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The eBike thread

unkel

A quick look seems that this doesn't really seem to fit in the cycling forum. So starting a thread here about all things eBike

I'll get the ball rolling. I have zero experience with eBikes. But I was going to build myself a battery anyway, for various reasons (like in bringing with me in my EV as a "petrol can")

I'm going to buy a solderless kit to make the battery (with 18650 cells I have removed from dead / old laptop batteries). This kit cah handle 20A max, and I would like the battery pack to produce 1kW constant. P=V*I so 1000W = 50V * 20A

This dictates that my battery needs to be nominal 48V (was thinking of making a 24V battery pack, but that won't be able to charge my car)

A quick browse on eBay and Amazon shows that you could buy a powerful 1000W bike conversion kit with everything needed except the battery for about GBP120 (a bit more from Amazon but peace of mind)

What to buy though, front wheel or rear wheel kit? Pros and cons? Any other advice?

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[Deleted User]

unkel wrote: »

Still not sure, but for now I'm thinking of going 500W front hub with 24V or 36V pack. And no plans to accelerate max from idle (don't want fork to break) or ever go above 25km/h, so not attracting attention to myself. Be a good boy on a nearly 100% legal pedelec

You'll be hard pressed to find a 24 v controller but perhaps you might find something from China.

Usually you'd find 24 v controllers designed for brushed DC motors using lead acid batteries back in the day.

unkel

I thought they made most of them in 24/36/48 like this:

Linky

unkel

I think this looks mighty tempting

36V 500W kit GBP129

Samsung 36V 4.4AH battery GBP39

I have a 36V charger from my youngest daughter's play scooter

All shipped from UK, so no customs to worry about. Including all shipment costs and Parcel Motel charges, we are talking EUR202. That pack can handle the full 500W at a 3c rating (13A) which it is rated for. Bit of a bargain pedelec, lads?

Henry Ford III

Deleted User wrote:

Not really, the discussion isn't about legalities.

Check the thread title.

unkel

It's my thread and it most certainly is also about legalities. I wasn't aware of the details, but I think we have now established exactly what they are. A push bike with a max 250W motor that will only work when the bike is being pedaled and that cuts out completely when the speed reaches 25km/h. The EU has established that this is identical to a normal pushbike with no motor. Everything over this is technically not a push bike any more. So we do not need any further discussion about this in here unless what I state in this post is incorrect.

I think I might go and order my 500W 250W kit now...

beauf

The legalities only apply to road/path use. On private land, or off road/path is different.

[Deleted User]

unkel wrote: »

I thought they made most of them in 24/36/48 like this:

Linky

I haven't seen one for 24 volts to be honest in a long time.

Not even sure if the ones I used to get had 24 volts as an option.

If you go the 24 volt route be sure that your motor will give any decent speed or torque at that voltage so make sure you use the ebikes.ca simulator I linked to earlier or you could find the power dying at 18 km/h for example.

unkel

Deleted User wrote: »

If you go the 24 volt route

I won't. Check my above links from this evening. The 36V hover board batteries are so cheap now that they make a compelling choice. And if I really like it and find my range is too small, I'll just get another one and parallel it with an XT60 splitter for double the range.

[Deleted User]

Henry Ford III wrote: »

Check the thread title.

It doesn't say, what's the legalities regarding electric bikes.......

[Deleted User]

unkel wrote: »

I think this looks mighty tempting

36V 500W kit GBP129

Samsung 36V 4.4AH battery GBP39

I have a 36V charger from my youngest daughter's play scooter

All shipped from UK, so no customs to worry about. Including all shipment costs and Parcel Motel charges, we are talking EUR202. That pack can handle the full 500W at a 3c rating (13A) which it is rated for. Bit of a bargain pedelec, lads?

That looks identical to the first ebike kit i installed back in a bout 2009 ish, I ended running 5 Kw through it with Lipo and hacking the controller, jaysus that was fun !

Yeah sure nothing to loose if you don't want to pedal.

Just be sure the batteries are not counterfeit, there's a lot on ebay, I see no battery specs ? Have they a bms ?

If you can try find a geared hub, more efficient and more torque for the same power.

unkel

Deleted User wrote: »

Yeah sure nothing to loose if you don't want to pedal.

Just be sure the batteries are not counterfeit, there's a lot on ebay, I see no battery specs ? Have they a bms ?

This is it. Yes batteries have a BMS. Seller has a good feedback and many of these have verified sold.

These packs are not suitable for most people making eBikes, as they have not enough capacity at just 4.4Ah. These were not made for eBikes, but for hover boards and children's scooters. Both were huge fads a few years ago, and my theory is there were too many batteries produced that are no longer necessary. These sell for less than you can buy the batteries for now. It's not worth someone's time to tear them apart and sell the batteries. At least that's my theory!

xckjoo

unkel wrote: »

I think this looks mighty tempting

36V 500W kit GBP129

Samsung 36V 4.4AH battery GBP39

I have a 36V charger from my youngest daughter's play scooter

All shipped from UK, so no customs to worry about. Including all shipment costs and Parcel Motel charges, we are talking EUR202. That pack can handle the full 500W at a 3c rating (13A) which it is rated for. Bit of a bargain pedelec, lads?

Just a heads up that I don't see a pedal sensor listed in the description. I'm sure you can pick that up separately though. I'd recommend the type that clip on so you don't have to remove the bottom bracket on the bike. The skin on your knuckles will thank you

Something like this :
https://www.ev-power.eu/EVBike-electric-bikes/SPARE-PART-Pedal-assistant-for-EV-BIKE-split-frame-mount.html

[Deleted User]

Seriously, don't worry about a pedelec, just pretend to peddle , don't act the idiot and you'll be grand.

[Deleted User]

unkel wrote: »

This is it. Yes batteries have a BMS. Seller has a good feedback and many of these have verified sold.

These packs are not suitable for most people making eBikes, as they have not enough capacity at just 4.4Ah. These were not made for eBikes, but for hover boards and children's scooters. Both were huge fads a few years ago, and my theory is there were too many batteries produced that are no longer necessary. These sell for less than you can buy the batteries for now. It's not worth someone's time to tear them apart and sell the batteries. At least that's my theory!

good luck !

RustyNut

Here's an old post about my home build.

I couldn't recommend them highly enough. I still haven't discovered a down side.

unkel

Looks like I do not have a charger, my daughters scooter charger is only 24V

Not to worry, a 42V charger (for charging 36V batteries) is just over €3k shipped from China:

Linky

These come with an XLR female connector. My battery has an XT60 female connection. How do you guys connect these? There doesn't seem to be any XLR male to XT60 male connectors for sale anywhere, except some vastly overpriced ones from specialist eBike sites

I suppose I could solder one.

[Deleted User]

unkel wrote: »

Looks like I do not have a charger, my daughters scooter charger is only 24V

Not to worry, a 42V charger (for charging 36V batteries) is just over €3k shipped from China:

Linky

These come with an XLR female connector. My battery has an XT60 female connection. How do you guys connect these? There doesn't seem to be any XLR male to XT60 male connectors for sale anywhere, except some vastly overpriced ones from specialist eBike sites

I suppose I could solder one.

Yep just solder. Make your own connections.

I used 30 amp Anderson connectors and have a crimp tool, dead handy. They can take huge peak current.

[Deleted User]

RustyNut wrote: »

Here's an old post about my home build.

I couldn't recommend them highly enough. I still haven't discovered a down side.

It says I don't have permission to view this link ?

unkel

Deleted User wrote: »

It says I don't have permission to view this link ?

Are you allowed access to the cycling forum?

unkel

Deleted User wrote: »

Yep just solder. Make your own connections.

Those XLR have 3 prongs but surely only 2 connections (positive and negative)?

Probably just as easy then to snap the cable of the charger and solder / crimp on a male XT60 connector?

xckjoo

unkel wrote: »

Those XLR have 3 prongs but surely only 2 connections (positive and negative)?

Probably just as easy then to snap the cable of the charger and solder / crimp on a male XT60 connector?

Ya to both. Probably just had xlr connectors lying around in the factory

unkel

Brings my total cost close to €210 now though

[Deleted User]

unkel wrote: »

Are you allowed access to the cycling forum?

Ah that's what it is, no I got a 6 month ban for mentioning ebike kits, they are Nazi's on that thread......

[Deleted User]

unkel wrote: »

Those XLR have 3 prongs but surely only 2 connections (positive and negative)?

Probably just as easy then to snap the cable of the charger and solder / crimp on a male XT60 connector?

Be careful, one could be for temperature sensor.

Just solder the connections.

It would be just easier to get some Hobbyking LiPo or LiFeP04 and make your own pack. You need an RC balance charger and power supply though but the beauty is that the pack could handle far higher power should you need it in the future.

unkel

Deleted User wrote: »

Be careful, one could be for temperature sensor.

Surely not on a €3 charger. It charges at 2A so I don't think temps will be a problem anyway

[Deleted User]

unkel wrote: »

Surely not on a €3 charger. It charges at 2A so I don't think temps will be a problem anyway

Most decent batteries/chargers should have temperature sensing.

Those batteries are probably LiPo anyway so you might as well just get decent LiPo or the safer LiFeP04 from Hobbyking and make your own pack.

unkel

Deleted User wrote: »

Most decent batteries/chargers should have temperature sensing.

I think it is safe to say no €3 charger ever made has temperature sensing

[Deleted User]

unkel wrote: »

I think it is safe to say no €3 charger ever made has temperature sensing

What charger is it ? link ? do the batteries have a 3rd wire too ?

[Deleted User]

OMG not again !

[Deleted User]

Fk_it24 wrote: »

Haha

Haha ? is that all you got to say ?