Lipo battery cut off

I'm using a couple of Lipo batteries to power a speaker on a trailer, I bought 2 low voltage alarms that plug into the balance cables but upon testing I found it to be unlikely that I'll hear them over the speaker. So would it be possible to modify the alarms so that they activate some kind of cut off device attached to the power cable instead? Each battery is 4s 10000mah.

Topic by ambientvoid 8 months ago  |  last reply 7 months ago


Recommendations for lipo cutoff device

I've been looking for a device similar to a battery alarm for 4s lipos that can cut off the power when any one of the cells drops below a certain voltage instead of just sounding an alarm, i've been told that i can get a bms circuit which should be able to do this and that i should try to find the best one i can but i don't really know exactly what to search for. can someone recommend a small and affordable bms please? i won't be charging through it as i have a separate balance charger, i want it purely as a cut off device for when the batteries are in use...

Topic by ambientvoid 5 months ago  |  last reply 5 months ago


Charge LiPo 3.7 240mAh with 3v?

I have been told that I need to use a charging controller to charge a LiPo 3.7 240mAh with 3v. I have searched and cannot find one. Any help? It needs to be very small as well. Thanks.

Question by Tuckoguy 4 years ago  |  last reply 4 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


I am getting the message Turnigy MAX 80W?

I am trying to charge by 3S LIPO battery. It is 6200mAh. The charger that I have is Turnigy MAX80W. I am trying to balance charge my battery. However, when I configure the charger to 6.2Amps and 11.1V and then I press enter and I get the message to press enter to confirm or press back to go back. However, when I press Enter; It just shows me the message 'Turnigy MAX 80W'. Some times it shows  me the message 'Input Vol Err'. I have a tripple battery supple HM8040-3 and I am providing 17V from it. I am really confused what then problem is as I recently bought the charger. Please help!!!

Question by Bam Boy 5 years ago  |  last reply 5 years ago


1S Lipos with 3 wires, what for?

I'm trying to salvage a 1S lipo from my broken mp3 player but it's the first time I come across one with 3 wires. http://i.imgur.com/yvkPs7G.jpg I can take better photos later if need be, atm I just have my crappy phone with me.

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


Question about using LiPo Batteries

Hello, I would like to use a 3V Solar cell rated at 45mA to charge a LiPo Battery (3.7V) rated at 200mAh. am wondering. How long should I allow this to sit in direct sunlight to charge without overcharging the battery? I would also be adding an inline switch to shut off current from the solar cell. Here are the links to the products I would be buying (In case it helps) Solar Cell: (Its about half way down labeled "3.0V 45mA Solar Cell") https://www.futurlec.com/Solar_Cell.shtml Battery (Note I'm only using one) http://www.ebay.com/itm/2x-3-7V-240mAh-30C-Li-Poly-LiPo-Battery-Pack-For-RC-Micro-Helicopter-Air-plane-/300715147936?pt=Radio_Control_Parts_Accessories&hash;=item46040502a0 Thanks

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


Using LiPo batteries in coil guns

Hello all, this is my first post! I have been theorizing for a while about coilguns, and have been doing calculations. here is how it goes: A single Lithium polymer battery can hold up to 3.3 Ah and discharge at about 30c (safely). We multiply 3.3Ah by 30c and get 99 A of continuous discharge. That’s a LOT of current, but, it is still not enough to fire a good projectile. So, I’m planning on having four of these hooked up in parallel to give out 396A. This is quite a bit of dangerous current, so my wiring will have to be gauge-perfect. The magnetic field that this produces is about 9.9 teslas, as  twice much as your average MRI machine. Yes, I’m utilizing a miniature MRI to shoot stuff. If you want to know how much force an MRI puts out, here is a great video to show you https://www.youtube.com/watch?v=6BBx8BwLhqg. I am planning on having a 2,000 turn coil, with the average distance from the projectile being 1cm. The ammunition is going to be BB bullets, which means our cross-sectional area is at least 7.65*10-4m2. Using those numbers, the initial force on the BB is 3,015,030N. This is enough to lift up 25 semi-trucks. On paper, this seems magnificent. However, I’m accounting for about 2% efficiency, taken into account at this step, giving us 60,300N. This is still an enormous force to take to a .5g BB I’m implementing the Impulse to be .05s using standardized E = F * t,  this gives us 3,015 joules of energy. Huh. that’s way more than we should expect. Let’s take into account the 2% efficiency rating again, and we get a more realistic number: 60 joules. 60 joules is ridiculous for a BB pellet. We’ll use Ek = 1/2*m*V2 to solve for V. I got about 1,553 m/s. This is faster than most guns shoot regular bullets. I will be using a 2-stage setup, and will make sure to  use proper electrical equipment. My question to you is; How accurate are these calculations? if I build this thing, what can I excpect?

Topic by bjohnson45 4 years ago  |  last reply 4 years ago


using a lipo charger to charge a SLA? Answered

Hey everyone ! I'm planning to use a lipo charger from my Ebike to charge some scooter SLA batteries. I'm more of a li-po guy and haven't tried charging 3 SLA's in series before. Original lipo was a 10s 8.8Ah 36V (nominal, maxed out at 42V) and had an on board BMS that took a stright 42V input from the charger. the charger for it will deviver 42V @ 2amp and will let current flow until it hits 42V then automatically shuts off. The scooter batteries are 3X 12V 20ah  (six cell I assume?) by all-means, I should be able to wire the three batteries in series, (3 x 14.5V = 43.5V) then my charger should be a direct replacement right? Still need to manually balance them occasionally but for daily use on a 2amp charge should be ok eh?

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


Lipo battery charge/discharge on the same port with button?

I like to have the battery charged and used on the same wires with a switch in between. How to achieve this? The switch has a on, off, ground and kill.

Question by DennisK20 2 years ago  |  last reply 2 years ago


Tamiya gearbox motor upgrade? Answered

Sorry about all the questions. Hi, I want to upgrade this to 7.4v so that I can run it from lipo.  https://www.sparkfun.com/products/319 Preferably I would like a motor that snaps right  in. Has anyone upgraded theirs?

Question by David97 5 years ago  |  last reply 5 years ago


2 identical tablet batteries in parallel

Hello, is it possible to put 2 identical cube u30gt2 7.2 volt batteries in  parallel? Does the internal circuit handle it? Each battery consists of 2 3.7 volt batteries in series. thx, Mark

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


Charging a small 3.7v battery from USB

Hey guys! I had this little flashlight that worked great for years. I would plug it into the USB port on the computer to charge it. When it broke I took it apart and it had a small battery connect directly to the 5v and GND of the USB cable. Is it OK to charge these small 3.7v batteries from just 5v without having to make a circuit? Is ok to just hook them up to 5v? http://www.xheli.com/hm-genius-cp-z-14.html?gclid=CJGkwffHuroCFUkV7AodY0kA8A Thanks!

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


Charge AND balance 4 Lipo packs? Series Parallel solution help.

I have x4 identical Turnigy Graphene Professional 5200mAh 3S2P 15C LiPo Packs w/XT60 - and I need 22.2v out of them for a portable boombox project.   I have x2 12S 30A BMS's to balance / charge on board and a 600w 48v 12.5 A power supply. By wiring up the battery packs in series then parallel to get the 22.2v output - if I then connected the BMS (either by directly wiring to each cell or using the pack balance plugs) would it would cause a short circuit through the balance wires?    The ideal solution would be a wall plug power supply that plugs into the (sealed) boombox and charges all of the batteries through the BMS's. Is there any way of achieving this through parallel charging (not a fan) or could I switch easily between the two wiring set ups?   I'm trying to avoid buying a £200 Lipo charger and connect the batteries directly or keep disassembling the boombox every time it needs charging. Thanks

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


How do you change 3.7 V to 12V?

I have 2 cellphone battery brick chargers. I took one apart and found it to have 6, 18650 LiPo batteries connected in parallel to a circuit board to charge it. I have a project that requires 12 V and I would like to use these in some fashion. I was thinking put the two parallel battery bricks in series to get 7.4 V and step up with a DC to DC converter. Which one would be appropriate?  To charge the LiPo's I was thinking of parallel connecting the two circuit boards from the 2 cellphone battery chargers to a single wire connecting to a 5V cellphone wall usb charger. The usb charger supplies 5V at max 2.4A. Any help would be appreciated! 

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


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  http://www.amazon.com/Yeeco-Current-Polymer-Lithium-Protection/dp/B010NM52LG/ref=sr_1_2?ie=UTF8&qid;=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!

Topic by merlinj 3 years ago  |  last reply 2 years ago


Limit DC current from LiPo battery?

Dear Colleagues,  could you please advise if there is a way to limit DC current from LiPo battery?  I need to push the high current (80A) through very low resistance circuit, but do not want to fry LiPo. So need to limit the current at 80A I am not an electronic professional, and all solutions coming to my mind are based on increasing resistance of circuit (by adding resistance manually, or constructing something like FET-regulated limiter). The problem here is that I will generate lots of heat, and need too much space for its dissipation.

Question by SergeyD15 2 years ago  |  last reply 2 years ago


Can I power a LED array with LiPo?

I want to power an led array of 10W LEDs connected in parallel with a LiPo. They are rated 12V and 1050A. So thought of connecting them to 5200mAh LiPo battery so that they all will get 12V and each will get less than 1050A. Can I do like this? Please suggest a cheap method to do this. Thanks Edit1: Thanks for all the answers. 1) The link for LED: http://www.ebay.in/itm/5-PCS-ACTUAL-10W-WHITE-LIGHT-LED-SMD-BEAD-CHIPS-BULB-LIGHT-LAMP-DC-9-12V-/281779856264?_trksid=p2054897.l4275 2)The battery is actually 11.2V not 12V, my bad. 3) I know I have to use individual drivers for all of them but I'm just trying out to find out a cheap alternative. 4) I want to make an array of 10 10W LEDs so thought maybe they will divide the current by themselves.

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


lipo usb charger drains phone battery Answered

Hi guys, tried to make my own minty boost. I used a 3.7v battery 14.8 w/h Dc/dc booster lithium charge controller switch and a blocking diode. my phone when plugged has a smaller charge than when i started charging. I have a diode from the charge controller going to the dc/dc boost and a diode from the incoming solar panel.  please help!!

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


what makes a RC LiPo discharge rate (C) is different ?

Exmple : 7.2v 800mAh 15C, 11.1 2200mAh 20C

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


can i connect 4 11.1v lipo batteries in series AND parallel?

I have 4 11.1 v 2200mAh  lithium polymer batteries, and i want to connect 2 in series to give me 22.2 v with same aH and connect the remaining 2 in parallel to  give me 11.1v but 4400mAh.  is the a configuration of the two pairs i can do to archive max voltage and mAh. thanks in advance.

Question by icey.hood 4 years ago  |  last reply 4 years ago


Whats the diffrebce between BEC and UBEC?

Hi, i am putting together a robotics kit with lipo batterys. I need a lipo cutoff. From my understanding both BEC and UBEC are lipo cutoffs. I am not sure about what the function of both of them is but from my understanding BEC is a cut off that supplys the battery voltage. I think that UBEC is a lipo cutoff that also has a voltage regulator for powering servos. Please correct me if i am wrong and explain what they both do. Thanks, David.

Question by David97 6 years ago  |  last reply 6 years ago


Is there such a thing as a switch that will close the circuit if the open voltage drops below 12 volts dc.?

I am using a LiPo battery to power a bike light and the battery can be permanently damaged if the voltage drops below 12 volts.  Is there a switch I can wire in parallel which will cut power if the voltage drops too far.  

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


How would you connect three electric motors to an rechargeable LIPO battery?

Null

Question by Sk8terthing 10 years ago  |  last reply 10 years ago


How can I make a DC to DC step down voltager regulator?

I want to make my own BEC (battery elimination circuit) for my RC helicopter, so that I don't have to spend $50 and buy one. I'm also very impatient when it coming to waiting for things to arrive in the mail. I have some basic electronic parts.  I have some N-channel MOSFETs, Diodes, Resistors, OP-amps, and comparators, A butt load of Capacitors, My helicopters ESC(electronic speed controller) uses a 11.1v Lithium Polymer(LiPo) battery, but my RC receiver can only handle 6volts Maximum, at about 2-3Amps. I don't have any wheels, so I can't exactly run out to my nearest RadioShack to buy an LM317 voltage regulator. so I'm here to ask if anyone knokw how to build a [step dowm voltage regulator] from basic components? Schematics ,and parts list would be appreciated. I have no idea how much current the LiPo battery is pushing, it exceeds the max range of my Multimeter which is 10Amps. fried couple of diodes, and blew the fuses it trying to measure the raw current. I need help please.

Question by alien200049655 6 years ago  |  last reply 6 years ago


Brushless motor not running,help needed..!!!

I have Turnigy 2836, 2350Kv outrunner connected to Hobbyking 40A SBEC ,Rhino 1550mAh 3S 20c Lipoly Battery and a Hobbyking servo tester to control the motor .when i try to start it makes two beep sound, vibrates and turns off.it was perfectly running last time i checked .which components' fault is this??? and how to check lipoly's voltage and current?can i use normal multimeter? thanks for the suggestion....

Question by ferraririder123 5 years ago  |  last reply 5 years ago


Help wiring a toggle switch??

Hi there, i need some advice on how to wire a toggle switch between a battery voltage monitor and a battery so that I can switch the monitor on and off as required. My problem is that i need to pass 4 seperate wires through the toggle switch however I do not know enough about how a toggle switch works to achieve this. Here is a video that shows what I am trying to achieve; http://www.youtube.com/watch?v=YPLNywzmnAk&feature;=feedlik This is a voltage monitor for a lithium polymer battery for use on an Airsoft Electric Gun (AEG) the battery is stored inside a plastic box ,which is shown below, and i would like to insert the voltage monitor inside the plastic box with a toggle switch for turining it on and off I have some pictures attached to show what exactly it is I am using and to hopefully explain more clearly. Any advice at all would be greatly appreciated as I am at a loss about how to approach this.

Topic by dwelby101 8 years ago  |  last reply 8 years ago


What can i do with 7.4V Lipo batteries?

I have 4 2000mah 7.4V lipo batteries just laying around from my cheapo drone. So i decided to do something with them, maybe make a flashlight or something, but i cant find any electronics to use with them besides RC motors.

Question by RolandsB1 2 years ago  |  last reply 2 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 https://www.instructables.com/id/DIY-Boombox-Ghettoblaster/ Thanks

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


Q1) after draining a lipo battery to around 3.3v how long can i safely keep it at that level?

Q2) what is the maximum safe time i can store a fully charged lipo before it needs to be used? i have 2 lipo batteries for a speaker trailer and until their first charge and use they are being stored at 3.85v. i have done some google research and i think for the most part i understand how to safely use, charge and store them. They won't be used very often, perhaps 5 times a year on average. 1) i have purchased low voltage alarms so that i will know when to switch everything off however i will in most cases be using the speakers out in parks and fields at least 30mins to an hours ride away from a power socket so would it be safe for the batteries to sit at such a low voltage for around an hour before i can get them on the charger again?  2) previously i used SLA batteries and was able to charge them safely overnight before an event while i slept but according to everything i've read about lipo charging i have to keep a close eye on them while they charge so i would prefer to charge them during the day prior to an event, however i'm concerned that several hours 'storage' at full charge might be asking too much...

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


Will a USB Mp3 player charge with 5v and 88MA? Answered

Will a USB device Mp3 (usually 5v and 100-400 mA) player charge with 5v and 88MA? Will it take longer to charge? Or will it overload the charger and break something? Will a fluctuating amperage, always below the device's requirements, damage the device's LiPo battery?Thank you! I'm going to make something cool!

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


stepping up 12V powerbanks to 30V DC

I bought some RC Lipo battery packs to power a speaker system but since then i've moved and my new landlords have thrown a fit about me charging them on the premises because of the (small) potential fire risk so one possibility im considering is using a powerbank or 2 instead as they have no problem with those. my problem is that the amplifier requires 30V but most slim powerbanks put out a maximum of 12V so could i either safely step up to 30V from 12V or join 2 powerbanks to step up from 24V?

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


Lithium polymer protector (LVCO)?

Has anyone used a very small low voltage cut off (LVCO) circuit on a lithium polymer battery? I found a nice collection of lithium polymer cells in a 'dead' laptop battery. Thing is, I don't want to be careful about over draining them and they don't seem to have a low voltage cut off circuit in the individual cells. Sparkfun sells batteries with a teeny LVCO system built into the cell package like this:  http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/BatteryProtection.pdf What would be a reliable source of similar reliable boards that protect from over discharge?

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


How to make a USB charger from a tablet battery? Answered

I have a tablet battery, L10C1P22 and it's in good condition. I was scouting through Instructables to see if anyone has made a USB charger based on a tablet battery. And I couldn't find one. So may be I haven't found it despite it being there. Can anyone direct me to a source that instructs or at least provides a brief idea of how I can make this happen. Or if someone knows how to, please please share it with me. I'd be very grateful. Thanks Amol

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


charging and discharging lipo and lead acid batteries in series/parrallel

Is it possible to charge a lead acid battery and a lipo battery of the same voltage but a different amperage in parallel , and discharge them in series , without one of them blowing up or being damaged? i want to charge a battery pack in series with a 12v charger , and run a 24v dc motor with them...

Question by wiebevandomburg.hotmail.com 8 years ago  |  last reply 8 years ago


Batteries, amps, and watts, oh my! Help with my speaker build?

Hey guys, first post here, so be kind, I suppose. :PI'm building a set of speakers, loosely based off of the super loud, super long lasting speakers instructable (found here https://www.instructables.com/id/super-portable-super-loud-long-lasting-battery-/ ) I wanted to take these, and make them significantly better.First of all, I was going to substitute in car speakers. The upside of that is that I also get bass without having to go out and buy woofers and wire up a crossover. I've been looking around on partsexpress, and it seems like most have an impedence of 4 ohms, and range from 75 to 150 RMS. I'm aware that the general rule of thumb is that you double the RMS for the amplifier. However, I'm not sure about soe of the other parts. Should the speakers be wired in series or parallel? If they're wired in parallel, should I be looking for an amp with 2 ohms of resistance, since it's two speakers at 4 ohms? If not, can speakers be easily wired in series?Next question, batteries. Where in the hell do I get some good LiPo batteries? I know this thing is going to go through electricity like candy, so I want high wattage and high capacity.The wattage brings me to my last question. These speakers are rated for a maximum input of 70 watts or more. I can't get a battery to go anywhere near that capacity. Will the speakers be harmed by a lower wattage supply? Significantly lower, I might add, most probably not more than twelve, even if I array the batteries into my own pack. How will that affect the speakers?EDIT: I could realistically reach more than that, although it'll start getting really expensive really fast.Sorry, one last; concerning the rule of thumb in which you should double the voltage of the speakers RMS for your amp, if I can't find an amp that does that exactly, should I have my amp be slightly overpowered, or slightly underpowered?Thanks for all the help on this one :)

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


wiring and charging 2 3s1p lipo batteries in series?

If i wire three 3s1p lipo battery packs in series, does it become a 6s2p battery and can I charger the 2\three batteries in that form(series). This is for a electronic long board battery. I would be using three zippy compact 5000mah 3s1p 11.1volt batteries.  Im want the total mah to be 5000 and output voltage to be 33.3. therefore the wirng like this would work but im not sure if i can charge it in series with 1 charger or if i have to charge them all seperatly if wired in series.  Thanks!

Topic by bluebox17 1 year ago  |  last reply 1 year 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


dc to dc step up converter for 22v 6 cell lipo to get to 44 volt , need advice

Im building a power harness for my hang glider, the project is very near completion, my brushless out runners require 44 to 48 volts. I am using two sets of 22v 6s in series, but the weight of two large 6s batteries banks is significant , what would be the potential to create this step up converter and what are the down side of designing dc to dc step up converter into my power system. My hope to eliminate the in series battery ( double battery  weight ) set up.  I suspect loss of amps or total run time ? what about problems with electronics  heat in the circuit, issues with ticky speed controllers, or the out runners , how will they be effected , or will these components work normally in a step up voltage / current  as compared  batteries in series. ( which is working beautifully ) I guess volts are volts, it just sounds to good to be true , double volts and less battery weight Any and all qualified opinion and advice is appreciated.  Thanks Jeff

Question by JeffR135 2 years ago  |  last reply 2 years ago


How do you connect three servos to one Blue Lipo battery?

Do you need an adapter? Just could some one help me or make an instructable on how to do this?

Question by chanman789 8 years ago  |  last reply 8 years ago


Multiple Speaker Building Questions! :D

Hey guys, first post here, so be kind, I suppose. :PI'm building a set of speakers, loosely based off of the super loud, super long lasting speakers instructable (found here https://www.instructables.com/id/super-portable-super-loud-long-lasting-battery-/ ) I wanted to take these, and make them significantly better.First of all, I was going to substitute in car speakers. The upside of that is that I also get bass without having to go out and buy woofers and wire up a crossover. I've been looking around on partsexpress, and it seems like most have an impedence of 4 ohms, and range from 75 to 150 RMS. I'm aware that the general rule of thumb is that you double the RMS for the amplifier. However, I'm not sure about soe of the other parts. Should the speakers be wired in series or parallel? If they're wired in parallel, should I be looking for an amp with 2 ohms of resistance, since it's two speakers at 4 ohms? If not, can speakers be easily wired in series?Next question, batteries. Where in the hell do I get some good LiPo batteries? I know this thing is going to go through electricity like candy, so I want high wattage and high capacity.The wattage brings me to my last question. These speakers are rated for a maximum input of 70 watts or more. I can't get a battery to go anywhere near that capacity. Will the speakers be harmed by a lower wattage supply? Significantly lower, I might add, most probably not more than twelve, even if I array the batteries into my own pack. How will that affect the speakers?Sorry, one last; concerning the rule of thumb in which you should double the voltage of the speakers RMS for your amp, if I can't find an amp that does that exactly, should I have my amp be slightly overpowered, or slightly underpowered?Thanks for all the help on this one :)

Topic by headinmysights 9 years ago  |  last reply 9 years ago


I need a circuit to reduce 11.1v Lipo battery to 2v?

Preference is to use a voltage regulator to get a constant voltage output. If it can have a LED in the circuit somewhere along the way to indicate when it is connected. Kind of know what I need but not enough to put a circuit together.....anyone help?

Question by Have-a-go 4 years ago  |  last reply 4 years ago


where can I buy a motor, lipo, esc and arduino?

I am building a device that goes around a track at set times and am not sure what I need and where I should buy it. I know that it must be able to reach 2000rpm to achieve the quickest time required but don't know which motor would be best.The fastest speed the device will need to travel is 10m/s. I have also been told that I will need an arduino, esc and lipo. I am a beginner and don't know where to start. Any responses would be greatly appreciated. Thanks

Question by alex cooke 4 years ago  |  last reply 4 years ago


Does a lithium polymer battery have too much amperage for a 555 timer? Answered

I'm using a 555 timer for a robot, and i was wondering, is a lithium polymer battery too much amperage for the 555 timer? because when i use it, the 555 timer warms up, to a point where i cannot touch it without getting burned instantly. If so, how can i reduce the amperage, so that it can be used with the 555 timer? I'm using a 7.4 volt, 1000mAh battery, it was originally used for a helicopter, but i re purposed it for my robot...

Question by Chowmix12 8 years ago  |  last reply 8 years ago


Piggy Backing a lithium battery (cell)

I have several questions.  But the basic idea is that I want to extend the runtime of a device (such as a cell phone, tablet, camcorder, whatever) by increasing the mah.  So here are the things I am wondering: 1)Many lipo batteries have 3 or 4 contacts, one is -, one is +, and the others are typically data or something.  can I simply connect additional lipo's (just the + and the -) in parallel with the corresponding contacts in the device? 2) Are there any ill effects of charging (presumably from the built in charger of the device, like a cell phone) and discharging (using the device) parallel lipo's? 3)  They will all have the same voltage rating, but do they all have to have the same mah rating? thankyou

Topic by guyfrom7up 8 years ago  |  last reply 8 years ago


Charge unprotected lipoly with desktop power supply? Answered

I have a few, almost dead 700ma li-polies taken from a macbook battery that would not charge. I have no formal Li-Poly charger, and most commercial charger will refuse to charge these batteries anyway- because most of them are lower than 2.7v right now. I wanted to see if I could revive these, which I have read can be done, using constant voltage and current.  My problem is how to charge these using a common desktop power supply. My setup right now is a charger set on 3.7v, multimeter in parallel (to measure the cell voltage), and a current of 20ma. So far, nothing dramatic has happened thus far. Thing is, the "shorted" light on my power supply is on, and the voltage says its around 2.8v right now (rising slowly). Is this just due to the battery charging? I mean, is this behavior normal for an unprotected cell charging on a power supply?  Also, please note that I do know what lipolys can do. I am not just gonna hook this thing up to 20v and leave to go to town. I am monitoring it, and have it in a large, thick plastic box that is 2ft from a door. I will not leave it on unsupervised. 

Question by astroboy907 6 years ago  |  last reply 6 years ago


What battery

Hi I have just bought a 60a esc and 5200kv set up. I have tried my 11v Lipo and it is so slow. What battery do I need to power it ?

Question by Pwinfield77 1 year ago  |  last reply 1 year ago


qi wireless charging question

If I get a Qi Universal Receiver (like for a cell phone), do I still need to use a Lipo charger with it to protect the battery?  Pics attached.

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


Please help to select a power source for 100W LED?

I want to make a spotlight using 100W LED powered by a 2200mAh LiPo. I understand I need a power booster for this. Please suggest one of the correct specification. The LED: http://www.ebay.in/itm/100W-LED-COB-Chip-CW-WW-Blue-Red-Green-Super-Bright-single-color-/331632451175?var=&hash;=item4d36d59e67:m:mxsTE0PLt5bDCjp8vJJs5CQ The battery: Standard LiPo of 11.2V. max current of 55A Thanks a lot

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


can i power a multi stage coil gun with 22v lipo with 2200maH?

I know i'm late on the coil gun band wagon but its still interesting to build. i have all the parts to make the gun (circuit wise) however with my power source, i don't know how many turns i have to do for best efficiency.. i have 18 AWG wire i intend on making my projectile 1" long and 7 mm Diameter. so the the coil diameter will be 7.5-8  mm.   thanks for help in advance, even a simple equation is welcome

Question by icey.hood 4 years ago  |  last reply 4 years ago