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No problem, Thamosy, I'm happy to offer my thoughts. The steepest hill is quite short, only 300-400m, but it's soooo steep if I wasn't feeling really up for it in the morning it would put me off cycling.. sad I know.. but some days I just didn't feel like it. Once I get through town it's mainly downhill to the coast, however coming back I have to go up this hill, it's not a steep gradient but it's about 3km long and can get me to the lowest big cog on the front in places and one route in particular has heavy traffic (for here anyway). Now I have the motor if I go full throttle my speed uphill is about 35km/h which is not much slower than the cars, it's a 50kph limit. On fairly shallow gradients there doesn't seem to be much difference whether you pedal or not, obviously if you pedal the battery will go that bit further but when you're putting 1000 watts into the motor your 100-200 watt effort doesn't make that much difference. Cruising on the flat around 38-42kph I'm drawing about 500/600 watts at 25-30% throttle. I tend to use the pulse and glide method, full throttle starts then freewheel for as long as I can, pedal on the flats to keep the speed up or if it's a bit hilly then I use the motor. If I were you I would stick with your 36V battery, if it can supply a decent amount of amps (30 odd) then you will not notice a difference in hill climbing power, the 48V battery will just give you a higher top speed, but in my opinion my bike is too fast at 48V. Also I wish I'd bought the 12Ah batteries, as they are lighter (marginally) and I could package them in the frame bag that bit better, I use 10Ah per day and thats worst case scenario. I'm seriously considering downgrading to 36V (means new BMS and charger) or going the whole hog buying more batteries say 72V and converting a registered and legal motorbike. I'm also looking to add rear panniers to make the bike that bit more practical as I'm using it a lot more often. As a motorcycle rider, I'd recommend you put the batteries inside the frame rather than over the back wheel, especially if you have steep hills. Though if you can mount them low at the back you'll probably not notice too much. I have no experience with rear mounted batteries. On one of my first runs one of the connections came loose on the battery (my dodgy wiring effort) and I had to cycle home, uphill all the way. With 8Kg of battery and 4kg of motor the bike felt like a total dog. Once you've added your ebike kit you do not want to run out of juice, it's doable but no longer a pleasant ride. If you are an experienced rider and comfortable in traffic then I'd recommend a top speed of 30-35km/h any more is asking for trouble from the authorities. Anyway thats my rambling over.. I just want to make one more point.. and it's very important.. when I first set out building the bike my concern was simply to get from A to B as fast and easily as possible. Now I can do that I find I take more scenic routes to work and absolute top speed is not that important, of course it's nice, but I simply enjoy taking routes I'd have previously thought were too difficult or slow and seeing new places. So my commuter machine is going to transform into a touring machine, I'll buy some panniers and a lock and make it that bit more practical.

Just to give you an idea of range, I cycle 30km every day ~19miles at an average speed of 35km (22mph), mainly flat but with a few long and a few very steep uphill sections. Without pedalling I use just under 500 Watt/hours of battery so make sure you check the pack size is up to it. If you're going to be pedalling with any effort you're probably looking at a pack size of at least 400w/hrs which would include some margin for windy days etc..

For reference my commute stats according to the Cycle Analyst: Distance ~30km Watt/Hrs ~ 500 Watt/Hrs per km 17 Average speed 35km/h Max speed 51km/h Round trip time: 50mins Amps used ~10A Those stats cover going home yesterday, pedalling with little effort, and today I didn't pedal at all (well a handful of revolutions) so absolute worst case scenario.

Hi Thamosy, To be honest I've always pedalled with the motor up hills so I couldn't give you a definitive answer until this morning.. when I didn't pedal! The steepest hill I cycle up is so steep it would have me zig zagging across the road and lifting my front wheel with every stroke of the pedals before I had the motor, even in the car I eventually have to change down into first, if I take a run up (dangerous) I can get just up there in second without stalling but I have to time it just right.. Before I had the motor I'd have to stop at the top of the hill to catch my breath, my legs would be burning and I'd be wondering what the hell I was doing this for.. on my trip there's another two hills just ahead, not quite as severe as this though but they're still hard going. Now I have the motor if I pedal with it I'm still a bit out of breath BUT according to my speedo I'm climbing the hill at around 15-17kph! While this does seem a little slow it's much better than the 4kph I was getting before the motor.. however thats with pedalling.. If I really go for it up any other steep hill where I'm standing on the pedals giving about 80% effort I can easily climb around 20-25kph - about as fast as most ebikes would go on the flat. As an experiment this morning I tried the steep hill without pedalling and kept a close eye on the motor temperature. d8veh is right, it's basically about how many amps you can put into the motor without frying it. Frying it WAS what I was most concerned about. All up weight with me on the bike is probably just under 135kgs, the controller is a 30Amp and the BMS is set for 30A continuous, 60A peak. I approached the hill at full throttle.. with a short run up it I was probably doing about 35kph, the speed soon scrubs off though and the speed settled around 6-7kph. The motor was coping okay but I didn't really like the idea of the motor labouring so I pedalled gently for a couple of revolutions and the speed soon went to about 10-12kph, then stopped pedalling and my speed settled again to about 6kph. All the time the CA is reporting Watt/Hr consumption of just under 1500! The motor heated up by about 20-25 deg C to about 45-50 (ambient temp at 8am this morning was 22 deg C according to the Cycle Analyst) This is what I was most worried about and the reason I went with the 10Turn motor despite Pauls recommendation of the 8T. When I get home which is uphill all the way, the motor temp is around 100degC, ambient temps of around 33-39degC depending. It was an interesting experiment today, I normally pedal with the motor and it's amazing what a difference it makes I find the motor mainly needs help just to start moving, once it's about 5-10kph there is a surge of torque and it accelerates briskly up to 40kph eventually topping out around 45kph. On the flat I can do around 38-42Kph consuming 500-600 Watt/Hrs. Shortly I will write up my experiences so far, but in short the kit has exceeded my expectations. However I also overspeced my setup, I should have gone with the 12Ah batteries (that bit smaller and lighter and most importantly.. easier to package!) It's also probably too fast, certainly on the dirt, my tyres are too skinny, there is no suspension and it's very tiring on the arms. On the road however it's an absolute dream, but again.. illegally fast and for that reason I couldn't recommend it. I haven't tried programming the controller yet as the Cycle Analyst which sits on the handlebars is a much more refined solution and it's easier to setup parameters in that than it is to program the controller itself. I've had to speak to Paul from EM3EV and the guys at Eclipse Bikes to sort out a few niggles (I wired the BMS up incorrectly and thought I'd blown it but managed to disconnect it as soon as I smelt the burning circuit smell!) It all seems to be working okay now. If you're still waiting for the motor kit to arrive I'd get on with building your battery pack, it took me quite a few tries to package it in the frame bag you see in the pictures, it was a very very tight fit and even now I'm not too happy with it. I've had to lay some thin plywood sheet to stop the cells from resting on each other. I though this would be most important off road as the cells may rub inside the bag and I don't want them getting damaged. Also I ended up building the pack for the bag, getting it wrong, almost frying the BMS and then building it the normal way (Eclipse kindly sent me lots of pictures of their build for reference), then breaking it down to fit into my frame bag. All in all I have spent about 9 hours building and rebuilding the battery.. Oh I also had problems with soldered connections, I had some bullet connectors on the battery - controller connection.. well needless to say I didn't do my side very well and ended up cutting them off and using a decent crimped connection.. I can do that properly! I'll report back after my first full month.. but I can say that I have bought a better bike to put the kit on.. it's arriving next week ;-)

Well here's the finished article.. I had a few teething problems with the battery and the Headway cells are LARGE, thats the disadvantage of LifePo4, however I finally managed to pack them in the frame bag and this is the final result. I need to trim the battery to controller wire down to size and I'll make the charger connector more accessible, there's a couple of well shielded holes at the front and rear of the bag so the controller will pop out the back and the charger will pop out the front.. http://iangrindley.co.uk/images/ebike/mac-motor-ebike-headway-48V-15ah.jpg

This is what concerned me about BMS Battery and Green Bike Kit, apparently they order from the same wholesaler or factory, from what I've read BMS have had a reputation for poor customer service so don't expect much. I contacted Green Bike Kit but had ordered from Paul before i got a reply back from them. However my biggest concern was not getting exactly,what I wanted, I've heard it's a bit pot luck getting a torque or speed motor, having said that their website has been updated recently and it has an option to specify the motor you want. What I appreciate about the Mac kit from Em3ev is that it's all setup and tested before it leaves the factory, I just had to plug a couple of cables in and flicking the on switch it all came to life, it was really very simple. Plus I got a half decent branded and well balanced wheel too.

Well I finally got some time today to finish the few things needed to get the bike running.. And quickly took my first ride!! First impressions are good, it's really hilly here and I'm getting used to the throttle but I had to slow down round corners going uphill! I was cycling with the motor, it makes you feel bionic! I had a few issues with the bike, namely tyres that don't fit, I'm still experimenting. And the ebrakes aren't compatible with my setup as mine is a cheap integrated brake and gear lever. I'll have to figure something out. I also couldn't fit the wired up battery in the frame bag with the bms and all the wires, it was just too tight. I also thought I'd blown the bms at one point but it seems to be working okay now.. In short my top speed was 46kph on the only flat bit and an average of 20 odd kph over 4km of some very hill terrain. I'm pleased with the performance it is pushing too fast for me at wot and cycling uphill feels downright bizarre! I'll post more later.

Hi Thamosy, I went for the 10Turn motor as I wanted a torquier motor to climb the 25-30% hills I have right outside my house. Paul said the 8Turn motor which is slightly faster would work okay. As I understand it, the 8T motor would be generating a more heat while climbing and the ambient temperature around here can be over 40°C for much of the summer, which doesn't give it much chance to cool off.. Hence I decided to go for the slower torquier 10T motor and then over volt it slightly to 48V to increase the top speed, not that I'm too fussed about going very fast.. but my setup should get me to 30mph or so on the flat which is more than fast enough for me, I mainly want the higher speeds for hill climbing. If you haven't seen it already you can use the simulator at Grin tech here, it's worth just playing around with it for a bit ebikes.ca Hub Motor and Ebike Simulator I used the BMC Trq for the 10T motor and BMC Spd for the 8Turn, not quite accurate but close enough. Stick your controller details (I used Custom 30Amp) in and battery (I used 52V 20Ah Ping). It looks like my top speed is around 33mph, peak efficiency at 25mph (say 75% throttle) with that setup. the thing that sold me most was a guy in San Francisco riding up a 20 or 30% hill using a Mac 10T without having to pedal.. MAC motor hill climbing test - YouTube

Hi Oigoi, Good idea! How big was the capacitor you used? What motor and controller were you using? I'm hoping that I'll be able to avoid any issues like this by re-programming the controller, either that or the Cycle Analyst but adding a capacitor inline seems like a good reliable solution!

Thamosy has started me thinking about how well I'd matched up the components, I ended up buying a 72V max controller in case I wanted to add more batteries in the future, however looking at the space in the frame I think it's doubtful I could get another four cells on, the main problem is cable runs and the little tabs holding them. Obviously if I buy more cells and increase the voltage I'd have to buy another battery charger too, an expense I'd rather avoid. I've just re-checked the specs on the controller I bought and it can draw a maximum of 30 amps, which is a prefect match for the BMS. So hopefully the BMS won't be tripping out due to a mismatched controller trying to draw too many amps from the BMS. 9 fet IRFB4110 Infineon Controller (Motor With Hall Sensors) I decided to go for a programmable controller as being a bit of a tinkerer I know I'm going to want to adjust the power delivery of the motor, ideally I would like to make it as similar as possible to a standard motorcycle engine, so you get max torque while you're moving not from zero so the bike flies away! This isn't so important for me, mainly for when I lend it to someone else. Also the controller is a high quality piece with genuine quality components, so it should be reliable and give me years of service and seeing as this is a commuter bike that's the highest priority for me.

Hi Thamosy, I bought the whole battery kaboodle as a kit from Eclipse, they can supply everything you need to build a custom shaped pack. The BMS was the one they had tested and recommended for use with the Headway cells so I plumped for that. As I understand it the cells can pump out 150 amps for a short period, much less for a sustained duration, so there's no problem taking that many amps from the batteries, however the controller I have is only rated for 35 amps max (I think) so I decided to go for the 30/60 amp BMS as it can handle 60 amps peak supply, 30 amps sustained. I don't think the cell is your 'low point' in the system, I think it's most important to match the BMS and your chosen controller, that way the controller can get all the amps it needs from the BMS and you don't end up with a situation where the BMS shuts down the battery pack when the controller draws too many amps. I'm no expert however so don't take that as gospel, you might want to drop the guys at Eclipse a line they generally respond to emails after a day or so. Here's the key parts of the Headway cell specs from the Eclipse Bikes site: Max Discharge Current (Continuous): 5C Max Pulse Discharge Current (30 seconds): 10C (150A) Recommended Discharge Current: 1C (15A)

Thanks, in the pic I was just testing for fit, the orange blocks put the zipper under too much strain so they'll have to come off. I was thinking of wrapping the batteries somehow but hadn't really considered the exposed ends bashing into each other!! So thanks! I can't find any decent foam tape over here, I was rummaging for some spacing material to wrap the batteries in when I looked at the box the batteries were delivered in, it's filled with a decent thickness of foam so I'm going to cut that into strips and make my 'cell blocks' with that, they can be properly insulated then with just a couple of wires popping out.

I didn't have much time over the weekend to work on fitting everything to the frame, but managed to test fit the components and it all looks like it should fit okay. http://iangrindley.co.uk/images/ebike/batteries-fit-snug-in-frame-bag.jpg The battery bag is pretty tight but I'll be able to get all the cells in there and the BMS too, the controller will be in a separate bag behind the seatpost. I'm going to run a small tube under the top tube to contain the wires from the handlebars going to the controller. I could run them through the bag but this bike will have to do double duty until it's paid for a dedicated leisure bike. The only thing missing from this pic is the seatpost bag with the controller in it, hopefully it'll be a very neat installation... http://iangrindley.co.uk/images/ebike/battery-bag-test-fit.jpg

Hi Frank, thats great advice thanks, I wouldn't have thought of that until after the motor destroyed my frame! I've added two washers on one side and a third by itself on the cassette side so hopefully won't have a problem.

Excellent D8veh, thanks for the info just what I needed to know. Over the weekend I connected a single cell to the dc converter at 3.60V and let it sit there until the amp flow slowed to nothing. I let it sit off charge overnight and it held a steady, but lower voltage. Then when I was happy I hadn't destroyed it I connected the remaining cells up in fours in parallel (4p?) and put the steady 3.60V on them until baked. Here's the part no. of the piece I was using.. LM2596HV (the HV stands for High Voltage) that is overkill for changing a single cell, the lower voltage (and cheaper) LM2596 would have been enough. However I want to input around 55V from the pack and convert to around 6V to run my bike lights. I am thinking of buying 8 of these and building a little float charger, two cells at a time. I'll see how well the BMS keeps them all in check. At a couple of quid each it's a pretty cheap way of keeping them all in line. http://iangrindley.co.uk/images/ebike/dc-converter-float-charge-single-cell.jpg Ignore the wire colours in the pic.. it was very late and I soldered the board upside down forgetting to swap the wires over.. I've only soldered stuff a handful of times so I was very pleased it all worked..

Thanks d8veh, I wasn't going to use a charger, just a simple DC converter. It would put out a constant 3.6V at 1amp (it's adjustable from 3-30V) I thought if I left it on long enough it would eventually saturate the cells at 3.6V and they'd stop pulling current, am I wrong in thinking that? I don't understand how the voltage would keep rising if the input charge is constant? Obviously I don't understand battery chemistry!

Which leads me on to my next question... I've test fit the torque arms, these are the V4 Grin Tech arms from ebikes.ca However with the torque washers on the cassette side the torque arm is pushed too far out and doesn't rest centrally on the seat stay. Is it okay to leave the washer out here, I guess the torque washer would be redundant on this side, but should I use the normal washer between the torque arm and the frame? http://iangrindley.co.uk/images/ebike/no-washers-fit-torque-arm.jpg http://iangrindley.co.uk/images/ebike/torque-arm-flush.jpg

Now I show my mechanical ineptitude! So the motor fits nicely, the wheel is true and everything looks good.. I've got a bag full of washers and bolts.. the bolts are easy.. they go either end of the motor shaft.. What are the washers for? I have two circular washers and two washers (torque washers?) with a lip on them.. I've put them on as I think they should fit.. Torque washer first, then normal washer, then bolt.. is that right? http://iangrindley.co.uk/images/ebike/finally-is-this-right.jpg

In other news... After three and a bit weeks in customs in Lisbon the motor kit finally arrived.. all present and correct wayhay!! http://iangrindley.co.uk/images/ebike/smaller-package-than-expected.jpg I managed to get the motor together okay, it's smaller than I expected, it all looks good quality and the Alex Rim looks smart.. I had a little time this morning to do a test fit, it all slotted together nicely, everything is tight and I didn't need to do any filing. http://iangrindley.co.uk/images/ebike/slotted-straight-in-no-messing.jpg It's starting to come together now, I'm planning on keeping the controller in the seatpost bag, I'll put a few holes in it for airflow, plus I need to butcher it a bit so the wires come out the front and down the seatpost rather than spewing out over the back wheel as in the shot.. http://iangrindley.co.uk/images/ebike/coming-together-controller-bag.jpg

Hi Frank, Thanks for the info, I'm going to have a go at putting a few cells together tonight and charge then from a 1amp DC convertor to about 3.6V Question - Am I correct in thinking the cells will stop pulling current when they are saturated at 3.6V? Thanks, Ian

I've managed to have a quick look at the batteries, I'm thinking of charging the individual cells in series using a DC converter. The idea is to get them fully balanced at ~3.6V before I build them into a pack. The voltages are not too far out of line max is 3.45V lowest is 3.31V Is this necessary when the BMS should be doing the balancing? I've heard that a BMS won't work optimally if the individual cell voltages are too far out of equilibrium? The DC converter can supply 1 amp (2 amps I think), when the cells are almost charged I've heard each cell will draw about 20 milliamps so the converter should be able to supply enough power, but not too much to melt any of the cells. I'm planning on just setting the convertor to 3.6V and leaving the batteries connected up for however long it takes. The motor is still stuck in customs so there's no rush to get them charged quickly. Obviously I'll connect a volt meter and monitor the amp flow, I'm expecting to see the amp flow drop as the cells reach max capacity, is that right or do I need to time the charge duration and disconnect at a certain time?

Commute detail I've ridden the bike a couple of times without the motor so I can compare apples with apples once I've got motor assist! My commute is 16km which I can cycle in 30 mins dead. The same route in the car takes 20mins (and costs me €35/week in petrol alone). There is a faster route I can take by bike but it's mainly off road, I'm pretty sure I was doing this in 25 mins last year, but my mind is a bit foggy now.. The fastest route in the car takes just over 15 mins. I'm not too bothered about beating any of those times with the bike motor, I'd like to be able to take the off road route to work so I can avoid the traffic and fumes.. but there's a couple of 25% hills to contend with and I always end up getting to work needing a shower.. My top speed cycling on the road run is 55km/h. Top speed so far on the bike 65.8km/h! just on pedal power alone.. well that and a bloody great hill!

The batteries have arrived! The battery box arrived yesterday, really pleased with the service I received from Eclipse Bikes (eclipsebikes.com| bikes | electric bike kits | Pedal | Power) really keen prices too. The box came well packaged, the batteries are sitting under all that gubbins.. http://iangrindley.co.uk/images/ebike/eclipsebikes-headway-lifepo4-batteries-package.jpg I've quickly taken the batteries out and placed them on the frame.. they are big! I'm not sure where they're going to go at the moment. I do have a frame bag on it's way, I'm going to have to decide to mount them in that, put them in a backpack (stealthy and easy to charge) or mount them to the frame somehow.. The main issue would seem to be placing the BMS, it has to be close to the batteries as the balance leads are fairly short. I'm feeling nervous about soldering all this up!!

I've made a few upgrades on the bike.. gone are the super skinny and rock hard hybrid tyres, in are a new pair of Schwalbe Big Apple balloon tyres.. so far they do give a more comfortable ride. These aren't the widest tyres in the line-up but are almost the widest I can get on my bike.. I'm going to order a pair of Kenda 8 Small Blocks as the Big Apples are not great on loose gravel which covers most of my commute. http://iangrindley.co.uk/images/ebike/specialized-hybrid-balloon-big-apples.jpg

The batteries arrived today, the motor has been stuck in customs for nearly two weeks now! It's supposed to be arriving tomorrow, fingers crossed!