how many 18650 battery do i need

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want to build   10 W

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how many 18650 battery do i need

Post by want to build » May 18 2018 3:55pm

HI im fromm canada and i d like to build required battery to use with a kit i can import o it coud be from ebay.ca too
i looked at

AW 26"x1.75" Rear Wheel 48V 1000W Electric Bicycle Motor Kit E-Bike Cycling Hub Conversion Dual Mode Controller
from https://www.amazon.ca/gp/cart/view.html/ref=nav_cart

and i would try to find good batteries maybe these https://www.ebay.com/itm/99-SANYO-18650 ... SwAwFatByn
from alarmhookup seller on ebay.


MY NEEDS

i ll use the bike to assist me with cargo in hills and flat but i will keep pedalling moderatly.

question 1 how may battery cell do I need to do 70 mile (while pedalling moderatly) with the hub presented 48v?

question 2 what about if i build a 24 volt battery pack for the hub for 70 miles while pedalling moderatly? im open to suggestions
question 3 should i use a different motor ?what would be the advantages ? how will less watt lower volt affect the use?

question 4 my actual tires are 28 inchs . can i put the 26 setup on it ? any modifications to do? here is my bike https://www.norco.com/bikes/city/hybrid ... -stepthru/
Last edited by want to build on May 18 2018 4:17pm, edited 1 time in total.

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Matador   10 kW

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Re: how many 18650 battery do i need

Post by Matador » May 18 2018 4:13pm

At 20Wh/mile for this motor,
You would need minimum 1400 Whr of capacity.
These cells, being around 2000 mAh at 3.7V meaning around 7.4 Wh,....

I`m guessing you you need a minimum of 190 cells. But these cells are low drain low quality cells, plus they seem to be more than 10 years old and with high internal resistance... Thus they will run very hot, and the high voltage drop will be synonymous with significant loss of performance. The heat generated will further cause a "chain reaction" causing furhter degradation.

I would not by that lot even for 20$, this is a pile of junk.
Alarm hookup do sell some good cells, but this is not a good choice.

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Matador   10 kW

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Re: how many 18650 battery do i need

Post by Matador » May 18 2018 4:14pm

the battery is the most important part of the ebike. Poor battery = no fun, regardeless of the motor and controller you have.

want to build   10 W

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Re: how many 18650 battery do i need

Post by want to build » May 18 2018 4:40pm

if i pedal most of time and just use for hills and litlle help , do i need 20 wh?
which one of his lot or other lot do you suggest to buy?
maybe best quality price to buy them still assembled(i dont mind taking them apart separatly)?

what is the diff between watt and watthour?

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Matador   10 kW

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Re: how many 18650 battery do i need

Post by Matador » May 18 2018 10:19pm

watts = intantaneous power... 1 watt = 1 ampere x 1 volts

watt-hour = a defined quantity of energy. For example 1 Wh represents the amount of enrgie given by 1W of power applied during 1 whole hour. 1 Wh also represents 60W applied during 1 minute or 3600 W during 1 second.
If your motor/controller sucks up 1000W, you could use up around 1Wh of your battery every 3.6 seconds or so...

I was not able to see your ebay link, but I google searched the ebay URL adress. If your gonna use a 1000W at 48V and you want a battery with less than a 100 cells in it, you need new cell or at least new old stock cells. Dont buy used 10-yrs old laptop cells. These are not meant to provide more than 1 amp per cells.

I suggest cells that can deliver 10 or more amps per cells of current (medium to high drain cells).
Laptop cells, even brand new are low drain cells. Such cells are a poor choice for medium to high drain application like ebikes. If you are to scavenge old cells to make a cheap ebike battery, use cells from powertools, not laptop batteries.

Laptop batteries will overheat and get damaged. I've been there, done that in the past. Don`t repeat my mistakes...
viewtopic.php?f=3&t=91040#p1328613

Not all 18650 cells are created equal:
Some 18650 cells chemistries and electrodes can only deliver 3.5 amperes/cell of juice
Other like the sony VTC4 can deliver 30A/cell of juice...
You want at least 8-10A capable cells for ebike application as a rule of thumb.... Unless you are willing to carry a 20 kg battery pack !

want to build   10 W

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Re: how many 18650 battery do i need

Post by want to build » May 19 2018 6:50pm

HI Matador and al,
before coming to endless sphere i read a buch and buch of stuff on ebike since i was non initiated. Now i think a have some notions but still im leaft with some questions.

I have read the link you showed. I also did some recherche on the web to understand the difference between high current and low current.
It is a more precise info to search for. What i understood is that if you battery pack has high current capacity, it has the possibility to give faster accelaration without getting the battery too hot. It is pretty much where my understanding is hahaha! Great to learn :P is this exact

Now, i have no understanding about the data you tested hahaha . I searched to see if Dbass has a shop online but found nothing. Are those cells cells he sells or cells he likes a lot? how much usd or cand approx ?

the motor im looking seems to be trottle power on demand if im not mistaken. does it offer the possibility to also be used as a pedec? if not can i add this fonction by adding some gear, it would maybe more simple. If not, how do you guys use the thumb part for long times without getting a tendinitis? in description it says dual mode hall effect non hall effect ? im not isaac newton lol https://www.ebay.com/itm/48V1000W-26-Re ... Swh1haAmO9
im very open to open good bang for buck...


if i pedal moderatly during flat and uphills (my online research told me it consumes around 12 whour from battery is that a reasonable estimation?) how many watt hour do i need and how many battery from dbass would be needed for around 50 miles to make it simple (with constant pedalling) i need exercise lol .

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molybdenum   100 W

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Re: how many 18650 battery do i need

Post by molybdenum » May 19 2018 10:45pm

The motor you link does not fit your riding style. Direct drive hubmotors produce an electromagnetic cogging effect and are difficult to pedal unpowered. Also, you will need to feed this much too much power to make it 70 miles without an enormous battery and you will need it powered all the time. If you want to pedal unassisted, get a small geared hub and limit the weight any way you can:

Geared hubmotors have a clutch and pedal normally unpowered. If you want occasional low level assistance, some suggestions for geared motors are the Q100 from BMSbattery (5 lb) or a heavier duty MG301-std geared hubmotor (5.6 lb) from ebikes.ca.
https://bmsbattery.com/ebike-kit/618-q1 ... e-kit.html
http://www.ebikes.ca/shop/electric-bicy ... -wind.html

Limit the controller to 250-300W max and you will be able to get away with a much smaller battery, and your bike will be light enough to pedal the entire 70 miles unassisted.
cute 128.jpg
In this simulation (http://www.ebikes.ca/tools/simulator.html), a 36V 28Ah battery will get you 63 miles running the entire trip. If you were to use it occasionally, it would get you the 70 miles for sure, otherwise you will need at least 36V at 35 Ah to go the distance at 250W.

At any rate, you will need high capacity cells to keep weight down and this will not be cheap. The High Energy – Samsung 35E for example, are around 3500 mAh each, and you will need 10 in series for 36V, put 8 strings of 10 in parallel for a total of 80 18650 cells, and your battery will be 36V and 28 Ah. The total battery weight will be under 10 lb and the entire setup will add less than 20 lb to your bike.
2012 Kona Dew Deluxe, Q128C and 9spd cassette, S12S sinewave controller, 48V Panasonic battery

e-beach   100 MW

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Re: how many 18650 battery do i need

Post by e-beach » May 19 2018 11:28pm

Around here I routinely burn 27 watts per mile. My city is all stop and go. For your purposes I would suggest 25 watts per mile. So to do 70 miles (70 miles X 25w = 1750w / 48v = 36.45ah battery.)

A battery that size is very large and heavy.

The upside is that batteries have been getting better in terms of capacity.

So say you get something like Samsung INR18650-35E 3450mAh - 10A cells and build a 14s 12p battery with 168 cells, we are talking 50 grams per cell, that would be 8400 grams which is 18.51 lbs just for the cells. Add every thing else the battery needs and you have a 23 to 25 pound battery. That is a lot of weight to push around.

:D
Favorite Quote: "This is L.A., sugar. There is no 'over the top." --- Chris Erskine

Current build: Liahona w/ cheap front suspension and suspension seat post. Yescomusa 36v 800w generic front hub motor. 15ah Headway triangle mounted pack. Tronsung 30 amp,

Previous Build:1992 Trek Antelope 800 - Bone Crusher (no suspension) - Yescomusa 800 watt 36 volt front wheel kit. Don't do it! Get suspension!!!

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Matador   10 kW

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Re: how many 18650 battery do i need

Post by Matador » May 19 2018 11:37pm

want to build wrote:
May 19 2018 6:50pm
HI Matador and al,
before coming to endless sphere i read a buch and buch of stuff on ebike since i was non initiated. Now i think a have some notions but still im leaft with some questions.

I have read the link you showed. I also did some recherche on the web to understand the difference between high current and low current.
It is a more precise info to search for. What i understood is that if you battery pack has high current capacity, it has the possibility to give faster accelaration without getting the battery too hot. It is pretty much where my understanding is hahaha! Great to learn :P is this exact

Now, i have no understanding about the data you tested hahaha . I searched to see if Dbass has a shop online but found nothing. Are those cells cells he sells or cells he likes a lot? how much usd or cand approx ?

the motor im looking seems to be trottle power on demand if im not mistaken. does it offer the possibility to also be used as a pedec? if not can i add this fonction by adding some gear, it would maybe more simple. If not, how do you guys use the thumb part for long times without getting a tendinitis? in description it says dual mode hall effect non hall effect ? im not isaac newton lol https://www.ebay.com/itm/48V1000W-26-Re ... Swh1haAmO9
im very open to open good bang for buck...


if i pedal moderatly during flat and uphills (my online research told me it consumes around 12 whour from battery is that a reasonable estimation?) how many watt hour do i need and how many battery from dbass would be needed for around 50 miles to make it simple (with constant pedalling) i need exercise lol .
If you want some Makita Konion cells, Doctorbass may be able to hool you up with a good deal on some 18650 cells. These would be cells from returned defective makita battery packs. Most of these packs are defective because of a faulty BMS, so the vast majority of cells in these makita pack are still as good as new or only have very few cycle. You can try to PM DoctorBass to get some of these cells.

One thing though, I would encourage you to read a lot on 18650, especially on how to handle 18650 safely before even attempting to dissassemble a makita pack of play around with these cells. You may already know that Li-Ion cells can be very dangerous. Some members on this forum even have had their house burned down because of lithium cell fire. Other people have had li-ion related injuries/serious electrical burns (we call it KFC here on the ES forum).

It is a sine qua none that you know about lithium BMS, max charge/max discharge voltages, how to isolate positive from negative to avoid shorting the positive end (use those cardboard rings !) the importance of balancing cells and the potential dangers of bulk charging an unbalanced lithium cell battery pack.

Konion cells (VTC3) or VTC4 cells are high amperage capable unprotected cells so they are especially capable of realeasing massive energy very quickly if mis handled (ex: if shorted out).
Last edited by Matador on Aug 22 2018 8:45pm, edited 1 time in total.

want to build   10 W

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Re: how many 18650 battery do i need

Post by want to build » May 23 2018 9:39pm

hi

i read a lot lately
i read Building battery from MAKITA Konion PACK twice hahah. some parts i read 3 times cause english is my non native language :)

I want to know about chargers
lets assume i get 350 cell from makita. and grab a 36 volt 350 w geared hub.

i read that after dissasembling, balancing them was not essential and would require a volt adjustable charger witch i have no idea what model to look for at how much?? is it one like that https://www.ebay.ca/itm/IMAX-B6-LCD-Dig ... 0009.m1982

ok what about once the pack is completed i used it and need to recharge it with a 120 volt nord american regular electricity plug, what charger can i use good bang for buch for touring ((charger than could maybe serve also for bigger setup welcomed)­. how does it work.

i would like to have subdivisions of ? volt if possible because in winter i would like to use those home made pack instead of the usual "groupe 24" or groupe 22 gel batteries in my wheelchair powered it uses 2 12v deep cycle gel batteries. I hope i can do that. for example of powered wheelchair: https://www.quickie-wheelchairs.com/Pow ... hair/2976p.

i would also like the pack to be subdivised in 2 or 3 subdivision for this reason: if i go for a short run i would only use 1 subdivision to be lighter. if i go on touring, i would bring all my subdivision.

i see utility in using 2 subdivision: when 1 subdivision is charging in a house i can use the other to visit around.

I also see security in having 2 subdivision instead of 1 only big pack: i would probably use one sub division at the time so that when it becomes empty , if im not close to a house, i can still sleep where i am and start the following morning with the other subdivision knowing that i absolutely need to find a place with electricity (120volt plugs )the next night to charge both of them or the 3 of them).

what charger would be able to charge one or both subdivision at the same time during on night?
i search for reliable good bang for buch relatively light charger for touring. ( i'm open to using 2 small charger instead of one big if it lowers the price or wheight.

thx a lot


thx

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