new ebike build what do you think?

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mrfeelgooddrag26

10 W
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Jul 22, 2013
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broken arrow oklahoma 74012
im trying to build my first ebike i now have the money to build it and want to do a lip rc battery setup.
my question is where do i start what do i buy how to i build the pack wire all my batterys together how to charge the batterys after there in the pack. all start off by telling you what i know witch is nothing lol.

basically i bought this kit
http://www.ebay.com/itm/Price-Cut-500W-48V-Hi-Speed-Electric-Bicycle-E-Bike-Hub-Motor-Conversion-Kit-/390687072922?pt=LH_DefaultDomain_2&hash=item5af6c3a29a

but i dont know what kind of batterys to buy or where to get them what chargers i need what balance charger i need stuff like that

id like to do a pack that can put out a range of about 30 miles on a single charge but i also want to build it cheap ebay links for parts would be great but im not opposed to other sites

id like to use like 3 or 4 of these http://www.hobbyking.com/hobbyking/store/__10279__Turnigy_2200mAh_3S_40C_Lipo_Pack.html

but im not sure how to go about charging and wiring them into a pack and hooking them to the bike
 
so i want to build a lipo pack that is 20 amp hours probably 5000 mah a piece for a total of 4 batterys at 11.1 each for a toal of 44.4 volts also the batterys would be 30c 3 cells my ebike motor is 48 volts at 500 watts what would be a good estimation of range on this kind of setup?
 
You'll need to take the information you have, along with your terrain, route, wind, speed you'll ride at, final bike weight, your weight, etc, and plug the various pieces of information into the various simulators for such things, to get the best estimate of range for that.

See the wiki here:
http://www.endless-sphere.com/w/index.php?title=Main_Page
for various simulator links. Ther'es lots more of them on the web than just those, too.

Without knowing the terrain, route, wind, speed, etc no one can even guess what your range might be. ;)
 
You'll need to read up on the various threads that tell about such things, many of them in the Battery subforum, like the "LiPo for Noobs" thread. Some of this (maybe all of it by now) is linked from the applicable sections of the wiki:

http://www.endless-sphere.com/w/index.php?title=Main_Page
 
Seriously consider safer batteries. If you decide to proceed with HobbyKing lipo, handle them with the assumption that there will come a time, most likely while charging, that they will catch fire and produce much smoke.

For 48 volts, use 12s lipo. You will need at least 10,000mAh with pedaling to go 30 miles. So use 5000mAh 6 cell batteries 2 in series and 2 in parallel.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9176

You don't need 40c batteries when the controller is going to handle around 10 amps.

Maybe start charging them all separately and buy the plugs from hobby king to join them together for use. You can use this charger
http://www.hobbyking.com/hobbyking/store/__11444__Turnigy_A_6_10_200W_Balance_charger_discharger.html
You'll have to charge 4 batteries when you ride.

As you get the hang of it this way, then you can wire the two parallel packs together, joining the balance leads too, and you can charge two at a time. Then get a second charger and you can charge all 4 at once.

There will be bad connections. If you don't think you can use a voltmeter to find them, don't start on this project.

Package the batteries so that they will be immune to damage when the bike is dropped.

Best wishes, and be safe.
 
Too many variables to give you an answer. With a 5000 mah 12S at 20mph on flat terrain, you are looking at about 5 miles without straining the battery. My usual trip to work is 11 miles, traveling at 25 to 30 mph, I can make it using 6 5000 mah, 6S batteries. I now use 8 batteries as there is less of a drain on the batteries. C rating doesn't matter too much as I am spreading the load across 4 bricks. '
 
For 30 miles at ~20 mph, you'll need 15ah os 12s lipo, or 6 of these.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16207
Wired like this.
12s3p6.JPG
And this charger.
http://www.hobbypartz.com/75p-1220-charger.html?gclid=CNa3z9_N57ICFayPPAod10MAPw
 
You will get at least 20 miles for sure, at 25 mph. But to say more we'd have to know what kind of bike, what speed, and what your full charge and when you plan to stop voltage would be.

For starters, if you only charge to 4.1v, you'd have more like 18 ah available, if you discharge to 3.5v per cell. But to make managing the pack easier, you might chose to discharge only to 3.75v, and then you'd have more like only 16 ah of usable wh.

So lets assume you went for a very conservative use. 16 ah x 44v = 704 watthours.

Lets say you ride fairly fast, and use 30-35 watthours per mile. 20-23 miles.

If you rode as slow as 18 mph, then you could expect about 30 miles. That's if you pedal hard enough, but not hard enough to sweat a lot.

Riding extremely slow, 40 miles is possible with a lot of pedaling pretty hard.

If you charge to 4.2v per cell, and discharge all the way to 3.5v per cell, you can expect to actually have 19 ah of real world capacity when the pack is new. Riding less than 25 mph, using 30 wh per mile, 28 miles is quite possible.

So 25 miles is not an unrealistic expectation if you are not going 30 mph.
 
Read all you can stand to of the Battery FAQ threads on lipo as a starting point.

Pay attention to the recommended voltages. 4.3v and 2.7v is not what we recommend doing, Those are the voltages which when exceeded, can result in your bike or house burning.

RC chargers when properly used, won't let your packs get much past 4.2v per cell charged. On the other end, going lower than 3.5v is not recommended at all.

Many of us run lower full charges and stop sooner to try to get more years from a set of packs.

There are about 500 ways to wire up your packs. All right for somebody except one. Don't connect packs in series, then connect the balance taps of the same packs in parallel with the main wires series connected. Do that, and you get Kentucky fried fingers when the connectors melt in your hands.
 
If you're going to buy 6s packs from hobby suppliers, be warned that there will always be the odd dud cell in the batch. There is also the risk that they weren't soldered together very well. Uncommon, but more common than we'd like.

I build packs from individual cells because I have more control over the quality, and I can make a more convenient 15 Ah pack by paralleling the cells first and using big copper conductors. They are a solid unit, and come highly recommended :wink: but they are considerably more expensive than buying ready-made packs from hobby shops. You also need to know a bit about soldering with big hot irons, so it's definitely not for everyone.
 
Here are some sites to read about rc lipo. When you understand everything here, you should be able to make a safe pack.
http://www.rchelicopterfun.com/rc-lipo-batteries.html
http://scriptasylum.com/rc_speed/lipo.html
 
For a rough idea how much quantity you need to go 30 miles, for a 36v pack, you'd want 25-30 ah of 36v to go that distance at 25 mph.

To go 30 miles on a small setup, you'd have to ride 15 mph or less.
 
As many people mentioned already in this thread, if you decide to go with Lipo's, make sure you take the time to read and educate yourself on their usage. Like many things out there, like taking your car out of your driveway in the morning, if you use them like they are intended to be used, follow the guidelines and saftey rules that apply to them, they are a perfectly safe technology.

As for your ebike kit, it come from the manufacturer CNEBIKES. I have set up a few of their kits for people in the past and I found they are excellent builds. You will enjoy it. And 15AH of lipo's should enable you to do your distance.

http://www.cnebikes.com/ProductShow.asp?ID=119

Wishes
 
first off i know its lead acid and no i do not care i dont go nearly far enough to need the range of a 600 dollar lithium pack i commute maybe 2 miles total everyday going to work and back 1 mile there 1 mile back and everything is so close to me that nothing is more than 5 miles away.

so basically my last ebike was a walmart cruiser bike with 12 amp hour ebay sla's with a 36 volt 500 watt rear hub motor it would do about 12 miles per charge. i ended up selling this bike to a guy at walmart in the parking lot that wanted to build it with lithium. so i sold it for about what i had into it and now i want to build another bike im looking to try to get around 18 miles per charge

http://www.ebay.com/itm/Max-Life-12V-22Ah-UPS-Battery-Replaces-20Ah-Ritar-RT12200-RT-12200-/251310695183?pt=US_Rechargeable_Batteries&hash=item3a8348e30f

http://www.ebay.com/itm/48V1000W-26-Rear-Wheel-Electric-Bicycle-Motor-Kit-E-Bike-Cycling-Hub-Conversion-/231132763662?pt=LH_DefaultDomain_0&hash=item35d096160e

http://www.ebay.com/itm/NOCO-Universal-Plastic-Battery-Box-Group-24-27-31-Boat-RV-Marine-Trailer-Snap-/400466087404?pt=Motors_Car_Truck_Parts_Accessories&hash=item5d3da38dec&vxp=mtr

also i want to use a keyed switch in this setup if anybody can suggest a decent one.

also my last bike did not have a battery box they where thrown into a handle bar basket so this time i want to use a battery box on my rear rack.

also the bike its going on is a 100 dollar walmart road master 3 piece crank front suspension fork i replaced the tires with lower profile city tires and double walled rims from my trek the tires are 1.95s .

also upgraded all the brake cables and shifter cables and housings on the bike and retuned the gears and brakes to my liking and put on new brakes all the way round and swapped out the grip shifts for a 3x6 set of thumb shifter off ebay works so much better than when i bought the bike

so my question is this how much range will i see out of these batteries? and how many amp hours can i put in the bike safely? i found lead batteries at my local battery shop that are 35 amp hours at 12 volts but i dont want to have so much battery that i blow up my controller or motor any tips suggestions comments feel free to chime in
 
Don't buy those batteries until you make mock-ups out of cardboard and duct tape, and then fit them onto your bike. I understand the desire to go cheap on the purchase of batteries just to get going (needing most of your money for the bike+ kit). But when the lead-acids wear out a month or two later, Lithium is cheaper in the long run. Dogman got over three years of frequent use on a Ping LiFePO4 pack, and many others have too.
 
the whole thing is i know lithium is better i just cant be bothered to spend the money to do it buying a 20 ah lifepo4 ping battery at 48 volts is not gunna happen anytime soon its not in the budget even if i saved up for a year i dont ride far enough or long enough to need the extra range or weight savings . i would love to go lithium but its an impossible upgrade. i have bills and a limited budget to have fun with projects like this so lead will have to do , and my last bike
i built i rode for almost a year before i sold it with lead batteries and they still held a pretty good charge when i sold it .

basically im gunna ride the bike full throttle to work and back everyday and cruise around town when i need to run around its not being built for range its being built to have fun with haha and if i eventually have to replace the batteries i can still buy aleast 3 sets of leads before i would have enough to buy lithium anyways

thanks for your input and all keep lithium in mind if i ever have the money
 
Four of those sla batteries for 48V is going to cost $166 and weigh 52lbs. You can get a 10ah 12s rc lipo pack for $141.90 + shipping that will only weigh 7lbs and give you the same range, and they will last longer.
You might also want to consider this newer motor kit from the same place.
http://www.ebay.com/itm/48V1000W-Electric-Bicycle-LCD-Display-26-Front-Rear-Wheel-Motor-Kit-E-Bike-Hub-/291040998674
 
Since you do have some experience now, you might consider an RC lico pack from Hobby King.

I just paid about $90 shipped, for a 5 ah 12 cell pack. Another hundred for a low end but safe charger, and you have a 5 ah 44v pack and charger for under $200. You'd also need a voltage monitor, but they can be as cheap as 3 bucks.

5 ah is plenty, with such strong lithium. Like you say, you only need about 4 miles of range. The pack will weigh about 4 pounds, and be really easy to carry.

On the other hand, if you aren't retired and sick and need a motor to ride 2 miles..... Sounds like the ebike is definitely in the fun budget, rather than the transportation budget.
 
really for me its all about having fun could i do rc lipo???. yes i could but i dont have any knowledge of how to safely use rc lipo and every time i try to learn about it it feels overwhelming to try to get started with it . with sla i know that i can safely charge and discharge my batteries without fear of hurting myself or others and theres not really a learning curve for sla . would i like to use a better battery tech yes i would but i dont have the skill to make it happen yet . building ebikes and riding them around is first and for most a hobby for me when i have spare money i like to build stuff im not looking to build a 3000 dollar ebike the most i want to ever spend building this is 500 bucks or less thats my budget for a project like this. if you guys can post links for basics on lipo and how to build packs and what not i would love to read about it
 
im currently running sla in all my builds i want to go into lipo batteries but i cant seem to find tutorials on what to buy or how to assymble packs together i see alot of people talking about what they built but i cant seem to find a straight up do this do that buy this buy that tutorial for getting started building a ebike battery out of lipo cells any links videos ect are greatly appreciated
 
Welcome, I would start by reading the many write-ups and posts listed in the FAQ in this forum. Here it is:

http://endless-sphere.com/forums/viewtopic.php?f=14&t=26621
 
To answer the thread title - where to start - nowhere. LiPo is not for noobs at all. Unless you are capable of putting out a fire and are willing to deal with a possibility of one each and every time you charge your pack, go with a safer chemistry, like LiFePo4 or NCM. Sure, it will be heavier, but not as heavy as to significantly impact the speed or range.
 
Generally I agree with Rollodo--you should learn a lot about what you are getting into before you do so.

There is LOTS of info already on ES that answers all of your questions, but you will need to browse the forums to find and read about it. Just about every week or two there is another new thread asking these questions, and sometimes there are lists of links posted by members in those threads.

There is a LiPo Noob thread linked in Dogman's signature, too, so find any of his posts and it's there, if you can't seem to find it browsing the forums.

I also highly recommend you read the first four stickies in this battery subforum.
 
Gregory might have meant this one...

http://www.endless-sphere.com/w/index.php/Building_a_LiPo_Battery_Pack

It is simple enough. If you are careful with RC Lipo then it will be fine. RC forums are also good places to check out how to handle RC Lipo...BUT......if you miss handle that type of chemistry, it will burn your house down. :shock:

Make sure you don't miss handle it and be sure to charge it in a safe, fireproof place.

Do the home work before you jump in.

:D
 
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