Go Back  Bike Forums > Bike Forums > Electric Bikes
Reload this Page >

24v Vs. 36v

Notices
Electric Bikes Here's a place to discuss ebikes, from home grown to high-tech.

24v Vs. 36v

Old 03-24-09, 12:49 PM
  #1  
Mike B.
Senior Member
Thread Starter
 
Mike B.'s Avatar
 
Join Date: Apr 2008
Location: Dodge City, KS.
Posts: 60

Bikes: Schwinn, World Avenue One

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
24v Vs. 36v

Ok guys...help me out here...I see and hear alot of people using a 36v system. It appears to be more popular as compared to the 24v....Why is that? More speed? I think (correct me if I'm wrong) given the same ah, the cost is more expensive for 36v batteries weather it be a sla or LiFePo4...correct?

For a new guy like me who would like a cheap entrance into an e-bike experience why shouldn't I go with a 24v system with sla battery and then, at a later date, up-grade to a LiFePo4 battery? Would I be disappointed with a 24v system? Also is it difficult to swap out batteries from sla to LiFePo4, weather it be 24v or 36v?

Finally does a 250 watt bl motor work as efficiently as say a 600 bl? Is that a consideration to be looked at also when deciding which system to use?

Thanks!
Mike B. is offline  
Old 03-24-09, 03:21 PM
  #2  
cerewa
put our Heads Together
 
cerewa's Avatar
 
Join Date: Jun 2003
Location: southeast pennsylvania
Posts: 3,155

Bikes: a mountain bike with a cargo box on the back and aero bars on the front. an old well-worn dahon folding bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Ok guys...help me out here...I see and hear alot of people using a 36v system. It appears to be more popular as compared to the 24v....Why is that? More speed? I think (correct me if I'm wrong) given the same ah, the cost is more expensive for 36v batteries weather it be a sla or LiFePo4...correct?
see below

For a new guy like me who would like a cheap entrance into an e-bike experience why shouldn't I go with a 24v system with sla battery and then, at a later date, up-grade to a LiFePo4 battery? Would I be disappointed with a 24v system? Also is it difficult to swap out batteries from sla to LiFePo4, weather it be 24v or 36v?
It totally depends on the system. It's a mistake to assume that the voltage alone tells you anything about the system's behavior. For a particular motor, higher voltage almost always means higher top speed, but it's possible to design excellent e-bike motors for use at 6 volts or 200 volts.

The number of watts determines the power of a motor, and watts equal amps times volts. (so two different motors may behave exactly the same when one is rated as 24volts30amps and another is 36volts20amps; both are 720 watts.)

A typical 250 watt brushless motor probably won't do what you want if more than one of these things is true:

you want to go up hills without pedaling
you want to go up hills that would be very difficult for you to ride up without a motor
you want to go faster than 20mph
you want to go faster than 12mph without pedaling
you are heavier than ~ 160 pounds
you want your e-bike to feel more kind of like a moped/motorcycle in terms of power

A 600 watt motor is sufficient for most e-bike users, unless what you really want is something that rides like a light motorcycle, or carries a very heavy rider up a very steep hill.

Finally does a 250 watt bl motor work as efficiently as say a 600 bl? Is that a consideration to be looked at also when deciding which system to use?
Your efficiency will depend on whether your motor is suited to the task at hand. A motor that is too powerful waste a lot of energy spinning its own magnets/electromagnets past each other. A motor that is under-powered will waste energy if, when you run it at full throttle, it is still not able to reach its range of ideal operating speeds (at least ~50% of the speed that the motor turns with the wheel off the ground). Ideally you'll have a motor that will be running at about 80% of its maximum no-load (wheel off ground) speed most of the time.

Last edited by cerewa; 03-24-09 at 03:24 PM.
cerewa is offline  
Old 03-24-09, 03:48 PM
  #3  
La Bicyclette
Banned.
 
Join Date: Feb 2009
Posts: 41
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Cerewa was very thorough and accurate in his post. Yes a 36v battery will cost more than the 24v, and the 250watt motor will not be great for going up hills. But you live in Kansas and there aren't that many hills so a 24v battery mated to a 250watt motor might be sufficient for you. It won't feel very powerful, it will just feel like that a very strong tail-wind is helping push you forward all the time.
La Bicyclette is offline  
Old 03-24-09, 04:52 PM
  #4  
cerewa
put our Heads Together
 
cerewa's Avatar
 
Join Date: Jun 2003
Location: southeast pennsylvania
Posts: 3,155

Bikes: a mountain bike with a cargo box on the back and aero bars on the front. an old well-worn dahon folding bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Yes a 36v battery will cost more than the 24v
... a 36v battery with the same number of amp hours as a 24v battery usually costs about 50% more.

But it also stores 50% more energy (meaning 50% more range [miles] or 50% more power [ watts ]).
cerewa is offline  
Old 03-24-09, 06:37 PM
  #5  
Mike B.
Senior Member
Thread Starter
 
Mike B.'s Avatar
 
Join Date: Apr 2008
Location: Dodge City, KS.
Posts: 60

Bikes: Schwinn, World Avenue One

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Ok...now my question has become...say I go for a 36v with say a 600w bl motor, would it be safe to say that a SLA battery pack with 36v w/12ah would have about 1/2 the life span of a LiFePo4 set up with the same numbers? Or would it be even less?

I guess I'm asking which set-up is the biggest bang (best value) for the buck?

Also are most dealers on e-bay reputable?...or do you guys know someone you'd suggest that is forth right (honest)? Like most...I'm not a big fan of getting ripped off, even more so when dealing in areas that I'm not well versed. Seems alot of this "stuff" is coming from China...trustworthy?

One last issue, if I go with SLA can I change it out, down the road, with a LiFePo4 w/o difficulty?

Thanks!

Last edited by Mike B.; 03-24-09 at 06:50 PM.
Mike B. is offline  
Old 03-24-09, 07:54 PM
  #6  
lildeph
Member
 
Join Date: Feb 2009
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
here my take

Yeah this guy cerewa is an expert on these ebikes i always appreciate his very useful input on all t ahese topics he seem to know it all (Big shout out to Cerewa! ) Okay imo the best way to get into the ebike world would be to buy a Ezip(about $300) and get a lifepo4 from ebay-people like ping batteries i heard were trustworthy. Ive been checking out sellers and prices out there and there is a guy on ebay screen name "Volgood" who has excellent prices on these batteries but dont know how safe it would be to buy from him but i suppose if u use paypal u should be fine.

My first experiment is going to add a 6v - 7ah sla battery to my currie pack to get my bike up to 17-20mph without any assist from me.Its the cheapest,lightest and most easy to do-for a quick burst.oiThen i think im gonna buy a lifepo4 battery from "Volgood" (24v-15ah) for under 200 bucks!!
lildeph is offline  
Old 03-25-09, 02:29 PM
  #7  
lfairban
Junior Member
 
Join Date: Aug 2008
Posts: 16
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
e-bay

The "Duct Tape" batteries from China on e-bay are advertised as LiFePO4, but they are inevitably LiCO or LiMn if you are lucky. They are not as good at producing high current levels, but they cost half as much and they are better than SLAs.

Also, the motor output power will not exceed the input power no matter how high they are rated. The max input power is the pack voltage V times the max controller current A, and the max output power is V x A x E, where E is the efficiency.
lfairban is offline  
Old 03-25-09, 03:51 PM
  #8  
FollowYourHeart
Banned.
 
Join Date: Mar 2009
Posts: 19
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by lfairban
The "Duct Tape" batteries from China on e-bay are advertised as LiFePO4, but they are inevitably LiCO or LiMn if you are lucky. They are not as good at producing high current levels, but they cost half as much and they are better than SLAs.
I agree and am certain that many of those companies could easily be cheating us because sometimes their prices are extremely low. Ebay is an extremely competitive field and seeing such a wide range in prices is a sign that something is not normal.

At least we have a one trusted name on ebay (pingping227). Across several message boards, everybody seems to be satisfied with their work... for me personally it's also because somebody looked into their construction and they use the prismatic pouch cells that make the pack the lightest and smallest possible. The few people who have had issues with their packs have had their issues taken care of by ping under the warranty so communication is present as well.

Even Green Cycles (located in southern california, not china, lol) take the ping packs, create an acrylic enclosure with the power plug/charging ports built into it and sell them for just a little bit higher than the raw-ping pack, but it looks like a much nicer finished looking battery pack. If one doesn't care to figure out how to wire-up their raw battery pack or doesn't like the look of duct tape, I would say this would be a good deal too.
FollowYourHeart is offline  
Old 04-03-09, 09:31 PM
  #9  
louispower
Member
 
Join Date: Apr 2009
Location: Hefei, Anhui province, China
Posts: 25

Bikes: beach cruiser bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
just a remind, maybe couldnot calculate the power by voltage x current, say 36v/20ah is 720w, this will be decided by the motor efficiency, most bl motor's efficiency ranges from 60% to 80%, by the peak power the efficiency is normally 60%--70%, so the actual power is only 720w x 0.6 (or 0.7) =400w--500w.

Another point is the max current your controller could handle, it makes no sense to use a battery with bigger max current than that of the controller.

The advantage of LIFEPO4 is very obvious.
louispower is offline  
Old 04-04-09, 03:29 AM
  #10  
recumelectric
It's easy being green.
 
recumelectric's Avatar
 
Join Date: Jun 2008
Location: in the desert
Posts: 932

Bikes: Trek Beach Cruiser, Sun X-2 AX (bent)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
OK, now I've got a question for you guys with the knowledge. Will a bigger volt system with bigger wattage (36 V Bionx kit vs 24 V Bionx kit) give me more torque?

I've been struggling with the start up from a dead stop and with the grinding up the hills. My knees are officially late stage arthritic. I'm OK with the smooth pedaling. I'm just suffering in the push-hard moments. Will more Volts and higher wattage help with this?
recumelectric is offline  
Old 04-04-09, 07:02 AM
  #11  
louispower
Member
 
Join Date: Apr 2009
Location: Hefei, Anhui province, China
Posts: 25

Bikes: beach cruiser bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
by a same current 36v powered motor will give you more torque than 24v motor does, if this 2 motor are with same technology & structure.
louispower is offline  
Old 04-19-09, 03:56 PM
  #12  
24X18
Member
 
24X18's Avatar
 
Join Date: Apr 2009
Location: CT
Posts: 46

Bikes: Scwinn S-750 Elec. Scooter

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thumbs up 24volt..36volt..??

It all comes down on your riding experiance..the terrain..
the weight of the rider added to the weight of the BIKE..
===
I have a 24-volt Scooter..at 500-watts is quite able..
I walk it up hills..
===
I'm moving toward a 48-volt system..I want to build my own from scratch..
I want a 1000-watt Motor..
===
Use your 24-volt..but make the move UP..
on your NEXT--EV.
24X18 is offline  
Old 02-17-24, 07:10 PM
  #13  
Jimbob381985
Newbie
 
Join Date: Feb 2024
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Ebike ancheer 24v36v48v60v motor 7500watt works great for what I use it for

Just wanna say best bike ever gotten and it works wonderful 26 inch bike frame soiled... Got it in August and been running it since then 295lbs here love it couldn't ask for a better one at 1st I couldn't get into the limits of speed till I upgraded to new display so now its even better than before so I'm just writing here to say no complaints here to lower the voltage just go into settings and try them out just make sure you remember your current settings are so if u mess up you can change it back just wanted to give some feedback on this lovely bike did some modifications to it myself and planing on upgrading to gas one this summer have a great day enjoy everyone
Jimbob381985 is offline  
Likes For Jimbob381985:
Old 02-21-24, 10:11 AM
  #14  
Smaug1
Commuter
 
Smaug1's Avatar
 
Join Date: Jun 2022
Location: SE Wisconsin, USA
Posts: 536

Bikes: Main Bikes: 2023 Trek Domane AL3, 2022 Aventon Level.2 eBike, 1972 Schwinn Varsity, 2024 Priority Apollo 11

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 235 Post(s)
Liked 316 Times in 193 Posts
You just bumped a 15 year old thread that is not relevant any more.

Welcome to the forum, Jimbob.
Smaug1 is offline  
Likes For Smaug1:
Old 02-23-24, 06:50 PM
  #15  
veganbikes
Clark W. Griswold
 
Join Date: Mar 2014
Location: ,location, location
Posts: 13,506

Bikes: Foundry Chilkoot Ti W/Ultegra Di2, Salsa Timberjack Ti, Cinelli Mash Work RandoCross Fun Time Machine, 1x9 XT Parts Hybrid, Co-Motion Cascadia, Specialized Langster, Phil Wood Apple VeloXS Frame (w/DA 7400), R+M Supercharger2 Rohloff, Habanero Ti 26

Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 4348 Post(s)
Liked 3,985 Times in 2,661 Posts
Originally Posted by CrimsonEclipse
...
Just FYI this thread is from 2009, 15 years ago I don't think those posters are still around.
veganbikes is offline  
Likes For veganbikes:
Old 02-23-24, 10:48 PM
  #16  
CrimsonEclipse
Senior Member
 
Join Date: Dec 2004
Posts: 1,094
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 555 Post(s)
Liked 639 Times in 376 Posts
Originally Posted by veganbikes
Just FYI this thread is from 2009, 15 years ago I don't think those posters are still around.
gotchya.
CrimsonEclipse is offline  
Likes For CrimsonEclipse:
Old 02-27-24, 12:26 PM
  #17  
Calsun
Banned
 
Join Date: Mar 2021
Posts: 1,280
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 608 Post(s)
Liked 382 Times in 288 Posts
Voltage drops with distance, in particular with DC voltage. Higher initial voltage provides higher end voltage at the motor and so the motor can produce more power. 12 volts DC has been common with cars and trucks produced since 19609, but with the length of airplanes 36 volts DC has been common for more than 70 years.
Calsun is offline  
Old 02-29-24, 01:57 AM
  #18  
tesla_exp
Newbie
 
Join Date: Feb 2024
Posts: 12
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 7 Times in 7 Posts
Originally Posted by Mike B.
Ok guys...help me out here...I see and hear alot of people using a 36v system. It appears to be more popular as compared to the 24v....Why is that? More speed? I think (correct me if I'm wrong) given the same ah, the cost is more expensive for 36v batteries weather it be a sla or LiFePo4...correct?

For a new guy like me who would like a cheap entrance into an e-bike experience why shouldn't I go with a 24v system with sla battery and then, at a later date, up-grade to a LiFePo4 battery? Would I be disappointed with a 24v system? Also is it difficult to swap out batteries from sla to LiFePo4, weather it be 24v or 36v?

Finally does a 250 watt bl motor work as efficiently as say a 600 bl? Is that a consideration to be looked at also when deciding which system to use?

Thanks!
it depends on the power output from the controller and how much current the motor can withstand.
A 24v 30A output from the controller should give you more boost as compared with a 48v 10A system, provided the mechanical efficiency is more or less the same.
tesla_exp is offline  
Old 03-01-24, 06:23 PM
  #19  
tds101 
55+ Club,...
 
tds101's Avatar
 
Join Date: Aug 2012
Location: Somewhere in New York, NY
Posts: 4,322

Bikes: 9+,...

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1112 Post(s)
Liked 847 Times in 591 Posts
Originally Posted by Calsun
Voltage drops with distance, in particular with DC voltage. Higher initial voltage provides higher end voltage at the motor and so the motor can produce more power. 12 volts DC has been common with cars and trucks produced since 19609, but with the length of airplanes 36 volts DC has been common for more than 70 years.
Originally Posted by tesla_exp
it depends on the power output from the controller and how much current the motor can withstand.
A 24v 30A output from the controller should give you more boost as compared with a 48v 10A system, provided the mechanical efficiency is more or less the same.
THE ORIGINAL POSTERS ARE LONG GONE! This is a dead, 15 year old, irrelevant thread...
__________________
If it wasn't for you meddling kids,...
tds101 is offline  
Likes For tds101:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.