electric bikes, and various other hobbies

Hi, I am new here. I am on the endless-sphere electric bike forum, and I have also written a few articles for electricbike.com...

I have a lot of time for reading on my job, which (right now) is operating a municipal water plant, making tap water. My interests vary, and recently I have studied Stirling engines, and air rifles.

I have recently become interested in finding the part numbers for a 24V 7S lithium mini power wall system (using 18650's)that is expandable over time, wheneverI can afford to add more solar panels and batteries.

Welcome

It's awesome that you have so much time to read on your job, bro. Did you ever try to build an electric bike yourself?

CarmeloH said:

It's awesome that you have so much time to read on your job, bro. Did you ever try to build an electric bike yourself?

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I have been into ebikes for about six years. I have two right now (I am in manhattan Kansas). The one I ride the most is a BBSHD mid drive. I also have a very powerful rear hubmotor ebike that is fun to give test rides on, to show how fast they can be...

If anyone has any questions about building an ebike, I'd be glad to provide free advice. I've written quite a few articles for electricbike.com

I'm actually in the process of making my own ebike and I have a couple of questions for you, if you don't mind of course.

I have a 500W limit in my city so I'm torn between single 500W rear hub motor and dual front/rear hub 250W motors, or, go illegal and get 2 x 500W (or 1000W) and hopefully it's not obvious. I prefer hub over mid-drive as I want the option to not peddle at all (lazy) and I think the mid drives have to be powered by legs to get any power out of them. Correct me if I'm wrong.

Any opinions on Golden Motor Canada? They have a nice hub motors with built-in controllers which seems better than having an external controller.

I'm also building the battery and wanted to you know your thoughts on fuse wires, if any and if you prefer a certain voltage like 72V over 48V as I plan on going 48V.

Thanks.

The first question is...do you want regen braking? It doesn't really add enough watts back into the battery to make that worth while, but the ebikers who like that say its a nice magnetic brake. It requires a Direct Drive hubmotor (on the rear).

Once you've answered that question, I havefour recommendations.

Like regen? Single large rear DD hubmotor (Edge 1500W at 48V)

2WD with regen...Small rear DD hubmotor and front geared hubmotor for 2WD (Yescom rear, BPM front both at 48V)

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Don't need regen?

large rear geared hubmotor at 48V (MAC), covered by cargo bags

2WD, big geared hub in the rear and smaller geared hub in the front (BPM rear / Bafang front)

As far as the legal watt limit, ride safe and you'll never be stopped, plus get a 250W sticker to put on the motor. Poilice do not use volt/amp-meters, and wouldn't understand the readout if they had one.

Do I want regen? Well, I guess I would depending on how it works. If it's automatic as in, I let off the throttle and it works or manual like I have to press a special brake lever. Auto sounds good, manual doesn't.

On the 500W max, I did think about putting a sticker or something that would show it was 500W or less but I imagine you're right about not getting their attention is likely the better route. I don't need to go 60+MPH .. I'm not looking to go crazy and hit highways!! I do want torque and potentially 2WD if it sounds as good as it is.

Thanks.

regen means that as you apply braking power, instead of wasting that energy as heat, it's stored in the batteries. So, yes, you do use a special lever for it. Unless you wanna run into a wall or a car, I suppose.
You don't want it automatic, otherwise as soon as you let off the handle, you start to slow down to a stop, even on a down slope. I don't think you want that.

Korishan said:

regen means that as you apply braking power, instead of wasting that energy as heat, it's stored in the batteries. So, yes, you do use a special lever for it. Unless you wanna run into a wall or a car, I suppose.
You don't want it automatic, otherwise as soon as you let off the handle, you start to slow down to a stop, even on a down slope. I don't think you want that.

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I'm familiar with regen, just not sure how it's enabled and yes, I would prefer it automatedso by letting off the accelerator, you'll slow down as if you were braking. Sort of how the Tesla cars work so you only need the physical brakes for immediate stopping or from 5>0 KPH.

Freewheel is also good because you don't use any electricity for coasting but if I wereto ride at a fixed speed, my power would be quite low during cruise anyway.

Some controllers have regen, and others do not. The controllers that do have it can have either one setting (on/off) or it is programmable. The programmable ones can be nice because you can set it to your preferences. Also, in winter?...you can't use "max" regen, you will simply lock the wheels and begin skidding with the bike getting sideways.

You can set up a programmable regen so that it comes on instantly as soon as you stop accelerating the throttle. You would have to always have a small amount of throttle to prevent the regen from activating. Another way to have regen is to have it activated by the brake handle. As soon as you pull the handle a 1/4 inch, it will start regen braking, but the brake pads will not be applying any pressure to the wheel.

There is a third option when you have a direct drive hubmotor. You can construct a "plug brake", and add a switch that can be activated in a variety of ways. That converts the hubmotor into a generator that is powering a heating element, and it is a simple magnetic brake that can be made to be adjustable if you like.

I highly recommend getting a frame that has dual disc brakes, even if they are crappy cheap brakes. You can easily upgrade those when your funds allow.

Some controllers have regen, and others do not. The controllers that do have it can have either one setting (on/off) or it is programmable. The programmable ones can be nice because you can set it to your preferences. Also, in winter?...you can't use "max" regen, you will simply lock the wheels and begin skidding with the bike getting sideways.

You can set up a programmable regen so that it comes on instantly as soon as you stop accelerating the throttle. You would have to always have a small amount of throttle to prevent the regen from activating. Another way to have regen is to have it activated by the brake handle. As soon as you pull the handle a 1/4 inch, it will start regen braking, but the brake pads will not be applying any pressure to the wheel.

There is a third option when you have a direct drive hubmotor. You can construct a "plug brake", and add a switch that can be activated in a variety of ways. That converts the hubmotor into a generator that is powering a heating element, and it is a simple magnetic brake that can be made to be adjustable if you like.

I highly recommend getting a frame that has dual disc brakes, even if they are crappy cheap brakes. You can easily upgrade those when your funds allow.

That's great news.

I plan on converting my existing Trek 7.5D and I plan on keeping the rims and get new spokes. I'm going to make the battery naturally and would probably make a triangle battery and put it in the middle of the frame somehow.

Thank you!

Oderus420 said:

I'm actually in the process of making my own ebike and I have a couple of questions for you, if you don't mind of course.

I have a 500W limit in my city so I'm torn between single 500W rear hub motor and dual front/rear hub 250W motors, or, go illegal and get 2 x 500W (or 1000W) and hopefully it's not obvious. I prefer hub over mid-drive as I want the option to not peddle at all (lazy) and I think the mid drives have to be powered by legs to get any power out of them. Correct me if I'm wrong.

Any opinions on Golden Motor Canada? They have a nice hub motors with built-in controllers which seems better than having an external controller.

I'm also building the battery and wanted to you know your thoughts on fuse wires, if any and if you prefer a certain voltage like 72V over 48V as I plan on going 48V.

Thanks.

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500w limit...lucky you! It's 250w here . Mind you I'm happy with my 250w mid drive.

A mate has a golden motor front hub and likes it. He has just bought a golden motor for his car conversion which is going well also.

250W? Yikes. I was annoyed about 500W being the max when I see people running well over 2000W.

I think Korishan made the point that how would they be able to know what size of motor it is? Do they carry multimeteres with them?

Oderus420 said:

250W? Yikes. I was annoyed about 500W being the max when I see people running well over 2000W.

I think Korishan made the point that how would they be able to know what size of motor it is? Do they carry multimeteres with them?

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Exactly!
I could easily have gone 500w or 1000.
I'd be very surprised if the cops would pull you over unless you were attracting attention, like going faster than the traffic etc.