Li-ion Battery

So I want to upgrade my psp battery, but all the cheap batteries i have seen on Ebay really discourage me from buying one. So, i have come up with my own solution; buy a low capacity battery, and switch out the cell. the problem is, that i don't know where to get such a cell! I want to order for a legitimate company, so that i cannot get ripped off, buying a 500mah battery claimed to be 3000mah i need >2000mah square cell approximately 3.5x1x5.2 CM Thanks!

Topic by Sandisk1duo 10 years ago  |  last reply 9 years ago


Li-ion battery

Whats the best way to reclaim some of my lost battery life from my laptop? Or is it imposable?

Topic by steven07 11 years ago  |  last reply 11 years ago


Where can I find good 18650 cells?

I want to build a custom Li-Ion pack using the 18650 cells. But, when I go to look some up online, all that really turns up are the knockoff brands in which they claim a stupidly crazy high mAh rating. So.... where can I get some good cells?

Topic by Dashing Rainbow Dash 2 years ago  |  last reply 2 years ago


How to reduce amperage from an 18650 li-ion cell to 3 amp 1.2 Volts?

Project is to adapt an 18650 cell to power an RC Glow plug. I just need to get the battery to power the glow plug to a working safe level. From my multi meter I read around 5 Amps out of the battery and around 4.3 Volts when fully charged. I have already tried a 2.7 and 3.3 Ohm resistor and its not worked. These look to have reduced the Amperage far to low. By plugging the battery directly to the glow plug it burns the plug out. From my understanding I need to reduce the supply down to 3 Amps and 1.2 Volts. Anybody have a suggestions? Further reading on the glow plug: http://en.wikipedia.org/wiki/Glow_plug_(model_engine)

Question by Harb247 6 years ago  |  last reply 6 years ago


how to make 12v battery from 18650 li ion batteries?

Hi, I have this led strip  http://www.supernight.cc/supernight-tm-5m-16-4ft-smd5050-rgb-double-row-600-leds-tube-waterproof-led-flexible-strip-light-12v-120led-m-strip.html Working Voltage is 12VDC. Working Current/meter: 0.8-1A the strip is 5 meter. 18650 x4 = 14.4 v 18650 x3 =10.8 v How can I make it work with 18650 li ion batteries? And how many battery must I use and how can I do that? I think that I need driver or booster to get a stabil 12v! work-time I need 5 h

Question by Cr77777 2 years ago  |  last reply 2 years ago


Balance charging li-ion ?

So I bought a replacement battery for a project. I tore down all the casing and got 6 18650. But I want to charge those batteries using the same protection circuit that was inside the casing using laptop battery adapter. Can someone tell me what are the terminal should i connect and how i connect? So far i found using multimeter that P-, P- is negative and P+, P+ is positive and there is no switch. The voltage can be checked directly. The circuit and battery is from Dell 1525.

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


Li-ion battery charger

I have taken apart a cheap disposable phone. i got a better phone because this one died. the charger still works though. i have 3 nokia 3.7v battery's. all the same. could i use this to charge the battery's in parallel.

Topic by chrischavez 10 years ago  |  last reply 8 years ago


Lithium Ion protection circuitry?

I was wondering.... The protection circuit for li ion cells in phones; is it a sort of regulator for the battery when charging? Or does it just stop the cell from being drained too far? I was wondering if I could use the circuitry from the prismatic li ions found in mobile phones for a 18650 battery....will the difference in capacity be a problem?

Question by .Unknown. 8 years ago  |  last reply 7 years ago


ReHab for Li-Ion Batteries??

Is it possible to get more life out of Lithium Ion batteries that no longer hold a charge? These things are great when new, but for the cost, they seem to crap out in a yr or 2. Specifically, 18v Ryobi cordless tool batts.

Topic by Toga_Dan 4 years ago  |  last reply 4 years ago


Li-Ion battery pack

Hi, I have 4x PANASONIC CGR18650CG LI-ION BATTERY 2250mAh 3.7v.  I have connected them in series and it gives around 14v. My internet router is working on 12v 500mA. Is this battery pack too much for that router? I was thinking to use that battery pack as backup for my router when there is no electric power, because it's winter and every few days there are problems with power. Thanks!

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


Li-ion vs Li-poly battery? Answered

I m currently searching for a battery that has an high discharge rate and I found these two:   Li-ion: http://www.ebay.com/itm/New-DC-12V-Portable-9800mAh-Li-ion-Super-Rechargeable-Battery-Pack-2-/180832863362?pt=UK_Sound_Vision_Battery_Chargers&hash;=item2a1a7a8482 Li poly: http://www.ebay.com/itm/5200MAH-6S-50c-MAX-100C-22-2V-Helicopter-Airplane-LIPO-PACK-BATTERY-BEAST-Nano-/360510967745?pt=US_Character_Radio_Control_Toys&hash;=item53f020cfc1 I need 40 volts so If I buy the Li-ion y will buy 4, and 2 of the Li-poly. I want to know which battery will be better for an high discharge for about 3 seconds, and about 15 times. I will use the batteries to create an high powered electromagnet to move steel. Thanks

Question by Kurt Gerhard 6 years ago  |  last reply 6 years ago


HELP please!! with Li Ion battery

1 st question: i have a 7.4v 2200mA li ion battery. my ip camera takes 5v 2amps what color resistor should i use and how many ohms? 2nd quesiton: i have a class 2 battery charger 12 volts 300mA is it good to charge my 7.4v li ion battery?

Question by dwstar79 7 years ago  |  last reply 7 years ago


How to build battery pack 9.6v from 18650 batteries?

I would like to create a good battery pack for my dead hilti drill. Originel nc-cd 9.6v battery. I have some panasonic cgr18650cg batterys here.  But when 3 in series, the voltage is higher. Maybe the drill can work with a higher voltage but I dont know. Will it work, would like to create first a 3S pack and maybe later a 3S2P  I need a PCB and thinking something like this one : http://www.ebay.nl/itm/12-6V-8A-w-Balance-Li-ion-Lithium-18650-Battery-BMS-PCB-Charger-Protection-Board-/321853922824?hash=item4aeffd1e08 Or this one? http://www.ebay.nl/itm/3-Cells-Li-ion-Battery-18650-14450-Input-Ouput-Protection-Board-PCB-12-6V-8A-/321804037521?hash=item4aed03ed91 And how to charge a pack, can I use a common 12v laptop adapter or other adapters or specia li-ion charger? I dont think the original ni-cd charger can be used with pcb's above?

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


Li-ion drill charger?

Hi So I've got a cordless panasonic drill for which the battery charger has been lost. I've been googlin' for a DIY way to make my own li-ion charger for the battery pack, but since these batteries seems pretty sensitive about the way they're charged, and none of the "how to:s" have focused on drill-packs (this one is 14,4v, 3,3Ah) I thought I'd ask the good people here on instructables for a pointer or two. :)

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


DIY battery setup help

Hi, I'm a first time DIY-er and would like to build a useful, long lasting battery pack for my *new* laptop (late summer). I'm 17, and this would be a perfect project for me to finish in the next few months. I'll be working with my dad and asking my physics teacher, who seems very all-knowing, for advice. My teacher understands electricity and batteries better than anyone else locally and is leading our STEM team, of which I am a member and need this experience. Keep in mind that I'm not just doing this to have a (much needed) battery pack for my laptop. I got most of my information from here and will most likely be purchasing new batteries. As far as the housing of the components, I have a hard plastic, 10+ year old lightly used blue lego container in the shape of a kid-sized briefcase.  Case: Old blue lego carrying case, 11” x 7.5”(9 including curved  front) x 3.5” Insulation tape Batteries: (x4) Battery holders: (x4) PCB: (protected voltage is higher, balance charger required) Balance Charger: Fuel Gauge: DC port: Wire terminals (for organization) Balance charge cords: Optional inverter: I heard about these being inefficient, so I'm not sure about it. Please inform me if there are any other parts that I'll need or if I've left out any information. Also Inform me if everything I'll need for a lithium battery pack is on this list. P.S. The case was chosen based on the fact that it will fit in my backpack with my books and looks much less alarming and more like a DIY battery than a black box or briefcase. especially with the fuel gauge and plugged in laptop.

Topic by leaf26 6 years ago  |  last reply 5 years ago


is there a way to "fix" a li-ion battery that wont take a charge?

I have an older (dell latitude c400) that works great, its tiny and weights only about 4 pounds. I got it 2nd hand about a year ago, ever since I got it the battery shows no charge even when the laptop is plugged 24/7. Is there a way I can "zap" the battery or something like that?? I've seen instructables about zpping nicad batteries but nothing about lithium ion ones... Any and all help will be appreciated.

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


Li-ion battery charging help please?

Hi, I have a couple of Li-ion batteries hanging around (one from an old mobile phone and one from an ipod mini), so I was planning to make an LED torch or something out of them. Anyway, can I use an old li-ion battery charger from a camera to charge them without it blowing a hole in my desk? Or whats the best way to charge them? Thanks!

Question by Ben Charles 10 years ago  |  last reply 8 years ago


Lithium-ion batteries for electric car?

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


How to charge a salvaged Li-ion battery pack?

I've recently salvaged a 11.1 V Li-ion battery pack from an old laptop battery.  Details : Voltage           :  11.1 V  (  ~ 4400 mAh ) Cell                 :  6 x Samsung 18650 22f  cells  (  3.7 V  and 2200 mAh ) Arrangement  :  3 packs in series , each pack having two cells in parallel  The charging circuit is intact.  How should I safely charge them? I'm well aware of the hazards related with improper charging of Li-ion batteries.  Can anybody please suggest some ways to charge it ? any tips ?   I need to know the proper procedure to safely charge (and discharge ) a Li-ion battery and what does a "protection circuit" do ? Thanks !

Question by electro18 4 years ago  |  last reply 4 years ago


Motorola Bluetooth charger to charge 3.7v li-ion batteries Answered

I have a little bluetooth charger that outputs 5.0V and 550mA, am I able to charge 3.7v li-ion batteries with this?

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


li-ion nokia battery charging with original charger, but WITHOUT THE PHONE?

Can anyone help to give some very basic answer i guess..Is it possible to charge the nokia phone battery, outside of the phone with the original wall charger connected to its + and - pins? I need this for my small LED project which i need to use li-ion battery LED flashlight. Thanks A lot.

Question by cdroman 6 years ago  |  last reply 3 years ago


What is the difference between Li-poly batteries and Li-ion batteries? Answered

I can't figure it out.

Question by bowmaster 9 years ago  |  last reply 4 years ago


Simplest Li-ion charger?

What is the simplest circuit that will charge a single Li-ion cell? It doesn't need to be fast - can I just trickle-charge the whole way? Does it need to be a constant current supply? vik

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


waterproof battery pack for 2-3 Li-Ion Rechargeable 2032 Button Cells

I need help making a waterproof battery pack for 2-3 lithium ion rechargeable button cells.  I want to run a strand of 10 led chrsitmas lights on button cells rather than 2 AA batteries.  please help. jtr10@netzero.net Thank you for your time Jeremy

Topic by jjrat10 7 years ago


Whats the proper way to wire a Li-ion rechargeable battery?

I have a Li-ion battery that I want to use to power mini portable speakers. I want to enclose the battery into the portable speaker's box and have a port drilled into it to recharge the battery. So what is the proper way of doing this? The Positive + and negative - of the battery is connected to the speakers right now, so would I just cut into the positive and negative and add my charging port? (I have the correct charger for the battery by the way) Hopefully I explained this well enough for someone to help, thank you!!

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


Solar Powered Li-Ion battery?

I have this Carrera RC car, and it runs on a Li-Ion battery. Li-Ion battery: 7,4 V – 900 mAh It is the Red Freezer Watergun Car, and the battery is on the bottom of the car. I wondered if anyone knows how i could cut the recharger wire (8,4 V – 500 mA) and attach it to a solar panel on the top of the car to constantly charge the battery. 

Question by articz82 6 years ago  |  last reply 6 years ago


Unknown Li-ion battery packs... How to charge them?

Someone gave me several Li-ion battery packs (BobS can use anything...). They are all different, but all put out 7.6 V. Apart from the cells (4 of them, 2 x2 parallel), they are stuffed with electronics. They have 2 input wires (sockets), without a voltage rating on them. I already fried one circuit board with 15 V (thought it was 12 V....!!!). A model number Google search did not reveal anything. What would be the voltage to supply the battery packs?? I would like to take the cells out and charge them just like ordinary rechargables. Put them in battery holders for power tools and portable sound system (all have different volatge ratings). Can I use the on board electronics (as is) to charge several ( more) cells in parallel?

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


Lithium ion battery capacity calculations?

     I'm working on a project that uses lithium ion batteries as the power source and cannot figure out how to calculate how long it will run for.  I have four 2.6Ah batteries connected in parallel, giving me a total of 10.4Ah of capacity.  They're lithium ion so the nominal voltage is 4.2v and the minimum I want to bring them to is 3v.  My project draws a constant 2.85W of power, regardless of the voltage put into it.  What I want to know is, is there any way to calculate or even just approximate how long these batteries will power my project before they run out (the voltage drops below 3v)?  The batteries are high quality, so the 2.6Ah rating is pretty reliable.  Let me know if there are more specifications needed or something.   Thanks ~Dudes

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


Charging Recycled Li-ion Batteries

I have busted mp3 players that I've already thrown away but decided to keep the Li-ion batteries in them for future use. Now i tried to connect them to LED's to turn into flashlights and they worked perfectly. Now the main concern is if i will use them as batteries for my flashlight how will i be able to charge them? Can I replace the jacks of the mp3 players' original charger with bulldog clips and just connect them to the terminals of the Li-ion batteries to charge them or do i need to connect a simple circuit for the Li-ion batteries?

Topic by rainrose 7 years ago  |  last reply 7 years ago


Li-ion battery charging question

I'm new here so hi first. Now to the question I've been making a portable wii lately and I've gone quite far, but I'm stuck at the power. So I've got two 20000mAh mobile batteries (10000mAh 4.2V x2 in parallel for one mobile pack) i was planning to connect the batteries in series to get the required 12v+ power to get the Wii running . Since this is a mobile battery it has a charging circuit for the battery in parallel . I was thinking how to charge the batteries in balance (in series) . It's quite confusing ,any help will be appreciated!( There is very little information of the batteries inside the pack, it only says [10000mAh Max 4.2V])

Question by WanjiangW 2 months ago  |  last reply 2 months ago


battery charging?

How can i charge my battery, i've lost my charger. the battery is 14.4V 1.5Ah Li-ion

Question by johnnywgk 10 years ago


Series Parallel 4S2P Li-Ion Battery Pack

Hey guys,I'm busy making a boombox*, my first version had an old small car battery inside which obviously weighed a tonne!Looking to make the switch to Li-Ion.I have already purchased for the battery pack:8 x Samsung 30Q Li-Ion batteries (3000mAh - 3.7V)BMS board I found online (CF-4S30A-A)2 x 4S 18650 Battery Holders.I'm unsure how to go about setting up the batteries and balance cables etc. Need the 4S2P configuration for the Voltage.I want to expand this in the future by increasing to maybe 3P or 4P (depending on how much space I'll need in my boombox).I have watched multiple YouTube videos but sick of watching 15 minutes of somebody soldering. I understand the safety aspects of Li-Ion.*I know this project could have been done with Raspberry Pi or Arduino but the rest of the guys who will use this would not be familiar with hence why I went with a Car Stereo.If anybody has any criticism, I welcome it but make it constructive!(I know I'll get a roasting for the terrible MS Word wiring diagram I made)

Question by alexmallaburn 7 months ago


Re-purposing Cel-phone Li-ION batteries?

Excuse me Please: I have a rather advanced Q on the re-purposing of Li-ION batteries. {history} the tiny battery within the SanDisk Sansa, I found to have a deplorable duration. So in disassembling the Sansa, I discovered it had a seemingly standard 3 pin Li-ION battery (red, green, black). Since a celphone of mine recently died, which I retained it and its battery, I decided to wire the albeit, larger, battery into the Sansa. I was gratified in the the Sansa worked as expected, but worked for literal contiguous DAYS at a charge!! (seems I had forgotten to turn it off in coming from the gym, to return to it the next day and it was still playing!) Now, my conundrum: due to the change in cellular tower technologies, and being forced to change to the newer "G" phone, I have an abundance of batteries, to which I continue to collect for myself and friends Sansa players with rewired batteries. In that the Motorola BQ-50 battery has four(4) pins, which are suggested as the following: pin 1 is battery + pin 2 is a communication line back to the phone pin 3 is a temp line back to the phone pin 4 is gnd pins 2 and 3 are used to tell the phone the charge condition of the battery and when the charge cycle is complete. would anyone here have the deeper electronics knowledge to advise me which pin of 2 or 3 can be omitted and still allow the battery to be charged via the USB like the original 3 pin battery? Thank you kindly for your time and knowledge. CAH

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


Power Supply from Phone Chargers?

Well I have a bunch of Li-Ion phone battery chargers lying around. Can I adapt one of these into a power supply? Or will the internal circuits to prevent overcharging a battery prevent this? Thanks! 

Question by transistorguy 7 years ago


Best way of charging Li-Ion batteries in series?

Hello. I've been working on a speaker project for the last couple of days, but I've now ran into a problem with the speakers battery. I have 4, 3.7 volt 9900mAh batteries, that I want to connect in series to achieve 14.8 V. What is the best way of charging these batteries in series, while still being able to draw power directly from the batteries? Also what amp should I use to charge the batteries as safe as possible? Would something like this be good for that?

Question by 1000Reasons 2 years ago  |  last reply 2 years ago


How to Charge 7.4v Li-Ion Battery Pack with CCCV

For one of my project i need to use 7.4V Li-ion battery of 2200mAh, Now i need to charge this battery pack efficiently. I'm searching for a charging circuit for the same but what ever i'm getting is a 3.7v charger or a charger not following CCCV methord. as mentioned in following link Link: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries Please suggest me a way to charge and discharge my battery in a better way.

Topic by ASHMILH 1 year ago


How to charge a Powerpack of 18650 li-ion cells 4s3p 14.8V?

I plan to make a portable audio system with 4 speakers and a subwoofer which are driven by a 12v TDA2030A 2.1 Amplifier. Everything is already packed in a small enclosure (approx. 30x15x30cm) and works fine so far. At the moment the amp gets it's signal from a 3.5mm audio jack and the power is provided via a 12v 1.5Ah wall wart. That's what I have for now. But that's not really portable right? So to complete my project I want to add 2 more things - a bluetooth receiver powered with 5v and of course I need to get this thing of the mains. That's where my questions actually starts. I've read tons of forum posts, instructions and watched a lot of videos about making a 12v battery pack but I'm confused with all that information. From what I've read 18650 Lithium-Ion batteries have an excellent power density and would suit my system best (small enclosure and portable). But of course I'm open for new ideas anytime. I planed to make the power pack out of 4s3p 18650's from an old laptop battery (don't have the exact data of them yet). So the pack would provide about 8Ah at 14.8V nominal. With a step down converter to 12v it't could power the amp and for the bluetooth I would use a car usb adapter to get the 5v needed. So far so good, but regarding the power pack I have a few questions. 1. Would a 3s4p (11.1V) arrangement be good enough to power the 12v amp since the 11.1V are in average right? 2. The biggest question I have is - How to charge that thing? As I want to have it as portable as possible, to be able to charge it anywhere from a normal power socket would be ideal. I know there are dedicated chargers for lithium batteries but they are quite expansive and not really handy to carry around. Is there any other solution to handle that? 3. BMS, PCB - I'm confused. From what I've read, to charge multiple cells they have to be in balance right? An over-charging and over-discharging can lead to fire/explosions and to prevent that a BMS is essential right? But first - how do i connect that BMS? Only to each of the parallel strings or to every single cell? Second, is it possible to use that BMS to charge the pack? Maybe also in balance? 4. For the case that the 18650 from the laptop battery are undercharged, where is limit to withdraw them and to charge them to balance with a TP4065 at 1A? That's it for now. Sorry for the long text and thank you for reading through it. I read so much on the net but didn't find the right answer for me.

Question by Johnny-Pi 2 years ago  |  last reply 2 years ago


Robot battery

Hi everybody I build my robot actually I have a 12v 12ah lead acid battery ( https://www.battery-direct.fr/Batterie-BP12-12.html). I would like to change it but I don t if I choose lipo or lifepo4 or li-ion? My principal goal is loose weight and size, so I think about lipo but I am not shure

Question by LaurentP30 3 months ago


batery charging

Having had to buy a dedicated charger for some 18650 cells (at my wife's insistence) I took an interest in these cells for the first time and their smaller cousins the 123a. At with maximum capacities I've come across so far of 3700mAh and 2000mAh respectivley that's twice the capacity of the battery in my smart phone and 2.5 times the capacity of the one in my basic bar phone. The smart phone width would accommodate 3 of the 18650 cells (6 days without charging at my rate of use) and the bar phone possibly 4 of the 123a's (70 hours talk time or 10 months on standby). Yes this would mean a custom made back, but there is at least one instructable on molding a GRP/ carbon phone back adjusting it to take extra cells and maybe ports just needs modeling clay. I suppose I could just carry a power bank, but why if the phone can be its own power bank? Removing the guts of a power bank and building a new phone back to accommodate them may be the simplest answer to this but, my questions are:- A) I've got old mobiles laying around could I use their charging circuits to charge these standard Li-ion cells? Assuming that is a yes that would mean a long charge every 6 days/ 10 months. I gather there are problems associated with parallel charging/ discharging of Li-ion cells and over discharging so, B) Any advice on doing this other than don't? On the assumption that's a don't or even if its not this strikes me as a safer possibility. C) Could a micro controller be configured to discharge one cell to its limit then switch to the next full cell. D) Could a micro controller be configured to charge one cell to capacity then look for the next under capacity cell and charge that. E) if so could it do both at the same time? If A is possible and the rest not then a multi position switch is  probably the answer.

Topic by Stan1y 3 years ago  |  last reply 3 years ago


Li-ion battery stores a weeks power for a home, from Panasonc

Www.popsci.com/science/article/2009-12/panasonic-will-market-li-ion-storage-battery-home-use-2011 As its a breach of copyright to post more than the link to the site, I am just saying that this device is what everybody needs if they want to be independent of electricity suppliers.

Topic by Lateral Thinker 9 years ago  |  last reply 9 years ago


How can I recharge 3.7v Li-ion batteries from cellphones... if I have 3 of them attached in a serial array?

I'm trying to turn a cheap pc-speaker set into a battery operated set. I have a lot of 3.7 Li-ion batteries from dead cellphones and I want to solder them into a serial arrange to get 11.1v. The question is... how to recharge them? is it safe to recharge with a 12v dc adapter? any other idea? Thank you!

Question by =PK= 9 years ago  |  last reply 9 years ago


Cheap Lithium ion batteries - help?

I picked up 4 Canon NB-4L batteries for 50p each, thinking that for the price they might be worth having. However, I don't have a charger - any help with this? I've got power and electronics and stuff. 3.7V 760mAh (Li-ion)

Topic by lemonie 9 years ago


Can i charge 3 18650 li ion batteries in series?

I recently take an old laptop battery a part and found 3 x "packs" of 3 x 18650 cells.I disconnected each pack and i was wondering,can i charge "the pack" using a TP4056 charger?(the charging current is 1A)l;(I want to make a portable console,so i need rechargeble batteries)This is the charger that i orderd:https://www.optimusdigital.ro/ro/electronica-de-pu...

Question by AnghelutaA 1 year ago  |  last reply 1 year ago


18650 at 0V and open-circuit? Answered

Something odd happened today. I went to use my Skyray king flashlight, but the output was very dim. I pulled the batteries out, 3 were at 2.7V, and one of them was completely dead. IDK how they discharged as I charged them not too long ago. They have protection PCBs in them so that is the first thing I suspected that tripped in the dead one. Sticking that one on the charger did not reset the protection PCB. So I pulled the insulation of the dead battery, However it is the battery itself has failed high impedance / open circuit. Even bypassing the protection PCB, I still only measure 0.001ish volt measured across it (the real measurement varies a large amount) and only uA of current short circuit. I applied 4-40V to it and measured no current flowing into the cell. Certainly open-circuit. I just thought this was peculiar, what is going on with this cell? I figured if it discharges all the way the internal resistance will go up a little, but to the point of becoming a complete open circuit!!! It is possible that a internal bond broke?

Question by -max- 3 years ago  |  last reply 2 years ago


Can I use a cell phone to charge any 3.7v li-ion battery?

I want to use a cell phone to charge 3.7v li-ion batterry that are shaped like a AA (same as laptop batteries)

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


How to store/ conserve unused Li-ion/ Li-po batteries?

Have several unused Li-ion and Li-po cells: My laptop battery, only used when working outdoors (is in summer). Half broken MP3 players, phones, a broken RC helicopter and some larger batteries.  Some might be useful one day in a future project. As I understand these cells slowly deteriorate even when not in use.  What is the best way to keep them in shape? Perhaps dry storage in a freezer? Charge them occasionally or have them uncharged?  Are button cells Li-ion cells?

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


Please could anyone Confirm what i intend to do is Correct ???

Hello again ! Ok well, after another week of major research, i have a theoretical concept for my battery packs that i intend to create but would very-much-so appreciate it if anyone could confirm that what im about to do is correct in the sense that it will serve my purposes! Scenario: I Have a pinhole wireless Camera & Receiver, the camera will be attached to an RC 1/10th Scale Buggy and the receiver will be near me, in a bag, on the floor... Instructions that came with the gear states: The Camera should receive 8 volts DC and will consume up to 200mA per hour... The Receiver should receive 12 volts DC and will consume up to 500mA per Hour... (Yet the receiver runs off a 9v battery!) As i am still waiting for some battery holders & a few other components to arrive i have put together the following for prototyping, please could anyone confirm that this would  work as i intend it to ? : Li-ion Pack (For Wireless Camera): 14.4v { Four x 3.6v Cells } Connected in series Charging Start @ 13.2v Charging Finish @ 16.8v To Emit 8 Volts, 1A Max: i will Use an ''LM2940T'' Semiconductor i will want to Either BUILD (preferably) a charger OR Buy this CHARGER... -------------------------------------------------------------------------------------------------------------------------------------- Normal Battery Pack for Wireless Receiver: 24v { 16 x 1.2v Cells } -Individually charged- + FOUR x 4-AA Battery Holders (In Series) To Emit 12 Volts, 0.5mA Max: i will Use an '' L78M12CV'' Semiconductor -------------------------------------------------------------------------------------------------------------------------------------- The usage i currently get from a humble 9v battery connected to the camera and receiver (two 9v batteries in total) is WORSE than abysmal and i only get upto 15mins of decent record-time from the wireless gear so i will be making the two battery-packs above to get a much-longer run-time.... Questions: 1. Will my power-packs work as i intend to use them ? 2. When i go to build the Li-ion battery-pack i really want to include some circuitry for Deep-Discharge Prevention & Over-Charge Protection, could anyone please point me in the right direction for a schematic please ??? A MAJOR thank-You to all that have helped me in the past & A-MAJOR Thank-You in advance for everyone's help again!

Topic by offtherails2010 7 years ago


Odd phone battery issue

So I just threw together 3 AA batteries and wired it to a female USB connector. I then plugged my phone in for charging. To my amazement, the battery meter tells me that the charger is DRAINING the battery. It's at 60%, but when I plug the charger in, it drops down to 20 within minutes. It then stays at 20, untill I restart the phone, where it goes up to 60%. The charging light turns on, and the status in the battery page is "Charging", but the battery is going down. I plug it back in, it goes down. It has 4.5 volts now, but before I did that, I had 4 aa batteries with a 5v regulator running, and it did the same thing. Don't blame that though, because it does the SAME thing when plugged into my laptop. This happened before, but I didn't know it. One of my friends had an Energizer portable charger that did the same thing, and I got pissed since i thought he drained my battery. This is a HTC mogul with an OEM battery and OEM cable. I don't know what's going on here, but I think I might just call sprint up and see what they say.

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


USB charged USB charger?

Hey all,      I'm looking for a combination of 2 circuits that I know exists already. I want to charge a Li-ion battery via a USB port in a computer or a wall adapter. Then (to save space and be more streamlined) I want to be able to use the same USB connection In the device I'm making to charge my phone from the Li-ion battery. If anyone could point me in the direction on this circuit that would be greatly appreciated.     Thanks

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


How to make a lithium-ion, usb power supply?

Sorry, but i have 4 18650's, and want to make them power a usb port. how do i need to set this up?

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