electric kit on semi recumbent bike (India)

Namaste. I have been working on my ebike for a couple of months. While researching, i came across recumbents & was quite fascinated by their design. So i ended up making a semi recumbent bike, which actually is quite comfortable.

https://www.youtube.com/watch?v=bTP2SpNtwJg

I got the motor from China - MXUS FX07. It is a geared motor & they call it a 200 watt motor.
I got a front wheel motor because there were some issues in the open size of rear wheel.
As of now, I am using 24v 14ah VRLA battery.
The performance is good. Some things to note are
1. The top speed is around 30kmph. I like it.
2. The acceleration is slow. The motor people say this is because of 24v & will get better with 36v or 48v setup.
3. I have not tested the full range, but with my rides till now, I assume it is between 30-35km on only throttle.
4. The bike slows down a lot on inclines (flyovers) which is annoying.
5. The controller is 7amp - 14amp. The weight of motor is 2.75kg.

I am quite happy with how this bike is running. A lot of people have ridden the bike, and even though it is quite unfinished, they were were very happy with it. So now I am thinking of setting up a shop for bikes like these. And wanted to get some insights.
1. if i use the motor in rear wheel, will the climbing capacity increase? I thing, a smaller wheel should be easier to move with the same torque, hence front wheel gives better climbing. The rear wheel is 24" & front is 20".
2. what brands should i explore for the motors. this is an economical bike (this bike cost me ~280usd. this was the first one. & i am pretty sure the next one would be less than ~200 usd). so i am looking for low budget motors. after reading good reviews about them here & on other forums, I talked to mxus, cute (for Q85, Q100), magic pie, bafang 8fun. mxus gave this motor + controller for $75. i don't remember others prices but they were slightly higher. magic pie was much expensive. it would be nice to know a little about motors & motor manufacturers. I am happy with the way MXUS people have been dealing but is there a better product in the same price range? Also, geared vs non geared?

PS - I used a 24v setup on this bike as I will be adding a solar panel on this bike as canopy. I could have used multiple panels but they were making big cost issues so I decided to go ahead with 24v. My next bikes will be 36v or 48v
I used VRLA batteries for testing the bike. Will be using Li-ion in the next setup.

20" wheel will definitely climb better.

More anything will be better. More amps controller might be the cheapest thing, but if you are buying a new controller, more amps and more volts will be even better still.

I'd suggest trying 36v, and a 20 amps controller. This will give you about 5-6 kph more speed. It will also almost double your motor power, which will be the big deal making the hills better.

Right now, your peak power is about 360 watts. Up to 36v 20 amps,, 36 x 20, and your power will be about 720 watts. Worth the cost. But don't go higher than that, with your small motor. 800w is about the max it can stand and be ridden hard.

Thanks dogman dan. I thought the max this motor could take was 500watts. Your info opens new things for me. Thanks.
Can you suggest any other motor. Or any special choice among the economic ones like mxus, cute, dapu, conhis, 8fun.
Thanks.

So, where are you located? I see kmh and USD, confusing.
Are you saying you got the motor and controller for 75USD? that is a
steal.
the motor in the rear will not increase the power unless you up the voltage and amperage.

Dan

Well, if you weigh too much, and don't pedal enough up the hills, then 7-800w will be too much for the motor. But go ahead and perk it up to 36v,, and if worried about the power, get a 15 amps 36v controller.

Lastly,, you can also limit to 500w simply by not giving it full throttle when you are starting up. Once moving, a few meters down the road, then give it full throttle.

DAND214 said:

So, where are you located? I see kmh and USD, confusing.
Are you saying you got the motor and controller for 75USD? that is a
steal.
the motor in the rear will not increase the power unless you up the voltage and amperage.

Dan

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Hi Dan. I am from India, hence kmph. Got the motor from China, hence USD.
Yes, I did get the motor + controller $75.
Its a decent product. Nothing great, but its RoHS certified, that means, Europe grade product. The Indian & Chinese version were for $55.
I understand that to increase power I will have to increase voltage or amp or both. But my question was if lacing it on a larger wheel will improve the climbing or hamper it.

dogman dan said:

Well, if you weigh too much, and don't pedal enough up the hills, then 7-800w will be too much for the motor. But go ahead and perk it up to 36v,, and if worried about the power, get a 15 amps 36v controller.

Lastly,, you can also limit to 500w simply by not giving it full throttle when you are starting up. Once moving, a few meters down the road, then give it full throttle.

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Yes, the next set of motors that I am ordering is 36v with 19A controllers. So power shouldn't be a problem then. I, however, have been testing the bike more and here are the observations.
1. when i push the throttle (its a thumb throttle), i hear sparking noise in the throttle. the light also flickers along with the sparking noise (not all lights, but only one light indicating the current battery status will flicker). The sparking is maximum during acceleration & when it reaches a contact top speed, sparking ceases. I asked the motor people about this. They say since this is a 24v setup in 20inch wheel (which is a little unusual for their product), the motor is taking behaving funnily. And this shouldn't be the case in 36v with 26inch wheel. I am not happy with this explanation. Has anybody faced similar problem?
2. I tested the bike on fully charged batteries today. It was a 32km ride. Around 50% distance was pedal assisted, 50% was pure throttle. the terrain was as flat as it gets with 2 flyovers inclines (back & forth). The avg. speed 22kmph. I weigh 75kg. The bike is around 30kg. The batteries were fully drained after 32km. I am a little disappointed with this. With 24v x 14ah = 336watt hours, i was hoping 30km on only throttle. What could be the reason for this. The motor rating reads 83% efficiency. Although, the motor company says 14ah will give 25km on throttle & 35km on PAS (which is in sync with today's results.). But how come, bikes like https://electricbikereview.com/surface-604/yunbike-c1/ and https://electricbikereview.com/easy-motion/easygo-race with 186watt hour & 206 watt hour respectively, claim 15-40km?
3. Sometimes, when i start from a halt & perhaps press the throttle a little too hard, the circuit breaks.the controller is rated 7amp nominal & 14amp maximum current. it seems 24v x 14amp is not enough to move me suddenly. When i give throttle slowly, it works great. perhaps 36v x 19amp will solve this problem too.

Overall, my main concern now remains the sparking thing in the throttle. Everything can be worked around with. Any insights on that?

If you get sparking anywhere during operation, then unless it's a brushed motor (where brushes would spark, but you won't see it cuz it's inside the motor), something is wrong.

I'd recommend opening it up to find the broken connection or insulation and fixing it before it either catches fire / melts things or the RF caused by the sparks damages something in the throttle or controller electronics.

The explanation provided by the motor people doesn't make sense; I expect there must be language/translation issues....

I take you are using SLAs. You can never expect the rated AH out of them when using them in this application. You are probably getting all expected.

As for factory ratings, don't believe them. as for reviews, I would say they are using Li-ion batteries. They get almost as they are rated.

Dan

amberwolf said:

If you get sparking anywhere during operation, then unless it's a brushed motor (where brushes would spark, but you won't see it cuz it's inside the motor), something is wrong.

I'd recommend opening it up to find the broken connection or insulation and fixing it before it either catches fire / melts things or the RF caused by the sparks damages something in the throttle or controller electronics.

The explanation provided by the motor people doesn't make sense; I expect there must be language/translation issues....

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Opening up the motor is a scary thing. There were some problems initially and i tried to get the motor checked in and around delhi. And nobody was ready to open it. People haven't seen a hub motors here. I guess i might have to learn and do it myself. :|
This is what the motor people said "some sparking noise in the throttle and light indicator of the battery ,it is because the speed is 25km/h for the 20inch size ,is
too fast ,please don't work the bike reaches the high speed. Next 36 voltage is no problem."

DAND214 said:

I take you are using SLAs. You can never expect the rated AH out of them when using them in this application. You are probably getting all expected.

As for factory ratings, don't believe them. as for reviews, I would say they are using Li-ion batteries. They get almost as they are rated.

Dan

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Yes i am using SLAs, but these ones are specifically made for ebikes. But Li batteries are superior in every sense i guess.
What is the cheapest (& safest way to make a Li battery). I went to one of India's biggest Li supplier. They import cells, BMS, charger from China. The only thing they do is solder & assemble. They are offering me 36v 8ah for 6100 + 12.5 taxes = 100 usd. I don't think this is too bad, but considering the rest of kit is 75$, this amount just seems too much. Particularly for Indian markets, where majority of bikes on the road are $80 - 100.

A friend of mine makes power banks for mobiles. But he won't make ebike battery for me as he is not sure about BMS. so i am thinking of getting a good bms from China (like this https://www.aliexpress.com/store/product/10S-15A-BMS-for-36V-li-ion-battery/623665_1195130789.html) & try to assemble it here. or get a whole casing thing + BMS (like this https://www.aliexpress.com/store/product/Electric-bicycle-li-ion-battery-case-Suitable-for-36-v-or-24-v-battery-assembly/623665_1235753020.html). Is there something i should keep in mind with this?

Hall effect throttles don't spark. I wonder if you have something else, like brushed motor, and a multi speed switch in there.

At 24v, some weird shit can be used.

so i am looking for low budget motors

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A place to find cheap 250W hub motors would be on taobao.com , but its all in Chinese as its basically China's largest online shopping site. I have personally used this 48V 1000w hub motor from this https://item.taobao.com/item.htm?spm=a230r.1.14.29.gavWt0&id=44020285859&ns=1&abbucket=12#detail seller before and it works well the price is about 80 usd and international shipping should add around 40 usd more to it. It comes with the controller and rims included, and you can choose the rim size from 16-27.5 inch or 700cc. I think problem here is the language barrier. I'm located in Singapore so im fluent in chinese and i managed to ship my things using a forwarder at around $3 per kg.

Heres a photo of the bike i build together. The battery is held in place and sandwiched by 2 pieces of plywood. XD I must say the seller did quite a good job with the double wall rim.

dogman dan said:

Hall effect throttles don't spark. I wonder if you have something else, like brushed motor, and a multi speed switch in there.

At 24v, some weird shit can be used.

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its a brushless geared motor. it could be something other than sparking. its just this really annoying flickering sound when the motor starts taking load. As of now, I am just hoping the 36v kit does not behave this way.

wire.rat said:

A place to find cheap 250W hub motors would be on taobao.com

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Checked the site. Things really are cheaper there. But as you said, language is also problem. Tried but couldn't find a lithium battery pack. Is there a way to get in contact with sellers directly?

Your bike looks nice. the battery placement looks a little odd though. Are you using a lithium pack or GEL battery?

Another thing. I am having hard time finding any casing for the batteries. So will be making them myself.
Since I am using GEL batteries, the only position i can think of is rear rack. One battery size 151 x 65 x 94.
So I will try 151 x 205 (+20) x 94 box. Is it OK to place controller in the same box as batteries?
Also, what is the best way to make battery secure from thieves. I will be adding a basic lock system on the rear rack (like this https://www.amazon.com/Electric-Bicycle-Battery-Lithium-Polymer/dp/B016QZW16S/) but I am afraid it won't be enough.

Any tips regarding this issue?

Unless you have a VERY stiff and well-built rack, I wouldn't put those batteries up there. They'll destroy the rack, and cause you handling problems as they wag the rear of the bike around.

If you look up various threads around here about rear racks and battery cases/etc., there are a lot of ideas. There is a whole thread about homemade battery housings, though I don't have a link it should be in one of the Sticky Index threads.

Controller should be out in the open air for cooling, or you may destroy it by overheating.

amberwolf said:

If you look up various threads around here about rear racks and battery cases/etc., there are a lot of ideas. There is a whole thread about homemade battery housings, though I don't have a link it should be in one of the Sticky Index threads.

Controller should be out in the open air for cooling, or you may destroy it by overheating.

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Thanks a lot. Went through some threads. saw some interesting things, particularly, attaching the battery on the lower side of Down tube.
Alright, the controller goes outside then.

Another thing, has anybody tired out / heard about the Leeds 250 series. They also use a 24v setup (but with 8fun motor, which I assume, is more efficient than MXUS). Just curious how that kit performs.

I was reading the threads for batteries, and came across a brilliant piece by Ypedal. He says,
'Sealed Lead Acid batteries are rated C/20, so a 10ah lead acid battery will deliver 10 ah if it is drained over a period of 20 hours, the problem with this is that on an ebike we use energy at a much faster rate and if we were to drain this 10ah battery in one hour ( 1C ) it would only deliver 5ah of usable energy, Lead acid batteries canot delivery their entire capacity when drained quickly, this is refered to as the Peukert Effect.'

Is this valid even for today's AGM batteries? Is this the reason why I am getting low range on 24v 14ah batteries?
Also, can this made as a rule of thumb that VRLA AGM batteries will give ~50% of the ah rating.
My motor has a nominal current of 7amp. How can i calculate the 'actual' ah of my battery?

Update : Went for a ride to test the battery.
Total distance - 24km
Avg speed - 23.8kmph
All flats. 95% throttle. 5% PAS usage at red lights / speed brakers. I stopped / slowed down 6 or 7 times and pedalled for a few seconds to catch up the 25kmph.
Battery - completely drained.

A thing i noticed is top speed keeps on lowering continuously. first 10km - top speed 30-32kmph. Next 10km it was 24-25 kmph. Last 3km it was 20-21. Does this happen in Li battery also?
I guess VRLA battery do underperform & there is a good reason why most people here don't use them. Lesson learned (in fact, learning )

If I use similar watt hours from Li -ion, around 350wh, will I get around 35km of throttle only range?

I own one of India's most popular electric scooter (Hero Optima+ ). It is throttle only & gives around 60km (on highways, around 50km in city) + 32kmph with a 48v 24ah VRLA battery. It is an 80kg bike & can pull 2 people (75kg) for 25 - 30km. I am using the same batteries that this scooter does (same company, same model, smaller ah). Is my motor also underperforming?

yes, this is why your lead does so poorly. Used as fast as you typically do on bikes, it delivers much less than the rated capacity. And,, in addition, you need to cut that half in half again, if you want them to last.

But lead can still be ok for some things,, trikes can carry enough, so you can pack a 20 ah pack and lower the rate of discharge. this helps a lot with all batteries, but particularly with lead.

Lithium batteries also drop in voltage as you go. This is one reason 48v got popular. at the end,, its still 42v, and pretty perky.

Ali express should have li batteries. Which to buy from is always a bit of a gamble there. They come, they go.

You might also look into Hobby king, for RC drone type batteries. They can be strung together to make bike size packs. They are a bit hazardous, so you need a place that is essentially fire proof to store and charge them. Not inside with the family.

Checked the site. Things really are cheaper there. But as you said, language is also problem. Tried but couldn't find a lithium battery pack. Is there a way to get in contact with sellers directly?

Your bike looks nice. the battery placement looks a little odd though. Are you using a lithium pack or GEL battery?

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I'm using lithium batteries in the ABS box thats on the frame of the bicycle. You can find lithium battery packs by searching for 36v锂电池 for 36v lithium pack. Yes you can get in touch with them directly using aliwanwang, but they speak only chinese, so you will have to use google translate. But still a good thing is that their prices are a bit cheaper than those on aliexpress

Got some info regarding VRLA from a helpful supplier (a really big supplier) in China. The batteries I use, though have Indian company sticker, are also imported from China. So i guess this info is pretty relevant.
http://imgur.com/ZK0M5Xn
According to this 7ah batteries give 4.95ah at 1 hour rate.
So in my case, where i use 14ah at a nominal discharge current of 7amp, I am pretty sure I get much less than 10ah.
That seals the deal for SMF batteries for me.

Coming on to Lithium batteries, I read Ypedal write, that he (& a lot of others on this forum) don't use BMS. He also emphasised that he never, NEVER, discharges the battery beyond a certain limit or charge it with wrong voltage.
So my question is, can a good charger & careful use while riding avoid BMS. I ask this because one of the suppliers is supplying li bottle packs at very good prices but without BMS.

Also, how much should a BMS cost? Few vendors on alibaba quote $20.

wire.rat said:

Yes you can get in touch with them directly using aliwanwang, but they speak only chinese, so you will have to use google translate. But still a good thing is that their prices are a bit cheaper than those on aliexpress

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Thanks a lot brother. Will definitely try this out and let u know

I really can't believe there isn't BMS in the pack. Unless you have a way to check voltage from each series string, NO WAY would I bulk charge them. If they are not balanced when you first charge them they will fall apart in voltage as you use them and charge them. I use LiPo from HK and bulk charge all the time but never let alone or not checking cell level before and after. I don't need to check them or rebalance them for a long time but safety is KINDA important.

NO BMS no way, unless you access the cells. I don't care being LiFe, Li-ion or LiPo, they all can discharge different and charge different. If you don't know it can cause a fire. maybe they won't but do you feel lucky?

Dan

DAND214 said:

NO BMS no way, unless you access the cells. I don't care being LiFe, Li-ion or LiPo, they all can discharge different and charge different. If you don't know it can cause a fire. maybe they won't but do you feel lucky?

Dan

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Got it. BMS is what i am getting now

BMS should be in all premade batteries/ should be plud and play as they say. Plug in the charger, charge it and then Run it.

any battery needs time to balance, so don't rush the charge and pull the plug the minute it shows full. let it balance, sometimes the chsrger will turn off then back on a few times. If you short charge it you will cause a out of balance, causing a lower range or AH of the pack.

Be sure the battery comes with a charger that is ready to plug into it.

Dan