home brewed

Hi all, my first post now that the nice moderator has finally allowed me into your very interesting forums.

I've built my own machine as the prices asked for factory are a little hair-raising for me and my pocket. Its based on an E-Bay S/H mountain bike with full suspension and a sturdy set of full length forks up front. To this I have bolted a plate to carry one of the 'electric scooter' motors I have found on E-Bay. Its part No. is:- MY1016 (24V 350W). This is married to one of the proprietry controllers that 'shoppingforspares' supply. I am using four 12V 14AH SLA's configured to give 24V at (approx) 24AH.

The machine runs well enough for my short work journey but does struggle on inclines. Does anyone have any knowlege of this motor and its capabilities?

Cheers

John

Hmmmm....... Not even a Hi and welcome......

I take it then that the only people 'allowed' an airing here are those who shell out over £1000 for a bike???

To be perfectly honest, all of the production models I have looked at are firmly based on the 'French Onion Sellers' design ethos. In other words... horrific. I set out, not so much to make a cheap bike, as a good looking and useful machine. I am firmly in the Internal Combustion camp, I have various (proper) bikes, A Fireblade, a classic Honda CB72 and a 50cc rev and go scooter. The rev and go is very comfortable, has a large underseat storage area, good weatherproofing and is miserly in its fuel consumption. Needless to say, it makes a mockery of any E-Bikes performance.

The downside, is as ever, government legislation. Were this France I would have no reason to even consider an alternative, but the UK's legislation does force annual MOT's, the incredably high insurance premiums demanded and road taxation. So I shall continue to evaluate and improve. I am content in the knowlege that I am hundreds of pounds in pocket and that I, at least, know intimately how these things work.

If I can find any way to make a real difference to either performance or range, I will gladly share that knowlege, but I am not convinced, so far, that this is a viable alternative.

Hmmmm....... Not even a Hi and welcome......

Lol sorry. Its easy to overlook new posts/posters on here. Welcome to the forum I am sure a few others will pitch in.

I started off with a kit and moved on to a Cytronex albeit second hand.

--- The UK's Best Deals on Dental Products

(They really should do something about their web site's title pages lol)

These are far from French onion sellers (nice analogy) looking bikes lol

PS post some pics as well. People loves pics

Regards

Jerry

Edited November 1, 200916 yr by jerrysimon

Hmmmm....... Not even a Hi and welcome......

 

I take it then that the only people 'allowed' an airing here are those who shell out over £1000 for a bike???

Nothing could be further from the truth, we have many owning low cost bikes, self made or second hand and often ancient, and all members are respected and appreciated. In fact a few of our longest serving senior members have the very cheapest of bikes, sometimes much modified. Maybe some like me leave thread responses to those most interested in a particular aspect, like making up one's own e-bike in this case, but with a small number of members entering at any one time (just 8 at this moment), there's always the risk of one of that class of member not being in to respond. Therefore once in a while a new post gets missed, but it's rare. Sorry yours was one of these, but be assured you are very welcome, as are your posts.

To be perfectly honest, all of the production models I have looked at are firmly based on the 'French Onion Sellers' design ethos. In other words... horrific. I set out, not so much to make a cheap bike, as a good looking and useful machine.

For most of the few years of the e-bike's existence, the market has been for utility bikes for shopping and the like, with a very high proportion of the buyers being elderly, so the market has matched the demand. The "enthusiast" user is still a very tiny proportion of the potential customers so the designs are for the most part appropriate. I well remember that when this forum opened the membership was well over a third in the 50 upwards age groups with many in their 70s, not a single member in their 20s and only a tiny number in their 30s. It's improved since then, but the bias is still towards the upper end and in any case, this enthusiast forum is hardly representative. As a Powabyke man remarked, the great majority of their customers wouldn't even be found in a forum like this, most being very much the sort of customer wanting bikes of the type you dislike.

 

I am firmly in the Internal Combustion camp, I have various (proper) bikes, A Fireblade, a classic Honda CB72 and a 50cc rev and go scooter. The rev and go is very comfortable, has a large underseat storage area, good weatherproofing and is miserly in its fuel consumption. Needless to say, it makes a mockery of any E-Bikes performance.

The downside, is as ever, government legislation. Were this France I would have no reason to even consider an alternative, but the UK's legislation does force annual MOT's, the incredably high insurance premiums demanded and road taxation. So I shall continue to evaluate and improve. I am content in the knowlege that I am hundreds of pounds in pocket and that I, at least, know intimately how these things work.

No different from many of us in fact, since we have a large number of current and ex motorcyclists in here, including me with 53 years of riding experience and at one time a mechanic in the motorcycle trade.

 

If I can find any way to make a real difference to either performance or range, I will gladly share that knowlege, but I am not convinced, so far, that this is a viable alternative.

Nor am I and I've posted threads to that effect. I think the moped is miles ahead in almost all aspects and could well almost eliminate e-bikes in the future.

.

Edited November 1, 200916 yr by flecc

And it is half term...... I have just returned from the south coast where we had cheats! shouted at us on 2 occasions all in good humour though! It was lovely cycling on the flat with nothing like the traffic we experience in south London.

when I clear my garage:( and buy a stand (bad back) I fancy a home build project. What would be an ideal donor bike I wonder............

Welcome to the forum John!

50cc rev and go scooter. The rev and go is very comfortable, has a large underseat storage area, good weatherproofing and is miserly in its fuel consumption. Needless to say, it makes a mockery of any E-Bikes performance.

ha ha. My 4kw X5 would mince your gasser in a drag race any day of the week! i would bet money on it.

Hi John

welcome to the forum. I don't post much, i just ask questions and add anything i think may (or not) be of interest to anyone.

Personnally i like to see DIY homebuilt machines.

Here's ours.

http://i219.photobucket.com/albums/cc224/gearhead188/ebike/IMG_7470.jpg

http://i219.photobucket.com/albums/cc224/gearhead188/ebike/IMG_7469.jpg

Both run Tongxin Hub motors (modified)and yuasa 36Volt 7Ah Sealed lead acid batteries and my own designed current limiter. My bike has covered at least 1500miles and the wifes bike 1000miles (although my batteries are due for renewal soon). We used them to get to work everyday and occasionally for holidays. Pictures above were taken on the tarka trail.

It may surprise you to learn how little£££ we have invested in these 'e-bikes' certainly not £1000. In fact i believe they are saving us money, i don't seem to be driving my car so much these days. For short journeys these 2 bikes are ideal.

BTW I am a firm believer in the Internal Combustion Engine especially in the V8 form.

I would like to see your conversion, it sounds interesting, can you post some photos?

Oh yes, i've seen 'monsters' ebike and i would put money on it to win also......(another smile)

Mel

Edited November 1, 200916 yr by wurly

Hi John

welcome to the forum. I don't post much, i just ask questions and add anything i think may (or not) be of interest to anyone.

Personnally i like to see DIY homebuilt machines.

Here's ours.

http://i219.photobucket.com/albums/cc224/gearhead188/ebike/IMG_7470.jpg

 

http://i219.photobucket.com/albums/cc224/gearhead188/ebike/IMG_7469.jpg

 

Both run Tongxin Hub motors (modified)and yuasa 36Volt 7Ah Sealed lead acid batteries and my own designed current limiter. My bike has covered at least 1500miles and the wifes bike 1000miles (although my batteries are due for renewal soon). We used them to get to work everyday and occasionally for holidays. Pictures above were taken on the tarka trail.

It may surprise you to learn how little£££ we have invested in these 'e-bikes' certainly not £1000. In fact i believe they are saving us money, i don't seem to be driving my car so much these days. For short journeys these 2 bikes are ideal.

BTW I am a firm believer in the Internal Combustion Engine especially in the V8 form.

I would like to see your conversion, it sounds interesting, can you post some photos?

Oh yes, i've seen 'monsters' ebike and i would put money on it to win also......(another smile)

Mel

Nice bikes i really like the black one,more info would be good you say the tonxins are modified is this to allow 36v or something else i am sure many members would be interested in your bikes but will probably miss this thread.

Hi all, my first post now that the nice moderator has finally allowed me into your very interesting forums.

 

I've built my own machine as the prices asked for factory are a little hair-raising for me and my pocket. Its based on an E-Bay S/H mountain bike with full suspension and a sturdy set of full length forks up front. To this I have bolted a plate to carry one of the 'electric scooter' motors I have found on E-Bay. Its part No. is:- MY1016 (24V 350W). This is married to one of the proprietry controllers that 'shoppingforspares' supply. I am using four 12V 14AH SLA's configured to give 24V at (approx) 24AH.

The machine runs well enough for my short work journey but does struggle on inclines. Does anyone have any knowlege of this motor and its capabilities?

 

Cheers

 

John

Welcome john,it can be a little difficult to join the forum if you have a free email account,this is to try and stop spam and it does seem to work,sorry you were overlooked to begin with, but if nobody else has used that motor answers can be hard to give, i found your motor on ebay it seems marked as a 24/36v motor,running three batteries in series at 36v should give some improvement over the way you are running it now,24ah would give pretty long journeys 36v 14ah should give extra power but still give at least 15 miles,but you would need to buy a 36v controller,and i would check with the seller that the motor runs ok at 36v before trying.

Nice bikes i really like the black one,more info would be good you say the tonxins are modified is this to allow 36v or something else i am sure many members would be interested in your bikes but will probably miss this thread.

Modified to overcome the weakness in the outer drive ring ( i have already had one break). I won't say much more until i have more miles on both motors.

Modified to overcome the weakness in the outer drive ring ( i have already had one break). I won't say much more until i have more miles on both motors.

Nice looking bikes. was wondering how did you deal with fitting motors....are forks alloy or steel? and did the motors fit or did you need to stretch the forks?

Another new member

Hi,

Another new poster here, with some details of my experiments in 'e-bikery'.

Have posted a short history of the track to this point in the 'introduce yourself' section of the forum.

Basically had a Nano for a while, and decided to try some experiments. Have since built:

My own smaller controller for the Nano, with a small 'lever' throttle.

Tried the Nano, using A123 batteries (another poster - Daniel Weck -, has put up some of the details of this in another thread).

Converted a Dahon Matrix, and a Claude Butler bike, with Tongxin motors.

Redesigned the wiring on both the later units, to make them more elegant, and simpler to use.

Attached is a picture of the Claude Butler conversion. Front bag has two A123*12cell packs wih 'batt1', 'off', 'batt2' switch, giving a total of aboout 10 miles 'pure assist', and well over 20 miles range, assuming you provide 50 to 60% from the pedals.

Best Wishes

Welcome Roger,

No picture ?

Very interesting to read about your project especially the battery. More details about any balancing circuit you use would be interesting.

Also if you recently purchased your Tongxin's I would love to know where you got them ?

PS just read your introduction thread. Its great to see you join us and look forward to seeing your work and learning about your experiences with the Tongxin and battery builds. I am trying to source a Tongxin for my Brompton and like you just want a small battery pack for my round 10 mile commute trip to work.

Regards

Jerry

Edited November 2, 200916 yr by jerrysimon

A123's

Hm.

The attachment ought to have worked.....

Trying again. It is comfortably 'sized', probably the script blocker in my browser decided to interfere!....

The A123's, are a modified LiPo battery, with some extra chemistry, improving their ability to stand high discharge currents in particular.

They are an interesting battery, but are small. To get a genuine 36v, you have to use 12 cells (the 3.6v/cell figure, is basically the 'just charged' number). The basic cell gives 2.3Ah, at 3.3v, so a pack of 12, gives you 39.6v 2.3Ah = 91Wh. They do genuinely perform better than most small LiPo cells, in terms of being able to maintain a larger percentage of this 'rating', when currents over 1C are drawn. So assuming your motor is around 200W 'continuous', so drawing about 5A (2.2C), they still give about 98% of this 'rating', and on hills, when your motor goes up to say 400W, and pehaps nearly 5C, they still give well over 90% of this rating. They can stand being discharged well down their power curve, without damage. But I think some people are a little 'overconfident' that they will self balance, so do give them a balance cycle if they have been used heavily.

I have tried them on the Nano, and on the 26" conversions.

Now I tend to be an 'assisted' rider, rather than an 'electric' rider, using the electric on hills, into headwinds, and sometimes for a fractional boost on pullaway in traffic. As an example, I rode a local 'loop' of roads, to visit a friend yesterday. Just over 15miles, and averaged 15.1mph. Given that the assist cuts out around 15mph, you can quickly realise that most of the ride is 'pedal powered'. Looking at the track graph, tells it's own story.

Basically. there is almost no time at all on the graph, spent between 0mph, and 12mph. There are then a number of sections on hills etc., at between 12, and 15mph. On the 15 miles ride, 11.8miles, was 'over' the speed where the assist cuts out, typically cruising at around 20mph, leaving 3.2miles with assistance almost certainly being used. This would agree well with the battery indicator, which had just dropped into the red under load (usually meaning you have about 1/4 left). I reckon on a single pack, giving around 5 miles of 'full assist' on flat roads (the cruising 200W ish output), but half this on reasonable gradients. There were two hills over 15% gradient on the ride, and both were done with full assist at about 12mph.

For me, having two batteries is great. You can leave the switch 'off', and ride as normal. Come to a hill, and hit battery one as needed. I don't think I'd be 'happy' riding with just one of these packs, since you'd only need to find yourself with a massive headwind/rain when you turn home, to be back with the misery of no assistance. However two packs gives about 10miles useable, and you can use gentle assist from one, saving the other for 'when you need it'. Also these batteries do chemically 'recover' a little. If you have been loading them hard, and cut the power, the voltage comes back up (normal), but it continues to climb over the next few minutes, and more power is then available when you ask again. So (for instance), with two packs you can get a little more range, by using a battery on a hill, and then switching to the other one for a while as it recovers.

Traditional (seems silly to talk about 'traditional' for a technology that has been around for for as little time as this....) LiPo packs, seem to perform less well when pushed up to high currents versus cell capacities, but are lighter for a given capacity. So (for instance), you could put together a 5Ah pack for little more than the weight of the A123 pack, bringing the 'C' numbers down. Currently the A123, is only managing about 80Wh/Kg, versus a 'best' from LiPo, of about 160Wh/Kg....

My 'ideal' pack, would probably be something like a 5Ah pack, with one of these 2.3Ah packs as my 'reserve'. This would potentially give about 300WHr, (about 1.3Kg for a 5Ah LiPo pack), and with current technologies would still total under 2.5Kg. :-)

Best Wishes

 

The attachment ought to have worked.....

and I thought I had steep hills.

.

Balancer.

Missed your question about the balancing circuit....

Dead cheap/simple. Used the higher accuracy version of the TL431 (5mV), with 0.1% resistors for the two setting the reference point. The rest are non critical, except that the main load resistor, needs to be able to handle 0.3W. Draws about 90mA, when the cell voltage gets above just on 4.2v. Far cheaper than any alternative I've seen, and seems to work OK.....

Best Wishes

Roger,

Very interesting and thanks for posting.

Did you purchase your Tongxin's recently or have you had them a while back from when they were more readily available ?

Regards

Jerry

Hi Roger,

You mentioned you have used your own smaller controller.

Any details on this? Enquiring minds are curious..

Thanks,

Robin

Hi Roger ! Nice to see you here after having had the privilege to speak to you in private. Your DIY knowledge and craftsmanship skills are most welcome on this forum !

Talking about throttle-only riding versus occasional assistance for hills and wind: I just recently posted about that, and I mentioned A123 batteries as a small-size alternative for my short bike rides (I currently use a 36V 10Ah LifePo4 battery from Li Ping). I will certainly use your advice as a basis to move forward with this idea. I believe that Freedom E-Bikes (Andrew Hamilton) is using the same design on his variation of the Tongxin-based Brompton Nano.

The ride diagrams/statistics extracted from my GPS tracker illustrate the benefits of low-powered pedelec cycling, just like your own conclusion:

http://www.pedelecs.co.uk/forum/electric-bicycles/4825-diy-stage-8-continuous-improvements-5.html#post62279

I hope you will find some time to share your designs with us, I've certainly enjoyed looking at photos of your realizations !!

Cheers, Daniel

Hi again

Hi Daniel,

It was your pointers to just what you were doing, an the threads here about them, that made me decide to 'take the plunge' and join over here.

I'll put together something about the controller. As you know this is 'ongoing'. Rides beautifully, but still having problems programming a really smooth pull-away. I'm probably going to try for a simplified version of the little throttle (simpler to make - the original was just too much work!.....), and this could be a useable solution on many other controllers. Also my brother wants this for a 'drop bar' installation.

Both Freedom, and the Electric Wheel Company, are supplying the controller made by:

<http://www.lsdzs.com/>

and have worked out what most of the connections on this do, so have simplified the wiring on the Nano a lot. What was supplied, was rather a 'bodge', with the original manufacturers wires coming out of the controller, then joined with Vero, heatshrink, etc., and these connections put inside the larger box.

The 'pity' for me, is that the A123, doesn't get up to the high density LiPo power density figures, if it did, it'd be the best battery for just about everything!....

Best Wishes

Both Freedom, and the Electric Wheel Company, are supplying the controller made by:

 

<http://www.lsdzs.com/>

I see. My Tongxin 80mm 180W 190rpm motor from Frank ( Das Elektrorad von Frank Scheftlein: Komplette Pedelec- / Elektrofahrrad Umbausätze und Ersatzteile von Bafang, Puma (eZee), Tongxin u.a. ) comes with a custom controller supplied by e-Crazyman / Keywin Ge (units manufactured by Shenzhen Sucteam). It's obviously a brushless and sensorless controller, with a 3-level power switch (nice feature) and Pedal Assist Sensor input. It's programmable using the ParameterDesigner.exe application (available via Frank with the data cable, or from the Endless-Sphere forums).

Regarding the A123 battery, I am looking forward to hearing more about these prismatic units !

Green Car Congress: A123Systems Prismatic Cell Lineup: Up to 5,300 W/kg in High Power Cell, 20 Ah Cell for PHEVs

A123Systems :: Products

http://www.a123systems.com/cms/product/image/7/medium/A123-017.jpg

http://img26.imageshack.us/img26/2289/a12320ah.th.jpg

Full size image: http://img26.imageshack.us/img26/2289/a12320ah.jpg

http://bioage.typepad.com/.a/6a00d8341c4fbe53ef011570962436970b-800wi

Cheers, Dan

Edited November 28, 200916 yr by daniel.weck

tat

I use to like the youngs brew kit. 40pints for only a tenner.

thx

Bob

Missed your question about the balancing circuit....

 

Dead cheap/simple. Used the higher accuracy version of the TL431 (5mV), with 0.1% resistors for the two setting the reference point. The rest are non critical, except that the main load resistor, needs to be able to handle 0.3W. Draws about 90mA, when the cell voltage gets above just on 4.2v. Far cheaper than any alternative I've seen, and seems to work OK.....

 

Best Wishes

Hi Roger

Welcome to the forum

I have a question (or two) about your balancing circuit diagram. I want to make my own battery pack with a balancing circuit and your diagram has given me a few ideas.

Am i right in thinking the reference voltage depends on the state of the cell voltage in the first place? I can see that the load resister stops the cell overcharging when it reaches 4.2V. How does the circuit behave when cell voltage is less than 4.2V, for instance, during discharge with regards to the reference point? Will the circuit still balance cells in a pack during discharge or is your circuit designed for balancing during charging?

Mel

Nice looking bikes. was wondering how did you deal with fitting motors....are forks alloy or steel? and did the motors fit or did you need to stretch the forks?

Hi Eddieo

Fitting the Tongxin was easy. I just filed out the slots in the steel forks, made the slot a little deeper (to make sure the v brakes lined up with the rims). Both bikes had 100mm wide legs, so no cleareance problems.

Battery choice is rearing it's head again. 7ah SLA's have been fine for our short journeys to work, but mine are showing the signs deterioration after 7 months of use. Trying to weigh up building my own pack or buying a small LifePo4 pack.

l like the idea of DIY and 'home brewed' ebikes even if my first attempts at designing/building fail:).

I have never laced a wheel before. It took 5 attempts following a good wheel building book. The next one i did was easy/easier. Stripping apart a Tongxin motor isn't a problem either, now i know how to fix and maintain them. It is an enjoyable learning curve.

Hi Roger

Welcome to the forum

I have a question (or two) about your balancing circuit diagram. I want to make my own battery pack with a balancing circuit and your diagram has given me a few ideas.

Am i right in thinking the reference voltage depends on the state of the cell voltage in the first place? I can see that the load resister stops the cell overcharging when it reaches 4.2V. How does the circuit behave when cell voltage is less than 4.2V, for instance, during discharge with regards to the reference point? Will the circuit still balance cells in a pack during discharge or is your circuit designed for balancing during charging?

 

Mel

The TL431 regulator used on Roger's circuit has a built in reference voltage generator producing 2.5v. That voltage reference is compared with the input voltage from the R1-R2 resistor network to determine when to switch the current through R3 and R4+D1 on. When the voltage is less than 4.2v, the TL431 regulator will be switched off and no form of cell balancing will occur - arguably cell balancing during discharge is pretty pointless as long as you have a per-cell low voltage cut-off function.

In addition to the low voltage cut-off function, the other shortcoming with this circuit is that it does not have the ability to disconnect the charge current to prevent cells from reaching too-high a voltage - merely to drain a small current should the voltage exceed a pre-set level. For example, imagine a pack with 2 cells, one fully charged, and one fully discharged (at 3.0V). A two cell charger would need to charge to 2x4.2v=8.4v. As soon as we switch the charger on, the fully-charged cell exceeds 4.2v and the cell balancer starts to burn off extra energy at around 250mA... However, the charger is pouring on the extra charge at 2500mA so the cell voltage still rises to extreme levels. I've seen this solved on some BMSes where if a single cell rises above 4.3v then the charger is temporarily disconnected until the BMS has the chance to burn off some joules.

Although it's a cell-balancer, it's not a full-featured BMS solution.