How can I make my own usb to charge batteries then use that to charge my phone?

So I am in the field a lot with the army.... and looking to make my own battery bank.... well I was thinking of using six 18650 3000mAH batteries in a parallel and series setting. Now if I set it up like this what would I use to charge these battery?

Question by dominick.j.pezza 4 years ago  |  last reply 4 years ago


Circuit for power bank? Answered

Hello, Need a circuit design for the following requirement. Checked online available circuit designs but not sure if they meet all needs.  Looking for circuit design as per following details. 1. It will have one or two, 3.7 volts 2600 mah 18650 lithium batteries 2. Batteries will be charged using smart phone mobile charger or solar panel 10 to 20 volts and around 500 mah to 1 ah input 3. Will have mini usb connection for the same on pcb 4. Circuit should have battery level indication. While being charged, when they are fully charged LED should turn on indicating battery full. Also there should be one LED to show that the charging is in progress. When the battery charge drops below specific level another LED should turn on. 5. If we use 2 batteries then they will be connected parallel 6. Output voltage of the batteries should be 5 volts (so step up is required) and current should be appropriate for mobile charging 7. There should be provision for 2 USB connections. Load can be mobile charging / USB mini fan / USB mini keyboard LED (could be 2 at a time) 8. Circuit should be safe enough so no damage is caused to batteries / load etc.

Question by rahuldj 2 years ago  |  last reply 2 years ago


Batteries and charger? Answered

So I got one of those one cell battery bank that come also with a little crank generator. So far I took both of these apart to make one into a 2cell. So now these batteries are a parallel, my ? is if the voltage stays the same with the charging board and the mah is double this should not effect the board correct? and or the batteries. So far its been working both batteries reads the same voltage so the charging board must work. Now hear is the thing that I am concerned with, if I was to add 6 more into a parallel then all batteries would be the same MAH right. This should not damaged the board?

Question by dominick.j.pezza 4 years ago  |  last reply 4 years ago


Portable battery bank to charge a laptop?

Let me start off by saying that this problem may well have no possible solution and I'm probably a fool for asking. I was wondering if there's any simple(ish) way to use an external battery bank with 2 USB ports on it to charge a laptop? The bank has 18,000mAh of capacity, one 2.1A, 5V USB port and one 1A, 5V USB port (total 15.5W). The laptop charger in question runs at 19.5V, 2A DC (total of 39W) and the laptop battery has a 3800mAh rating. Thanks in advance for any replies :)

Question by CustardInc 4 years ago  |  last reply 4 years ago


Usb battery bank help and questions ?

Well i want to add like a battery pack instead of the 9 volt batteries i have now and this a ruff model i made today, but i will make a better case but back to my question is would this work? http://www.amazon.com/Tenergy-2000mAh-Capacity-Battery-Security/dp/B001BA292A/ref=sr_1_11?ie=UTF8&qid;=1347244925&sr;=8-11&keywords;=9-Volt+Rechargeable  or do you recommend something else it has to be rechargeable,  

Question by imnew59585 6 years ago  |  last reply 6 years ago


how many batteries in your bank?

Great project Steve! my dad lives offgrid in the high desert of oregon: state thus far he uses several dc mills and solar panels.i greatly look forward to building this project with him in the future.also i wanted to compliment you on your willingness to explain and re-explain already stated facts......i first read and looked at your steps then took the time to read all the "Q&A" (yeah all 562 of them).after having done so i have no questions other than how large is your bank and what type of batteries did you go with?(we started with a bank of 32 12v ,but are now replacing them with long life deep cycle 6v cells)<large investment cost has us gathering them a few at a time.its great to see so many people gaining interest in going green.This project is without a doubt the best mill ive seen and your patience/willingness to let others pic your brain and promptly kick back thorough and accurate answers is commendable..most prodigous!looking forward to checking out all the links you provided. best personal regards, Luke A.R.S KV7M

Question by Coolhand Luke 10 years ago  |  last reply 10 years ago


HOW TO MAKE SMARTPHONE POWER BANK AT HOME ?

I have samsung s duos gt s7562 and the big problem is its battery. whenever i have to go out for a day long, i have to suffer for its poor battery back up. in market several power bank is available, but its costly. i want to make myself. i need atleast 3000 mah capacity power bank. So what should i do ? please tell me.

Question by pprasara 4 years ago  |  last reply 4 years ago


How i can make 400dc-450dc from a 9 volt battery??

I want to charge a capacitor bank of 400-450volts, but I don't know how.

Question by Kurt Gerhard 7 years ago  |  last reply 7 years ago


How to make a 230v AC power bank?

I would like to make an AC power bank but don't know exactly all the parts to get any help.

Question by OTKZuki 3 months ago  |  last reply 3 months ago


Convert 48V battery bank to 12V for boat appliances - Is this inefficient?

I need a 48V bank for an electric motor on my boat. I also need 12V for my appliances. Obviously keeping both a 48V and 12V bank would be most efficient but the space required and cost of maintaining 2 banks is a bit much. So I was thinking of using a 48V DC to DC convertor to convert a 48V bank to 12V for my boat appliances(lights, pumps, etc.) http://pt.mouser.com/ProductDetail/Murata-Power-Solutions/HPQ-12-25-D48N-C/?qs=sGAEpiMZZMtwaiKVUtQsNaluUzA10QGezHFBNv8sYMI%3d But how much would I lose in terms of efficiency? Would the losses be too great? Would the bank of 4 x 12V 100AH batteries connected in series give me roughly 4800W ( 4 x 12 x 100 = 4800) or 16 hours of 300W use when drawing only 12V after the conversion?  Or would the available AH be much less due to the losses from the conversion?

Question by mchin2 5 years ago  |  last reply 5 years ago


How to make power bank with 8 rechargable AA batteries?

I'm a nobody at electronics, electricals and stufs. well i have some rechargeable batteries for some reasons,. 2 of my friend has a portable power bank for their phone. then curiously thinking if i can make that kind of stuf.. (DIY),.. if it possible please help me make this... my AA batteries is 1.5V with 500mah of power if i'm right. , then multiply by 8 so that will be 12V with 4000mah of power? right?. then i want this to charge my phone... recently searching i need to drop the voltage to 5, because if not, my phone battery will or might explode., then my phone will be damaged?.. so i need to make a circuit,, then that my problem, i dont know any thing about resistors and things like LM317, just i don't know anything about that.. i need it be able to be recharge and charge my phone, so here's another question, expect the wee did make something like that, then how will i be able to charge it?, it's 12v right from the inside? right?.. that all, hope we can make something like this,, if there's a related post, which has been already answered, if this is not possible.. That all.. Advance Thanks for helps... 

Question by ZoneOne26 4 years ago  |  last reply 1 year ago


can I use AA battery bank to power an inverter (3000ma 12v)? Answered

Can I use AA battery bank to power an 50w inverter (3000ma 12v)?

Question by celalboz 9 years ago  |  last reply 8 years ago



What is the right way to connect the cells of this battery pack, and tips on making a power bank? Answered

Greeting makers, I have a few questions about connecting Battery cells, and making a DIY Power Bank. And I'd like to hear your opinion on it. I have 12x Ni-Mh 1.2v 3000mAh AA betteries laying around. They are brand new and I thought of using them to make a Power Bank. Since most phones use 5v for charging I wanted to connect 4 cells in series giving me 5v and 3 of these packs in parallel for an end result of a single 5v 9000mAh Battery Pack. But when I started to connect them I realized that there are 2 ways it can be done, and I am not sure which is the right one. Is there any difference at all?  I will add a picture below, as it says more than thousand words. Furthermore I would like to ask for your opinion on how to proceed making a functional power bank. Just wiring the cells straight to an Usb port doesn't seem like a smart idea.  What would I need to make sure it is safe for the devices it charges? And how could I make the Power Bank rechargeable via Usb? Thanks in advance.

Question by icemaciop 3 years ago  |  last reply 3 years ago


Charging mobile with a 6V lead acid battery?

Hello, I want to make something like power bank. i want to charge my mobile with a 6V 4.7Ah battery. My mobile charger is rated 5v 500mA. How to make this circuit?

Question by Rahul Mitra 5 years ago  |  last reply 2 years ago


Wiring Two Ports on a Phone Battery Bank in Parallel?

If a power bank claims that each port on it can charge a device at 2 amps, if I connect both ports together in parallel, am I able to get 4 amps? Or would it be just like trying to double the voltage off of the same battery, and not work? I have an Intel Compute Stick, which requires 3 amps to run. However, battery banks that provide more than 2.1 amps per port are super rare. Would it work to wire them in parallel?

Question by RocketPenguin 2 years ago  |  last reply 2 years ago


What's the best way to store pedal &amp; solar power into a battery bank?

I'm looking to power some blenders & other small devices with a battery bank & I want to store power in these batteries from pedaling bicycles & possibly solar power. Just need a little help on all of the essentials and how much power I will be able to garner through a system like this. Thanks!

Question by nicksisson 10 years ago  |  last reply 10 years ago


Capacitor-bank safety issues

Okay, so I'm going to be the wet-blanket old guy.... Has anyone considered adding a topic to this group (or an I'ble) on electrical safety with supercaps? Even the low-voltage ones put out tremendous current, enough to put you into convulsions or stop your heart (50 joules) if applied correctly. These devices are amazingly cool to work with -- better than batteries when you need high current, outstanding AC line filters, and terrific party toys when you need some bang for your buck. They can also turn around and bite you on the arse without warning...

Topic by kelseymh 10 years ago  |  last reply 9 years ago


Could a 12v LED light strip be powered by a portable power bank

I don't know the exact specifications for my LED light strip but i know a 12v 2500mah lithium battery powered it for at least 2 or 3 hours, unfortunately it was a crappy Chinese knock off battery that damn near blew itself up after repeated use and i can't find a replacement that doesn't look like exactly the same battery. with that in mind are there any small power banks with a 12v output that i could use? or is there some means of boosting a 5v output power bank which seems to be the most widely available type?

Topic by ambientvoid 2 years ago  |  last reply 2 years ago


Diy LED strip light powered from a solar powered battery bank (for painting/drawing at night)

I like to paint nightscapes and so far headlamps are not working so well for me. I used a portable light bar one night that worked well (on loan) but it was too heavy. I've been through stores looking for the right thing...and harbor freight came close. But I need something lighter weight and less expensive.  Two or three led lights don't cast enough light and 30 led storebought lights are too much light. I have a solar powered phone charger with battery bank (with usb connections) that I now plan to use as the portable power source. I plan to use a pringles potato chip tube as the light housing that can be attached by clips to my pochade (really a mod'd cigar box) on top of a camera tripod. I guess my main concern is weight on the box, so I thought running a cable off a power source hanging from the tripod would be more secure and less likely to fall in my palette (as has already happened). I need help figuring out the circuit board; and also choosing the right white led for color purposes. Any thoughts?

Topic by sreudianflip 1 year ago


Modifications to LED Bar Graph Volt Meter for 12volt batteries(and Battery banks) Answered

Hi I found this LED bar graph voltmeter athttp://www.solorb.com/elect/solarcirc/vom/index.htmlI want to understand how to build this voltmeter.But please read the solorb website page before posting, for more info.1. What is an offset resistor???2. What is a 'span'(see pic notes)2. For 12v operation,short J2 and J5,but what to do to all the other unconnectd 'J 'wires, just join the wires or what?3.To use without the Blue LEDs, just remove the two LEDs or any other connection/shorting is required????4.What is switch S1 used for ???, I do NOT want to manually push switches while the meter is in operation.5.How to stop the blink-LED mode, I want the constant display mode always.6.There is also two arrows shorting two pins on the IC with words 'Adjust for 12v'?????????7.How to calibrate the circuit accurately???PS:- If you want to know more about a larger part of this project,visit https://www.instructables.com/community/Voltage-Regulator/Kabir

Question by mhkabir 9 years ago  |  last reply 8 years ago


Is this lion battery bank expensive? 150AH @12-14v

I was thinking about how much would cost making a lion battery bank with enough amps/hours to feed a car audio system (stereo + sub amp). Since this setup would drain around 25-30AH I definitely want a battery bank with around 150 AH capacity to get at least around 4 hours of music at max potency. Woulds this be so expensive? I know that lion batteries are getting cheaper and cheaper, but any idea about how much would this cost? I have made a research on ebay and amazon, I could not get an average idea, and considering many brands lie about the specs, I better first ask here to hopefully get some references. Thanks.

Topic by johanx4 1 year ago  |  last reply 1 year ago


Whats the best way to charge a 48 volt battery bank with a 110 volt(140 max) DC Wind generator?

I would like to use my 110 volt Jacobs windcharger to charge my 48 volt battery bank. Then possibly switch over to water heat elements as a dump load when the battery bank is full. This last step could use the full 110 volts. The Jacobs is rated at 20 amps, about 3000 watts.

Question by ShadowB 9 years ago


Big battery bank project. Circuit related questions?

Hello everyone! I have a project in my mind and I would love some guidance and some ideas if possible. I already have a lot of 18650 batteries in an “acceptable” state (1800-2100mAh each) and I am planning to make a large battery bank, for use in camping mostly (smartphone charging, led bulbs, electrical air pumps 12v, etc) I did read a lot of articles in here about battery banks, but i didn't find something as complex as my idea. I have already made a 12v battery pack with 12x18650, 3 rows in parallel, of 4 in series in each row. My goal was to operate a 12v air pump for inflatable mattresses. It worked like a charm! (Also created with instructions from here! Thanks for that!) But since my “DIY disease” does not leave me in piece… I want to build a large enough pack that can support the following: 1) 12v car plug 2) 5v/1A + 5v/2.1A USB plugs 3) charge circuit for the battery pack, so I will no longer have to remove the batteries to charge them separately 4) switches in each plug 5) led voltmeter also with switch ?) at some point I would like to add a circuit to charge it with a solar charger or a mini wind turbine that i will create at some point with my 3D printer, but for now let stay with the basic stuff! For the case i will use a modified screw organizer case, with those classic 18650 black holders from ebay. (photo below) The case will fit almost 8 to 10 holders (4x18650), so we are talking for 32 to 40 batteries... My main concern is the circuit design. I have done a few simple things in the past, but this is a bit more complicated and that is why I want your guidance/ideas. How to safely connect all those things together or maybe suggest a different plan/design, cable thickness, etc... Links gathered so far: I am thinking about 4S in a row. Is that too much? Or should i consider 3S? 3S Li-ion Charger PCB with BMS For charger... something like this maybe? 12.6V 5A Charger optional... maybe i could fit sothing like that, for laptop charging? 150W DC-DC Boost Converter for 5v 1/2.1Amp charger i m looking at this. 5A Charger Step down Module for usb/12v plugs/voltmeter i am considering this option. Thanks in advance for your time!

Question by the_phantom_boy 2 years ago  |  last reply 2 years ago


solar and wind controllers charging the same battery bank?

1. can this setup work?  2. if yes... will the wind controller see the high charging volts from the mppt controller and diverts the load even though the battery is not full 3. can i add some switch to let one charge while the other is off 4 get a controller that can dual charge

Question by hitek 4 years ago  |  last reply 3 years ago


Best way to light small bank of LEDs?

I was trying to help someone put together a small lighted prop for a Halloween costume, and quickly realized I knew enough just to be dangerous.  The result should be simple, for someone who better knows the intricacies: 9 superbright 3V LEDs, arranged in a circular pattern about 4in dia., powered by a small pack of batteries which CAN be located elsewhere on the costume, with a small wire run. Initially the thought was "oh, well, 2 AA's gets you the 3V, you're good..." Then we thought, "to make hooking up the LEDs simpler, attach them end to end, and then each end of the loop of LEDs goes to the two batteries."  Of course, totally wrong.  After realizing the glaring problem, it occured to us that 3 9V batteries would instead get us the requried voltage to light them up. Then, realizing again this should work but that there might be some finer points to know, I started looking up some information online for similar projects.  My big fears, having not tried this out yet, are that: 1) The string of LEDs or batteries may get hot. (Seen a lot of posts like this.) 2) There is some glaring inefficiency in this setup that could be more simply redone. For example, is it better or worse in any way to run three strings of 3?  Would batteries last longer if a different configuration of batteries or wiring were used? 

Question by dcenteno 6 years ago  |  last reply 6 years ago


What is a reliable 12v battery charger under $30?

I'm looking for a battery charger to charge my 12v 8a battery which I use to light my 300 LED strip in the garage. What charger works best and doesn't break the bank, so under $30?

Question by kingtrout1 3 years ago  |  last reply 3 years ago


Which battery should i use?

VOltage dosent matter, all that matters is that it gives a minor shock when touched. The bank of batterys wil be going through a auto ignition coil to amplify the voltage. What should i use?.

Question by DonkeyDeathMan 9 years ago  |  last reply 9 years ago


NiChrome Power Source? Answered

So, I'm doing a project that needs to boil maybe 8-10 drops of water very quickly. I was thinking of using NiChrome wire to do this as in the included diagram (sorry low quality, MS Paint). However, I can't seem to find an appropriate power source. So, I need some easy to obtain powersource that is also relatively small. Something like batteries, a capacitor bank, or anything similar. Remember, it has to be able to boil of those 8 drops pretty fast, lest they condense in another part of the pipe before the desired pressure is reached. 

Question by LiquidLightning 8 years ago  |  last reply 8 years ago


When building a capacitor bank, is it necessary to have a charging circut? Answered

So, I am going to build a capacitor bank in parallel, only a few regular caps from cameras, how would I go about charging these? Do I have to use the circut or can I just hook the battery to the bank for a bit?

Question by Speedmite 8 years ago  |  last reply 8 years ago


Battery Powering an Rpi3 and Monitor?

So I have plans to assemble an Rpi3 laptop with a battery and display and all that. So I need a way to battery power my Pi. Could I power my Pi3 (5v@2.5a) a usb power bank (one that could provide 5v@2-2.5amps obviously) with perhaps a step down/set up regulator? But I still would need a way to power the screen. Most driver boards want 11-12v and I don't know how to provide that. Maybe wiring batteries in series or parallel? I'm not exactly sure on how that works but I'm new to LiPo's so I'd like some help please. Thanks!

Question by gupperino 2 years ago  |  last reply 2 years ago


How can you charge a capacitor bank from 9v without a flash circuit from a camera? Answered

I need to charge a capacitor bank but the only easy way i can fid is to use the flash circuit from a camera. Here in Aus these are hard to obtain and i really need a portable and reasonably cheap Capacitor charger for a project. Please help me, any links to sites i can buy materials for a charger and especially circuit diagrams. Thank you.

Question by Doddity 9 years ago  |  last reply 2 years ago


Can a laptop charger be modified to charge capacitors?

Well. I've been wanting to build a coilgun for some time now, so I decided to look into it. Capacitors are safely (or as safe as you can get) charged with DC current (batteries). But I don't want to go out and buy batteries whenever I want to use the coilgun. So... can I somehow wire it to charge a "capacitor bank". I was thinking start somewhere with cutting off the computer-plug?

Question by Crail 9 years ago  |  last reply 9 years ago


Retrofitting a battery pack into an ebike.

Ok I was just looking at this ible. And noticed the type of battery the guy used.  So I did some googling and ended up here. Wondering to myself about trying to retrofit this type of battery into a veloteq challenger from 2008 or so. Remembering that its a 48 volt pack built from 4x 12volt lead acid 20amp batteries(cells) wired in series thus to stack the voltage and not the amperage.   Now I know amperage is simply a measurement of consumption so I'm guessing that these Yellowtops are way above the usual 20amp's that the veloteq asks for but I'd imagine that shouldn't make much of a difference.  Seeing as I only want to throw on two of these as to not blow way past  the weight restriction on the ebike itself by hitting 48 volts with four of these also to avoid breaking the bank with an 800$ purchase.  Could I not add some sort of transformer to step up the voltage to 48 volts or something like this? Any suggestions are welcome but I can't imagine this would really be all that bad of an idea.  I'd imagine it should boost the range somewhat if not a fair bit.  I'd imagine that my assumptions here are not far off but I'm here to either be validated or corrected. Or even educated if someone has any suggestions or advice.

Topic by chamunks 6 years ago  |  last reply 6 years ago


Power banks and solar cells -could be great Instructable for you to make!

I was lucky to score a nice and real 8000mAh power pack with a solar cell from my local discounter.Realising the solar cell is more a gimmick than of real use I started to wonder....We all love our mobile devices and really hate that they need to be constantly charged up again.On long outdoor trips people used to carry a lot of gear and vital supplies.In todays times it almost seems that solar and battery power start to replace food and water.No trip is complete without pics, selfies and videos, some even take a drone with them.So: are there ways to increase your luggage weight by thinking smarter?Modern technology has come a long way and moves faster ever year.Solar cells are no exception here.Be it foldable setups or now even roll ups of flexible cell systems, you have the total freedom of coice.But then again: You are going on a week long camping trip in the middle of nowhere...Going on foot or using a bike means you need to keep the extras down or hire someone to carry them.Here are some of my yet to be finnished ideas:As long as you don't use them commercially feel free to make an Instructable or just use the ideas!1. Pop up amd normal tents.They seem to be the new standard now.Big with no poles on the inside and even someone who never used a tent can set them up.With the design comes a certain way of folding everything to pack it.Flexible solar cell designs won't break and can often be arranged so they would actually be able to replace parts of the outer tent material.And if it could mean they would get kinked too much and too often they are still perfect to create some "strap on panels" that can be rolled up and included with your foam underlay or mattress.A 200 or even 400W system can be transported easy and has less weight than a 80W fold up solution that you struggle to secure on your backpack or bike.2. Trackers!What is now almost a standard for fixed installations is still not seen in mobile setups.You pop up your panels, connect the power packs or batteries and go fishing, hiking or whatever.The sun moves on, the efficiency of the panels suffer.There are a lot of great Ibles for these solar trackers, from simple to 3 dimensional.Kites loves to use carbon fibre rods to reduce the weight.A tracking frame to hold a good sized flexible panel would count at less than 300 grams....In return you get up to 40% higher effiency and overall output compared to a fixed panel!Roll the panel up, fold the frame and you end up with a quite small roll that is easy to transport and very low in weight.3. Battery backups.No matter how long and well you planned, the weather might let you down shortly after your trip started.For a lot of comitted people that is no problem.The lack of power though can cause some to struggle to keep their video logs running.Your small drone might be great but it only lasts for less then 30 minutes until you need fresh batteries.Similar story if you use stabilizers, automatic tilt and pan gadgets or just a 360° camera.Just your cell phone alone can be a hassle if you use it as the main thing for GPS, pics and videos.At least one set of spare batteries seems to be a must have these days.For a lot of things it does make sense, for others not so much.Unless you really need ongoing power it might be enough to just charge you empty battery at the end of the day.But then the sun is down and options are gone for solar energy.In the RC area we can find a lot of powerful battery packs.Usually around 14V but 40 or more are no problem.And if you check the E-bike and scooter sections you will find some quite powerful and light weight battery packs.If you go outdoors a lot and for longer periods of time then it makes sense to replace the multiple battery options with just a single one.Use a high power backup battery with your solar system.DC-DC converters make it possible to literally combine everything with everything.Select the battery size so it will suit your charging needs and capabiliteis of the solar setup.Once time to close the tent you enjoy electricity to finnish your logs while your batteries are being charged during the night from the backup.4. Emergency generator.We all know these cheap gadgets like crank up torches or cranking mobile phone chargers.Nice to play with, utterly useless if you actually have to rely on them.A full charge for your modern phone might mean you crank for at least half the day - good luck!If you already carry a supply of gas for your cooking needs then these new fuel cells running on butane might be nice.Some of the Kickstarter projects actually made it into production!Prices though are more for real fans or those with enough money...But a small RC engine can drive some nice DC motor with very little fuel....In return you get a pocket sized generator that can charger your phone fully in the same amount of time a wall charger would...

Topic by Downunder35m 3 months ago


My coilgun capacitors aren't going above 30v

I made a coilgun out of disposable cameras. i have 6 capacitors running in parallel. I followed these instructions  https://www.instructables.com/id/DIY-How-to-make-a-coilgun-from-disposable-camera-/?ALLSTEPS   .When i power it on the capacitors make their usual noise and they start charging fine then when they hit 25-30v they shut off and don charge any further. What is going wrong? The power source is 2 AA battery running in parallel 

Topic by eric95204 5 years ago  |  last reply 5 years ago


Power Banks vs. ac wall outlets

I've observed in many power banks, that they charge up my phone a LOT quicker than a conventional ac adapter plugged into a wall socket. Why is this so? Many of my friends share the same observation. I'm building a simple power bank myself, and I want to make sure I can enjoy this feature when I use it too. I plan to use this instructable as a guideline with some modifications: https://www.instructables.com/id/Rechargeable-homemade-Power-Bank-super-Easy/ I'll be using four 3.7V batteries in parallel and stepping it up with a step up converter, so that the mAh value gets added up (forgive me if I'm wrong, but I believe mAh adds up when batteries are in parallel). Will this arrangement give me faster charging times like the power banks available in the market? Is it a safe circuit? Please suggest as I am eager to build this :) Thanks in advance :)

Topic by AshwinN3 3 years ago  |  last reply 3 years ago



Where to find lightweight 12v batteries? Answered

I need a set of lightweight 12v batteries with a lot of power (15 ah or higher). I have an air conditioner that draws 3.33 amps and runs off 24 volts. My idea is a battery bank with two 12 volts in series to make 24v. I hope to run it ~5 hours off a full charge. I found these on eBay but they weigh 10lb each, which means 20lb for 2 of them. My goal is 10lb or less total weight: goo.gl/KcdIfW A single 15ah+ 24v would work but I cannot find one anywhere. Thanks!

Question by benbl19 2 years ago  |  last reply 2 years ago


How do I connect a wind turbine to a battery bank through a 1N1190A blocking diode?

Diode I have is seen here http://www.reuk.co.uk/40-Amp-Blocking-Diode-1N1190A.htmI am building the "Chispito" turbine, but I don't have the blocking diode they recommend, I have this one.

Question by groundhog593 10 years ago  |  last reply 10 years ago


How to get constant 5.2V from ~1-7 Volts?

I have multiple solar panels (3V, 6V). I want to build a charger for bicycle, to keep my battery powered lamps (DIY) battery alive. Currently, I use my DIY lamp with a USB Power bank (5,2V , approx. 50k mAh), but my lamp contains 39 LEDs, and they are ultra-bright LEDs, so they drains the battery fast. So I thought if I connect some solar panels to it, I can charge power bank during daytime.

Question by Sp1k33 3 years ago  |  last reply 3 years ago


convert 12v cordless battery to solar charge

My first post- great site! I'm a complete idiot when it comes to electrical; does anyone out there know of a way to charge a 12v cordless drill battery with a solar panel- the eventual end result being to power a bank of LED lights and can all LED lights be powered with DC, if so how many could I expect to run?

Topic by screefer 11 years ago  |  last reply 11 years ago


Make battery supply for 9V synthesizer

I have a Roland D2 Groovebox that I'd like to use portably. It uses a 9V 1000ma AC adapter that I've misplaced. I prefer battery powered stuff so figured I'd take this as an opportunity to try to make it so. I'm comfortable with some soldering and cable splicing, but definitely lack the electrical knowhow to even know what questions to ask. I'm interested in either buying a battery housing for disposable battery power (AA thru D cell) or making a wire that can plug this into a rechargeable power bank. I assume this may be an existing product but, again, I don't know how to search for it (and, again, would also be happy to whip one up).

Question by ThomL9 8 months ago


can i set up a capacitor bank to start up my car if the battery is dead?

a huge advantage to capacitors is low leakage (for some types) and i want to know, first of all, how much energy a starter motor needs to start the engine? one of my constraints is money (>$200) so if it works, but i can't afford the capacitors, then oh well. also, i want to know if i can make a simple circuit that would sense if the battery is dead and then switch to using the capacitors and also be able to recharge the capacitors. im also worried about the amount of leakage of capacitors with such high capacity (which might defeat the purpose of this idea), and where i could actually put the rig that would be safe from heat, and still have access to the starter motor. if this is feasable, i just might make my first instructable out of it: the invincible starting car

Question by the judge 8 years ago  |  last reply 8 years ago


18650 battery pack question

Hello everybody, I need to install (build) a recharging battery pack for my plant shelf.  it will be running an arduino nano, just 3 leds (3mm 20ma each) 1xNTC and 1x water sensor probes (nails).--  no LDR no yellow LED. . I was thinking about getting a 2x 18650 battery holder - I need more battery hours, should we wire the batteries in parallel to get more mAh and boost them 3.7V to 5V. so basically this is what I am trying to custom build to get more hours; DIY Mobile Power Bank Case Kit . I would just buy the mentioned product BUT under specifications>battery it says the capacity range: 1000mAh and below. but the batteries I have are 3.7V @ 5000mAh. does this mean that the remaining 4000 will be lost because the system can't handle it?  . basically what I am asking for is how can I make a long lasting arduino nano powering 18650 battery pack BUT also with a recharging module. these are the items I found that may work together, please remember that I have no electrical experience from before. I have learned everything that I know from instructables, this is a too advanced build for me to figure out without asking a few questions. thank you for your patience, let me know if I have to clear anything out. batt holder:  recharger: boost: am I even in the right track with this thing? can these be connected together and a switch. again, the goal is max battery life.. maybe add 4x 18650 - 2in parallel + 2in series, 7.4V to arduino Vin, eliminate the booster, even more battery life ? . thank you in advance, love & peace akin,

Question by Akin Yildiz 4 years ago  |  last reply 4 years ago


Solar LED project

OK so I am new to this but I have an idea I want to take the solar panels off some of those garden lights and charge a small battery pack (AAs or 9 volt) to run a bank of white LEDs to use as lights in some basement rooms. Can anyone help? I am very new to circuits and think I have a good idea but don't know how to do it.

Topic by MBIOS05 10 years ago  |  last reply 10 years ago


What is the most efficient and portable way to convert 3 volts (Battery power) to around 400 Volts?

I need a portable and efficient way to convert battery power (3 volts) to around 400 volts. I will be using alkaline batteries... This will be used to charge a high voltage capacitor bank.

Question by brooklynlord 8 years ago  |  last reply 8 years ago


To even out my current coming in can I use 12v Gel batteries or should I go to a bank of wet cell batteries?

I have a chispito like wind generator and a radiator fan that I will place on the Air conditioner fan outside. When the Air Conditioner kicks on, I will be generating DC. My plan is to take both sources into a charge controller tied to a bank of 12v batteries, then into an inverter. I have purchased two 12v gel cell sealed batteries to get up and running with. Do I need to use wet cell batteries or can I go with the Gel Cell batteries? By the way my generator creates 3-6 volts in a good stiff wind anf my radiator fan creates 2-4.5 volts when the Air Conditioner is running. Thanks

Question by markmc99 10 years ago  |  last reply 9 years ago


could i use a split charge relay to controll charge to batteries from a wind generator?

Hi. i am making a wind generator for my home. i have made the generator but need a charge controller for the batteries. i would make one but i have no idea how to and can't find any useful schematics. then today i thought. what if i used a split charge relay? i could connect the turbine to the alternator connections, connect my battery bank to the car battery connections and a dummy load like a water heater or something to the leisure battery output. what do you think? yay or nay? thought i'd ask first in case it will ruin an expensive battery bank. thanks in advance :) 

Question by ljarrald 8 years ago  |  last reply 8 years ago


How do i go about choosing LEDs for a project? Answered

So i'm planning on building a battery bank to charge my phone and other usb devices . I wanted to also use it as a flashlight, My size is limited, since i was planning on using an altoids tin, and i'm already stuffing two 18650 batteries inside. What i want to know is what is the brightest led i can use that wont need a heat sink? or at least one that will dissipate enough heat into the tin alone.

Question by Tomahawk92 4 years ago  |  last reply 4 years ago