350 watt hub motor tests

deacon

deacon

minor bike philosopher
I have tried to use this 350 hub motor numerous times but never liked it at all. I have decided to try it again this time to see if I can get better range on the batteries. Maybe a hybrid pack will work for a better range with this setup. If so it might be a good bike to take to the lake and like that. I still like my rhino better to run to the store ect.

I have it so I might as well test it. For instance, I know I got four miles on the 12ah sla pk and 10ah nimh pk combined on a rhino bike. So I am going to put the two together tomorrow after I build a half butted trailer to carry them.

No matter what happens with this test, I am a winner. I found a schwinn 24" from the seventies. Big steel tubes and best of all it's a real girly step through. It's the color of american style mustard, the color of something you might find in a baby diaper, but it is the ideal frame for me I think. The hub is on a 26 inch wheel it's got a little extra height in front, but still very easy to get on... If worse comes to worse it will be easy to mount my spare rhino on it. Just in case I ever find someone to ride with me.

I did have to take the chrome fenders off of it. Too bad they were kinda retro classy.
 
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Why don't you try to re-lace hub onto 24" wheel? You'll get more torque , therefore better pull uphill. 350 W hub is too much pedal assist in my book.
 
I'd like to see you make it into some sort of friction drive/rhino. It would be ultra quiet and pretty simple - no chain or anything. Maybe you could just cut a ring of inner tube and rubber cement it to the outside then mount it in a child's bike fork attached to the seat post. Get those creative juices flowing and do something that has never been done before (like you always do!!) - jd
 
If you really want to get some range i.e 20-30 miles your going to have to re-think the battery chemistry and open up the wallet IMHO. The cost of Lithium batteries has dropped considerably the last few years, a 24v or 36v packs capable of serious range could be had for under $us400
Problem with SLAs is you will never get even close to the quoted ah with lithium chemistry the quoted ah is realistic. You will also get upward of 2000 charges from Lifep04 cells, if you calculate the SLAs life span of 400 charges v's cost you will find the Lithium is the better deal.

Best of luck

KiM
 
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I know you are right from the last round of experiments, I really have no use for 20 mile batteries. I was and am more interested in weight reduction. If a battery pack will do ten miles and weight about a forth of an sla pack, I would be good with it. that's pretty much why I was looking into nimh. They seem to be easy to work with and the weight is about usable if I can ever build them for a reasonable purchase price.

I need a little trailer for stability so I don't mind pulling a battery pack along, but I would like for it to be smaller and lighter than the trailers I have to build for the Sla packs that get me about 5 miles now in this terrain.

I started out saying I wanted a bike that would do ten miles an hour and go ten miles. It should also be less maintenance than the gas bile. Easier to store (wife complained about the smell) not noisy for the neighbors sake.

I have the ten miles an hour no problem now. I just need to get to the ten mile range and the easy to store parts. I need to make a couple of modifications on this new bike even if the hubber bubber works well enough.

I began thinking I would leave it pedal assist and just ride it for the exercise, but knowing me it will wind up with the rhino on the rear wheel and the bub on the front wheel and share a battery pack. Probably use the rhino to climb hills and the hub to cruise. The two motor thing kind of interests me now.
 
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Something like this would be ideal would get you a lil more than 10 miles cut the weight by more than half and the size is less than a shoe box and is good for 1000's of cycles

24V 15AH V2.5 LiFePO4 Battery Pack

269 +19 freight comes with free charger.
Ping has a good reputation on the Electric vehicle forums too, excellent customer service.

KiM
 
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KiM said:
Something like this would be ideal would get you a lil more than 10 miles cut the weight by more than half and the size is less than a shoe box and is good for 1000's of cycles

24V 15AH V2.5 LiFePO4 Battery Pack

269 +19 freight comes with free charger.
Ping has a good reputation on the Electric vehicle forums too, excellent customer service.

KiM
Click to expand...
Don't know much about the tech part, but I'm wondering why this pack is limited to 350watt motors. I run a Currie 450 watt motor and use SLA 24volt 12ah battery packs. Price is right for this pack, but it's application falls short for my rig.
 
grouchyolfart said:
Don't know much about the tech part, but I'm wondering why this pack is limited to 350watt motors. I run a Currie 450 watt motor and use SLA 24volt 12ah battery packs. Price is right for this pack, but it's application falls short for my rig.
Click to expand...


The 450watt motor would pull to much current for the cells in the pack. You would need a pack with a higher 'c' rate to handle to higher amps the 450watt requires. You could run the pack but it would damage the cells if you you attempted to pull more current than the cells can put out (actually the BMS would protect the cells by cutting the power if you hit the LVC of the cells during use). Lifepo4 a
must be kept in between certain voltage levels usually referred to as High Voltage cuttoff and low voltage cuttoff...i forget the exact voltage for the lifpo4 i run the Lithium Polymer myself they need to stay between 4.15 and 3.2v go under or over you start damaging/reducing cell life. Your SLAs are also only good for 1-2c max your 450watt motor is killing those prematurely also. Destroyed my first set few years back in several months. Have you got any form of onboard monitoring to see what the current draw is?

KiM
 
That last part is what I'm finding out withe nimh pack. it's not putting out enough to cover the 900 watts the bike runs at. That's why I'm going to try working with the 350watt hub for a while. But yes I'm still going to run it with a hybrid pack. For one reason the hybrid packs on the rhino gave a little more kick to the performance. If it does that with the 350 it would be a better ride. I have the trailer built, now I just have to get the thing ready to go. Tomorrow I plan to do some testing.
 
deacon said:
For one reason the hybrid packs on the rhino gave a little more kick to the performance. .
Click to expand...

I'm sure your aware but for those that aren't higher volts increase the top end speed of the
electric motor, the ah increases the range, this is likely the reason your hub motor has moire 'kick'
with the hybrid pack also it would likely see less voltage sag under higher loads, this will drastically effect the 'pull' the motor has on start up and hills.

Best of luck with the pack and the trailer anywyaz, got some pics by chance maybe some video?

KiM

EDIT: sorry i didnt notice the blog link, checking pics now :-)
 
The Thundersky 20ah are rated for 2C continuous, 10C impulse. I think most LiFePO4 are rated similar. C is a factor of the ah, so 2C 20ah is 40 amps capacity. A 450W motor @ 24V nominally draws 18.75 amps (450/24). It may draw more under heavy load but there's enough reserve there so it shouldn't cause a battery problem. Deacon's 900W @ 36V draws 25 amps, so he should have enough reserve with a 20ah LiFePO4 too. All of this shows the value of the Wattmeter. Maybe I'll get one - jd
ps I read somewhere that impulse is less than 5 seconds no more often than every 30 seconds.
 
KiM said:
The 450watt motor would pull to much current for the cells in the pack. You would need a pack with a higher 'c' rate to handle to higher amps the 450watt requires. You could run the pack but it would damage the cells if you you attempted to pull more current than the cells can put out (actually the BMS would protect the cells by cutting the power if you hit the LVC of the cells during use). Lifepo4 a
must be kept in between certain voltage levels usually referred to as High Voltage cuttoff and low voltage cuttoff...i forget the exact voltage for the lifpo4 i run the Lithium Polymer myself they need to stay between 4.15 and 3.2v go under or over you start damaging/reducing cell life. Your SLAs are also only good for 1-2c max your 450watt motor is killing those prematurely also. Destroyed my first set few years back in several months. Have you got any form of onboard monitoring to see what the current draw is?

KiM
Click to expand...

Thanks Kim. Now that I think about it, even Deacon mentioned something about the "C" ratings. My 450 Currie is a geared motor. Could that make a difference? My first set of batteries are going over a year, now, and I bought the rig used. My rides are also short. 4 mile round trip with one fairly steep hill. The trip out is actually a very slight hill climb all the way against wind. I usually use the motor most of the way with pedal assist. Coming back, I use the motor to get up to speed and coast most of the way, except for that one steep hill. No onboard monitoring system except for the LED lights on the throttle and they don't really say much. Just pretty to look at. :D
 
You guys should pick up a Turnigy Meter from Hobby City they are cheaper than the Watts Up meter. I have a Watts Up a Turnigy meter and a Cycle Analysis they are all good choices and a must to monitor your pack IMHO.

jdcburg- most lifepo4s are definitely not rated similar either buddy. Thundersky are reasonable battery but nothing to write home about, they aren't in the top choices for use on a bicycle due to their large size and weight. Want good quality Lifep04 at a decent price hard to look past Headways they are a 10c rated cell. Personally i use 25c 30c burst on my ride. My pack drops less than 4v when i pull 140amp when i want to have a lil 'fun' launching off the mark or powering flat out up steep hills. Another good cell is the A123, there is a relatively new A123 prismatic cells available in 15 and 20ah 12v config, they workout at 2.50 per ah. Member on Endless Sphere Cell_Man is the best place to get these, he also offers BMS and charging solution.

Whatever lithium though it is better choice by a looooong shot over using SLA, if you can scrape together the initial $$$ required for Lithium i highly recommend it over simpky getting by with SLA the performance is night and day, i have used both so i speak from experience here not what i have heard others report, there really is no comparison.

KiM
 
I agree KiM , but $$$ can be an issue and these guys aren't in pursue for best performance there is - just reliable, sufficient power and range , CHEAP bikes. It's a fun of building and tinkering with darn things that matters the most (and if imagined performance is achieved - great- and move on to the next goal) - I'm just paraphrasing deacon . The others just want to ride and not to poke around much , so they order kits.
Few members (myself included) had posted all about efficiency , battery chemistry monitoring and charging and so on and , in the end of a day , everybody does what he think is the best for him.
SLA's are widely available and cheap (and it can be even scavenged for no money). As 1st level upgrade in chemistry , I would go with NiCd (also widely available) with some monitoring system and very smart charger , but people think in a different ways so you can see the results.
 
140 amps and 25C? YIKES! My whole house draws less than 100 amps. I've never heard anybody here say they have a motor larger than 600W, although Deacon's overvolted puts out 900. That's only 1.25C using 20ah batteries. My 350W nominally draws .73C so 2C continuous is plenty for most of us here. At $.50/wh TS are hard to beat and they come all put together in a nice compact box. Headways are $.62/wh unassembled. Pings are $.72/wh assembled. Then you have to add on shipping and delivery time, sometimes from China, which can be expensive and slow. At half the weight of SLAs, TS seem like a good deal. Others may be slightly smaller, lighter and more powerful but it all depends on your priorities... - jd
 
Well the hub motor has just been retired like me, permanently.... Darn thing won't run worth a tinkers dam and it is hard to pedal, if it dies. I think I'm going to stay with the rhino drives.

One thing about those batteries, we are all talking about. I know for a fact that the lowly sla battery will put all the amps it has on demand. That's why I blew a 40amp circuit breaker when running a rhino without a controller. Those batteries were a ,mere 17ah not twenty or forty. They could have been 12ah and still would have done it because I have blown thirty amp fuses with them.

First of all if I needed to commute 20 miles a day to work, and if I wanted to use a bike, or I were in a state the really insisted that I go green. The first thing I would buy would be a high quality, high performance motor system, not a DIY thing, Then I would indeed buy about 125% of the battery requirements I thought I needed. Yes I would buy Lithos because then I could easily justify the expenditure for both. The performance and convenience would far outweight the dollars. When you look at the cost of an auto or motorcycle the cost of a good ebike is a bargan.

My first priority would be a drive system that was almost a 100% dependable. It would not be something I built in the back of my house. *(Not that it can't be done, I just lack the skill and patience to do it.)...Then my second priority would be batteries that were both dependable and predictable. Sla is not predictable though they are dependable within their power band. (Short run, high draw). It is hard to detemine without a amp/watt meter what the condition of the battery is at any given time. That might also be true of the lithos. The meter thing is kind of like a gas gage on a china bike a heck of a good idea, I have run out of gas on that thing three or four time in the 6 months that I rode it.

I have kinda come to a decision today about the bike. It is not a necessity for me at the moment. I no longer drive a car but my wife does, so when we go anywhere she drives her car. My bike is for pleasure and is a hobby. I could never stand the pain of riding it ten miles. That six miles to the lake almost kills me lol. Old is not fun.

The battery test was not a total waste of my time and money. I think there might be a good use for those nimh batteries on a better drive system where twenty amps is all you need to climb the hills where you live. With the true D cells at 10ah each (if they indeed are) you would only need two strings to make a twenty ah battery. Two strings would be pretty easy to monitor. If you charge each 12v pack individually just look for on that would come close to the other then check each string. Find the one that won't charge up and then check the cells. not a big deal.

The problem with me and the nimh is that I would need a 36v 30ah battery. That is 90 individual batteries. A lot in other words. The buy in could be $300 easy. I might as well invest double and get the Lithos. Even three hundred is more than I want to spend to go five miles now and then. I have the 18 (LOL) ah nimh so I will try to find a use for them. I might add to them if I can do it inexpensively now and then.

I also might look into rebuilding sla batteries. If I could find a source for them. That would be a cheap way to go for batteries. I don't mind pulling a trailer full of batteries along behind me. It makes the bike more stable to be honest.
 
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