Dadplus2

I am running it in a 26 inch wheel. I am using Lipo nano Turnigy 4000 mah 5s 18.5v x2 link here. The controller not sure of the make it all came second hand (unused) but it is 15amp I believe.

Thanks for the quick responses I was thinking of a cute wonder if I can use the same rim. What's currently the best source for cute motors? Cheers

As some of you may remember last year I built a lightweight electric bike around the Tongxin motor and lipo nano. Ive had great fun running it with no real problems. Suddenly today while on a longer than usual run there was a metallic crack from the hub then that was it no power. The wheel will spin with no load but only very slowly. Is it all over has the hub given up do you think? Any pointers welcome.

That's interesting so more volts do equal more RPM even on a hub rated at 190rpm. I am currently running a max of 36V which tops out at 15pmh

Looks like a minimum order of 100 from the Outrider link. What's wrong with putting it on a 26" wheel is it a speed/torque issue?

I am wondering if anyone has one of these motors they wish to sell. I have built a little bike see this thread.. It works really well but tops out around 14/15mph so I would like to try the faster spinning motor. Thanks in advance.

Thanks for all the technical info you guys know your stuff. I can see why these batteries are not used in commercial applications just overly complex for the average user. I think if I do build a few bikes for people then I would go down the BMS Battery route it seems a good way to build a competent electric bike on a budget. I like the look of their frog batteries they seem similar to ones used by Electric wheel and other components seem to be used by other electric bike resellers. My bike has evolved slightly in that I now have an IP68 plug in the top of the battery bottle and the weight is now 13.6kg. I have to say its an absolute joy to ride and really zips around 0-15 in just a few secs up the hills no problem at all. I'm just checking out the range now up to 8 miles and 3.89V. Who knows with enough interest I may turn it into a little side line business based in Exeter, not sure if there are any members in the southwest?

I've just done 4 miles and tested the batteries and they are showing 3.9v. Better news, I've also just ordered the cellog 8m so looking forward to getting that. As an aside I've had a fair amount of interest in this bike and a couple of requests to build similar lightweight machines. I may be doing some more.

Thanks for the info 3.4V seems like a high number if they are full capacity at 4.1V. I checked mine yesterday after about 5-6 miles and they were at 3.7V all roughly the same. Charging took 1.5hrs. Will look into a CellLog

I've changed this now so the wiring is encased in rubber, allowing the controller to keep cool. I probably won't use this bike in really bad weather. I currently have no method of monitoring each cell on the bike, when I charge the batteries I can see how the cells discharged and whether it was even. I could invest in a cycle analyst but they are pricey and I don't think it can monitor each cell. Not even sure how this could be achieved.

Cheers guys, these batteries seemed to have no problems under load nothing go warm. I picked the nano lipos as they seemed to have a good spec, lightweight, very little resistance and therefore not be too stressed under load. They also apparently have twice the life cycle of a normal Lipo battery. This should be an all weather bike (hopefully) as I intend to encase the controller and wiring in rubber. I need to improve on this part of the project and also put in some sort of plug so I can disconnect the battery bottle easily. http://www.dhdesign-uk.com/bikes/IMG_0846.JPG I will also black out the hub to make it look at bit nicer.

First run Well after spending a good few hours in the garage leaning how to solder putting all my EC3 plugs on then soldering wires heatshrinking then Anderson connectors I was ready to test out the system. Battery charged and checked all wiring ready, connect the batteries, flickering red light at the throttle and NOTHING! Phoned Alan (sorry Alan thanks for listening) had another look at the fuse and it must of part blown 15amp fuse, I believe the controller is limited to 13amps. Changed the fuse all good wheel spins. The set about routing the cables along the bike using some half round PVC trunking and cable ties. I than made up some rubber sleeving to go around the controller and to keep the top of the battery bottle on. [ATTACH]2765.vB[/ATTACH] [ATTACH]2764.vB[/ATTACH] Finally got it all up together this morning weighed it 13.8kg bit heavier than I was hoping and took it for a test ride. All very nice and smooth, I have a steep hill just round the corner so went up that relying more and more on the motor to see how it coped. All good until it popped. The fuse again well to be more accurate the fuse holder. Close inspection revealed it was rated at 10amps. Need to find a better holder! [ATTACH]2763.vB[/ATTACH]

All the bits have finally arrived - thanks Alan for the hub and wheel etc. The batteries won't fit into the expensive Camelpak bottle so I've got an aluminium one now and cut the top off it. Really nervous now though as the batteries come with next to useless plugs on the end and won't even plug into the Turnigy charger. I have to cut them off and solder on some EC3 plugs all new to me. Thanks Amigafan2003 I pretty much copied your list of supplies. So assuming I can get the plugs on and charge the batteries worried I'll do it wrong, the plan was to connect the batteries in series and then charge them using one of the two balance plugs. No idea which one so I may just charge them separately on the balance board for now. Then its the wiring up, probably straightforward as the (unknown controller) is prewired with Anderson connectors, I may ditch these as the are pretty fat and would need waterproofing. Lots of fingers crossed!

I guess range is subjective when potentially so many factors are involved. The only true measure must be an average speed throttle only on a flat run. Following on from earlier in this thread I wonder whether a lighter bike will have a significant increase in range. I think I will have to invest in a cycle analyst even though they are quite expensive. My batteries are going onto a plane in Singapore.

That's a pretty powerful pack, what kind of range do you think it will give? I've only ordered x2 5s 4000ah packs but am hoping for around 20miles assisted

I've added up the weight of the bits and it should come to just under 4kg so I am aiming to get under 13kg for the project. Hopefully I will get some progress up next week.

Thanks got one now.

Thumb throttle for project needed anyone have one, thanks.

I've got part one completed now with the bike built and tested. Its around 9kg at the moment and the reason I mention this is that, its amazing how different it feels to ride. http://www.dhdesign-uk.com/bikes/bike2.jpg Once you take off the gears and all the other stuff it seems to go up hills so much easier. I had always thought that it was pointless having a light bike if you could just go on a diet and loose a few pounds and it would be the same. Seems not though. I am therefore hoping that will translate into an electric bike with different characteristics taking less power to move forward and up, leading to less stress on the motor and battery. Waiting for my bits to turn up before I can get cracking.

I still may try push button control to keep is simple but am looking at Hall Effect Push Buttons does anyone have any comments on these types of switches. Hall effect linear sprung return Or Hall effect momentary I suspect this is just a push switch for hars environments ie uses magnetic fiels instead of contacts?

OK I think I understand, forgive me though I am not electrically minded I'm the fool that can do it for a pound. Question: So the pot kind of takes the place of a throttle? You push the 'switch to make' motor has power and off you go, then adjust the amount of power to the hub via the pot switch. Then you want to stop pull brake, power is cut, then when you release the brake is the system armed/live again? That bit must be wrong.

Sounds interesting have you actually seen a practical application of this kind of switch/pot on a bike?

You may well be right about the single speed thing nice to try it though. I'm now also going to try just a 'boost' type switch with no brake cut-offs. Possibly two of them. Has anyone tried this?

I've started building up the bike cobbled together from another bike and some bits, not finished yet the forks will go and some brakes to go on. I've ordered the Tongxin and controller, batteries and charger. http://www.dhdesign-uk.com/bikes/IMG_0826.jpg

OK following that logic if my set up battery output is 37V I need to limit the output through the controller to around 14amps. My controller is rated to 20amps so I need to set it to 70% max motor current. I'm also looking into whether I can limit battery discharge through the controller to keep the batteries safe, as I believe thats an issue with these batteries. I see I could use an onboard meter but would prefer not to.