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Old 03-14-2017, 12:51 PM   #22 (permalink)
TexasElectric
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Join Date: Feb 2017
Location: Texas
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teoman
I've investigated the idea of using a plexi-glass tube to put the cells in series, but the problem I ran into was the cells have a 32.75mm diameter and the closest sized tube I could find was 1 1/2 inch (38.1mm) inner diameter tube. I'd have to play around with securely filling the 5.35mm gap between the cells and the inside of the tube. For the time being I've tabled the idea.

samwichse
I've since backed away from my plans to solder the cells. I'm going to spot weld them.

PS. I'd love to have "screw terminaled" cells, sounds like they'd be easier to work with.

I'm considering kits from eBay. There is a seller in Michigan "eBikeling". He sells Chinese no name hub motors, and brands them with his companies name. I know this because his hub motors and rims use the exact same make/model parts as most other no name Chinese hub motors on eBay.

48V 1500W Direct Drive REAR 700C eBike Kit Electric Bicycle Ebikeling | eBay

What's nice about this guy "eBikeling" is that he is based in the US and offers free shipping, whereas the Chinese sellers are asking over $100 for shipping to the US.

I know about the stigma of buying no name Chinese products. Although, 3 years ago I purchased a set of no name Chinese carbon fiber wheels for my road bike on eBay. I put around 2,000 miles on those wheels, I had multiple situations where I was riding at speeds in excess on 40+mph with no concerns of them failing on me. I sold the wheels right around 2,000 miles of use because I needed the money more than the wheels, but they were still in good condition when I sold them.

My thoughts with this motor is that (irregardless of who/where I buy it from), I plan to only use this 1500w motor at 1/3 or less of it's full potential and by doing so it should last a long time: as apposed to buying a 250w or 500w motor and pegging it at 100% every time I use it. Plus it doesn't hurt to have a little extra power.

Grant-53
I will look into mountain bikes with suspensions in that configuration.



Update on where I stand today
Last week my BMS arrived from China. (fast shipping, only took 10 days)





In addition to the BMS, the Kapton take I ordered arrived. I need to re-place an order for Nickel strips. I accidentally bought Nickel platted tape instead of strips.

I am moving at the end of this month, but before I can move I have to take care of some maintenance to my home. In my free time I will continue working on assembling the battery.

I flip-flopping back to the idea of using a 29r mountain bike. My research online (as well as talking to the local bike shop mechanics), tells me that 29r mountain bikes use 700c rims (same as road bikes). My biggest concern is being able to find a good quality bike. I know Specialized makes good quality bicycles, (as I am currently thinking about buying a brand new RockHopper 29r for this build). But finding a used 26" name brand mountain bike (full suspension or hardtail) that's my size, in good condition and priced around $500-$700 is hit or miss.

Lastly, this is a new configuration I am looking at for my battery. The battery pack (once assembled) would be mounted on the down tube.

5p, 16s



I don't wan't to come off sounding like a snob when I talk about buying a brand new name brand bike. In the past I've bought el-cheapo stuff (electronics, bikes, cars, etc...). Sometimes you get lucky and you discover a diamond in the rough, but generally speaking "you get what you pay for." My current bike is a Colnago cyclocross bicycle. It's not cheap ($,$$$) by any means, but I've had it for over 3,500 miles and it's required very little tweaking/tuning and takes a beating from time to time.

For my e-bike build, my feelings are that the bike is the foundation (and should not be skimped on). The Batteries I bought are good quality (not el-cheapo). The motor I am considering (from eBikeling) is rated for 1500w, if I only use 300w-400w of the motors potential it should last a long time. Likewise the BMS I bought (albeit a no name Chinese brand) is rated at 48v 60a, if I'm running 6-8 amps through it, it should also last a long time.

I would have purchased the BMS through a name brand US seller, but I was unable to find a LiFePO4 48v 60a BMS for under $100 in the US.

Last edited by TexasElectric; 03-14-2017 at 01:16 PM..
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