If I could do it all over again... first ebike lessons

Hey guys! Back with another informative thread from my point of view...

I intend this thread to be a review of what I've learned since building my first ebike and riding it for 100miles. I figured since I hit the 100mile mark I now have some say and weight here...

Review:
Battery - I build my own 48v battery. Custom layout to fit underneath the top rail of the bike. 13s 7p. 91 cells. Every single series connection has a separate deans connection so I can monitor each series voltage. Took me forever and I used a gazillion glue sticks but the battery is super solid. Built it with a 30Amp BMS
Charger - Some cheap CC CV 48v charger for like $12 off ebay. I believe its a lead acid charger and not a real li ion charger. The current is constant till it reaches cutoff voltage which from my understanding of Li-ion, this is not correct. I went cheap here which if I intend to keep the bike I should purchase a real charger...
Bike - OLLLLDDDD Trek 80C Sport. I don't think its a kids bike but its a steel frame with steel dropouts. Solid bike and was a good frame for an ebike build
Hub motor - I went with a cheap 1000w kit off ebay. I think it was around $140 all in all. I modded the wiring to 12AWG from the controller to the motor.
Controller - Generic controller that came with the kit. Works well and I modded it with an additional thermal pad for more cooling efficiency. This is mounted to the down tube where the bike seat goes.
Tires - Tubed tires, replaced the front tire with a 3" wide kind of hook worm pattern. Nice tire and it grips really well.


Ok, now to the meat and potato's...

What would I buy different?
This build I went SUPER cheap. I mean replacement 18650 laptop batteries for the battery cells...used batteries too. Cheapest I could find. All the cells in the bike reach at least 1900mAh which means I should have around a 12-14Ah battery at 48v. IF I could do this all over again I think I would go with just all NEW batteries. I used solder wick wire and soldered each cell. This seemed to work really well. I think the big thing here is getting the right charger. I went cheap with the charger and the BMS cuts out too early and the battery isn't really able to balance effectively...so my loss there

What I've learned while riding?
I like to go FAST!!! With 1000W I can get upto around 35MPH... I'm limited by voltage and current of the battery here. I've also learned that a non-suspension frame is possibly the worst idea ever for an ebike. GOSH, its KILLER! You have no idea how bad it can be till you actually have a bike with no suspension and you're trying to go 25+... Its BAD! If I could do it all over again, at least get a bike with a front fork suspension. that is a must. After 100 miles the bike is still a lot of fun, however, I almost feel like 2000w or heck maybe even 3000w would be way more fun. Upping the voltage to at least 72V would be a good idea.

Should I build or buy a pre-made battery?
I build my own battery primarily out of interest, cost, and the general understanding and ability to create my own stuff. I'm technically inclined but not an engineer (yet) so I figured I'd love building the battery too! I've built everything from computers to snowmaking machines. The advise I would give is plan your design before you buy anything. This will help reduce any extra costs by what you didn't buy and you can settle on exactly what you want. I would steer away from super cheap laptop batteries that have 18650 cells in them that are not genuine name brand like Toshiba or Lenovo. The reason being is they're typically filled with cheap 1-2C Chinese cells that tend to fall off a cliff in capacity and performance after just a few cycles. You may be able to find decent 2000mah cells but give it 6 months time and 10-50 cycles and you'll see that capacity dwindle to something like 1200mah. That is what I experienced in my first battery. Now I'd recommend name brand cells like LG, Sony, Sanyo or Panasonic.

I'd be happy to answer people's questions here that might be interested in building a bike from the ground up for the first time. I'm glad I did it, I planned on using it as a commuter bike but I have yet to ride it to work, primarily because of trail construction delays preventing me from riding in.

I'll add more content as time goes on. Thanks all! The forum has been great for providing me with helpful information!

Batteries-I use LiPoly. Although they weren't as readily available when I started, I would have started w/ the biggest bricks that were practical to fit into the space. I my case, I evolved from 6S/5000 mAh bricks wired 2S/3P or 2S/4P to 6S/10000 mAh bricks wired 2S/2P. This simplified the wiring, but more importantly, I went from 6 or 8 balance taps to only 4. That allowed me to......

Charging-I would have avoided RC balance chargers w/ their attendant power supplies altogether. Messing w/ balance boards and all the related balance wires was a PITA and the "toy" chargers have not been particularly reliable for me. I now bulk charge w/ the easy to use, quiet and indestructable Mean Well HLG series LED power supplies and ck the cell Voltages w/ a Battery Medic. On the very rare occassion I need to balance, I have 4) B.M.'s. I have also learned to buy only the quality Blue B.M.'s, not the junky Black ones.

Philaphlous said:

What I've learned while riding?
I like to go FAST!!! With 1000W I can get upto around 35MPH...
[...]
You have no idea how bad it can be till you actually have a bike with no suspension and you're trying to go 25+... Its BAD!

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What I'm hearing is you claiming you like to go fast, but in practice you don't like it.

The more stuff you add to your bike to disguise the true effects of speed, the closer you get to a driving a car-- with progressively more of the consciousness-lowering effects that lie down that road.

I limited my latest e-bike to 25mph, but when I'm not dashing around trying to get somewhere quickly, it seems that I settle somewhere in the 15 mph range. Below about 18 mph, wind noise is minimal, pavement defects don't usually make me cuss, and I am much more aware of what's going on around me than I can be at higher speeds.

I go faster if necessary to mesh with congested traffic. Or if I'm in a hurry. But that's not especially fun riding.

As for the lessons I remember from my first e-bike, many years ago:

-- A good bike turns into a bad bike when you burden it with a lot of lead. So don't do that.

-- You don't have to be able to motor as fast as you can dash on a pedal-only bike; you can still raise your average or point-to-point speed quite a lot.

-- A heavier bike plus higher speeds make good brakes feel just okay. So having excellent brakes is a good idea.

-- Adding systems always, always means adding points of failure. So all else equal, simpler is better. For best results, minimize the number of electrical components, number of plugs, number of moving parts, etc.

Coming from riding a road bike with 100psi 700c tire, the front suspension and fat tires on my front suspension/hardtail e-bike seems downright cushy ... even at 30+ mph. Also, I thought that "bunny hopping" over obstacles was one of the fun things about riding a bike. :^)

That said, the nice thing about building your own bike is that you can make it the way you like it.

wturber said:

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That said, the nice thing about building your own bike is that you can make it the way you like it.

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Exactly. It is also unusual that a first build is fully satisfying. The first is making you define what and how you like to ride. I find that one season of daily commuting does make yourself clear about how you'd want the next. For sport and off road, it might take a longer time, maybe even a few bikes before finding your optimal ride.

I have built 8. My street commuter is entirely satisfying, but my dirt bikes never been perfect and I am still looking ahead to build better. Of course, seeking performance is making the process longer, and it is more complicated to achieve effective performance riding mountain trails.

MadRhino said:

wturber said:

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That said, the nice thing about building your own bike is that you can make it the way you like it.

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Exactly. It is also unusual that a first build is fully satisfying. The first is making you define what and how you like to ride. I find that one season of daily commuting does make yourself clear about how you'd want the next. For sport and off road, it might take a longer time, maybe even a few bikes before finding your optimal ride.

I have built 8. My street commuter is entirely satisfying, but my dirt bikes never been perfect and I am still looking ahead to build better. Of course, seeking performance is making the process longer, and it is more complicated to achieve effective performance riding mountain trails.

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completely agree. Just built my first dedicated commuter, and very happy with the results. Probably helps that this was about my 4th build, if you count a few motor/battery changes on my norko as 'new builds'. Never been happy with my dirt bikes though, never been able to make one robust enough, hence trying now to do a custom frame, and moving away from hodge-podge to taking the time to make it work right the first time. A lot more time in design, more time in implementation to hopefully all but eliminate any time in repairs (beyond normal maintenance type stuff).

I think it was very wise of me to get my first ebike motor the MXUS 3000W V2 straight from the factory, with a Lyen 18fet and a Cycle Analyst. The unwise part was jumping in with Lipo and buying 8S iMax rc charger from Hobbyking, the charging was so slow at 150W. What I should have done was just buy a 36V Headway pack and a corresponding charger, or buy the bolt on cans and DIY.

markz said:

I think it was very wise of me to get my first ebike motor the MXUS 3000W V2 straight from the factory, with a Lyen 18fet and a Cycle Analyst. The unwise part was jumping in with Lipo and buying 8S iMax rc charger from Hobbyking, the charging was so slow at 150W. What I should have done was just buy a 36V Headway pack and a corresponding charger, or buy the bolt on cans and DIY.

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Well, using RC lipo may have been a mistake for you if you don't need the power density. Charging them with a small RC charger sure was a mistake, pretty much like buying a 2 stroke 250 MX and ride it at 10 mph in the backyard. I bulk charge mine in 10 minutes, and would never buy Headways to add a boat anchor to my bikes.

See, the mistake of one may be the the right thing to do for another. There are so many different bikes on ES, for so many different requirements. We should make an app, asking a list of questions about user requirements and automaticly present him with a list of corresponding building threads. :wink:

It is important to have a quality charger. A faulty charger can contribute to, or cause a devastating fire. A quality charger will have been designed to fail in safe ways to avoid triggering dangerous conditions that can cause a fire, such as shorting the pack or overcharging it.

A quality lithium-ion charger will not charge a battery that is at too low of a voltage. It may charge initially at low current if the voltage is too low, but it will stop after a short time if the voltage does not get in range. It will not charge at all if the temperature is out of range.

Once the voltage (and temperature) is in a reasonable range it will charge at constant current or constant power until the voltage rises to the max allowed voltage for the pack. This will be a precise value, it is important that this value not be exceeded.

Once at the CV portion of the charge the current will begin to drop as the battery completely charges. When the current drops to some level, generally a few to ten percent of the full charge current, the charger will declare the battery "full", and either shut off, or continue to charge at the constant voltage and low current. This "tail" charge is helpful to allow the BMS to balance the cells. Ideally the charger and BMS should be matched in voltages and algorithms to coordinate the end of charge either by the BMS or by the charger.

A quality charger may also have timers to stop charging at some length of time.

It will also have circuitry to present a proper load to the power system, having "power factor correction".

It will have proper cooling design and overheating shutdown protection, and other safeguards, and be UL or other national testing lab recognized for safety as appropriate.

MadRhino said:

Well, using RC lipo may have been a mistake for you if you don't need the power density. Charging them with a small RC charger sure was a mistake, pretty much like buying a 2 stroke 250 MX and ride it at 10 mph in the backyard. I bulk charge mine in 10 minutes, and would never buy Headways to add a boat anchor to my bikes.

See, the mistake of one may be the the right thing to do for another. There are so many different bikes on ES, for so many different requirements. We should make an app, asking a list of questions about user requirements and automaticly present him with a list of corresponding building threads. :wink:

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Those of us w/ lower-powered bikes have greatly benefited from the introduction of the "HIGH Capacity" 10C Multistar LiPoly, which trades off high discharge rate for a greater capacity(for the equivalent size of the higher discharge units), w/ the added advantages of larger form factors and a lower volatility.
I now have a pack that is about as close to "plug and play" as Lipoly can be, the only extra care being it must be left @ a storage Voltage when not being used. But going from 3.90V/cell to 4.10V/cell when ready to go out only takes 20 minutes and w/ a little foresight, is not much of a hassle.
W/ the unsettled events in Asia, I just ck'ed what it would cost to stock up(LiPoly stores very well). Right now, the 4) Multistar 6S/10,000 mAh brick I use to build my main pack would cost $280 shipped. That's a 20,000 mAh pack that will easily discharge @ 25 to 35 Amps w/ less than a 1V of sag. There is still no other chemistry that even comes close to that cost/performance ratio.
The other advantage is, I can use a larger pack, which means I seldom need to "top off high" or discharge low, which extends service life. No "range anxiety" here.

MadRhino said:

Charging them with a small RC charger sure was a mistake, pretty much like buying a 2 stroke 250 MX and [strike]ride it at 10 mph in the backyard[/strike] riding the reeking smoky noisy murderous bastard anywhere, at any speed.

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Fixed that for you.

Chalo said:

MadRhino said:

Charging them with a small RC charger sure was a mistake, pretty much like buying a 2 stroke 250 MX and [strike]ride it at 10 mph in the backyard[/strike] riding the reeking smoky noisy murderous bastard anywhere, at any speed.

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Fixed that for you.

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I am glad you did. Now maybe you will stop telling me I should be riding motorcycles instead of powerful ebikes.

Thanks for the lessons learned. Always helpful to us noobs

Dont buy any new ebike with a Bosch mid drive because they are over priced IMHO.

Ask yourself how fast you need to go , how much torque you need and how long distance will you travel , what terrain you will travel on then arrange your ebikes motor/battery/controller /frame/ components to a performance level that is slight HIGHER then those specs. Hardly anyone ever says " GEE , I WISH MY BATTERY PACK HAD LESS CAPACITY AND OUTPUT '

Go with a SENSORLESS controller/ motor combo. I have Lyens 18 fet sensorless and it works great . There isn't a need to have all those extra thin hall wires anymore. Its just more stuff that can break.

Read as much as your an, before buying/ building your ebike.

Try not to be to concerned about TOP SPEED. My ebike can do over 50 mph, but 95% of the time I stay around 20 mph or less.

Dont do stupid things with your ebike, that will eventually cause all the ebike community to suffer from new draconian laws .

After building my ebike (BBS02 on a 1974 Nishiki touring frame) a bit over 2 years ago, and riding well over 20,000km on it, the main things I've changed on it were getting rid of the stuff I don't really need.

I got rid of the display, replaced with a simple power meter with V, A, Wh. Disabled the PAS (seemed pointless), and eventually replaced the integrated controller with an external 25A Infineon (original one ate too much snow/water). Changed the 38x700c tires with a set of 2.1"s on chromed steel 26" wheels because weight and drag weren't really important anymore. Dropped the 8 speed cassette for a 5 speed.

Controls consist of a throttle and the power switch on the controller. And a kill button that I've never used.

It gets more reliable all the time. At this point it's down to replacing tires, chains and brake pads when required. My current commute is 26km each way, 5 days a week. Plus my everyday running around for shopping, fun, etc.

I haven't even had a flat tire since I can't remember when, but it didn't start out that way. It's been a process of evolution. Mechanical selection if you will.

I cruise at 35kph or so most of the time, close enough to the legal limit (32) and about the upper limit of where I feel safe riding in a bike lane. Not because of the bike, it's totally stable going 60, and the old butterfly brakes (with modern pads) have more than enough stopping power, but drivers aren't expecting bicycles to be going that fast and they make shitty decisions based on that.

I say do not procrastinate, just be persistent and get to it and buy whats needed and get to riding.
I waited a long while and in one of Justins video's he says thats what a lot of people do. I say probably because of the initial cost involved. Which is another tip, spend wisely and do not cheap out.

I was pleased with the first purchases I made - the MXUS 3000W V2 motor and Lyens 18fet and Justins Cycle Analyst. Mistakes, LiPo and RC Charger. Should have went ebikes.ca aka Justins/em3ev battery and charger something like 15-20Ah.

Speed wise I currently cruise at 32kph/20mph and go fast at 40kph with the rare occasions of 50kph on full charge of 48V on 4T motor.

The last 2 days I put on some mileage fishing the river with rides of 35-45km a day.

Wouldn't change a thing.

First ride, 10s10p laptop cells razor e300 scooter 24mph, no controller on off throttle with relays using a dc motor direct to battery (ghetto)

Second ride, 12s2p multistar lipo razor e300 scooter 28mph, 3kw dc controller and motor pot throttle (dangerous fun)

Third ride, 16s2p multistar lipo brushless scooter 48mph, 4.8kw trapiz controller (not tbag really )

Fourth ride, Thought I'd learnt enough now so I got an a2b metro to repair and my god did I set myself a challenge that helped me learn loads, still at 10s6p stock pack has loads of life, mxus 3k in a 16 moped rim, 12fet sinewave Bluetooth 40amp controller.(headwork but riding it makes it worth it)

Fifth ride, Got a small scooter on the go goal is to be at 20kg and output 5kw with gearing that turns 6k rotor rpm into 20 mph so I can climb with efficiency to have a good range off road. (Next year on this one)

I spoked a wheel as a kid and it was oval more or less so the amount of research I done on rims tyres and spokes to make my own wheels for the a2b was insane this was my major hold up, Spoking a wheel was not good enough I needed to know the ways of the wise to learn how to do it properly, the electric and mechanical stuff I have a bit of advantage on but battery's and controllers are new things that I've learnt massively on and I want to get involved on a lebowski 6fet and program the parameters for the motor but that will be on a future ride if I'm lucky enough to get my hands on one some day.

Never stop pushing boundarys, we all have different levels and types of skills along with access to equipment that can help us make something special, but time and persistence with a mind that's willing to learn can get you more than far enough.