA). If you do not put in power saving mode and continuously use, only rate of discharging will be slower.

Does using cheap China MB-102 Breadboard power supply has risk to mobile?

I am not electrical engineer. It is DIY, open source way. But, you have multi-meter to measure outputs and match that with your charger’s output ratings.

Unless MB-102 Breadboard power supply is damaged, chance of becoming direct 9V supply is low. We told the fact – most of the Android phones rated for 5V 1500 mA input. We are supplying less than half current (700 mA).

Android and other smartphones pack certain fail-safes in case of high/low voltages to an extent. Hence they accept charge to the limit of their capacities and you do not need to worry about their batteries. If 9V becomes direct, most modern mobiles can handle.

Outside official wall socket charger, all unofficial ways has minimal risks. Any electronic thing has protection to handle input voltage within 9V. Up to 12V some circuits can tolerate. Mobile phones have IC to again regulate the voltage. If IC blows away within warranty period, you can send an old innocent family member to claim charger made it.

How it Works?

USB port of Ywrobot MB-102 Breadboard power supply actually for output for supplying to development and prototyping boards like Arduino. Other companies’ MB-102 Breadboard power supply may not have this feature. There is manual written in Chinese which was deciphered by an Russian on Onion for the circuit diagram in English. It is actually kind of Open Source hardware. Here is the circuit diagram :