Hi, when you are stranded in a place where there is no electricity and your phone is running out of charge and you want to make an emergency call!,

Tadaaa!! here are the hacks for charging your phone without your charger or electricity.

I live in Chennai and I used this hack to make an emergency call when we were affected by flood previous year, There was power cut continuously for about 120 hours(5 days) during floods. This hack had worked out for me so I'm sharing with you.

Note: *Using both hacks you can charge up-to 20%(single time) on an average. You can get that much amount of charge even from used batteries for feature phones ( but mAh<1100), But for smart phones you need to put some EXTRA like using NEW long life batteries.

(*)-Values mentioned may vary depending upon the mAh of phone, Type of battery and adapter(if) that you use.


  • KEY(I used wire)


Step 3:

Polarity of terminals of car adapter is clearly shown in the pictures, bottom BUTTON type is +(positive) while side RING type is - (negative).

Connect one wire to the negative terminal to close circuit with battery OR USE KEY TO CONNECT NEGATIVE TERMINAL WITH BATTERY.



Connect those terminals with 9 V battery closing the circuit with either wire or with key.




If you don't have 9 V battery don't worry and try to get some AA sized batteries (I recommend Alkaline or heavy duty) from your other devices like cameras, mp3 player, flash light,etc. and start charging your phone using the below instructions.





Step 10:

Before connecting, cut the usb edge.

follow the pictures for instructions,

I have connected OTG and then connected it using spare usb if you want you can also follow the same to save your charging cable from cutting it. Even if you have no other option than cutting your charging cable you can Fix it using SUGRU after usage.

After cutting, Inside USB: RED is +(POSITIVE) while BLACK is -(NEGATIVE) connect them correspondingly to the battery terminals.

Step 11: CHARGING!!


This hack can give you enough amount of charge in your phone with which you can make an emergency call. Remember, I wouldn’t go around charging your phone using this method on a daily basis but in an emergency or a no other choice situation this is a great alternative way to charge your cell phone.

Thanks for reading my article. Please do support me by giving me feedbacks so that I can make it better,

Also please do hit FAVOURITE and VOTE me if you like my article

<p> This is great!</p>
<p>Could be life saving. I voted for you.</p><p>Thanks for this :)</p>
<p>I use #1 trick in my Motorcycle. Attache battery wires and add a On/Off button. </p>
<p>that's a good one, I thought of that before, but didn't think about using the car charger to get to the + - leads. Question, what if the only battery was a car battery and you were stranded from a car problem (but battery is okay). Would that charge or fry the cable? Can you use a make shift resistor if the voltage is too high?</p>
<p>Its not the voltage but the amps of car battery which very high for the fuse capacity of your car charger. So you can't use car battery directly. Yes of course check this link for </p><a>charging phone from car battery<br><br></a>
<p>The fuse is to protect the circuit of the charging wire. If it gets grounded some how by accident, it will pop the fuse instead of melting the wire and possibly causing a fire. Connecting directly to your car battery is totally fine. Connect it as he has done in this instructable. </p>
<p>Connecting it directly to a car battery is the same as plugging it into your cigarette lighter socket. In other words, it's totally fine to connect it directly.</p>
<p>The awesome news in this situation is that your cigarette lighter likely works if the battery works. <br><br>If you had a car battery and needed to charge a phone you could probably get away with the USB adapter, two wires, and some jumper cables. You don't want to be holding the thing that might blow up, so I'd want to be able to distance myself from the USB adapter while making the positive connection. <br>1 battery ground <br>2 usb ground<br>3 usb positive<br>4 Visual check between USB positive and ground (no touching)<br>5 Battery positive. <br>6 USB explodes or phone charges =) (Phone does not explode unless samsung for unrelated reasons) </p>
<p>this Samsung..... Note 7?</p>
<p>Nope, Its not Samsung.</p>
<p>The only difference between connecting the adapter to the battery and connecting the adapter to the cig lighter is that the cig lighter is on a (usually about) 15 amp fuse. Othewise it's directly connected to the battery through the fusebox.<br><br>Additionally, since you normally use the cig lighter adapter when the car is running, the alternator is usually pushing closer to 15V at you rather than the lower voltage of the battery at rest.</p>
İf you are using a cigarette lighter Type adapter, you can connect this to a regular car battery. However, take extensive care not causing short circuit since car batteries are carrying larger power and a short circuit might burn your hands
<p>Thanks for sharing, Dude you need some circuit to drop down voltage from 12 to 5 V</p>
The battery just has to be between 6 and 14 volts DC. The reason this hack works is because the battery is not used to charge the phone, it is used to power the Car to USB adaptor. And the internal workings of those can take a very wide range of voltage. Some as low as 6 volts, and some as high as 30volts. But the lower the voltage the more efficient the charge, because the adaptor essentially clips the source voltage off at 5volts, and all the left over voltage is converted into heat.
<p>The car charger has a switching voltage regulator that can handle a wide range from 6 to 30 Volts, so any external source of DC power 6 volts or higher can power it and charge your smartphone. And for the high voltage question, a regular car can generate only up to 16 V, so the car charger can handle that, too.</p>
<p>As long as there is still a charge in the car battery, it should energize the accessory port even if the car is not running. </p><p>You may have to turn the key to the &quot;On&quot; or &quot;Accessory&quot; position depending on how your car is wired.</p>
<p>Next instructable request: how to make DC/DC converter embedded into used 9V battery, to power your phone via microUSB cable. You need old 9V battrey, unpack it, make tiny PCB with effective impulse IC PWM controller and input/output capacitors (what PWM IC can you recommend to use ? scheme in USB chargers can be ineffective but maximally cheap), and solder contacts from old battry, and on-board microUSB connector. In result you will get DC/DC converter looks like 9V-battery on one side (snap it to charged new battery -- this contacts will give you reliable machanical and electrical contact), and tiny USB connector on other side. It is not emergency, but helpful if you carry it in your bag and make fast charging just bye 9V battery next shop.</p>
<p>Comparing to ordinary power banks -- this thing can be very small, and VERY lightweight, and supercheap in mass production (add LED and tiny switch for more usabiility)</p>
<p>This is a great hack, especially when you travel overseas (like me too). The two smaller pictures in step 3 are not very <br>clear. It would be good if there was a closeup that maybe didn't involve<br> a black background. And an additional image showing how you would do it<br> with a key. Thank you!</p>
<p>I dont know full about that but small doubt why cant we connect charging directly to battery instead of connecting to car adapter and then to battery</p>
<p>Hi, Dude adapter rectifies, step down and gives you 5 V, If you directly connect to batteries which has voltage more than 5 V it can<strong> damage your phone</strong>. However smart-phones have in-built features to auto-stop charging If the input voltage is more than 5 V. </p>
You can directly connect the cable to the battery. I've done it. the car charger just saves you from cutting your cord.
<p>Although I love these types of DIY things, sometimes you need to determine if it's the most convenient or viable option. In this case, just buy a backup charger and keep it in your car. I'm not knocking the idea, but if you have to set it up with all these items, it's easier (and definitely more reliable) to just have a back up charger.</p>
Agreed!!, That's why I have mentioned that this hack is only for situations when we are not prepared !&nbsp;<br> Thanks for your suggestion :)
How many lemons would this take? Just kidding. This is a good reminder of the acceptable voltage range!
<p>Lol, I hope this <a>page</a> will convince you! </p>
<p>You guys have obviously never studied electronics or you would know that Voltage is only a Potential. The phone only uses 5V and that is all it will draw. The current, on the other hand is an absolute and you really should try to match it as best you can. If you feed 500 milli-amps into a device that only wants 250, you will generate heat and maybe wreck the phone. But there will be a certain amount of time pass before that happens, probably more than enough to get your call out. This, of course. also assumes that you can connect to a cell in a place that has no electricity. GL</p>
<p>No, that's wrong, I think it is you who needs to study electronics, It seems you've mistaken Voltage for Current. </p><p> With the exception of LEDs, electronic components do not 'take all they can get' and self-destruct. For any component, the manufacturer's spec sheet provides the minimum, typical, and maximum ratings for its Voltage and Current. Further, even IF every component required regulation, it would be automatically handled by the phone's power management system.</p><p>It's the Current that varies in response to a load of a device's tasks. An example might be an LED clock, it will pull different Currents depending on the number of segments lit at any given time.</p><p>Voltage, however, IS critical when powering circuitry. Voltage-sensitive components contain junctions and insulation that excess voltages will destroy. Most components do have a voltage range within which they are happy and perform as expected, but that range can be very narrow. The voltage requirements of microprocessors is very strict, a minor deviation of even a fraction of a Volt can have extreme consequences. </p><p>That aside, today's phones usually require 5 Volts with a small deviation tolerance. The reason is simple, the microprocessor monitors the incoming voltage and will reject anything out of range. This is somewhat paradoxical because the internal battery is usually rated at 3.7 Volts, and the processor is rated at a voltage that is lower still, typically between 1 and 3.3 Volts.</p><p>There are many people offering comments containing sloppy or incorrect electronic information, so I will conclude my overly-thorough blather with a blurb about the car charger unit. This charging unit plugs into a vehicle's cigarette lighter to access the 10-15 Volt DC supply. Inside the chunky 'cube' resides a switching 'buck' converter circuit that provides 5 Volts after efficiently (&gt; 85% typically) converting the input voltage that will accept (depending on model) between 6 and 30 Volts. </p>
Great idea for a 5 day power out, try two 9Volt in series with your car charger so 18volts to 5vdc, should get your phone 50% charged, then do it again with two fresh 9volt batteries, to get it close to 75-100% charged. My two cents of advice.<br>cheers<br>Canada
<p>this is really a good idea.. at least with no doubt.... an emergency call can easily be made.. or if you are not using any smart phone but a regular small phone, like nokia 1100 or something... this trick is super awesome. I really give it 100votes!</p>
<p>You could connect several 9v batteries together (neg to pos) and get <br>more charge out of them. It would even work with nearly-dead batteries.</p>
<p>yea, thats cool !</p>
About how much charge would you get? I know all phones are different, but rough guess?
<p>The phone may have a battery with about 8-12Wh, the 9 volt battery about 4.5Wh. The total efficiency can be estimated to about 60% (75% efficient car charger adapter, 90% efficient charging circuit within the phone, and a little loss in the cable). So this give you about 20-30% of charge.</p>
<p>If you leave the phone on the batteries longer will it absorb more charge?</p>
<p>Obviously yes, the longer you charge a device, the more energy will be stored. However this is only true if the batteries stillhave some energy left.</p>
<p>As long as the voltage in the charger exceeds the charge in the phone's battery, then yes, it will keep charging.</p>
<p>The electron flow will continue until both batteries have equal charge levels. Two fresh AAs in a good charger should charge a phone to around 65%, give or take.</p>
<p>Thanks for sharing information!</p>
i believe a 9 volt battery has a capacity of around 500 Mah, cell phones are usually 2000-3000Mah, so it would be designed to get a bit of a charge, essentially making an emergency call. <br><br>I've never made one but some. capacity would be lost through the transfer.
<p>Cell phone batteries are typically 3.7V (lithium batteries). So a cell phone battery of 2000-3000mAh holds about 7400-11100mWh of energy. A 9V battery is typically 500mAh, which is about 4500mWh of energy. So theoretical max charge is 61%-41% for a perfect transfer. There are converters that can drive a battery down to close to zero (called Joule Thieves). With those you can get close to 90% energy out of the battery.</p>
<p>Thanks for sharing!</p>
<p>We can charge our phone upto 20% on an average which is enough to make an emergency call.</p>
<p>So, like... I am a science teacher and I have the concern that the voltage is not quite what the phone expects. The phone wants 12V and is getting 9V. I know we are taking emergencies, so even if you fry your phone, it is probably worth it to save a life.</p><p>But I want to know, IS THERE A BIG DEAL with the input being 9v verses the 12V it would want to have? Will the electronics inside the phone regulate the voltage?</p>
<p>Hi, Thanks for sharing !, Phone can intake only 5v, Its the job of adapter to convert 9 V to 5 V. Car adapter which I used has a input voltage limit of 9 to 24 V, so in such cases you can even use 12 V battery to charge !. In most of the cars as far as I know, inside car most of the output voltage is 12 V.</p>
The car battery produce variable voltage that can range from 10 volta to 14+ volts. The USB power line is spec'ed at 5Volts. <br>Being this is DC, you cannot use a transformer, and somce the voltage from the battery can very considerably, these Auto USB devices use a Voltage Refulator, which essentially chops the output voltage at 5Volts and diaipates all the extra energy as heat. So, actually, the optimum battery would be closer to 6 Volts to minimize energy loss through heat.
<p>&quot;diaipates&quot;? what? Maybe you meant dissipates.</p>
<p>well on the same note what the heck is a Refulator ? I have not come across this part in my cars my entire life </p>
Trolls trolls everywhere... if you're going to criticize typos, be sure to get your own grammar right.

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