Cargo trike build

[WheezyRider]

Wow. I'm used to AliExpress vendors inflating their specs but that's in a different league!

I think the person who put this together has used 2200mAh 18650 cells, then somewhere, someone along the line has added another zero, well maybe there was a decimal point and it got left out somehow...then the whole pack suddenly became called 22000mAh, the reasoning being along the lines of: well it's made from 22000mAh cells isn't it? What else can make it sell? I know, let's copy the name Panasonic and paste that on the side.

Looks like an 8.8 Ah pack to me. Cells may be decent 2200 mAh cells, or they could be some cans filled with rubbish with just enough content to give 4.2V with a voltmeter, you just don't know, and, how likely are you to get your cash back if it is a total load of crap?

If it is 22000Ah and 4 cells in parallel, that's 5.5 Ah per cell! From the dimensions, it looks like 18650 cells and even the best branded cells only go up to about 3.6Ah.

I think it best to walk away and buy a decent pack. Either build your own with genuine cells, or splash out on a genuine commercial pack, which will be hundreds of pounds for 22Ah.

 

[richjmaynard]

I'm (slowly!) coming around to the idea that buying a specific ebike battery is the safest thing to do given the demonstrably false advertising of the suppliers on AliExpress.

Would something like this be a good choice?

36V 15.6Ah SilverFish E-Bike Battery Electric Bike Li-ion Accu with USB Port for MiFa, Rex, Prophete, Aldi

Power up your MiFa, Rex, Prophete, or Aldi electric bike with our 36V 15.6Ah SilverFish E-Bike Battery, featuring a convenient USB port for on-the-go charging. Enjoy extended rides with reliable Li-ion technology.

yosepower.com

 

[WheezyRider]

I'm (slowly!) coming around to the idea that buying a specific ebike battery is the safest thing to do given the demonstrably false advertising of the suppliers on AliExpress.

Would something like this be a good choice?

36V 15.6Ah SilverFish E-Bike Battery Electric Bike Li-ion Accu with USB Port for MiFa, Rex, Prophete, Aldi

Power up your MiFa, Rex, Prophete, or Aldi electric bike with our 36V 15.6Ah SilverFish E-Bike Battery, featuring a convenient USB port for on-the-go charging. Enjoy extended rides with reliable Li-ion technology.

yosepower.com

They are ok, I bought two last year, but back then, they were only £165. One I had to repackage as it had a bad solder joint (see my post on Yose Power Failure on this forum) and the other is a bit iffy on the keylock switch. The batteries inside are well assembled and the capacity seems reasonable for unbranded cells.

I would not rush into buying a battery pack just yet, until you've decided on what motor type/voltage and figured out total bike weight and desired range etc. I'd do a bit more planning and designing first. You don't want to spend a lot of money on a battery pack to then have to buy another one later that does what you need.

 

[vfr400]

Cells may be decent 2200 mAh cells ....

Do you know somewhere I can by decent 2200mah 18650s for 40p? Look at the price of that battery pack. Maybe you didn't see it.

 

[WheezyRider]

Do you know somewhere I can by decent 2200mah 18650s for 40p? Look at the price of that battery pack. Maybe you didn't see it.

Yes, like I said, most likely cans with crap in them, but you never know. Someone in China could have picked up a job lot of surplus 2200 cells that were ok...but, you just don't know.

In Poundland you can buy 2200 Ah 5V power packs for £2 each. It comes with case, packaging, charger cuircuit, cable, is distributed to shops and sold from a shop with an overhead and VAT paid. I assume Poundland still makes a profit on it. So the cell can't be far off 40p each.

 

[soundwave]

 

[vfr400]

In Poundland you can buy 2200 Ah 5V power packs for £2 each. It comes with case, packaging, charger cuircuit, cable, is distributed to shops and sold from a shop with an overhead and VAT paid. I assume Poundland still makes a profit on it. So the cell can't be far off 40p each.

I've seen a UK company making those out of recycled laptop batteries from the tip.

This tested one only delivered 1100 mah at 1 amp before it cut off. To make an ebike battery out of those cells, you'd need 100, which would weigh 5kg. This is bullshit and completely irrelevant. That Aliexpress battery is bullshit and completely unsuitable. Please don't try to make excuses for it, as it will only confuse guys that don't understand these things.

 

[WheezyRider]

I've seen a UK company making those out of recycled laptop batteries from the tip.

This tested one only delivered 1100 mah at 1 amp before it cut off. To make an ebike battery out of those cells, you'd need 100, which would weigh 5kg. This is bullshit and completely irrelevant. That Aliexpress battery is bullshit and completely unsuitable. Please don't try to make excuses for it, as it will only confuse guys that don't understand these things.

Hmmm, you seem to have misunderstood my posts. I think I made it quite clear the Ali express battery was not something I'd recommend and it was false advertising as it could in no way be a 22000mAh capacity pack and even the probable notional 8.8Ah capacity would be dubious at best. I also told the original poster to walk away and build their own pack from genuine known cells, or buy a genuine commercially available pack.

I also want to make it clear I am not recommending anyone build an e-bike battery out of Poundland power packs, I was just giving an example of cheap 2200mAh cells. I am not concerned about the 1100mAh in this example you give, that is about what I would expect from a nominal 2200mAh cell driving a voltage step up controller to 5V, with a cut off at 3V or more. However, the shortcoming here is the current draw capability of these cells is not great, probably a max of only a couple of Amps per cell, which is not great for e-bike applications unless you had a load in parallel (10s 10p would not be so bad for a 250W motor...and the weight, I wouldn't complain too much about 5kg! My Powabyke originally came with lead acid batteries and they were far more than 5kg and had less than about 10Ah usable capacity).

So should you even consider making a pack with such batteries? Sensibly, no. This is because you need cells with very similar characteristics, or the whole pack will not work properly. You would need so many cells to start with and then reject a lot of them. Then you would have to spot weld loads of these cells together and wire them up. It's not worth the hassle, buy named brand cells from a reputable supplier, with a capacity of 2.5 Ah or more and with known discharge characteristics.

I don't think these cells are recycled, I think Poundland would be taking a huge risk if they caused someone's house to burn down and it turned out it was because of recycled dodgy cells - you'll have to take that up with Poundland, maybe with an FOI request? It would make a good article on a consumer programme if you can prove it.

 

[richjmaynard]

Thanks for all the support so far!

As it's the weekend, I've been dreaming and casting my net a little further afield.

I've been reading about a friction drive system that uses a brushless motor as the roller itself. Super low parts count! I'm not scared of a little bit of laser cutting and welding as you can see.

My weekend dreaming head is thinking about this now...

Kepler Bottom Bracket Friction Drive For Sale (Finally)

I am pleased to announce that my latest friction drive is finally ready for sale to the general public. This has been a long time coming and is the culmination of many hundreds of hours testing and countless miles. The drive has been designed to be as simple as possible but at the same time...

endless-sphere.com

As I understand it, friction drive is less efficient due to the transmission by roller, but won't the lack of gears and other moving parts make up for this?

Tyre wear shouldn't be too much of a problem as we are looking at relatively lower mileage anyway.

Thoughts?

 

[sjpt]

I don't think the efficiency loss in gears is nearly as high as you'll get from a friction drive. Tyre wear is generally the biggest issue though, but for your small mileage may be a worthwhile tradeoff. Low mileage also means efficiency is less important; making a small battery a bit bigger is cheaper than making a big battery a bit bigger.

Locating the friction drive near the bottom bracket will maximize crud and make efficiency and wear both worse. I'm not sure that's designed for British weather. It may be with your dual front wheel (and probably very low speeds) that the dirt buildup will be less of an issue.

 

[vfr400]

Hmmm, you seem to have misunderstood my posts. I think I made it quite clear the Ali express battery was not something I'd recommend and it was false advertising as it could in no way be a 22000mAh capacity pack and even the probable notional 8.8Ah capacity would be dubious at best. I also told the original poster to walk away and build their own pack from genuine known cells, or buy a genuine commercially available pack.

I also want to make it clear I am not recommending anyone build an e-bike battery out of Poundland power packs, I was just giving an example of cheap 2200mAh cells. I am not concerned about the 1100mAh in this example you give, that is about what I would expect from a nominal 2200mAh cell driving a voltage step up controller to 5V, with a cut off at 3V or more. However, the shortcoming here is the current draw capability of these cells is not great, probably a max of only a couple of Amps per cell, which is not great for e-bike applications unless you had a load in parallel (10s 10p would not be so bad for a 250W motor...and the weight, I wouldn't complain too much about 5kg! My Powabyke originally came with lead acid batteries and they were far more than 5kg and had less than about 10Ah usable capacity).

So should you even consider making a pack with such batteries? Sensibly, no. This is because you need cells with very similar characteristics, or the whole pack will not work properly. You would need so many cells to start with and then reject a lot of them. Then you would have to spot weld loads of these cells together and wire them up. It's not worth the hassle, buy named brand cells from a reputable supplier, with a capacity of 2.5 Ah or more and with known discharge characteristics.

I don't think these cells are recycled, I think Poundland would be taking a huge risk if they caused someone's house to burn down and it turned out it was because of recycled dodgy cells - you'll have to take that up with Poundland, maybe with an FOI request? It would make a good article on a consumer programme if you can prove it.

Wall of text for nothing. The guy wanted to know whether that battery is any good. The answer is "no". As soon as you said "Maybe" and bring in more complicated things, it could be confusing for him or anybody else who reads it and gets ideas from it, which is not helpful at all. Thankfully, he seems to have got the message.

 

[Nealh]

The Kepler installation bracket kit appears to be quite good, last time I Iooked at it well over a year ago it had a remote cable so you can detach it from the tyre at will as well as using within reason an small brushless RC motor. The VESC techy bit is the bit I can't get my head round though I believe he was going to make up the import techy bits as a kit as well, the downside is it wasn't damp/wet weather ridable.

 

[richjmaynard]

Sensible Monday head on...I don't think friction drive will be good for transmitting the extra power needed for a cargo trike, especially on the (admittedly rare) occasions where it will be used in the wet. I was also slightly excited about regenerative braking but it seems marginal at best given the conversion efficiencies.

I think I'm going for a TSDZ2 mid drive to make use of the rear derailleur for hill climbing with a cheap e-bike seat tube battery to keep the wiring short

Now I need to look around and find the cheapest supplier. I reckon people avoiding public transport has increased demand for e-bikes and put prices up? Or is it just the arrival of summer?