How many 18650 cells to power a Scooter? Battery talk #4 

I have a 1600 watt compact scooter. It came with a 48v 12amp/hr lead acid. now it runs 208x 18650 li ion batteries in a 16P13S 48v 48amp/hr Battery pack. it saved like 5 lbs, but quadrupled the range.

Really excellent explanation. Very clear; very methodical; no fluff; very logical.

You forget to mention the loss of weight. The 18650s will weigh about 16/17 pounds while the SLA's were 78. 60 pounds is 20% lighter? That means faster speed or longer distance on the same charge.

Excellent video. Love the simplified info man. Thank you!

Your calculations on the available power from the lead acid battery pack is inaccurate. While 20Ah x 72v *should* = 1.44Kwh, it really doesn't. The amount of usable power stored in a lead acid deep cycle battery is generally expected to be 50%-80% of the rated value and the rated value is at a 20 hour rate... So you can get 50%-80% of the rated capacity but only if you draw that power over 20 hours. The 20 hour rating(and ALL lead acid ratings in general) is misleading. To have any real idea of the available power from a lead acid battery you have to take into account Peukert’s Law. The more current you draw from a lead acid cell the less efficient it becomes. At very high drain rates you will lose a significant amount of power due to this problem with lead acid cells... and cheaper lead acid batteries tend to suffer more from this than better batteries. A Peukert’s Law constant of 1.1 may be seen with VERY high quality batteries, but might 1.4+ on cheap no name lead acid batteries. At a constant of 1.4, drawing 10 amps from a 20Ah battery you'll reach 80% discharge in around 30 minutes... not the 1.5 hours you might expect if not taking Peukert’s Law into account, and not the 2 hours you might expect if not taking into account Peukert’s Law or the maximum depth of discharge. Something else to consider in respect to the depth of discharge in lead acid cells is battery quality... with cheap batteries 50% is recomended since beyond that they begin to see a lot of damage and will have a much shorter life, with good batteries you can usually discharge to 80% and still get the same number of charge cycles as you could on a cheap battery at 50%. Lithium cells don't really have this problem, at least not to the point of being a problem... so you really only need a lithium battery pack rated for around half the rated capacity of the lead acid cells to get similar performance... and as a bonus you don't have the same amount of voltage drop over the discharge range that you do with lead acid batteries. These are just a couple of reasons that lithium batteries are becoming more popular with the RV crowd.

is there a spreadsheet or a calculator that can help with battery pack design and battery selection?

good example Jehu! I believe that a scooter motor rated at 500 W, refers to cruising power. Peak power usually is about double and is needed during acceleration, heavy load or uphill driving. looking at the form factor of 6 individual 20Ah Lead Acid batterries and the solid block of 150 18650s, I think he will have difficulties getting that block as it is into the space freed up from the Lead acid batteries. Any suggestions on how to set up the same battery capacity if you have to stash em away in half a dozen different locations throughout the scooter ( as his setup with lead acid would have been)

found this channel and quite enjoy it so far, but your jumpcuts are KILLING me

@ Jehu, didn't see this video for 2 years but got to add something. There are lot of electric scooters where it rate the power as some number like 500W in this case, but capable of dawing lot more power, at the peak it would draw even more than 13A as he say, so here 500W isn't the max peak. Of course there are some manufacturers who rate the the peak power.

Hey Jehu, this is really helpful - I''m not sure if I have seen anything so comprehensive, showing the process. Excellent job, thanks.

Since it's 8 cells at a time, you could do a compression pack in a tube arranged 4x2 and then stacking 18 or 19 high. Thin metal sheet between each, foam loaded thicker plate at the top, moderate pressure and no soldering needed. Pretty good price for those cells although that is a high power cell which you don't need in that scooter application at all. You get around 200A capability with those cells and you said you only need 7-20A. A standard LG 2600mAh cell might be half the price.

Middle of the video is wrong. The motor is pulling all the power, it peaks at 13A when accelerating.

you can get led 12 volt it help on cars or tucks for turns and head light. there are thing can make your wire ring better. you're the first I have heard talk about efficiency of wiring.

Most understandable explanation ever given on the matter!

Bravo, bravo!......thanks! Very very useful information! This is the best video yet to explain making a pack using 18650 batteries.....

Why so bouncy?

I know this is an old video, but the 36V Lg battery packs sold by alarm hookup on ebay would seem to work. Roughly 8 of those packs would give you 160 cells. 4 x 2 in series would add up to 72V 17.6 ah. Packs would cost $26-34 each depending on quantity purchased. Cost would be $208-272 .... cheaper than if you were to buy individual cells.

This format is great,thank you! Practical information clearly stated and hearing the $ price is something not many you tubers do... I like!

The website for the cells he wanted noted their nominal v at 3.6, which makes the math even easier. 20 cells for 72v nom, 84v peak (web page says 4.2v peak). So 160 cells would be 8 strings of 20 in parallel.

I hope you see this jehugarcia I could really use your help! I'm trying to make an 18650 house battery for my camper van and I'm stuck as to what I'll need to do to get the 18650 pack to work with my solar charge controller. I'm thinking the battery will be 12v 3s84p (3000mah cells) to give me a 252 Ah battery @ 12v. I feel like I can figure out how to build and connect the 18650 cells, but I don't know if the Renogy Tracer charge controller that I have will correctly charge the battery, if I need a battery balancer, or if I need a different charge controller entirely. Thanks! Love your videos you're the Mad Max of electricity.

SLA's run a big voltage drop under load. So that 13A under load needs the actual voltage. I'd work off 72V charged (72/4.2)= ~18 cells and under charge to 72V. minimum two strings but add as many as you can in parallel.

We could use a formula - I use a 24v system that draws 25 amps from a dc motor connected directly to two 12v batteries connected in series to run my riding mower for 40 minutes. Most people know the volts and amp draw. If you could give use a couple of formulas, it would help lots of people. Example - volts x amps = so many 18650 batteries needed. Thanks and keep posting. You help us lots. 👍 Also, how do I tell how many amps I can draw from one 18650 battery? And how can I tell how long I can draw amps from one 18650 battery. That will help me decide if I need 150 or 500 batteries. I may want to run a battery pack for 2 hours while drawing 20 amps from a dc motor.

What about the BMS for charging that pack ?

Hi Jehu! You said you will post links to all the materials needed to build a battery pack that you showed in the video. Can you please provide us with the links?

Cheapest way to get high discharge 18650's is to buy drill battery packs, these are purpose built for high discharge, and being store bought they have genuine cells. Here in Australia you can do this and get each cell for around only 3.9 dollars each with this method. With an electric scooter, the type you would use on footpaths and such, these only have around a 250-300w motor in the average models. Now you want to be able to likely use your scooter for about an hour before it's flat. This means that you will need at least a 40 cell battery, the total battery will only weight around 2kg. Yes it's very easy indeed. If you have even just a 100w solar panel at home, it can fully charge your scooter in just 3-4 hours.

The house idea is particularly interesting, my buds and I entertained the idea of running a house on lead acid batteries years ago but the number of batteries and size made it almost impossible due to lack of storage room and ventilation issues. now with the lithium ion batts- it may worth looking at again. Up here in Canada we're charged (pun intended) more $ during certain hours (you know like the hours you need it the most)- it would be great to charge on cheap power at night and then run off the batteries during the day. this would be a great project to see done via diy..

Excellent walk-through on this. Very much appreciated.

my plan was to make a 4 x 5 12v bank. I was going to connect 4 battery banks each in pos x5 neg 5x5 then treat them as individual batterys and put 4 together to make 12 volts

Thanks for the education! Have special need in mind . Will see if I can work out the particulars based on this informative video!

Jehu did u ever consider solar on your van to charge your car in daytime

he can improves the energy capacity and travel distance by converting to lithium battery cause 18650 dramatically reducee the weight and space needed.. by additional amp hour per parallel cells for each 19cells.. Depends on his budget..

Revolt RV400 Chinese bike in India with 150km range has removable 20kg 18650 battery. So some 445 cells considering 45g each.

Great job as always. (But I have a suggestion LOL) I would highly recommend he double that set up. Now or later when he has the money. The reason I say this I think he may be caught offguard by the all or nothing difference in batteries. Lead acid has a slow decline. So you kind of get an idea of when you're running low. 18650 gives you hundred percent all the way until you're walking LOL. Not much warning. Of course he will see a difference in power off the line of course and he will probably get more distance due to the loss of weight. Just my two cents. Because I'm bored. LOL

So simple, so practical. Thanks so much for a great video.

Hi. I see that is an old video but i said it anyway. You talk about 30 amps and that is when is acelerating. I have an e-scooter 48v 800 watts and when is rising speed it draw 33 amps. Now 33a x 52v (lifepo 16s) = 1716w but when is at full speed it go down to about 16 amps. And it is just how it works.

lead acid batteries are about 12.5 to 13 volts fully charged the 13.8 volts you stated are what the alternator/charger puts out to charge them

I have been toying around with the idea of powering my shed off a battery system. Its going to cost around $1,700 to run electric - so if I can build a systems that charges with solar for less than that - Im game. I know this is an old video so you may not be reading comments anymore but it could be an interesting build. Without going into specifics, I will be needing to power a portable AC for a few hours, LED lighting, and possibly some small electronics (battery chargers) and at times a miter saw. I know the LED lights and smaller electronics will be easy to run but its the high amp stuff like AC and Saws that will put the system to the test. If you had $1,250 to make an overkill system that can handle just about anything - how would would you do it?

A 20s 8p pack would be Ideal replacement for OEM and parts are easier to source 20s 10p pack would be exactly the same as the link

If someone has to use a 8p (or more) configuration anyway he does not need to use high amp cells. This way he could either save money by using cells that are only rated for 7-10 Amps or gain capacity because low draw cells usually have 1/6 to 1/3 more capacity for the same price.

i have been wanting to convert a honda 80 elite to electric, would be sick. put some lights on the underside, would be super fun to take out

Awesome details of custom battery pack mathematics!

Pb or lead acids are 14.4 fully charged but dip when left to sit after charging

Great video mate love this channel and electric vehicle conversion

I'm guessing the higher current draw of the motor is due to the resistance load that the motor is experiencing... The lower current draw would probably be from a free/no resistance load on the motor.

Just want to add that the lithium batteries have 30% or so more *usable* power than the lead acids. Not sure how his controller handles lead acid voltage drops or the math on pack size but he could get the same usable capacity with a smaller lithium pack.

My nominal 250 W ebike hub motor uses 600 W power, then i am riding on the hill. Also I have an other 250 W motor on my Ninebot ES1 scooter. The app shoes about 500 W peak power on sport mode, riding uphills. So it is absolutely normal, that 500 w, 72 V scooter uses 13 Amps, while driving (see. 5:00 Your video). Good luck.

Also bear in mind there would be a considerable reduction in weight therefore corresponding increase in range would be about 3rd of the weight

I like the practical examples. Could you make a video on the popular Raspberry Pi (newest version)? You can power it via USB but how much of a battery pack will keep it running for how long? Also maybe how big of a solar panel would make sense to keep it running forever?

Cool just wondering would you need to but the cells with a protection circuit? Or wouldn't you need to because its already built in the scooter?

The only thing not accounted for was that the usable AH for the original battery should be 1/2 the capacity which is 10AH. He could build a 10-12 AH 72v battery pack. Awesome Channel :-)

your videos are very well thought out and informational i really like what you do

since you finish your battery for your samba, how many of the 18650 have you change, or what was the life expectancy of this use 18650

Intersting would be what benefits you could get out of the 18650.. like compare the weight or the dimensions and how much more power you could get out :)

BTW Jehu thanks for the link the charger is a bit expensive but after reading the description sounds well worth it thanks for the quick replies

Hi Jehugarcia, love your work with the battery applications, the battery powered VW and the power wall. That's the future. You're living in the future while some of us are still learning the ropes. I've been thinking of doing a similar motorcycle project where I swap out the lead acid for lithium batteries. I only use the battery to start the motor then I guess the lights run from the alternator while the bike is on. I've watched most of your other videos and I understand that there is a need for making the pack with a BMS to control charge and discharge and to also protect the batteries. With a lead-acid battery being at 12V 6Amps, does that mean I'll only need 12/3.7=3.2 lithium batteries in series and 3 times that in parallel giving me a total of 9 batteries? 3 cells at 3.7v 2500mAh will be 11.1v 2.5Amps. Using 3S3P will give me 11.1v 7.5 Amps. Am I correct using 3S3P or did I miscalculate somewhere?

Strange, when I look up the Taotao ATE 501, the specs say it's a 48 volt bike. The 72 volt bikes are th3 804 and 805.

Great work thank you very much for your videos. I cannot find the video that you discuss the various inverters that can be used on a home system. Can you please help? Thanks again.

Is it important to add cooling to the batteries? The Tesla model S cycles antifreeze through the cells then passes them a heat exchanger.... I want to build an 8000 watt motor ebike and in the planning phases.... wondering if through your experience if it's wise to figure out a way to cool them? Some computers cool the CPU in the same fashion..... Add heat sinks...? What's your take

So to simplify even further...you want to reverse engineer from total watt hours needed, which is power, down to each individual cell's requirements? I assume there's wiggle room in the middle of this equation? Quite a bit based on which 18650's one is looking to use? (Price is a big factor, for me anyway.) My mind is telling me instinctively that there is a nominal configuration of parallel/series ratio? I have to study more. Trying to find the best config to create an e-bike cell for a Schwinn Meridian adult trike for probably a 48V 1000W front wheel hub motor....Any kind of "standard" configs for those right now? Can't find the EXACT vid for that. Any help appreciated. Thanks!

Can you show how you would make a 120-160ah lithium car battery used for car audio. We use alternators that charge anywhere from 250amps up to 400 amps. Commonly 270-350a. One amp can draw anywhere from 100-900amps. My current set up has 1 350amp alt 8 batteries and a 7krms amp that draws max of around 650 amps. I am looking to run more power. How many alts would I need to maintain 120-160ah lithium battery.

Hi your videos are awesome and i have a question. How can i power up a drone? The majority of drones last few minutes and i need something lightweight to last. Thanks

You can't just check the amperage, when these batteries hit hard currents, they tend to drop in voltage so you're calculation won't be correct. Not sure *how* much it drops as it depends on the battery type they are using. It would still be high power but nothing like the total calculated power.

Sorry I've gone back to this video, I've seen this with E-Bikes the motors are rated at say 500w but the controller like on mine can push 23 amps, so 23 x 36v is 828 which seems to be right when I check my watt meter, so is my motor actually 800w and not 500w like the question of the moped in question, as I have this argument that here in the UK we can only have 250w but most bikes are 36v and the controllers are 13amps max so they are in fact nearer 500w which means they are illegal even though they are from a manufacturer stating road legal bikes?

Brushless motors of 500w can draw up to doble depending of the energy, so a 250W brushless motor can drain 500W peak

Really enjoy these videos. Thanks for the explanation.

I would have recommended a more power dense cell, as he is not in need of such a high amp draw rating after assembling 8 cells in parallel...

Can someone tell me if the series batteries also count in the parallel total?

Man...i really like your videos. Keep it up!

A fully charged 18650 cell has a voltage of around 4.2 volts. When working on the math, you have to multiply by 4.2v other wise the voltage will be to high for the controller. But needless to say, I can run 60v on my 48v controller that I have on my ebike. Also you won't need 155cells, you'll need 144cells.

I have a 1999 kx250cc 2- stroke motocross dirtbike chassis/ frame. what motors would you recommend and how many 18650 lithium batteries would be recommended to achieve the 39/40 horsepower equivalent to the 2- stroke engine which powered it in the past? This would be a fun project for me. I am hoping that I can some how custom fit and shape the battery pack without cutting,welding,modifying the chassis/frame same goes for the motor installation without mods if possible. Any ideas or suggestions would be greatly appreciated.I am on a tight budget and hope by diying the battery module/pack and purchasing the required motor; that it will be far cheaper than buying the parts and paying the labor for a complete top and bottom end rebuild on the gas engine.Thanks, Sean.

I don't get it. My Tao Tao ATE 501 came with 4 12v SLA batteries. Fully charged they should put out about 55v. How can we assume that 72v would not over-voltage the motor and burn it up?

I think the 500Watt is the continuous power of the motor, the peak power of this motor will be mutch higher than that. To think a 500Watt Motor can only deliver a maximum of 500Watt is a common mistake. The 500Watt ist the output power of the motor without getting to hot. For example, I have a small 120Watt Motor in a small elektric skateboard. I massure the output power and it delivered more than 300Watt peak for e shot time.

Hi, He says that 19 Cells in Series & 8 in parallel. One series of 19Cells can provide 20A draw, but by connecting them in parallel would provide 20A*8=160Amps? So is the 160A then the max possible draw? and the motor just draws what it requires?

Look inside your controller and look at the combined spec of your capacitors. On my 24v controller I have a capacitor with 35v 1000up. So I assume any voltage up to and including 35v.

What if you are building a new vehicle from scratch? How do you figure out how many Ah to make your battery? Let's say you want it to go 100 miles per charge. If the vehicle weighed 500lbs, 1000lbs, 2000lbs, or 3000lbs, how would that effect the plans for the battery?

Wouldn't the battery pack get real hot under load and cause a short circuit?

i am having an electric Ricksaw which is fitted with new batteries and it gives more mileage to my vehicle when i changed the new to old one having 12v,11v,12v,9v it is not giving sufficient mileage but i charged the batteries for more time than new one but why it is discharging quickly and what is happening inside the batteries please make an video regarding this

I bought a 24v 12Ah Li-ion battery pack from a local vendor. How can I test the pack or confirming the ratings? Please guide.

So IF I had a 48V 1000W bike tire motor, like the kits you can get on bikeberry, amazon or newegg. I would need Strings of 12.9 (13) in series, to get 48v. 13 x (9.25) = 120 Watts per, so i'd need 8 strings of 13 batteries in series? (If were talking VTC4's or VTC5's that can handle 30-35Amps)

I was wondering if in the scenario of the 20a cells. Is that not too much amperage? 20x8p = 160a continous.

i used lead acid batteries of 48v both new one and old one can clearly explain the amps in ah ,may of small lithium ion batteries

OkI bought some Westinghouse 18650 batteries at Walmart. It doesn't say on the package how many amps You can draw off of them.

Hi I've got a small question would really help my project how many 18650 cells are equal to one car battery

I was gonna ask a similar question regarding my ebike,, 24 volt motor,, in wheel ,, however after charging the battery lithium iron , with standard supply,, left the battery for 2 hrs and fully charged measured 29.3 volts ? Thanks Shane uk

Hey bro love your video thanks for helping us out people who doesn't know anything about batteries and learning about batteries voltage and capacities and series and parallel I have a question when building your battery does it matters whether the battery is 3.7 or 4.2 volt whenever you building it for putting on your nickel strip does it actually matters whether it is full charge or storage charge I am trying to build two types of battery which is a 36 volt 9 mp and a and a 24 volt for my electric scooter greatly appreciate some healthy tips how many cells do I needed in parallel and in series thanks greatly appreciate if you help me

Your calculation of energy comparison is charming and simple but not quiet right. Lead acid battery characteristics have the Peukert Effect during discharge and you also do not want to discharge a lead acid battery as deep as you easily can do with Li Ion. Ergo: with your calculation you will have far more USABLE energy out of the Li Ion cells then you ever could use from a lead acid cell by only nominal capacity comparison. I would guess about 40% more! In my experience the comparison of usable energy of lead acid and Li-Ion technologies was always a convincing fact.

Hi! I want to know what are the materials required to make battery for scooter?

Jehu, how would I calculate the "other direction"? How would I determine how much power my off-grid house is going to consume so I can construct a battery the right configuration?

Great vid, love your work! I know this is an old vid but maybe you can help me - I have a stripped G20 Chevy van (no engine, no trans, just 2 seats) I have a 24V 4kW DC motor laying around my shop - would it move the car at least to 30mph if I connect it directly to the differential? plus how many cells would be needed?

oh by the way, the 60V20AH Lithium battery has a built in solar panel that puts out 15w.

I have a 36 volt Golf Cart. How many modules (of 36 volt battery packs) am I going to need to get my golf cart to go about 10 miles?

Talk about a complicated application I'm building a Solar plugin Prius. I would like your expert opinion if this is even possible. I calculated that I can get about 600w of solar panels on top of this car, not sure what the voltage output will be yet but I will convert it to 48V regardless. I bought a shitload of +SJ 18650 6000mAh 3.7V will be making 48V packs out of them soon. So the sun or household power will charge the 48v packs(not sure how many yet) kinda want to make them as flat as possible and hide them everywhere. Then I will run that through a 48v DC to 240v AC power inverter and than through a full wave bridge rectifier to 240v DC(not sure what the voltage drop will be?) The Prius gen 2 battery has a nominal voltage of 273.6 V This is my attempt at an key word economical DIY EV.

Looking to convert a small 800cc car with a direct drive 30kw motor without any change of axles. I was looking to purchase one Tesla battery module (444 cell) to go with it even though I do not know how to estimate range on this. Right now I am interested to see if I CAN do it. Could you suggest some cheap but reliable air cooled controllers if my plan so far looks valid? Also, how long does it take to deconstruct and refit a small car - generally?

I have a small row boat that I also use a trolling motor- Currently I use a 12v deep cycle marine battery- Is it possible to get more power and a lighter battery pack to power this?

I have a hypothetical question: Could you balance charge every cell to 4.2 volts by charging every cell in parallel? *If I connected 10 cells in parallel and applied 4.2 volts would that work?*

Love the vids. Im going to plan a honda 125 electric motorcycle. Fat dude so total weight is 700 lb. only need about 55 mph top speed and 20 mi range. Can you please help me with the recipe. Thanks for helping save the planet and all the information you have shared. SteveR

Jehu, Thanks for the cell fuse link in this video, been trying all different wire sizes with little to no success, and have been unable to find a full description in your previous videos. Just like to say thanks for such a great series of videos, and congrats on your samba. Because of your series i have decided to build an electric jeep for the wife, using a warp 11, and mostly 18650's. I was hoping you could do a video with diagram of different ways to parallel/series while making packs, and more on simple balance techniques (wire to first set of cells? last set. this all is fuzzy to me right now) I have noticed that you prefer to build packs of 3.7 nominal, and then series those packs into higher voltages. Is this because it is easier to charge at 3.7v as apposed to 7v/11v/14v~ because it eliminates the balance circuit ?? Also, i have an idea for pack building id like to share but i would like to email is that ok>? Brian-

I have a question how far does your VW van go on your batteries. Could you do a set of videos on how you converted your van to EV. Thanks for your videos.

Love your videos! The music is great too but there seems to be an unclean cut in the loop you use for these battery talks. Every time it hits the end of the loop it sounds like a guitar strum that gets cut off or something. I can't stop hearing it :P. eg. @0:40

SKOOOOTERS! Cool. Interested in doing this sort of thing for school.