Some basic questions - my first eBike
First off, let me say Hi, been busy catching up in the forums and doing a lot of research. I gave up owning a car and my license years ago and I just dusted off my old daily driver to be my first "subject".
The bike is going to basically get me weekend fishing in the Rockies just west of Calgary, and I'll camp and fish with it as the base, maybe with a solar battery charger to help where power isn't available. The round trip is mostly flat, but west to east so I expect a headwind. Overall distance is about 150 KM, with maybe 30-40KM where I can't easily recharge.
To be short, I decided on a Nine Continent Kit, but mostly because of the addons and features that the vendor dropped into the package. I read Justin's account of his ride across Canada and drooled so much over the electronics and thought put into it. I also like some of the mods, such as regenerative braking.
At the middle of this area I can't charge in is a 16KM downhill grade which I think could come in handy, or just cook the electronics and fry the batteries. Certainly, the new LiFePO4 batteries may help out since they appear to have a "fast charge" mode and they don't seem prone to cooking off.
Battery-wise, I found some 12V 26Ah SLA's at a very nice price, a solar 12V charger that might disappoint, a very good price for light LiFePO4 batteries, all of which I would provide links for if I weren't very cautious as a new guy...
The first battery set (while I save for the drool material) is going to be those SLA's, but they weigh a total of 36lbs, so I need to expand to a trailer. I'm still thinking of adding a dual-motor controller later and adding a hub motor to the trailer, but have questions as to the effect of a trailer suspension...
Good choice on the nine continent. That's a pretty efficient motor. For the batteries, I'd go with a 36v40 AH Thundersky or Sky Energy from evcomponents.com.
You could get 30 x 2 = 60 miles out of the pack easily without pedaling. If you pedal, you could easily get 80 miles out of it without the pack even breaking a sweat.
They are kind of expensive but these are the cheapest and best lifepo4 for your money on the internet. I recently bought the same kind but I got a 36v20AH thundersky.
$44 for a 3.2v 40AH cell
Get 12 cells for 36v. That'd be about 12 x 44 = $530 + shipping and extra = $600. The same pack at other places would cost you probably $1000.
It's up to you. I recently upgraded to lifepo4 and it's amazing. The difference is huge. You'll be spending probably $150 - $200 for the SLA's anyway. Remember that once you are done riding with the SLA's, you have to let them cool and then charge them immediately. You don't have to do that with lithium. The lifepo4 will last you 5 years or more or 2000 charges. The SLA's might last a year.
If you do get lifepo4, make sure you learn how to properly use them.
Originally Posted by CowtownPeddler
Welcome. If you're really interested in LIFEPO4s at an affordable price, have you looked at the ThunderSky 4-cell pack (prismatic) offered by Elite Power Solutions? http://elitepowersolutions.com/produ...products_id=74
The 20AH 4-cell (12V) pack is $128 USD and the 40AH 4-cell pack is $240 USD (without balancers) or $275 with balancers. You can wire these 12V packs in series to create the size battery that you need. If you buy a pack without balancers, you shouldn't have a problem adding a BMS boad, just make sure the specs of the BMS match your controller's demand for amps. I'm not sure what shipping would cost to Canada, but it should be cheaper than ordering a LIFEPO4 pack from China. Anyway, welcome and good luck. If you haven't checked it out, I'd suggest you go to the Endless Sphere forums since the only bikes they discuss are e-bikes. It's a marvelous source for info on all things e-bike related. http://endless-sphere.com/forums
Last edited by nwmtnbkr; 02-11-10 at 08:46 PM.
or yeah, elitepowersolutions.com is good too.. That's where I bought mine.
Yeah, found a US manufacturer can do 36V20AH with charger for about $520usd, the SLA's will cost $210 without a charger, the SLA's are 16lbs heavier and overall weight is a factor. If I do two LiFePO packs, I end up 4 lbs heavier than the SLA's, so I'm saving.
Just not really sure how far 26AH will get me with pedalling and such. I also just discovered aluminum front forks so I'm thinking of starting small and investing to beef the frame up. I can stretch this over time and do it right, I think.
You may find that SLA provides an adequate range if you're willing to pedal. I live in the Rockies of Montana, west of Glacier National Park. I installed my Currie conversion kit last summer and have not had problems traveling 25 miles with 1 SLA battery (still had juice left in the battery when I got home). However, I pedal and reserve power assist for steep hills. I'm planning on building my own 24V 20AH LIFEPO4 with the 4-cell packs from Elite Power Solutions. I've been dragging my feet because I've been torn between LIFEPO4, which is safer, and the high C value of the more dangerous LiPoly batteries. The delay has worked to my advantage because Elite is now offering free shipping for orders placed online.
With lifepo4, you don't want to use more than 80 % of your pack and that's with a BMS. So lets say you use about 15 AH. The 15 AH on a lifepo4 pack should get you about 30 miles. I get 2 miles for every AH and that's without pedaling. If you pedal, you'll get more.
yeah if you want 20AH cells, elitepowersolutions is actually cheaper than evcomponents I think. For some reason, though, EPS's 40 AH cells are a lot more expensive than evcomponents.
With SLA's, I could barely get 3 miles range out of my batteries. When I switched to lifepo4, I get tons of range. I still haven't actually maxed the battery out yet. I think part of it is that lifepo4 doesn't have a peurkert effect like SLA so when you are in the middle of the run, you still have about as much juice as you had at the beginning. Whereas in SLA, if you are in the middle of the run, the battery is almost dead and therefore , it can't carry you as far and so it's like two times as bad.
Last edited by morph999; 02-11-10 at 11:34 PM.
Well, the EB-20-12 pack from ElitePower at $439 uses 3 ThunderSky 4 cell packs and as far as I can see, this is the cheapest and possibly the best value for LiFePO packs I have been able to find - and it ships from the US...
The SLA's I found are all about 12lbs each and the best Ah per weight seems to be the Leoch DJW12-26 (12V 26Ah).. Never mind any other options, I checked them all and a 20Ah pack would cost anywhere between $700usd and $2200 (A123 developer kit)... DeWalt batteries would cost more than that....
Still not sure why you would have such horrible performance on yer SLA's - I was reading about 4-6mi per Ah is normal, and to only get 3mi, you would have to be very heavy, not peddling and speeding uphill in a headwind with a fully loaded trailer. Doesn't make sense to me. Hopefully someone can add some real-world observations here.
I finally broke down and decided to go for the rear hub drive, I've already gone flying off a MTB at 40mph and I don't want to try my luck like that again, and I don't see a short term need to beef up the MTB frame before carefully considering other frame options (recumbent). The chances of my aluminum front forks giving are way too high.
I had originally had this idea of a front hub drive, trailer hub motor and this neat chain kit I saw from Czechosolvakia with a freewheeling crank. The power requirements would be huge and I've decided that's overkill, never mind slightly "illegal" in Canada due to legal speed limitations. At least with the hub motors and the kit, I can "set" a maximum speed to comply and confuse....
Still, back to the regen question and range... I can't say for sure, but it seems to me that the obvious problem with regen cooking electronics and batteries must be related to either voltage or amperage being fed back from the hub during the regen cycle. Certainly, I would have to be very careful with SLA's, and less careful with LiFePO. This brings the question...
I've been seeing LiFePo chargers up to 6A (http://elitepowersolutions.com/produ...products_id=79) and I'm pretty sure that an SLA would cook off if I charged it at that rate for a long period. (Actually, there's a 20A version of that charger) I'm not so sure that a solar charger is worthwhile (see: http://www.brunton.com/product.php?id=420 ) since it takes 12 hours to charge a 12V 40Ah car battery, it would take (estimated) 18 hours to charge a 36V 20Ah SLA, and I'm not so sure it could be "altered" to work with the LiFePO cells (see: http://elitepowersolutions.com/produ...products_id=74 )
The kit I'll be buying has regen, and uses the throttle and regen braking to charge, with two basic modes... You can use the throttle during regen braking to increase the regen, or not touch the throttle. I assume that not touching the throttle would "prevent" the possibility of cooking electronics and using the throttle *may* be very useful with LiFePO batteries - if I could ever get some sort of info on this "fast charge" capability. Apparently using the "fast charge" can shorten the cycle life of the batteries. That 16KM (10mi) downhill grade could come in useful after all... Shame there's a fully serviced campground at the base of the hill.
There are many threads on the regen issue on the web but the general consensus seems to be that it doesn't do that much to extend range and certainly effects average speed because in order to get the most out of regen you will be going downhill slower than you are able to go up. It works better in automobiles because they are much heavier.
The surest way to extend range is to pedal along with the motor. I call this staying on top of the motor and you will see what that means when you get to ride one. You just need to find the right gear(s) to do this and as much effort as you want to apply will be repaid in extended range. Doing this I can get 40 miles (64k) out of a 12Ah LiFePO4 battery in hilly terrain without using my regen, although I do use a brushless hub which has a good amount of drag, but the regen is so strong that my setup on a pusher trailer just skids the tire when it is applied. Great for coming to a stop though! Actually I have never used more than 8.2Ah of my battery and have yet to come up against the BMS which is fine with me because the hub motor drag is so bad that although my pusher setup is relatively light it is like riding a resistance trainer and without the assist it would not be fun to drag it home. More likely I would just hide it beside the road and continue on and come back and get it later, or at least that is my backup plan.
Here is the Czech chain drive kit I was mentioning earlier - verrah sexy.... http://www.bike-elektro-antrieb.ch/home.htm I was wrong, it's Swiss... You might have some issues is you don't read the language, but....
I wouldn't bother with regen. I've heard it doesn't really help that much.
If you want to know how long it would take to charge your lifepo4 batteries, take the capacity and divide it by the amps being charged with.
So if you have a 12v40AH pack and you are using a Black and Decker 12v charger and you use 2 amp charge, then it would take 20 hours to charge it if the battery was totally depleted. If you have a 12v20AH pack and you only use half the pack (10AH used) and you charge with 10 amps then it would take only 1 hour to charge that pack. I use a 12v black and decker SLA charger on mine and I put it on the "Gel" setting and it works fine. I got 3 of those 12v20AH packs from elitepowersolutions.com and I charge it one 12v pack at a time and my charger can do 2/10/15 amps. Most of the time, I use 2 amp charge since I don't normally use a lot of the pack when I ride. The recommended charge rate on the 20AH packs are .3C which is 20 * .3 = 6 amps. So the recommended charger would be a 6 amp charger for the 20AH packs but using 10 amps probably wouldn't hurt it but I wouldn't go much higher than that.
You can also get a 36v 6 amp charger somewhere online and that should work as well. The first charge, though, I would monitor all the cells to make sure none of the cells go above about 3.8v per cell. So if you have a 36v lifepo4 pack with 12 cells...the total charge should not go over about 3.8 x 12 = 45.6 . I normally charge mine to 3.65v per cell which is about 43.8v hot off the charger then they settle down to about 42.9v after a while.
And if you want to monitor your cells, this is a great way of doing it...it has an alarm on it so if you go to low on your cells, it will warn you. Remember you dont' want to go below about 2.5v per cell on lifepo4 or you will ruin the cells. This is an 8 cell monitor for about $29. You'd need one more to cover all your cells.
So the solar charger at just over 2A would take 13 hours for ea of my SLA cells *3 = 39 hours of sunlight. It would take 10h to charge each of the LiFePO batteries (20Ah*3 batteries [4 cell LiFePO units]) = 30 hours of sunlight at the end of my ride. I need to rethink the SLA charging for sure at 2A... I wasn't going to do my "trip" until I had the LiFePO's.
I have two routes - north with a serviced campground (sounds good right now at 50KM/30mi) and south (about 65KM/41mi, a parking lot) - where I'll get with only sunlight to recharge with and only one day to camp. Solar charging is most definitely out....
The upside of the south route is that I only have to ride through 2 creek valleys in beautiful subalpine terrain (11 KM) to hit a long downhill (16KM) - after that downhill is a campground with service, and then it's a flat ride (50KM/30mi) home. I'd include maps, terrain models and such for this trip but...
My one constraint was that I have to do it in a weekend, with hopefully some time for prime flyfishing for brook, cutthroat, rainbow and bull trout, all very world class. I'd leave Friday nite and be back hopefully Sunday dinner with time to clean up before work. This means I have to shave lbs off my camping and fishing gear because easily 1/2 the weight in the trailer will be batteries.
I had already decided on the 6A charger for the LiFePO4 (3.3h recharge time)...
One thing you probably have never considered about owning a car and having a driver's license is that you are tracked in every police database by your driver's license number. As a culture-jammer, I have no reason to be so tracked. As a tree-hugger, I can't justify burning a tank of gas to get to where I can launch a bike. I need to get there, and I want to relax and have a good time, and this eBike may just help me go be happy for a while. Endorphins are good, adrenalin is awesome, but why overtax the glands?
I may be a little under on some of the mileage estimates for the goals....
I just realized the $439 LiFePO packs include the charger... Even cheaper and they look quite nice...
Da latest - no advertising intended, cell cost/wt
Conversion Kit (Vancouver)
1 X NC26R [26 inch rear Nine Continent Kit (2807 hub, 25A Infineon Controller, throttle, Cycle Analyst)] $490.00 (cad)
2X TorqArmRev3 [Front Universal Torque Arm with double hose clamp.] - $60.00 (cad)
1 X eZeeEbrake [Ebrake Cutoff Lever, uses magn reed switch. All metal constr.]$40.00 (cad)
1 X 35A_upgrade [Swap 25A controller for larger 35A model] $10.00
Looks like shipping will be 20-30 bucks ($650 max)
Battery: (Phoeniz, AZ)
36V20AH (EB-20-12) $439.20 -> 20lbs
Charger (TSL36-6) $79.20
What can I do with a Lead Acid of 20 lbs
14Ah – 9.26*3= 27.78 lbs (http://www.atbatt.com/product/22081.asp) $50
20Ah – 13.*3 = 39lbs (http://www.atbatt.com/product/22082/...v-18ah/battery) $51
22Ah – 12*3 = 36lbs (http://www.atbatt.com/product/22505.asp) $47 ea
26Ah – 12*3=36lbs (http://www.atbatt.com/product/22508/...v-26ah/battery) $69
* Suggest the 26Ah - $210, charger extra
http://www.brunton.com/product.php?id=420 to charge ($620)
** Note – looks like it could charge the ElitePower battery, takes a day to charge a 12v 40Ah)
** Battery conditioner
Bedini's Free Energy Generator.How it started.
I was cleaning a kitchen one day with George Pringle in Tofino. He mentioned that he wanted to build a device to charge batteries, but he wasn't sure how to go about it. I asked him to show me what he had and I would do my best to try to figure it out.
I have to admit, the theory stumped me, but I was able to read the diagrams enough to figure out how to build one of these devices.
I'm hoping I can get my nephew to build one for a science fair project when he gets old enough. Maybe I'll get around to it sooner, ya never know.
Diagrams "A-Field" Motor Theory Diagram
<many diagrams not included...>
Except from John Bedini's Website
Imagine having a small D.C. electrical motor sitting on your laboratory bench powered by a common 12 volt battery. Imagine starting with a fully charged battery and connecting it to the motor with no other power input. Obviously, the motor is going to run off the battery, but by conventional thinking it will stop when the battery runs down.
Impossible, you say. Not at all. That's precisely what I have done and the motor is running now in my workshop.
The rest of the paper shows how he took 1 dead SLA and used this device to fully charge it once he had it spun up from a partially charged SLA.....
Last edited by CowtownPeddler; 02-24-10 at 05:20 PM.
if you get lifepo4, just make sure you never go below 2.5v per cell or about 30v total for a 36v pack. It's the individual cell voltage that matters, though. That usually only happens once you get 95 % of the pack used, though so on a 20AH pack, that would be most likely after you've already used about 18 or 19 AH of the pack. I say "most likely" because we don't know the exact capacity of each pack. It's a good idea to buy a 8s Celllog monitor for $29 to be sure. Or, just make sure you never get close enough to doing. I only use about 50 % of my pack so I know that I'll never get close. Also, using 80 % or less of your pack, prolongs the life of the lifepo4 pack. It's just like lead acid in this regard. A watt meter where you can count the # of AH used is also an option. I have a $25 Turnigy watt meter. I would have rather bought a 8s celllog monitor, though instead and just bought one more celllog monitor.
you can get one at hobbyking. There's also a couple more models there that are 6s cell log monitors that do the same thing are a little cheaper but might not be as good of quality. Great thing about these is that they have an alarm and a programable low voltage setting so you can set the lvc to whatever you want and it will alert you when one of the cells goes that low.
No worries, it's a feature...
Also, the first time you charge the pack, make sure you monitor all the cells. None of the cells can go above 4.2v or they will be damaged (overcharged). The cells are technically charged once they reach about 3.65v just so you know. After I monitored my pack the first time, I didn't monitor them after that. There is a little bit more involved with lifepo4 in monitoring them but it's not that hard. I use a 12v black and decker charger for mine. I didn't buy the elitepowersolutions charger because someone told me that it sucked. I use two chargers...
1) 12v black and decker 2/10/15 amp charger
2) 3.2v 2amp lifepo4 charger
The 3.2v lifepo4 charger is for topping off the individual cells. If you aren't going to get a BMS, this is pretty much a very good idea. The reason is that you want to maintain your cells to be somewhat balanced. They don't have to be perfect but if you builk charge them (use a voltage like 12v or 36v on them ) then you run a possibility of overcharging one cell if they are not balanced very well. So the first time you charge them, it's a good idea to charge each one individually and then bulk charge them after that.
How I charge mine is that I set a timer and I use my black and decker to charge one 12v pack to about 80 % completion then I use 3 individual 3.2v chargers to top each cell off. This is my "BMS" (battery management system). You can also buy a BMS circuit board to do this kind of thing automatically but I do mine manually since I got the time and patience to do it.
Yeah, I can only hope the 4 cell units have a BMS, no info yet.. All I can say at this time is that "they look cool"....
I'll let ya know on the charger, I haz the gearzorz...
As for the cells, I was hoping to top them off via solar, mebbe no luck there, but... I found some flexible cells out of China (*ugh*) and I *might* have a product out of the USA...
Thanks to all for the info... Between this forum and the others that you folks pointed to me, I've spent the last 3days absorbing all the info I can. I must say that I'm finding my idea a little hard to implement given current battery technologies and such.
However, I have all my questions answered, and thanks Morph for the battery info. I think I can build the BMS I need and use it for all the LiFePO needs, all questions on range and charge answered and especially the regen stuff. I never expected to get a lot back, but there are some great ideas for optimizing return, critical for me = distance between charges.
I just can't avoid going to the heavier (2.5kg) 40 AH cells, but at least I should have no problem keeping the investment up to snuff.
Wiring the battery packs is going to be a little tricky, but I'll be running seperate cabling for a cell monitor (Cell log is nice, but some others have better features), balancing charger and the BMS. I doubt I'll ever lose a cell except to some wierd mechanical failure.
Some of Doctorbass's little experiments are really tempting, but I find 70km/h a little scary (I have hit 60 peddling, and then I hit the car...)
As I build the kit, I'll post pics. Still thinking of going recumbent for the lower wind resistance.. *sigh*
Oh, and I still haven't given up on solar charging, but I think small steps:
1: SLA 26AH (get running, test range, LiFePO should be better numbers)
2: Thundersky LiFePO 20AH pack (use to build/test battery config, BMS, charging)
3. Thundersky LiFePO 40AH pack (the final build)
The bike kit is going rear hub drive for braking/regen, I only use the front brakes as backup for the rears to avoid air time, I'm not sure why I looked on the front hub drive as easier or more portable...
I'm definitely going the Infineon 35W controller with the 9 Continent hub, Cycling Analyst kit. Too many benefits and lots of flexibility as I see it, and I wanna really tune the LVC in the controller - if it hasn't been already...
I'd like to get something so I can measure more accurately the return from the motor though.
In terms of BMS, I'm taking the hobbyist route. I did find some really cool bolt-on packages for the Thundersky cells, but I've never been afraid of a little soldering and testing. That Christmas tree Doctorbass built should scale down nicely to 6S packages. I'll always run two, so the BMS design seems perfect.
The hardest part was finding the cables to wire the batteries so everything could be plug and play - an RC site provided all of that.
I'm still working on water-proofing the BMS... Tricky since airflow is needed for the cooling (fans will be needed)...
If you do decide to go with SLA, I would recommend the B&B EB 20 - 12 AKA the EB 12v20AH . EB stands for "electric bike" so they are specifically made for it. I've read comparisons on SLA's and the EB 20-12 gets 5 AH of usable capacity more than the other regular 12v20AH batteries. In other words, you'd be able to go 5 to 10 miles more on the B&B EB 20-12 than other SLA's.
Yup, exactly what I was going to do - and they went down in price in the last few days. Noticed them today at 10% less than I thought was a good price. Made me rethink the whole SLA first approach. Think I'll buy them first with the necessary cables to make em into a pack ang get the cell monitors as well. Then I'll build out the BMS, attach them to it and then upgrade to the 40 Ah cells.
It's funny, but unless you go really cheap on the SLA's, you can have a 36V 20Ah L1FePO or 36V 26Ah SLA (both with charger) for about the same cost, with significant weight advantages to the LiFePO. Granted, I "upped" the SLA charger to a dual 20A unit, I figured it as necessary compared to the 3.3 h of the L1FePO charging unit. Giving that "step" up saved me about $700 on the overall budget, cutting two weeks off the timeline.
I also managed to find a 110+lb trailer with the hitch I want at the same price as my original spec, so the weight of the 40 Ah setup isn't a problem.