Introduction: Make 4 Useful Things From 9V Battery
Are you thinking what to do with 9v batteries when they run out of juice? Don't worry,In this Instructable, I will show you 4 ideas to reuse your 9v battery parts.
I never throw my used 9V battery from various projects.Last week I saw, there are plenty of 9V dead batteries on my storage box.So I thought to reuse it.Finally I made the following stuff for my upcoming camping.
1. Flash Light
2.Battery Clip
3.Mini Hand Fan
4. Li Ion Battery pack
Step 1: Parts and Tools :
Parts:
1. 9V Battery ( Amazon )
2. 0.5W Straw Hat LED ( Amazon )
3. 100 Ohm resistor ( Amazon )
4.Tactile Switch ( Amazon )
5. DC Motor ( Amazon )
6. Mini fan Blade
7. Wires ( Amazon )
8. Li Ion Battery ( Amazon )
Tools :
1. Wire Cutter ( Amazon )
2. Needle Nose Plier ( Amazon )
3. Soldering Iron ( Amazon )
4. Glue Gun ( Amazon )
Step 2: Prying the 9V Battery
First identify the weak spot somewhere along the seams, and pry until the internal parts pops open.Slide the interior out and use a cutting plier to disconnect the batteries from the clip.
After opening the metal cover I found the following useful parts
1. Battery Clips
2. Battery Tabs
3. Metal Jacket
All of the above parts can be used for DIY projects.
In the following steps I will show you, how to make 4 useful things by using the above parts.
Safety Precaution :
Make sure that you, and especially your kids if they are doing it, are very careful cutting the jacket of the old battery. The chemicals inside are NOT user-friendly and can be nasty or toxic if spilled out.
Know more about 9V Battery
Step 3: 1. Flash Light
This flash light is really good for emergency or a camping light. It's compact and runs by most common and versatile 9 Volt battery. You can switch it on and off and its so small you can fit it any where.
Glue the LED :
First trim the LED legs and then glue it to the battery flat battery clips
Step 4: Add the Resisstor
Glue the 100R resistor to the side of the LED leg.
For more brightness you can use lesser value of resistor.
Calculate the resistor value by using this Online Calculator
Step 5: Add the Switch
Straighten all the 4 legs of the tactile switch.
Trim the diagonal legs by a cutter.
Glue the Switch as shown in picture.
Then bend one leg of the resistor toward the LED leg and trim the other leg.
Step 6: Prepare the Clips Terminal
Among the two terminal, one is projected type ( Negative terminal ) and other is flat (Positive terminal )
Flatten the projected parts by using a needle nose plier.
Step 7: Make the Circuit
Solder one leg of the resistor with the positive leg ( long leg ) of the LED and other leg with the switch.
Solder a metal wire to the clips terminal ( looks like Star ) and then to the Switch.I used the trimmed leg of resistor as a metal wire.
Step 8: Glue the Clips
After soldering, apply glue on both the surface and join them together.
Apply more glue, to insulate the conductive parts.
Now the Flash light is ready for test.
Carefully clip it on a fresh 9V battery and press the switch.
Step 9: 2. Battery Clip
You can make awesome 9V battery clip from the salvaged parts.Its pretty simple
Solder red and black wire to the the two terminal of the clips.Then apply glue to join them together.
Step 10: 3. Mini Hand Fan
You can also make a portable hand fan by using the salvaged parts.It is great for relaxing outside and cooling off.
Make the battery clips as described in the previous step.
Solder the clips terminal wire to the motor terminals.
Glue the motor on the bottom surface of the 9V battery.
Install the fan blade.
Step 11: Li Ion Battery Pack
The salvaged tabs can be used to make Li Ion Battery pack.
Remove the paper coating on the tabs.You can first wet it and then pilled up.
Apply glue on the battery surface and join them together.
Clean the terminal surfaces thoroughly then apply soldering flux on it.
Solder the tabs carefully.Your battery pack is ready.
You can parallel as much you need. I used to two just for the demonstration.
Safety Precaution :
Solder the tab carefully or you may use a Spot-Welder to do that.Excess heating of Li Ion Battery may leads to thermal runaway where it shorts inside, heats up, emits hazardous fumes, catches fire and potentially explodes.
Follow me for more DIY projects and ideas.
Thank you !!!

Runner Up in the
Trash to Treasure Challenge

Participated in the
Metal Contest 2016

Participated in the
Summer Fun Contest 2016
82 Comments
7 years ago
when I was an appy i welded a spanner to two terminals of a 24 v truck battery with my hand stuck underneath.....it got really hot and very unpleasant and painful very quickly....I still have the semi melted spanner 30 years later which I keep as a reminder never to do such a silly thing again...
7 years ago
While I applaud the author for making something from trash, this is NOT economical! I don't think a light or a fan makes sense when the purchased alternative costs about the same and lasts significantly longer. Around here 9v batteries go for about $2 a pop. For the same $2 I can buy a little AA flashlight that lasts 3x as long on a 50-cent battery. The same goes for the fan. I picked one up a few years ago from the dollar store. It uses two AA batteries for a grand total of $2 and I'll bet it runs 5x longer than the 9v equivalent. As far as the parts go, I have 9v battery clips I bought off eBay at 99 cents for 10. If you made minimum wage disassembling batteries you would lose money trying to disassemble 90 batteries an hour.
That said, when I needed ONE clip I did take apart a 9v (to make the LED flashlight 12 years ago when such things were still a novelty item). It made sense considering the time it would take to order them and the wait 2 weeks to get them.
7 years ago
That's not too bad and a good way to "test" if you don't have a meter. DO NOT UNDER ANY CIRCUMSTANCES however, use this method to check a 6 volt lantern battery.
7 years ago
A 5th use is of course a paper-weight. The standard 9 volt "transistor" battery is well suited to this task having nicely rounded edges that will not damage paper.
The 6th use is for the positive terminal on another dead 9 volt battery. It can be used to contain and store minute quantities of water--perhaps as a water bowl for one's pet cricket.
Reply 7 years ago
I just spewed a minute amount of my beverage when I read this. Thank goodness I had a spare 9 volt handy.
Reply 7 years ago
Enjoy !
Reply 7 years ago
Congratulations on being finalist! You instructables are really awesome!! :-)
Reply 7 years ago
Thanks...
Same to you too :)
Reply 7 years ago
Awesome ideas..I really like it.
Thanks for the suggestions.
7 years ago
Me 65+ to age... worked all my llife within elec. back in those golden years we did not have these fancy multimeters, we checked out the wall outlet (230VAC) for to check if the wire was"hot" or not, this is how it goes: 1. have the unicolated end of the wire to be checked 2. be grounded 3. lick one of your fingers to be wet enough 4. tap the unicolated wire with a "wery" fast wipe. 5. If it tickles some, then the wire is hot
This story is "TRUE"
Reply 7 years ago
Not to be recommended, but as an industrial electrical person, I have more than used up my nine lives. The fact that I am here now is down to good fortune and thick layers of dry skin. More than once I have had hold of a UK 240-V wire and felt nothing, but the bang when it touched neutral or earth tells otherwise. The golden rule if you want to try this insane method is one hand only and wear some thick rubber-soled shoes. Also avoid cheap power supplies with floating outputs. A 12-V DC PSU can put out 120-V relative to earth - using a metal-cased laptop on bare legs can give you a bit of an unwelcome tingle. An implanted cardiac device makes me much more wary now.
Reply 7 years ago
Not really a response to you, but your comment inspired my thought.
I don't recommend it, but I've put my finger right on a hot main to prove a point with a live 470v main. If you are not grounded on your body elsewhere, and have good boots, it's not going to kill you. IF YOU ARE NOT GROUNDED. That's the important part. Ground out, and you're not going to be a happy camper if you survive.
I am an ex-electrician. I can attest to working live wires, and surviving, yet having them blow up when the tip hits ground due to incorrectly labeled breakers. I've been shocked more times than I can count. The worst feeling of them being an overloaded, and unbonded neutral wire (yes, the white wire can shock you on older or inproperly installed services that are not up code).
No matter how well you trust your partner, always test the wires with your meter/ticker. Always question your ticker. They're handy, but I've had several that would chirp on dead wires, and not chirp on live ones. When in doubt, get the meter out.
Reply 7 years ago
That's why birds can sit on 220,000V lines and live, they are not grounded or connected to another phase. (do they get a static shock as their bodies charge?)
Reply 7 years ago
Awhile ago, a raven was pecking at a power pole, while sitting on the wire! he was lucky that if he hit it, it would be only 220 or so volts! I still think that would kill the bird.
Reply 7 years ago
More birds get killed htting the wires.
They must have some capacitance. If only they knew what a stunt they are pulling. When the linesmen are working on live overheads, the protective gear is impressive. On the "millies" thing, frequency is also important. Humans can survive quite high amperages if the frequency is high enough. DC is the killer causing spasm. I've just had a nerve conduction test involving many thousands of volts. One of the most painful procedures I have ever had and won't volunteer for that again.
Reply 7 years ago
One would think it was a 117V mains and not 240V otherwise you may not be telling us this story.
Reply 7 years ago
Until sometime in the 1970's areas of Bristol had a 110V supply. As a kid I had a Saturday job at vacuum cleaner repair shop (some miles from Bristol) and we had a 110V supply for that very reason.
BTW "it's the volts that jolts and the millies that killies" - so providing the time was short and the resistance high.... But not a smart way to test ;) Having said that, as kids we used a long length of grass to test cow fencers. Touch the wire with the tip and slowly slide the grass stem, making the distance to your hand shorter until you felt a jolt, or not!
Reply 7 years ago
As far as I know, only US has low voltage mains. Normal mains voltage as in Australia & Europe is somewhere between 220V & 240V.
Reply 7 years ago
At a quick count, I found 47 countries other than USA that have a 100-130V standard.
Reply 7 years ago
In Australia now the nominal mains supply is 230V and up to 250V 50 Htz . In the US it's 117V nominally at 60 htz. In Europe it is 220V nominally at 50 Htz.