Hello. By way of introduction, I have considerable interest and have done considerable reading & research on the subject of electrifying an ICE vehicle, but my actual hands-on is nil at this time. My The reason for my interest is a] personal economy and b] the pure fun of a project. I have no real interest in the politics of ICE versus EV.
Project goals are modest: I want to be able to use the vehicle for my daily commute to work (16 mi. one way); weekly trip to the supermarket (18 mi. one way) and Saturday and Sunday trips to the beach (22 mi round trip). My initial inclination was to build an updated version of R. Q. Riley's UrbaTrike. After several discussions with the motor vehicle authorities in my jurisdiction, I concluded that the prospects for titling and registering such an animal here resided in the niche between "slim" and "none". After determining that a motorized bicycle would also be banned, and an electrified bike would not quite meet my speed/range requirements, I narrowed the scope to an electric motorcycle.
I found and bought John Bidwell's "Secrets of El Ninja". I'll assume that book is well known here. Bidwell not only writes from personal experience, but imo he also excels at making distinctions between ideal and practical solutions. The recommendation to use FLA batteries is a case in point. However, I take issue with the safety aspects of his recommendation. As a long-time rider and survivor of one high speed and several low speed drops, the last concern I want added to those experienced by any two-wheeler jockey mixing it up with auto traffic is that of spilling H2SO4 all over my legs in the event of a mishap. Another drawback to Bidwell's plans in my mind is that while using the cheap battery solution tantalizes with thoughts of keeping multiple power packs at different locations and swapping them at need, the geometry of locating the batteries within the cycle frame pretty well eliminates this as realistic possibility.
While musing on Bidwell's ideas about locating batteries in a trailer, it struck me that using a sidecar (aka hack) platform for batteries had certain advantages, particularly when using FLA:
1. A cycle with hack is fundamentally a trike, with increased stability at the price of some handling quirks vs.
two-wheeler (the steady weight & low cg should actually reduce the problem of raising the hack on left-handers)
2. Since the hack remains "flat" and is not under the rider, risks posed by acid leaks from FLA batteries are reduced)
3. Using a 6 ea. 12V batteries in a 72V. 2 x 3 arrangement produces a single-level "module" that is nearly "square"
4. Increased flexibility of the battery layout allows using choosing a battery form factor by capacity, not what will
fit.
5. It should be relatively easy to engineer a 6-battery module to allow the entire power-pack to be swapped. For
example, I could keep a second pack at work. Since the office (work commute) is in nearly the same place as the
supermarket, I could swap packs. That would make the pack use for that trip closer to 20 miles than 36. In turn
(in theory), my DOD should decrease and ultimate battery life should increase considerably. I may be able to talk
someone who lives near the beach into keeping a spare pack as well.
6. One of the main drawbacks cited by Bidwell for non-pancake motors is consumption of "in-frame" space needed for
batteries. While I will probably stick with a swingarm-mounted, Etek-type motor as Bidwell recommends, this allows
more design flexibility.
7. It might be feasible to have a much smaller (~500 ah 72V) sealed battery pack located within the frame to provide,
say 2-3 miles of range with the sidecar disconnected. Much exploring of the trade-offs is needed before making
this decision.
8. Greater battery "over-capacity" should lengthen my "riding season" by allowing operation at lower ambient
temperatures without incurring too great a DOD. The more I use this contraption, the quicker the ROI begins.
9. Three wheels on the ground vs. two should also increase (if marginally) the days per year of use.
I'm not kidding myself that there are no "gotchas". I'd be carrying more weight in batteries than the passenger and/or baggage that the hack was intended to carry (up to 2x, actually). OTOH, that weight will be "passive" and the cg will be very low. Nevertheless much attention will need to be paid to ensuring that the hack stays attached to the cycle, and making some provisions against the event that it doesn't (NTM requirement for a rather larger tire than is customary for a sidecar). Much greater attention to safety checks of frame, tires, suspension, and brakes will be required for both major components. Carrying a passenger in the sidecar in addition to the batteries would be a major safety issue and will not be attempted. The expense of acquiring both a donor cycle and a suitable donor hack will likely double the non-electric system expenses and greatly increase the difficulty of locating those donors. Maintaining a remote "battery depot" not only increases the capital cost of the batteries, but requires duplicating charging technology at each depot.
Before I start spending money and (more) time on this project, I'd like to subject it to the scrutiny of those here who have already attempted EV conversions (as well as any peanut gallery spectators like myself) for the purpose of poking holes in any erroneous assumptions or failures of logic in my scheme. Thanks in advance.
-Roland
Roland -
I'd suggest you invest the extra money that the hack would cost you in Lithium (LiFePO4) rather than going with a hack (aka "sidecar" to folks unfamiliar with the term).
In summary (I believe you covered all of these in your description):
PROS:
1) Yes FLA have generally been considered better than SLA for traction applications. However, SLA has proven capable - as long as you buy the appropriate model. Note that FLA's suffer the worst from Peukert's affect - so although they can provide ample power (high C rating) it has the biggest effect on their effective capacity.
2) Yes FLA are more easily maintained so might last longer than SLA - not sure about the metrics here.
3) Easier conversion because you can use the hack for battery storage
4) Increased usability when converted because you can use the hack for additional storage
CONS:
1) FLA's in the US are likely a legal gray area to use for this purpose (I'm not a lawyer so I don't know for sure - on the one hand there are laws surrounding the transportation of FLAs, on the other hand 99.99% of cars on the road has an FLA under the hood. You don't say where you're from - but it might be worthy of some further study.
2) Buying a bike with a hack for the conversion will probably cost you more and thus negate any cost savings.
3) Adding the complexity of a hack will make this more unique and more challenging as in yet to be discovered ways (there are other hacks on over EV Album though). This of course might be a good thing - if you like challenges.
Given those pros and cons then if I were you I'd spend the extra money on LiFePO4 batteries rather than on a hack.
If money is no object (hah!) or the budget supports it then a hack using LiFePO4 would be great! Especially if you use one of those "sidewinder" type setups that "lean with the bike"
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.
There's a guy who lives in my area (silicon valley) who did this side car approach. I don't have any contact info for him and I'm not certain whether he ever finished it. However there is at least one other person with this idea.
Since batteries are rectangular they fit better in a rectangular compartment. However most motorcycles do not have rectangular bodies. One of Bidwell's other books, El Chopper ET, has you drastically modify the frame and build in a rectangular battery compartment.
Um, are you really going to regularly swap 2-300 lbs of stuff around? That's how much a battery pack will weigh.
Also if you keep packs at various locations you'll need a way to keep those other packs charged. Lead-acid batteries do not deal well with being left semi-discharged for long periods of time. That cuts the useful life of the battery. So your remote pack(s) will need their own charger(s).
I think it would be easier to arrange permission from your employer to charge the bike at work.
I kinda think of it in another way. The pancake motor takes up more front-back space than does the non-pancake motor. This means the gap into which you put the pancake motor has to be longer. I'm not describing this well, I know. So I'll describe it another way.
My Lectra motorcycle has an Advanced DC A89. This is not a pancake motor but the other kind. It's mounted on the swing arm. There's room between the rear tire and the frame for the motor to sit. It takes having a long enough swing arm to fit the motor into that space. Since the pancake motors are wider the swingarm has to be even longer.
If you want to study other conversions there's an extensive set at http://evalbum.com
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
I hope this was a typo, I think a 50AH 72V pack would fit but 500AH is a lot of batteries.
Grandpa Chas S.
Hi Roland,
interesting idea.
One main difficulty I would anticipate is that you would not be able to monitor the charging process at your remote locations.
This would likely not go well for very long.
You would also need a hoist of sorts to lift the whole lot in and out.
A trailer would be so much easier to switch over - just place the whole charging setup and batteries into it and swap over whole trailers. No lifting required, but more expensive I guess.
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I will do the cost exercise just before I start buying equipment, but my clear impression is that Li-whatever tech is still a lot more expensive than FLA when BMS is taken into consideration. NTM that some variants of Li tech have some unresolved allegations of fire danger that have yet to be conclusively resolved. I'm figuring on <$500 for a donor bike, and a like amount for a hack chassis. If the cost advantage for the (sidecar parts plus two FLA packs with chargers plus controller) and a (Li pack plus controller/BMS plus charger) that affords roughly equivalent speed and range is insignificant or negative, then I'll probably go with the Li tech. That is contrary to my expectations, however.
-Roland
Yes, El Chopper and El Toro (on-line supplement to El Ninja) both cut out the front tubes of the engine cradle and replace it with a fabricated squared member that becomes the front of the battery cage. I don't like it. I'm no cycle engineer, but it's pretty clear to me that the removed tubes provide considerable support to the bottom of the triple tree. I forgot to mention in my hack advantages list that it eliminates the need to drill bolt holes through the frame, another Bidwell item that gives me pause. If I did batteries in the frame, I'd have the battery cradle welded.
Yes. I plan to build a new body for the hack, so I can provide for this, I envision the battery cradle as a removable member equipped with inline skate or scooter wheels. Hoist the pack, roll the cycle out from under, lower the pack and roll it to the charger. Might even be possible to design this so the hack body raises and the pack can be rolled off without a hoist. I think I did mention the need for a charger at each "depot" in my long post. My understanding is that the opposite is also true - FLA have a relatively long shelf life when fully charged. I can easily get permission to charge at work, and plan to do so. It's the food shopping and recreational trips to the beach that concern me a bit, since time to recharge (assuming availability) will be problematic. I do want to maintain close to 50% SOC in all "normal" use if I can.
I'll need to review Bidwell's exact comments on the disadvantages of the non-pancake motors. I do recall that it was a geometry issue vs. the batteries. I'll concede your point, but I remain confident in the general concept that moving the batteries out of the frame drastically increases design flexibility.
I was mentally converting back and forth between AH and WH and had a brain fart. I meant WH...
-Roland
Aware of the monitoring issue but haven't attacked it yet. My impression was that this can be somewhat automated for FLA if a separate charger circuit is used for each 12V unit and the cell-to-cell is monitored weekly or bi-weekly. Bad assumption?
I though about the trailer first, and yes, it does have those advantages. OTOH, it negates one the big advantages of a cycle in traffic - being able to quickly change lanes. i deal with a lot of summer tourist traffic here... Also, while both trailer and hack induce some negative handling issues, the hack would be beside me and obvious at all times, while the trailer would be behind me and could easily be forgotten at a critical moment.
-Roland
To explain my Li comment. Of the Li- derivatives I'd only consider LiFePO4 - that addresses the safety issue to my satisfaction. I wouldn't use a large number of FLA's in a moving vehicle - because of the safety issues. I'd use SLA's or Lithium. By the time you spend money on good SLA's plus the $500 you save by not going with a hack then you're likely into the price band for cheap LiFePO4's - the jury is still out on whether cheap LiFePO4's are a false economy. There are quite a few folks using Thundersky cells (the current holder of the most "value oriented" cell award!). The folks over at Electric Motorsport like them. Some folks on this board dislike them. To be sure these cells aren't as good as the best LiFePO4 cells - but the question is "are they good enough?"
For a BMS check out Bob McCree and Gary ??? over on endless-sphere.com they seem to have a low cost, highly modular solution that will work with any LiFePO4 pack (and could be further tuned for other chemistries). For Lithium prices they may have to come down a bit more yet - but they are falling all the time. They should be affordable "real soon now", right?
I agree with you - I wouldn't want to modify the frame if I could get away without it.
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.
Roland, another very important issue to consider---how fast will you be riding? That's a crucial issue when considering potential range.
A rough calculation for lead-acid is that if you half the speed, than you double the range. For example, with my small 35ah 72v pack, if I normally get 10.5 miles riding 45 mph average, than if I rode 25 mph, I would get about 18.9 miles range.
I like your idea. Here's my take on using a side car. Why not leave the gas engine in the donor bike? You could integrate a direct electric drive system of the rear wheel. By putting the transmission in neutral you could ride on electric until the batteries are discharged, than switch to gas if you need to go further. This'll be easy to do since you will be able to store all of the battery capacity on the side car. And if the project doesn't work out well, than you'll have a working gas bike.
One of the worst aspects of doing a conversion for practical transportation is that it can be very limiting. And, if it doesn't work out well, they are often hard to sell due to the limited range. Leaving the gas engine and stock components would allow for much more flexibility, and versatility, without any limitations. You could remove the side car and have a working gas bike, or add the side car to ride on electric.
This idea stems from what I'm working on now. I'm planning to get a Honda Civic conversion running. I see thousands of dollars, and hundreds of hours in expense. And, the vehicle will have a limiting range. Instead, I'm thinking of "electrifying" a Suzuki Sidekick that I drive now while leaving all of the gas components in place. I think that would be a much better investment. I'll start another thread on this, sorry for going OT.
[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri
I'm aware of the speed issue. For my intended use, I should be able to cruise at 45 MPH, 50 would be better, but that is the fastest I would need to go (as important to avoid excessive closing speeds with traffic from behind as to get to destination in acceptable time).
Your suggestion is fascinating. I was already toying with the idea of using the in-frame ICE engine (or a substitute better suited to constant RPM operation) as a genset (which remains a possibility). But why would I want to deal with the complexity of driving the motorcycle rear wheel from both power sources when I have a perfectly fine wheel in the hack which is not currently earning its keep ;?> I'd put the battery pack and the motor in the sidecar. That potentially leaves the motorcycle drive system exactly "as is". Is this "discrete hybrid" idea something new? This would add two complications: to be able to operate both power systems simultaneously (which I will assume is a necessity) will require either sophisticated computer control or dual throttles with some kind of mechanical safety inter/disconnect; the electric motor/drive train will need to be capable of freewheeling - no point in going to all this trouble and expense in the name of economy only to introduce extra drag on the ICE system via magnetic drag on the hack wheel... I'm thinking that similar to the Toyota and Honda hybrids, you would use the electric system for stop and go driving and extra acceleration, and use the ICE system by itself to cruise. If out of gas, or too high DOD on the battery pack, you could use the alternative system to limp to a gas station or electrical outlet. Now, the next question is (given my original trip length/frequency parameters) how much electrical power is needed for this design, and what is the optimum V and WH for the battery pack. Certainly the second value will be much lower than the ~10KWH I was originally shooting for. If you move this to another thread, pls take this reply along because I'd like to participate...
-Roland
First, I'm not sure I accept 6 as a "large number of FLA" in the context of safety. The Trojan T-1275 is 10.37x7.33x10.88 " 6 of those is ~600 cu. in. If 75% if that volume is electrolyte (my SWAG) that is ~2.5 gal. of 30% H2SO4. Now, I certainly don't want that much sulphuric splashed all over my lower extremities, but even in the event of such a catastrophic sidecar wreck that all of it spills out on the highway (recall that part of the justification for sidecar vs. cycle wrt FLA is stability of orientation leading to decreased probability of spills) that would be unfortunate, but imo would constitute neither an extremely lethal danger to drivers and passers by, nor an ecological disaster.
Second, all the numbers I have thus far found appear to completely blow away anything remotely resembling a cost justification for LFP in this application, in any possible scenario. Working backwards from my range parameters, my storage goal is ~10KWH @ 72V. For the aforementioned 6 ea. T-1275 that would cost ~$990, weigh 492 lbs., occupy a space 25.75x21.375x10.875" and, assuming 50% DOD, would last ~550 cycles (see: http://tinyurl.com/28s56e)
To meet the same requirement using Thundersky LFP40AHA units would cost $8,400 (84 @ 3.2V @ $100 ea.), weigh 265 lbs., occupy a space 22.5x18.4x12.6" (actually probably more - this does not allow for gaps for cooling purposes) and last ~650 cycles (see: http://tinyurl.com/2h2txd) chart at bottom right of page, the deep cycle service chart - this is not specific to TS, but from what you wrote it seems reasonable to assume that TS would not last longer than an average or statistically standard LFP) There is no question that the LFP solution is superior in terms of KWH/Lb and KWH/cu ft., but not as much as I had supposed. Certainly not enough to justify a cost factor of 8.5 (without even bringing the cost delta in controller/BMS and charger tech into the equation) for a gain in charging cycle life of 18% (I had an apparently mistaken impression that LFP were far superior to FLA in cycle life at high DOD). If I have found bad data or strayed on any of these assumptions or calculations, I welcome correction...
-Roland
Roland, I think that's a new idea. In any case, I know of no electric motorcycle that has ever done that. There are electric push trailers for bicycles that I've seen which would be the closest thing I can think of.
That may be marketable if you find it works well.
Integrating the two throttles is beyond my skills. I'm sure the parallel hybrid cars could give you some ideas on how to do this. For my commute, I would only want to run pure electric most of the time because I can easily do this with a relatively small battery pack. Those times when I would want to run further than the electric range would permit, I would just ride on electric until the batteries are mostly discharged then switch to gas. I know running both systems at the same time would improve efficiency some under these conditions, but they won't be often for me. This would definitely be worth setting up if you needed to use the gas engine for every trip. Also, running from both systems could be controlled manually by using the electric motor for low speed, accelerating from stops, and for regen braking. And using the engine for maintaining high speed. But this ofcourse can't be as efficient as a microprocessor controlled integration of the two with smart algorithms.
My logic in keeping the gas engine would mostly be for versatility. I don't want to plan my life around my electric vehicle limitations. But, most of the time I will not need to travel more than the electric range would permit, so statistically an electric makes great sense. What doesn't make good sense is the fact that I may just happen to need to travel 70 miles one day, or just little further than the electric range the next. Just because the "average" commute is well within the electric range, doesn't mean an electric will be suitable. That is a misconception, and I hear it too often. This of course is mostly repeated by EV idealists. I prefer to be more of an EV realist.
As far as freewheeling, that can be done, but a motor doesn't actually add that much drag. And if this is done than it would make regen much more complex (requiring somehow to engage/disengage freewheeling). I think regen makes a lot of sense. The etek type motors don't appear to exhibit any cogging, and the series or separately excited motors will not add nearly any drag but they will be rotating mass that may reduce efficiency some. Hopefully that efficiency loss can be more than compensated for by using the motor for regen and starting from stops when running from the ICE mostly (say when the batteries are at a low SOC).
The WH needed would still be high, because I'm considering a plug-in hybrid. If you don't want to do a plug-in type hybrid where most of the energy will come from electrical charge in the batteries, than the benefit in gas mileage may not be very significant. In that case, it may just be better to buy a low powered scooter for 70-80 mpg.
What I'm looking at with my Suzuki electrification is on the average, driving about 500 miles per gallon used. That's an order of magnitude greater than most traditional hybrids. This is because most of the time I won't be using any gasoline, so that is just an average of the gasoline that I will burn when needed divided by my total driven miles.
Roland:
For the aforementioned 6 ea. T-1275 that would cost ~$990, weigh 492 lbs., occupy a space 25.75x21.375x10.875" and, assuming 50% DOD, would last ~550 cycles
Probably more along the lines of 750 cycles. Bob Brant in "Build Your Own Electric Vehicle" has a cycle graph specific for Trojan T-105s which should probably be fairly similar to T-1275 in terms of cycle life.
Roland:
and last ~650 cycles [for LFP]
These batteries are not LiFePo4, they are just lead-acid with LFP in the model number for the graph you linked. LiFePo4 should last over 2,000 cycles according to some manufacturer specs, and may be much higher for others (15,000+ for Altar Nano for example).
Some important factors with LiFePo4 are that they have a much lower peukert effect, meaning much more of the rated capacity will be usable in an EV application. About 50-60% of the rated capacity for flooded lead-acid will be available to 100% DOD depending. Also, the voltage sags considerably, so the nominal energy available will be quite a low margin. On the other hand for LiFePo4, I would expect over 90% nominal energy available (or rated capacity * nominal voltage). Also the LiFePo4 would have better cold weather performance.
Additionally, the LiFePo4 life doesn't end drastically according to life cycle graphs I've seen. It more slowly and linearly deteriorates with cycles. This means, even if they "survive" 2,000 cycles to 80% capacity of when new, they may survive another 2,000 down to 60% capacity and be usable still. Lead-acid on the other hand die quickly when their rated cycle life is about gone.
[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri
Here's the other thread:
Don't Convert It. Electrify It!
[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri
Hi all, I just stumbled across this thread via Google search on "electric sidecar". Looks like there's a wealth of info on this site.
My situation is like this: I've been riding motorcycles for about 40 years and I now own a 1981 BMW R80G/S and a 2001 Honda XR650R. My four-wheeler is a Toyota Tacoma pickup truck, which is my main ride because I'm usually accompanied by my two dogs when I drive anywhere. (I use a company vehicle for commuting to work.)
I'd like to have a "three-wheel pickup truck" -- a very utilitarian sidecar rig, ideally with two-wheel drive as some of the dirt roads around here are very sandy and we get snow in winter. The sidecar would be used for hauling dogs and/or baggage, building materials or whatever, and a human passenger would ride pillion.
This idea is something I've thought about now and again over the past few years. Now I want get a little serious and do some research on feasibility.
I had been thinking all-electric might be good, but the idea of retaining the gasoline engine and adding electric as a second power source might be even better.
If anyone has info that might relate to this project I'd appreciate any links or whatever. Cheers!