Wife got an ebike, now I want one. Help please!

[filmoreslim]

Greetings! As the title states my wife just picked up a used e-bike on craigslist and now I want one for my commute. I'm about 185lbs and my commute is almost completely flat, 16 miles round trip. Was hoping for something that would let me cruise at ~25mph with leisurely pedal input (I don't want to be sweaty when I get to work). Was trying to keep the total price under $1000, I do have a 20 year old steel Trek mountain bike that I can use.
I was looking at the 48V 1000W rear hub kits on ebay that seem to be around $225 or so like this one: http://www.ebay.com/itm/26-Electric...929537?hash=item565d71d881:g:TpkAAOSwstxVf79e. I was also eyeing the Cali-bike 48V 20AH battery $575: http://www.ebay.com/itm/48V-20AH-Li...133972?hash=item3f5bdcc254:g:UpcAAOSwm8VUuxOH

That puts me around $800. Another option is a bike I saw on craigslist today. It has the BBS02 750W mid drive with a 48V 11.6Ah Panasonic down tube battery with NCR18650PF cells. It is built on what looks to be a $1000 commuter/cyclocross bike and they want $1599 obo for the whole packagehttp://sfbay.craigslist.org/eby/bik/5578652315.html. Definitely more than I wanted to spend but seems like a really good deal. What do you guys think about those options? Are there others I should consider?

Thanks for your help!

 

[wesnewell]

The 48V 1000W DD kit will be more reliable. You'll need ~500wh of battery for a 16 mile commute at 25 mph. Pair the kit you listed with a 300A rated 15ah 12s rc lipo pack (666wh) on sale for about $135. Add a charger system for $100 or less and you're set for at least 10K miles before needing to replace the batteries.

 

[dogman dan]

I'm biased toward hub motors, I'll admit that.

But while the mid drive bikes are VERY NICE, for most people a hub motor makes a better commuter. No shifting, more reliable, (the motor at least), just a more no thinking about it needed kind of ride. This is good in the city, save all your attention to not getting hit by a car.

Mid drive for the win when the load is extra heavy, the hills extra steep, or the riding is technical off road single track trails.

48v 15 ah is all the battery you need, so you could shave a few bucks there instead of the 20 ah.

 

[Lurkin]

I have a BBS01 bike which I commute 80km per day on.

The only reason to switch to a hub motor is the wear and tear on the drivetrain. With mid drives, you get the benefits of using the gears of the bike, which is particularly valuable if you have sub 500w power or encounter hills (which you've said you don't). It comes with the disadvantage of wearing all of these parts with the additional power being run through it and the increased chain wear (and knock on of cassette and front chain ring) are notable and make for a more expensive commute.

Needless to say, I have more than one hub motor bikes being put together to replace it with.... be wary buying second hand home made builds.... you could be buying someone else's thrashed turd. Be especially careful with second hand batteries, they do have the ability to burn your house down.

 

[filmoreslim]

Thanks for all replies! I'm glad you all talked me out of the mid-drive, I wasn't looking forward to paying that much money. As far as the battery is concerned, i think I want to stay away from LiPo. I want something a little more idiot-proof, and I don't want to catch my house on fire. I really like the form factor of the triangle packs because they keep the weight low and I wont need to mount a cargo rack. The down tube batteries are cool too but I haven't seen any over about 12ah. Can anyone recommend any alternatives to that CaliPack I linked? The shipping on EM3ev batteries really kills that option for me.

 

[wesnewell]

Why don't you buy some of those hoverboard li-ion packs. Your beliefs that 18650 calls are safer than rc lipo cells is brought on from false info. You're just as likely to have a fire with 18650 cells as you are with rc lipo. Maybe more so since you think they are safer. Standard charge rates for rc lipo is 1C, with some taking as much as 5C or more. Standard charge rates for 18650 cells is 0.2C, with most limited to no more than 1C or less. Anbd discharge ratings are even much worse. Even some of the best are no more than 8C, while most common ones are ~ 1C. 10C is about the weakest rc lipo you can buy. I would never use an 18650 pack, but whatever floats your boat. It's your money and house.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=27241

 

[filmoreslim]

Why don't you buy some of those hoverboard li-ion packs. Your beliefs that 18650 calls are safer than rc lipo cells is brought on from false info. You're just as likely to have a fire with 18650 cells as you are with rc lipo. Maybe more so since you think they are safer. Standard charge rates for rc lipo is 1C, with some taking as much as 5C or more. Standard charge rates for 18650 cells is 0.2C, with most limited to no more than 1C or less. Anbd discharge ratings are even much worse. Even some of the best are no more than 8C, while most common ones are ~ 1C. 10C is about the weakest rc lipo you can buy. I would never use an 18650 pack, but whatever floats your boat. It's your money and house.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=27241

Yeah I've only been researching this a few days, so all the RC LiPo stuff is still a bit overwhelming. I can't seem to find a real noob guide on what I need to get started. From what I find I think I could wire up 6 - 6S 20C 5000mah packs http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html into a 12s3p to get 44.4V and 15 mah. How do I monitor the voltage on each cell to make sure I don't over-discharge? I see they have these little buzzers that appear to plug in to each pack, do I get those? And what kind of charger should I get to make sure I properly monitor all the cells and don't over-charge? Do I have to charge each of the 6 packs individually? Do I need a BMS?

Sorry for the dumb questions, like I said I haven't found a clear and concise guide to all this stuff.

 

[Lurkin]

I've found 18650 packs to be safe. A pre made pack form a reputable supplier with a BMS and charger designed for it is straightforward and easy.

I'm assuming you in the states. You may want to check out Luna Cycles, they also have pre made packs and frequently have them on special.

 

[wesnewell]

Yeah I've only been researching this a few days, so all the RC LiPo stuff is still a bit overwhelming. I can't seem to find a real noob guide on what I need to get started. From what I find I think I could wire up 6 - 6S 20C 5000mah packs http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html into a 12s3p to get 44.4V and 15 mah. How do I monitor the voltage on each cell to make sure I don't over-discharge? I see they have these little buzzers that appear to plug in to each pack, do I get those? And what kind of charger should I get to make sure I properly monitor all the cells and don't over-charge? Do I have to charge each of the 6 packs individually? Do I need a BMS?

Sorry for the dumb questions, like I said I haven't found a clear and concise guide to all this stuff.

No, not dumb questions. They've just been asked and answered hundreds of times here. You don't need to monitor individual cells while riding. You do that every time you charge in one of many ways to safely charge. Search youtube for charging lipo. You'll find lots of ways from parallel charging to whole pack charging at once. You can even use a bms if you want to.. Here's some links you should read.
http://www.rchelicopterfun.com/rc-lipo-batteries.html
http://scriptasylum.com/rc_speed/lipo.html
https://endless-sphere.com/forums/viewtopic.php?f=14&t=39666
https://endless-sphere.com/forums/viewtopic.php?f=14&t=47294
https://endless-sphere.com/forums/viewtopic.php?f=3&t=73871

 

[Wheazel]

Quality 18650 cells can´t really be compared to rc-lipo in my experience. (talking about hobbyking lipo)
The 18650s are made with much more consistency, and it is very rare to find a faulty cell. I have not found one in about 1000cells, but I know othgers have.
How often does your laptop catch fire?

From the many rc lipo packs I have used for rc planes/multicopters/ebikes etc, I have had a bunch of shitty cells. Talking at least 10.
Some bad upon arrival in the mail.
And this fact alone makes rc lipo much more likely to end up under dangerous conditions, if they arent carefully monitored.

 

[dogman dan]

Re the hover board batteries. Seen the vids? Guy learning to ride it flies across the living room, hover board slams into the wall.

Try taking your bike battery, throw it against the wall a few times, see how safe it is after that.

Nothing wrong with the idea of getting a good well made 18650 cell pack, bms equipped, and NOT throwing it against walls.

But a dirt cheap, shoddily made pack is not safe because it has NMC or whatever cells in it. No matter what you get, you should consider what could happen, if you are charging it and it starts heating up.

I just mean common sense shit, like don't set the battery on the couch, the carpet,,,then charge. If in the garage, think about where it's parked. Right next to the gas for the mower? of course not.

 

[Nightstone]

Just built 2 ebikes for my wife and I. I like you was going to go the hub motor route. Until I realized how much money lipo's would save me. I ended up going with a BBSHD, New Diamondback Bike, and 3 4s 16000mah HK batteries. Total cost shipped to me was around $1250. I now have one fast, efficient bike.

Here are the pictures.

NS

 

[filmoreslim]

Thanks for all the help everyone. I definitely have a better idea now what direction I want to go in.

 

[Nightstone]

4 years of lipo experience here. Almost daily. I use them at much higher amperage's than for an ebike application. They get real hot. They don't blow up. If you short them they have a safety tab that burns in two. We have tried at the flying field to get them to blow up. All we ever get is a smolder.

I can burn through a 4s 5000mah in under 3 mins. Over and over and over. Millions of RC and Quad-copter users use them daily. Plenty safe for all those folks.

Out of over 100 hobby king lipo purchases I have had maybe 3-4 that came bad. Another 2-4 that had short life spans.

The thing with hobby king is to minimize loses. Don't buy 1 expensive battery when you can buy 3 cheaper ones and limit your exposure. If you get a bad one these days their return policy is pretty good.

3 4s 16000mah batteries were $162.00 shipped. On my bike thats around 40 miles on a charge if I do some pedaling. I'm riding about 5 miles a day with a bit more on weekends. With up to 300 charge cycles its going to last a while. Thats money well spent. Pretty cheap too.

Again... Think about the millions using Lipos around the world at much Higher Amperage levels safely. Millions...

Oh... Here is the vid that sold me on a mid drive. https://www.youtube.com/watch?v=FkL9r9emi_k

NS