(Comments from Blogger)
2015-06-11 by Unknown
Ive got two of these I bought off ebay a few weeks ago. Both battery packs were able to be recovered via bulk charging and watching the individual cells to see if they stayed in balance. One the bms works fine and all features do as well. There seems to be bleeders under the pot material. the other is the same as your pack. Its fine but the bms wont let the charger see the pack so I use bullets and charge both packs with in parallel. The bleeders seem to work on the non-bms pack so I would say all Im losing is lvc on that one but that’s not an issue my commute is 60% of the pack then I charge in the am. My guess is there is (given nothing seems wrong with the bms and the fuse has continuity) there is a software reset that is needed to be done to the bms’s that aren’t happy. Just a guess. Im going to try shorting pins together (you never know) on the “bad” bms one. But im not worried about using it with the bike without lvc. Id say charge and use.
About charging the curve tosh picked (since I have one pack that works) is charge at 8.4 amps to 28 volts and stop. So nothing hard to emulate. After the factory charger stops charging the cells quickly drop down to 26 volts so 2.6 volts a cell is where they are really stopping. So charging to 26.5 volts and ending at 3 amps cutoff gives me the same result in case you want to charge it manually.
Sure would like to find the reset switch/command.
2015-06-11 by Russell Graves
Thank you! That is very useful!
If I find out how to reset the BMS, I will certainly update this post with information on it. It did seem like the pack was balancing when charging through the high amperage connectors, which the bleeders working would explain.
2015-09-06 by Foosh
Great article and teardown. I have a similar issue with a recently obtained Schwinn Global GDS.
It has a Protanium Part# BP-L2410EH2 pack rated 24v 10Ah and should charge at 29-30v 2A.
The pack is completely dead. I opened it (finding the same 25+ screws) and was able to access individual
I’d be willing to send it to you if you could swap out new cells for old ones, that exceeds my level of electrical comfort - howevre most of the plastic mounting posts are cracked, so other than the aluminum shell I’m not sure reusable the case is.
2015-09-06 by Russell Graves
I believe the cells are flat, pouch-type cells. I’m not sure I have a source for those or not. I’ve had other queries on that pack, and I find a few places that list them, but cannot get their shopping carts or payment systems to work, so I’m not sure I can actually obtain them.
Schwinn really has left a lot of people up a creek without a paddle with their ebike systems. Exotic batteries, and they stop supporting them as soon as they’re done selling them.
2015-10-18 by A Siegel
First, excellent article.
You are right about ‘turning into scrap’. I have a tailwind. Variety of reasons why, but I have two packs. One is 100% dead. The other, one sent me as a ‘free’ replacement, is slowly dying. (The status starts falling to 2-3 dots w/in under half-a-mile, even with light usage … I got the Tailwind to enable me to do a 30 mile roundtrip commute with some support. This battery dies with an 8 mile roundtrip with the same amount of electric support …)
I find it reprehensible that there is not some path for maintaining / upgrading these. What I would really like to do is upgrade into that 10Ah (or better) using more modern batteries. This should be open sourced to enable keeping these bikes rolling …
2015-10-18 by Russell Graves
You can certainly do such a thing, but there just aren’t enough of these bikes out there to justify the engineering expense in building a pack commercially. There’s plenty of space in the outer pack to put a nice set of batteries, and I strongly suspect it would be trivial to build a 10AH+ pack.
Someone is trying to cram a 13.3AH pack into the outer shell on Endless Sphere: Bypassing the Schwinn Tailwind LTO BMS - Endless Sphere
That said, I just don’t think it’s worth terribly much effort - I don’t think the Tailwind is that good a bike. I’ve got one (on loan to a friend), and it’s just not very good in my hilly area. I suspect it’s nicer on the flats.
If I were you, I’d buy a commercial 24v/15AH (or so) pack from someone, remove the Tailwind pack entirely, pop the battery contact spring housing open, and run the power lines from the 24v pack into there. Pull the spring contacts out if it’s easy and run the lines through there. Hook up in whatever means needed, secure the pack on the rack, and call it good. If the bike works for you, that’s going to be the best option, and it skips the engineering effort involved in making a custom pack to fit in the Tailwind pack form factor (which is sort of silly to start with). If you need it to be removable, use Anderson Powerpole connectors, and it’ll be fine.
2015-10-19 by Unknown
I have a Schwinn Tailwind with a dead battery. The bike has sat from some time because my commuting needs have changed, and I have another bike. It would be great to get the battery operational again. I would find some ideas that could possibly restore the battery of great interest.
2015-10-19 by Russell Graves
I’ve written about bypassing the BMS here: http://syonyk.blogspot.com/2015/07/bypassing-schwinn-tailwind-battery.html
2015-11-26 by 2₵s
Great play by play. I love this bike - own 3 of them. Have been intermittently reading what I can since my first purchase when dealers were dumping them for a song, so I learned early on to baby the battery. It’ll be a sad day for me when all the batteries finally die. I wonder about the feasibility of swapping to a different battery system.
2015-11-27 by Russell Graves
On the plus side, if you’re taking care of the batteries, they should basically last forever. The LTO chemistry is insanely long lived, so just don’t let them go flat and they stand a good chance of lasting the rest of your life.
As far as a different battery system goes, it’s not hard. Find a pack that is around 28v fully charged, 24v nominal, and hook it up.
2016-01-07 by Unknown
I have had a tailwind for a few year that I purchased through Performane bicycle at a close out price. I was commuting to work about 11 miles away. I had a pack on top of battery compartment and I carried the charger to recharge at work. On flat bike paths most of the way and really enjoyed riding to work. I’m 260 lbs so I never expected 20 mile range - my best estimate is 14 miles but depends on headwind and how much I work the assist. I’ve charged a few hundred times and I do not believe I’ve lost range.
Big draw back was family did not appreciate that I had a motor although I did get some exercise. It is a heavy bike and great to not use motor for extended periods for a good work out / exercise. I just purchased one for my wife for $450 (had nice eBay bucks burning a whole in my pocket). For this price I figure I can keep at least one of these batteries running. The new EBay bike indicated that it has a working battery.
Not a great bike but reasonably good. I actually really like the overall comfort of bike while riding. I also have high in canondale but the schwinn Tailwind is my go to bike. And looking forward to riding with wife who can now keep up. For me it’s more about the extended range while bike riding that I like about this bike, overall comfort and I can get to work without needing to take a shower.
I’ll be disappointed if battery fails. Now having two batteries I have at least a backup. By babying batteries I always store indoors and charge often. Maybe there is something else I should be doing?
Thanks for all the efforts to better understand battery and put some pressure on Schwinn and Toshiba. I too tried to contact both companies with no luck getting any support. Primarily Iwas just trying to buy a spare battery or figure out how to reset dead battery. I’m electrical engineer who made the switch to marketing many years ago. I can follow the technology but I any deep battery troubleshooting is outside my comfort zone.
2016-01-07 by Russell Graves
The good news is that the lithium titanate batteries should last basically forever if well cared for. Charge them regularly, and you shouldn’t have any trouble.
If a pack does fail on you, it should be possible to obtain another 24v battery and wire it up to replace the stock pack - there doesn’t seem to be any communication between the pack and bike other than voltage.
2016-02-18 by Unknown
do you have a color picture of the connectors and wires that go from the brakes and motor and pedal control into the box that the battery slides up against? firstname.lastname@example.org thankyou.
2016-02-19 by Russell Graves
I do not, sorry. I will probably do some more development on this bike at some point, though.
2016-03-30 by SPARKY
I’m buying 2, 20" frame, Tailwind bikes, battery’s dead. I’m expecting to go for 24v, 15a liFePo4’s. They are PAS. I wonder what kind of Nightmare it will be to add Thumb Throttle? Sparky
2016-04-02 by Russell Graves
I don’t think you can do that easily. You’d be better off replacing the whole power system if you’re going to start modifying it.
I’ll be doing some additional posts on the Tailwind here soon, though - I have mine back (loaned it to a friend), and there is a steady stream of traffic to posts about it.
2016-04-12 by Sara Walfoort
I have used the Schwinn Tailwind, and really enjoyed it! My sister and I used them to complete a 35 mile (each way) bike trip last summer. We went about 20 miles, then stopped for lunch, opting to 'charge up" the batteries while we ate. Since pedal assist is on an “on demand” basis, we opted to use it only when heading uphill, when facing a headwind, or to get out of a high traffic location more quickly. We had plenty of power left on the battery by the end of our trip, so we celebrated by using the highest level of pedal assist steadily for the last couple of miles. That was fun! Since you generally use the power only as needed (the bike rolls well unpowered), a battery range of 10-15 miles can reflect a ride range of double that. With the quick charge feature (a 10-15 minute charge while eating lunch), we were able to easily complete a ride of 30-40 miles.
The rising interest in bike commuting makes E bikes a really good option for many city dwellers. I’d encourage SOMEONE to figure out the battery pack issue, so these “dead” Schwinn Tailwinds could be put back on the street.
2016-04-12 by Russell Graves
It’s not an awful bike, but it’s not a very good electric bike either.
I did figure out how to bypass the BMS - http://syonyk.blogspot.com/2015/07/bypassing-schwinn-tailwind-battery.html covers it. So you can make one with a dead battery usable.
But there are radically better bikes on the market right now, for not that much more than a used Tailwind that requires a good bit of work to get functioning. If it’s the best you can afford and you can do the battery repairs, sure - go for it. But it’s not a good general solution. It’s a niche bike, at best, and not an amazing one.
2016-05-18 by Unknown
I like the blog, I’m an electronics engineer into anything green. I bought a Tailwind for $300 including delivery. I felt that even if I couldn’t get it working, it would be worth it in parts. I’m working my way back to the batteries. The controller was, like most components on this bike, cheap Chinese made off the shelf stuff. I was really disappointed with the plastic lights - total value =$0.25! Handlebar components are all cheap. For what was intended to be a $2K bike, it sure has a lot of crappy components. Oh well, the sturdy frame will make an excellent experiment platform. It is a usable but heavy, sturdy bike, good when powered, no way otherwise. I’m starting on the battery pack, currently running 2 series 12V SLA batteries. First problem… no (no-load) charger output. That has to be fixed first before I start on the battery pack. Anybody have a charger to loan? I don’t even have a good bench supply yet. Cheers.
2016-05-22 by Unknown
I’m having a blast investigating this bike. Did you know that you can still get a battery for this? 24v 36v 48v, in the exact same rack with controller? It appears that the only thing Schwinn here is the frame (recognizably strong and heavy). I’m just going to order a new rack… in the meantime I’ll play with the old battery pack…
2016-05-22 by Russell Graves
Greg - would you be willing to contact me via the contact form? I’d be very interested in reporting some of what you’re finding. Digging into it is still on my list of things to do, but TBH it’s very far down on the list right now.
2016-05-30 by Unknown
Hi Russell, sorry this is late. Sure, I would be happy to help in any way that I can. I’m using SLAs and trying to decide whether to source or build the new pack. SLAs on the rack make the bike pretty tipsy - and I’m just graduating from a wheelchair (accident last summer) so the leg muscles are weak, but riding is easier than walking. Enter the Schwinn Tailwind (or should we call it Tailspin?). I fell that it was worth the $300 to get me into the electric bike world.
I’m planning on building a website too for electrical\renewable anything that interests me. I have lots of photos of the assembly and may write an assembly manual for the bike. All I got was the data sheets for some of the components. Trying to decide if there is any money to be made here… but either way it will be fun.
2016-05-30 by Russell Graves
I doubt there’s much money to be made, but it’s very useful stuff to share - especially in our throwaway world.
I’ve considered building a proper 18650 pack into the Tailwind enclosure - would you be interested in testing such a thing?
2016-06-02 by Unknown
I am totally interested in helping with batteries any way that I can. How do I get to your contact form?
2016-06-02 by Russell Graves
Contact form on the right column, below the “other posts” listing.
2016-06-22 by Unknown
Hi Russel. Reading the previous posts I assume that 7 series of the typical 3.6 li-ion batteries should be ok if I want to make my own battery for this bike close to 24V, right? For example I have 14 LG cells of 3.6V and 2600mah. If I make a 7s2p pack should give 25.2V 5.2Ah, close to the original pack. Do you thing that might work?
2016-06-22 by Russell Graves
I think that sounds reasonable enough. 7S would be around 29.4v fully charged, which is close to the stock 28v, and the existing low voltage cutoff should be close. You’ll probably want a voltmeter to monitor it or a BMS that will do it’s own low voltage cutoff, though.
2016-06-23 by Unknown
You are right. Always with a bms. I already found one with this configuration… Now the problem is that the original charger has too high the Amps for the new cells. It’s output is 29V and 8.4 amps! I guess it might hurt them, 2Amps should be enough. Any suggestions of how I can reduce that number instead of byuing a new charger? Thanks again!
2016-06-24 by Russell Graves
Get a charger that matches your new pack. Don’t try to modify the existing charger. It’s designed to charge the LTO cells, not anything else.
2016-07-07 by Unknown
I heard crazy lennys ebikes in madison offers a throttle kits for 100 bucks. Dan
2016-07-07 by Unknown
and has “new” tailwinds for 300 bucks
2016-07-18 by Saddletramp
I have 2 12 volt Mobility Scooter battery’s in new condition. If they will work on the tailwind I will hook them up & mount them to the bike. This is my only transportation. I am desperate to have transportation. @ 61 years old I can’t walk very far. Any help at all would be greatly appreciated. I can no longer afford a car. I will beg for advice if needed.
2016-07-18 by Russell Graves
They should work if you hook them in series.
2016-07-18 by Saddletramp
Thank You ever so much. I paid 400.00 for the bike still in the box. It’s a beautiful machine. I have built gas powered bikes & still have them. Can’t put them in the rack on a bus because it has a gas tank. A battery will go boom too. Thankfully they are not smart enough to figure that out. I will wire it up & let you know the results.
2016-07-18 by Saddletramp
Bought a Pannier bag for the top of the rear rack. From what you have discovered the battery controller should handle the load of the 12 amp hour batteries. Should give me about 55 miles between charges. Only getting about 15 with the stock battery. I have to make this work, or starve to death.
2016-07-19 by Russell Graves
The controller won’t draw more than what it needs - the battery capacity doesn’t matter. The power gauge may be slightly off, though.
A 12Ah 24v pack (which is what you’re building) is about 288Wh. The stock pack is around 100Wh. You should be able to reliably get 20 miles, but I wouldn’t push the lead acid packs to a full discharge as they will die quickly. Try to keep them above 50% charged if you can for longevity - lead acid really, really doesn’t like a full discharge.
I’ll be interested to see how this works out for you.
2016-07-19 by Saddletramp
I am Very grateful Russell. I should have this going in about a week. I hope. Without the motor the bike is very hard on me. When I get this to work there should be hope for other Tailwind owners. Such a well made bike should not be left to rot in the garage.
2016-07-24 by Saddletramp
Battery box is complete. Controller does not see the 25 volts. Looks like I will have to replace it also. Any ideas on what I should get? I have so much work in this I can’t stop now.
2016-07-24 by Russell Graves
“Sunk Cost Fallacy” in action…
Where are you tying the battery pack into the bike? There’s a keyed switch on the left side of the front of the battery enclosure that needs to be turned on to power the handlebar controller.
I’m really not sure about the nature of the controller - I haven’t reverse engineered the whole bike. I suspect the box on the side of the front fork is the controller, but haven’t verified this.
2016-07-24 by Saddletramp
Hi everything on the bike is stock & working as of last week. I too the bms off the battery & mounted it back into the enclosure as if it was on the battery. Went Positve to pos , Neg to neg. The two large spring loaded where the battery makes contact shows 25 volts. Turn the key, push the handle bar button nothing. Should show three leds. nothing there.
2016-07-24 by Saddletramp
Russell imagine the bike is stock with the exception of the 2 12v battery’s in a bag on top of the rear rack. Voltage too the large flat connectors that meet to the key box mounted to the rack. Key is on, normally the pad on the handle bar shows 4 led’s at full charge when the on button is depressed to On. Nothing happens at all. No lights no anything.
2016-07-24 by Saddletramp
Hi, I just found a 24V 250W controller on EBay. Wired with very similar features the Tailwind has. It will take a month to get here. All I can figure is Schwinn built something in that Battery Management system that if it don’t see everything it needs it won’t activate. Paid 10.00 for the controller. If it angers me I will put a China Girl 66cc gas motor on it & just ride it as I would the bikes I built in the past. It’s too sweet of a bike to give up on. But I’m not there yet. Hoping to make the electric work so the Bus will except it on the rack.
2016-07-26 by Saddletramp
Russell I hope I am not annoying you. I have everything to make an ebike from scratch now, and I am searching for a wiring diagram to make it all work. Only thing I have seen yet on youtube is for kits that plug together. I just hope the controller comes with a diagram depicting what wire goes where.
2016-07-26 by Russell Graves
I doubt it will come with a wiring diagram. You’re usually on your own with controllers from China - at best, they might have a set of labels on the sales page.
I haven’t really dug into the system, so I’ll be interested to see what you find. Any chance you’d be willing to ship me the spare parts you pull off for analysis?