Electric not there yet

biknut

Member
Joined
Sep 21, 2010
Messages
31
Sheeze, you must have an iron ass. 50 miles is plenty of range for me. By then I'm ready to get off the thing, so charging isn't a problem. All my china girls only had about 45 mile range.

After riding this I could never go back.

 


darwin

Well-Known Member
Joined
May 26, 2008
Messages
2,914
Our trails here have expanded by a hundred miles in the last 5 years or so, maybe more. I've seen some bikes that look just like the pic and the ah's are getting to be 32ah 48v and even higher. Problem is you need to make sure the cells are Japanese or Korean name brand cells for quality. You need to buy from a co that's been around awhile so you can get parts in the future and have a warranty that's worth the money. A lot 90% of the co's out there today won't be around in 5 years. Also you want a quality bike with quality parts. No wallyworld type bikes. The friggen batts need to be taken care of like a human baby I kid you not. It is widely understood to keep your batt if stored to 50% charge for any length of time. Use your battery only in between a 20% to 80% charge to maximize it's charge cycle life. Never let your batt get below 20% or it drastically reduces battery life cycles. In order to do all this you need a charger that's programable to properly charge it to a certain level. Only one charger out there that does this right now costs $300, Grin satiator batt charger. Lots to an electric bike, it isn't just charge and ride. Those batts are expensive so if your not rich you better take care of it. EBR is the bible forum for electrics, you get real world reviews not made up sh*t.
 

biknut

Member
Joined
Sep 21, 2010
Messages
31
That's one of the main reasons I couldn't go back to gas. You can't ride the city bike trails on a gas bike. Dallas is building them all over the place too. I like to ride social bicycle rides too like critical mass, and occasionally some other organized ride. Of course a gas bike is about as welcome as a skunk in a spacesuit, even they could ride that slow for 10 miles.

All my ebikes can fit in anywhere I want to ride. I feel like I have so much more freedom.
 

biknut

Member
Joined
Sep 21, 2010
Messages
31
I've never had a battery problem. I don't do anything special. I charge 100% after every ride. If a fast charger is offered with the battery, that's the one I use. I just retired my first battery, an 18ah 72v pack after 5 years, and over 10,000 miles. It came with a 6 amp charger. As a matter of fact I just bought a replacement for it a couple months ago. The replacement is 24ah 72v with 80 amp bms, and 200 amp burst made with Samsung 30Q cells. Cost shipped with a 4 amp charger was $1400, half the cost of the smaller 18ah original. Battery's are getting better, and cheaper at a quickening pace.

This is my Fatty. I bought this 30ah 48v battery on AliExpress for $625 shipped, plus $90 for a 5 amp fast charger. It's made with Samsung cells, but cheaper ones than 30Qs.There's nothing special about any of my chargers, but it's not beneath my dignity to open one up and tweak a pot a little. This battery has been through 4 winters and heading into 4th summer. It's still close enough to it's original capacity that I can't tell much difference. It has about 6500 miles on it.



 

Tony01

Active Member
Joined
Jun 21, 2016
Messages
219
The problem with 18650s is they sag hard when you try to pull their rated amps. Or even a fraction of their rated amps, as compared to pouch cells. You do not see 18650s rated for 10c continuous. Their cost is much higher when you consider the price of a spot welder and the time consuming process of building the pack. Or the additional cost of those plastic pack builder pieces. Energy dense yes, but that is about all they have going for them.

Of course if you are only looking to pull 50 amps max then anything will work, but if you want 200 or more 18650s will not do (74x200=20hp) unless you are only going to pull 5c or less. So to get 200a from a pack of 18650s you are looking at around a 40ah pack. Better to get cells rated for higher c’s that do not sag so hard, that you can run harder for longer.

The pouch cell I tried to blow was not fully discharged. It was at about 3.85v.

Here is a 2s2p of my cells and custom bus bars I fabbed from full round edge aluminum bar. My pack is gonna be a zigzag setup like this but in 20s3p and perhaps later 21 or 22s3p if my controller can take it.
 

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biknut

Member
Joined
Sep 21, 2010
Messages
31
The problem with 18650s is they sag hard when you try to pull their rated amps. Or even a fraction of their rated amps, as compared to pouch cells. You do not see 18650s rated for 10c continuous.
You can't really just say this, because it's like comparing apples and oranges. You may be confusing voltage drop with sag. 18650s drop the voltage more over the life of the charge, but the LiFePo4 actually sag more. Cells no matter the configuration, pouches, or 18650 come in different chemistry's, and discharge rates. The stock battery that came in my red bike was a high discharge LiFePo4 chemistry made with pouches. My new battery pack is made with high discharge 18650 30Q Samsung cells rated for 15 amps. It out performs the stock battery by a small margin. My limiter is set for 65 amp, but usually recorded 67 amp with the LiFe pack. The 30Qs see 69 amp before the limiter can hit, and I see a couple hundred more watts.

LiFePo4 sag more then the 30Qs, but they average a higher voltage over the life of the charge. The 30Qs don't sag as much, and so are stronger in the first half of the charge, but in the latter half the voltage drops a little below the LiFe. Between the two, I prefer the 30Q. Honestly I've never been that impressed with the pouches. They seem to wear out faster then the 18650s to me.

Stealth doesn't disclose the specs on their LiFe pack, but my new 30Q pack is 20s, 8p. It can sustain 8 x 15 amp continuous, or 120 amp. Way more than I need, but with a 65 amp limit the cells are never really working very hard.

The triangle in my Fatty is much lower spec in comparison. Even though it's also made with Samsung 18650 cells, they're much lower discharge. It's rated for 30 amp continuous, but I have a 35 amp controller. That battery pack is working hard, and gets pretty hot in the summer. Even so, It's doing very well handling it's miserable life heading into it's 4th summer.
 
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bakaneko

Well-Known Member
Joined
Nov 16, 2015
Messages
1,217
Well I sold my electric bicycle, I'll miss it. 50 mile range is not enough for me I need 100 to be happy using throttle only w/some pedal assist. To be where I needed to be another $1300 battery was needed to accomplish the task. Too much money just can't do it. Some day maybe but not today. I do like electrics though, so quiet and torquey if you have a 750 watt motor. Just wanted more range, the co I bought from stated 100mi range. It's doable with an athletic person w/lots of assist. Well that's just not me. Back to gas motors and I'm excited w/the 53cc's available and that new GX 50cc coming out. Gonna try a GEBE kit out this time.
Imagine this with your Juice ebike of course in frame as a production version...

 
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