Lithium Ion Battery Shut Off

Hi, my name is Jackson Pugliese, and I am currently building a battery pack that will be consisting of multiple lithium ion batteries. Getting the pack itself together, is not an issue at all, however, what is an issue is battery shut off when charging.  I would like to be able to charge my battery pack with some form of laptop charger, that outputs 12v, for a 14.8 volt lithium battery pack. The main issue is overcharging. Lithium ions explode, or catch fire if they are over charged, and thus is not an option for me, so to find a solution, I searched the internet, and two things came up.  Option one, use some form of battery charger, that automatically shuts off when It is fully charged (which i do not want to do because I want to do it differently hence the instructable) And Option two, which came up alot, but i do not fully understand is I use something such as this;=1456701414&sr;=8-2&keywords;=protection+circuit+module+14.8+volt I do not understand what it truly is, nor how to use it, and would like someone to explain to me both of those things. Everything I am doing is safe, because I am using a en closer for lithium ions, in case if they explode or catch fire, so know one has to worry about anything not working. Thank you very much everyone for your time, and have a wonderful day!

Posted by merlinj 2 years ago

Over-Charging Capacitor

What happens if you connect some form of dc power source that supplies 100 volts to a capacitor that is rated for 100 volts, and leave it plugged in for a long period of time. would it eventually "over charge" and explode? would it over heat? would it loose its  ability to store energy?

Posted by merlinj 2 years ago

Charging Li-Ion 3.7 V

Just bought a 3.7v  batt for my new laser (class 3b,  200mw)  The batt place had no charger for it. Hoping it will arrive in time for show next weekend. If charger doesn't arrive, any suggestions for charging Li-Ion without overcharging/blowing up batteries?

Posted by Toga_Dan 3 years ago

Dell INSPIRON 5100 Battery

Http:// Buy Dell INSPIRON 5100 battery 6600 mAh 14.8V ( Compatible with 14.4V) Li-ion now! Rechargeable, removable Li-ion battery pack designed to work with Dell inspiron 5150, Dell INSPIRON 1100 SERIES Laptop Batteries and more. Overcharge and short circuit protection. Factory price, fast shipping, full 1-year warranty and 30-day money back!

Posted by asdfmakewish 7 years ago

Looking for cheap LiPo 3s low voltagle cutoof/balance circuit

Looking to add portability to a boombox project I built. Want to just grab a LiPo r/c pack and use a 3a 12v SMPS to charge it with. Know of a good battery protection circuit? This will be going to a non tech minded friend. So I'd like him to just be able to plug in the PSU when he is home without the worry of overcharging and be able to run it until the low voltage cut off is hit without worrying about killing the batteries. Any suggestions? It would be for this Thanks

Posted by Cancerkazoo 5 years ago

Making a set of iPod speakers from computer speakers.

I have a set of stereo computer speakers that run off a 9v power supply, I'd like to replace this power supply with a bank of 8 1.2v cells (9.6v) that I could recharge with the original (9v 94mA) power supply. First of all, would I need to regulate the voltage down to 9v, or will 9.6v be fine on a simple amplifier circuit? Secondly, would I need any circuitry to allow the 9v supply to charge 9.6v worth of cells? Would some kind of auto cutoff circuitry be necessary to prevent overcharging of the cells, or would common sense by not leaving it charging for long periods suffice?

Posted by Pir8 Pablo 8 years ago

The parts needed to build a solar powered light?

Hello everyone, I'm trying to build a solar powered led (2nd part would be to add a USB port) and I'd like to know all the parts I need to get it working nicely. Apart from the obvious things like an led, battery, on/off switch, wires and solar panel will I need some sort of controller for charging the battery as well as not overcharging it?  I'd like it to have a 1W panel, a 1W led and battery which can run the light for 5 hours (so 5Wh right?) If it is easy enough I would like to build one which has a USB port as well so I can plug in my USB fan. Thank-you for reading.

Posted by Full Metal 4 years ago

Solar Boombox Upgrade

Ok so im looking to upgrade my DIY portable boombox for the 2nd time and one of the things i want to add is a solar panel to supplement the battery power from my 12v 7ah sla battery, that by itself will currently run the thing for about 3hrs at full blast. The new version will have Directed CSX-650 component speakers: (bottom of this page) and the amp will be one of these:;=43 , so what id like to know is what tech spec should i be looking for in a solar panel that would be capable of charging the battery while the boombox is not in use and will supplement the battery power to extend the run time while it is in use? Also will i need some kind of circuit/component to prevent overcharge of the battery? Oh and is there some kind of simple light/gauge i can wire in to show the charge level of the battery?

Posted by ambientvoid 7 years ago

Voltages for 7AH, SLA batteries

So I've read all on the web about the voltages of a lead acid battery, and according to sites like This One the battery should be full at 12.69v or so. The only thing is I'm getting 13.02v on one SLA, and 13.08v on another. One of the batteries is brand new, and the other is out of a UPS. Are these batteries badly overcharged, or am I just really ignorant and can't find a simple site listing SLA voltages :) The batteries were not connected to anything for about 12 hours before I took the readings, and I have tested the multimeter I used, and it is accurate.If it helps, the battery says:Constant voltage charge(25C)- Cycle use: 14.5-14.9V- Standby use: 13.6-13.8V- Initial current: 2.1AAny advice / help would be greatly appreciated!PS) The main project is powering a computer with these batteries. I've done that so far and it draws only around 1.8A, so hopefully it could last for quite long! (~5 hours or so)

Posted by cb22 10 years ago

Charging BoostCaps

I recently got a few of the 3000 farad 2.7 boost caps from electronic goldmine.  I have a quick question about charging them.  Applying a higher than rated voltage before the capacitor is charged all the way would be fine, right?  The voltage drop should cause the source voltage to approach 0, thusly below the 2.7 volt rating.  As an extreme example, lets say you simply hooked up a 9 volt battery to it.  Since the battery can only supply like 200mA, the voltage drops to nearly 0 as the capacitor appears to be a dead short.  The dielectric (or ion exchange or napheon membrane or whatever it is in a ultracap, lol) should be fine, correct? My main goal is to later hook up one or two of these for a regenerative brake system of something like a small gokart or bike or something.  Stopping at 30mph is like (assuming 200kg total mass) 20k joules, and each one can hold about 10k joules, and assuming a max efficiency of like 30 or 40% (I think itd be much lower, though), these capacitors could brake a gokart going fairly several times without having to be discharged inbetween cycled (but of course they would be).  For braking, could these essentially be hooked up directly (of course with pwm, and other things, but in essence:) to the motor with a little protection circuitry to prevent overcharging the capacitors?  Or would the higher voltage instantly puncture and destroy the boostcap?

Posted by guyfrom7up 7 years ago

Solar Panel Messenger Bag : Current help?

I found a super cheap solar charger at goodwill and couldn't pass it up. ($2 for this thing!)  It's supposed to charge car batteries through the OBD2/EOBD plug. It's rated 240mA @ 18V, 4.3W What I was wondering was, if I just lobbed off just the end of the connector to have the DC wires, and left the voltage regulator, could it power a laptop?  Through the laptop's own AC!!!!! adapter?  I recently discovered that the NES was an AC device that did fine on DC power but it's kind of a different story when it's a macbook. Or instead of through the standard adapter, straight to the laptop power port itself?  Probably after making another small current regulator to get the right voltage.  The adapter accepts AC 1.5A 100-240V 50/60Hz as input and outputs +16.5V DC 3.65A Or possibly lob off the voltage regulator on the solar panel and seeing what I can max out at?  I'm open to a lot of suggestions.  Evidently it has some sort of protection circuit to prevent overcharging the battery so I dunno if that would help or hurt this endeavor.  But having an integrated toteable power supply would be pretty neat, always charging my macbook.  Or even my DS lite or GBA SP.

Posted by stalledaction 7 years ago

The electronics for powering a pump via solar power

So I've been tossing around the idea of making a automated garden that uses solar panels, much inspired by a vermiponics instructable I saw but I have some questions of theory and practice I'd like help with before I go into it. I've worked with simple electronics and have a fairly good grasp on the theory but nothing quite this complex or with components I'm not familiar with, so I'm looking for advice. 1) Solar panels must need something like a capacitor or battery to store the energy for the motor to use, and how would I get this reservoir to trigger at a high enough voltage so that the motor can actually spin and I don't just end up with a motor charging a battery that is discharging across a motor at a low enough current that it doesn't spin. 2) preventing the battery from discharging back into the panel, I assume one would use a diode for this but I'm curious if there's anything additional that is required 3) If I wanted to try adding further automation by adding an arduino with a mess of sensors, would powering the arduino from an additional battery charged by the same panel work (I assume this would slow down the charging of the motor's battery). 4)  Safety features to implement so I don't do things like overcharge the batteries/ suggestions encouraged. The arduino is currently gravy for the project, worst comes to worst I can set up some simple level switches.

Posted by squirrelchaser 2 years ago

NES Zapper laser gun w/sound effects

Hi Everyone, I came across the NES Zapper laser mod that burns things recently, and it lit a fire under my backside to do a similar build.  I've scoured various other resources and have yet to come across exactly what I'm looking to do.  And yes, I have already done a forum search for this project.  So, since I found the NES Zapper laser gun on Instructables, it seemed only right that I reach out to the Instructables community for assistance in making this project a reality. I am a rookie at this sort of stuff, but really want to make this happen.  I would like the battery to remain inside the Zapper, rechargeable by way of the female AC adapter connector.  I'd also like to add sound effects, so a speaker and soundcard is going to be needed.  I need help with the wiring circuit so I can adequately power the Laser, LEDs and sound effect without frying anything.  Below is a list of the components that I know of, I know there are others I'll need which is where I hope those of you reading this can help me out. 1 x Nintendo Entertainment System Zapper pistol 1 x 230-250mW 532nm laser 1-3 x Diffused Green LEDs 1 x Rechargeable CR123A 3.7 Lithium-Ion Battery (OLight has built in circuit board to prevent overcharging, over discharging and over discharge current) 1 x CR123A battery housing (found on thingiverse) Any help would be greatly appreciated.  Thanks in advance! Dan Solo

Posted by DanSolo81 1 year ago

Rechargeable Battery Help?

I'm sick of throwing away AA batteries, and I go through a lot with my camera flash. The only rechargeable, multi purpose batteries I've used were some generic energizer ones I got some years ago, so I need your recommendations.I'm willing to spend a bit more for a quality charger/batteries that will last. For batteries, I'd like to support Eneloop, as they sponsored an instructables contest in the past. They are significantly better than Energizer/Duracell, right? How does Rayovac compare in price/power?For a charger, I was looking at the the BC-9009 by La Crosse. It has good reviews, charges slowly for a slower drain, prevents overcharging and has all sorts of other features. It comes with 4 AA, 4 AAA batteries and a case for $40. See it here:;=electronics&qid;=1251579646&sr;=8-1I don't know how good the la crosse batteries that it comes with are, though. The BC-700 would work fine and can be bought alone for $30.For packaging reference, I need to have at least 8 AA batteries, but would definitely use any extra AA or AAA that might come with it.So, what do you have to suggest? Thanks!Update: I read that energizers may be better than eneloops for things that use a lot of power quickly (like a camera flash) while the eneloops are better for things that use it slowly (like a remote control). Is that true? I'm concerned about getting batteries that will store a lot of electricity over many charge cycles, but not so much about them holding a charge during storage.

Posted by Weissensteinburg 8 years ago

Advice needed - DIY off-grid solar electrics DC charging via AC from generator

Hi all, new to this forum... I'm looking for some advice regarding an off-grid electrics setup i'm running. Currently i have a PV solar panel charging a battery bank through a charge controller. It's a 12vdc system. For 240vac i use a small (500W) inverter. For larger loads i use a diesel generator. The inverter is basic but very high quality sine wave, it doesn't do any charging nor does it automatically switch the load between the AC of the generator and its own AC (i do this manually). In order to recharge my batteries when there isnt enough sun (which is often!), i use a simple AC powered charger that isnt specifically designed for off-grid/solar applications. In other words it is not "intelligent" and doesnt have bulk, float or equalization settings - it's just a DC charger that gives decreasing current as the voltage of the batteries rises. In fact it is very prone to overcharging if left charging for too long and will keep putting current into the batteries even after they've reached 15.5vdc or more. My question is this: is it a good idea to feed the DC charging current from my AC-fed charger into my solar charge controller in order to allow the charge controller to regulate and/or limit the charge as appropriate? I did this for a period of time and it seemed not to cause any problems. However, my AC charger did eventually blow its recrifying diodes although i'm not sure if this was due to a separate issue with the AC power coming from my generator which at the time was an old one and may not have been giving proper AC voltage (it may have been low due to engine speed problems). The solar charge controller is a PWM type. The way i had it set up was the DC from the solar panel and the DC from the charger in parallel to the charge controller. If there is no difference between the DC from the charger and the DC from the solar panel, i don't see how there could be any problem as it amounts to the same thing as having two 12v PV panels in parellel. However, what i dont know (due to insufficient technical knowledge) is whether rectified DC is any different to the DC from a solar panel. My setup is as follows: 1 x 200W 12vdc PV panel 60A tristar PWM solar charge controller 2 x 6vdc Trojan t105 batteries wired in series to give 12vdc Mastervolt 500w pure sine wave inverter (12vdc in, 240vAC out) SDMO 6kva diesel generator (240vAC) Wolf Max 50 battery charger (AC powered 40A DC charger)

Posted by RionZion 2 years ago

Suggestions for a cheap, simple robot unicorn build

My 5yo daughter has figured out that her mad-Scientist daddy can make crazy things come true.  For her birthday, she got a real unicorn and a princess crown (see picture attached).  Now for Christmas, she has her heart set on a ROBOT unicorn, and I think I'm going to try to tackle this, but I need to keep the scope tight so that when Christmas arrives, I'll have a deliverable for her. (My instinct always leap to grandiose ideas like actual quadrupedalism that would balloon the time/effort/money inputs into the stratosphere.   My biggest obstacle to make this work for Christmas is to stick with K.I.S.S. principles.  I can do basic welding, woodworking, fabricating, stitching, etc.  I'm reasonably good at electronics, and am a professional programmer with a degree in Aerospace Engineering.) Here is my rough  build plan:  (Completely open to improvement suggestions) 1)  Build frame out of 1/2" square steel tubing and weld together.  Leave large torso cavity for electronics and batteries.  Feet will have wheels concealed by a hoof shroud.  Feet will be upgradable (see tech features below) 2)  Use blue foam to rough out body shape.  3)  Cover with about 1/2" of soft foam covered with felt.  Use yarn for mane and tail.  Cover should be removable and washable. I'm trying to figure out tiers of work so that as long as I get the basic frame and covering down, I'll be able to increase/decrease the scope to ensure I'll have a deliverable for Christmas.  Here are the tiered robotic features I am envisioning: Tier 1: Make the saddle bounce at about .5Hz with an amplitude of roughly 1/2".  Possibly make head/neck bob up/down in sync. Tier 2:  Add horse sound effects Tier 3:  Build sensors for the reigns and stirrups.  Monitor if stirrups get pushed inward in a basic kick the horse motion.  Monitor if one reign or both are being pulled.  Make sounds effects based on inputs.  (E.G.  Clop, clop of hooves begins when stirrups are pushed in, and stop when reigns are pulled.)  NOTE:  Since they have access to real horses, keeping the controls reasonably close to riding a real horse will make this double as a trainer/simulator for her and her friends. Tier 4:  Upgrade wheels to powered.  Move based on reign and stirrup inputs.   Max speed will be very slow (40fps or so), so that it can be used inside safely.  Movement is mostly just to augment her imagination, not to move like a real horse. Tier 5:  (Not much chance I'll get this far prior to Christmas)  Upgrade software, sound effects, etc. Current back of napkin ideas: Frame will probably have 3 pieces: legs/torso, neck/head, Saddle/back  Saddle/back removable for electronics access. Neck/head will be joined to torso in 3 spots:  the top point will be anchored with a chain link between two eye-bolts, the other two points would be on the sides of the bottom, with compression springs pushing the neck and torso away from each other, limited by a mechanical linkage.  This should give reasonable motion ability, and allow the two base points to become the sensors for the reigns being pulled. I'm thinking a small 12V deep cycle battery, and 12v salvage DC motors powering the wheels.  Depending on the motor torque, I'll either power the back two feet and keep the front feet as swivel casters, or power all four and turn tank-style. The budget needs to stay reasonable, say $100ish.  This is a kids toy, and I've got lots of other mad-scientist projects to pump money towards. Outstanding questions: Motor selection, cheapest with high enough torque Good, cheap way to make seat and possibly head oscillate.  Mechanism needs to not break even if a 200lbs rider sits on it.  (Doesn't need to work when overloaded, just can't be permanently damaged when overloaded.) Locate inexpensive 12v charger that won't overcharge if left connected, but will charge a 3ah battery reasonably quickly.  (Or schematics to build one)  Essentially, looking for a best bang-for-buck charger. Least expensive way to play audio clips?  I've got plenty of horse-sound clips located, but I need a way to play them economically. Not sure how much force will be needed for movement.  I'm assuming a 70lbs rider/robot max and that it will primarily operate on flat surfaces, potentially on carpet.  Can't burn out if overloaded.  Suggestions on simplifying this?  Suggestions on simple improvements?  Ways to keep the costs down?  Sources for economical parts?

Posted by SvdSinner 5 years ago

Long Range Off the Grid WiFi Repeater

Hello Everyone,  I've got quite the project that I am undertaking and I am looking for a bit of advice. This will be my very 1st forray into long-distance wifi, as well as off-grid power resources, so Im biting off quite a bit at once! I have a friend who has been helping me with the research who has a much firmer understanding of both electricity and hardware, but he will be out of town for the next week and I would like to get a bit of progress on this while he is gone. SO, I shall consult the hive mind known as the internet. Alright, this project consists of creating an uplink between a remote shed, and a home in a nearby city, with a broadband connection. The rub, there is 10,000 ft mountain range in between the two. We have a site were we can put a repeater node at approx. 10,000 ft elevation, that has wonderful line-of-sight to both locations. However, this site is very remote, and will have to run off the grid obviously. The distances are as follows: Home to repeater: 3.96 miles (thats with Google Earth following the contours of the          mountain/valley, not sure how to make it just do a straight angled shot, so thats a rough estimate) Repeater to Remote shed: 2.68 miles (same issue) Background environment info: shed has generator + 60w solar array with 3-4 deep discharge lead RV batteries at 7400 feet. Has spring fed running water, which could be utilized for power as well, as obviously its always running. Repeater location is at 10k, as stated. Moderate to high winds very likely (data from peaks of similar altitude in the general area show gusts ranging from 40-60 mp/h, temperature ranges of  averaging 7 to 90+ for a the later part of July and August (F). Obviously, its very possible to get soemething below this, though the lowest Ive ever seen at the shed has been -15 (f), I would say most winters we could get a few nights that see temps below 0, but not often. Equipment Ideas: So to pull this off, we have come up with two ideas for the network equipment, which I shall discuss 1st, then I will show you what we have come up with for power.  - Network    - Repeater Node: rb433 wireless access point ($99.00)         with 2 r52h mini PCI wifi chips ($59.00 x2)         2 8-18 inch satelite dishs converted for long-range WIFI use (20.00 x2) OR instead of a rb433, we could use 2 WRT54G Linksys routers like this. (I also have 2 BEF 801.11b routers that are legacy to the WRT54G. I would like to use this if possible! Now, I know that this later choice would increase power use by about double. From what I have been able to find, the WRT's would at anywhere from 4.2w to 8w of power. Anyways, I like this later choice because it would be significantly cheaper for the equipment, but do you have any other ideas? I know that the RB433 would work great, but its rather expensive all said and done after I throw up the power as well. Plus, if it takes a lighting strike, its out of commission, and 2 cheap linksys routers are much cheaper to replace! Anyways any input here would be great! - Power  so power to the repeater node is the real challenge. We crunched the numbers and came up with something almost exactly the same as below: From the datasheets, a routerboard will draw between 6-10W. So design for 10W. Over 24 hours you will need 10Wx24h = 240 Watt.Hours of power. For 7 days, you need 7x240Wh = 1680 Watt.Hours. A single, large deep cycle 110Ah 12V battery gives you about 1320 Watt.Hours of power, almost meeting the requirement. Now, to look at the solar panels: A good rule of thumb is to install 6 times the wattage that is drawn by the device. This is because only about 8 hours a day in sunny weather gives you maximum power output from a solar panel. So the other 16 hours you need to draw from the battery. (So already you need 3 times the wattage drawn by the device to break even each day) To generate 1 full day of extra battery power per sunny day, you need another 3 times the wattage. This is how we arrive at 6 times. 6 x 10W = 60W. So at a minimum I would recommend 60W of solar panels. That qoute comes from and which is a project from a guy in South Africa almost exactly the same as the one that we are working on. The numbers came out to be about the same (Though they were a bit different when we calculated for the WRT54G option.) so, 60w of power generation to keep a decent charge on a battery. Now, we have a 60w panel at the shed, which is rather large to take up to 10,000 ft and place on the side of a mountain, and given the consistent wind element up there, we are hoping to do a hybrid system of both solar and wind. This is where things get tricky. A perfect balance, or even a more wind heavy balance would be great, such as 30-40w wind 20-30w solar. That keeps the panel size down, and uses a power source that runs 24/7. A Faroun Savonius wind turbine seems like the best system, but the controller to prevent overcharging etc is where I get nice and lost, having breached into very unknown territory.,129060.html This looked at 1st like a good, cheap system to use a controller board for the wind, but my question is would the controller board that comes with these solar panels (see below) work for both. That below is the setup that we use more or less at the shed, with some mods, such as a better alternator.;=solar&Mo;=5&cm;_re=1_en-_-Top_Left_Nav-_-Top_search⟨=en-US&Nr;=P_CatalogName:BC&Sp;=S&N;=4001192&whse;=BC&Dx;=mode+matchallpartial&Ntk;=Text_Search&Dr;=P_CatalogName:BC&Ne;=4000000&D;=solar&Ntt;=solar&No;=3&Ntx;=mode+matchallpartial&s;=1&topnav;=&Nty;=1&s;=1 So, can a small, 30-50w wind turbine and generator be built, with a small solar array to power this thing? I dont care if we have some down time, this is primarily going to be used as a system to get a weather station with web cam to send in hourly photos during the peak hours. I can have the system at the shed shutdown automatically  using some cron jobs in linux during the evening to conserve power. When there are people at the shed, we would like to be able to get a good enough wifi connection to use a wifi device (such as an android phone or ipod) to use as a voip phone in essential communication. The teenagers aren't going to be chatting with their friends for hours, but we would like to be able to put a short call through in case something goes wrong, or we just need to get ahold of someone at the shed or in the city. Next the equipment at the shed should be comparable to the repeater node,  sans 1 antenna and just some low power embedded system. We would like to get a webcam and weather station hooked up on this end, but that can wait for upgrades later if needed, if power doesnt allow it. like I said, a simple water turbine could be used (something similar to the wind turbine perhaps?) and even another wind turbine could be built to add extra power dedicated to running any system at the shed, though I dont think the wind is quite regular enough to be viable here, but if its cheap, we could throw it on anyways. equipment at the home in the city is simple, just use an extra laptop or desktop we have laying around to be server/router, hook up antenna to this, broadcast connection, run the weatherstation/webcam web server off of this. So, thats the plan, but load of input is needed to try to come up with this. We hope to try to keep this sub $1000.00, but the budget could go higher. This is DIY at its finest! Thanks in advance for you help!

Posted by kydan 8 years ago