Crashing and Regen

[JN2Wheels]

New to the Forum.  So, Hi.

I'm possibly the definition of Brammo's target market.  Coming from an SV650, mid-thirties, professional, and Greening up all aspects of my lifestyle and consumption.

So, a few quick questions for the powers (and posters) that be.

1.  Regen.  Engine braking is obviously a huge part of the ICE experience, and while coasting can be efficient, it also results in loses through braking.  I've read everything here, so I know that regen is apparently not coming with the Empulse.  Is this still the latest?  Once the tech is ready, I think an interesting implementation would be for a switchable system, controlled by a left-hand "clutch" lever!  Gasp!  Think about it, want to reduce braking and use the regen system to modulate speed, just close or ease off the throttle.  Want to coast, as if you're in neutral (downhill, long roll down, etc.), pull in the "clutch" lever.  Seems like an ideal implementation to me.  Thoughts?

2.  Crashability.  I see the RR has frame sliders, so hopefully that will be available with the cafe-flavored build.  But how (if at all) does the jostling and impact of laying the bike down effect the useful life of the battery pack?  Any thoughts or experience from the Enertia here?

Excited for 2011!

[Brammofan]

Howdy JN and welcome to the forum.
1. Yea! you searched and found the answer... which, as far as I know, is still the current answer, which equals "no."  The left hand lever idea would be cool - but until they can get a better return from the regen, I wouldn't bother - it adds complexity with little payoff.

2. Never crashed - although I did break my Enertia's fall off of a hitch rack.  No battery effect that I can determine. 

[Gavin]

Like any motorcycle...you crash hard enough, you total it.

Now the batteries have no moving parts and such, so I imagine any minor spill and no issues...

Any major spill and...well who knows...none of us want to be the first to test that

Gavin

[protomech]

1.  Regen.  Engine braking is obviously a huge part of the ICE experience, and while coasting can be efficient, it also results in loses through braking.  I've read everything here, so I know that regen is apparently not coming with the Empulse.  Is this still the latest?  Once the tech is ready, I think an interesting implementation would be for a switchable system, controlled by a left-hand "clutch" lever!  Gasp!  Think about it, want to reduce braking and use the regen system to modulate speed, just close or ease off the throttle.  Want to coast, as if you're in neutral (downhill, long roll down, etc.), pull in the "clutch" lever.  Seems like an ideal implementation to me.  Thoughts?

I'd really like to see regen on an electric bike. I will admit that this is more an idealistic standpoint than a practical one.

Kinetic energy recovery works fantastically for cars. They have a lot of mass and can be fairly aerodynamic, so they lose the bulk of their energy (at sane speeds) to rolling losses and to heat under deceleration. Hybrid cars work so well because they can recover (full cycle efficiency about 50%) kinetic energy, and they also tend to tweak aerodynamics and rolling losses to increase total efficiency.

Kinetic energy recovery on a bike is a neat idea. The problem is, bikes lose far more of their energy to aerodynamics and rolling losses than to heat through the brakes. And unless you have a chip yates-style front wheel recovery system, you're limited to how much total torque you can use to what's available from the back wheel. And you don't want to lock your back tire. I recall reading the "typical" range extension from rear-wheel KERS was around 6%.

[Richard230]

I have an EMS GPR-S with a D&D sepex motor that uses regenerative braking. When you touch either brake lever (it has brake levers on both bars, like most scooters and bicycles), the bike slows down fairly rapidly. (Personally, I preferred the system Vectrix used to activate the regen that had a throttle that could be moved beyond "closed" to activate the regen system.) I paid about $800 extra for this regenerative braking feature - mostly due to the cost of the big motor.

Frankly, while the regen is fun and useful to save your brake pads, it doesn't extend the bike's range much. I ride up and down a lot of hills and it only feeds between 2.5% to 3.5% into the battery pack. So it isn't worth the money, unless you have an AC motor that can accommodate regen with little additional cost.

In any case, my feeling is that regen is more valuable when used on a heavy car, but on a motorcycle it doesn't do much because of its light weight and poor aerodynamics. On my bike it feels about like the compression drag that you feel when closing the throttle on a 4-cylinder IC motorcycle. I once braked while traveling downhill at 70 mph and saw 60 amps being generating for a few seconds, but most of the time I will see under 30 amps and again that is only for the few seconds that it takes to come to a stop. Note that my motor normally sucks about 150 amps when trying to keep up with auto traffic on an expressway and that draw is for minutes at a time.

I think that coasting downhill without regen is just fine - as long as you have a good set of brakes.

I too have an SV650, along with a couple of BMWs, a Yamaha and a Triumph.

[JN2Wheels]

@ Richard230 and protomech,

Seems like you two are in agreement that the gains from a regen system are fairly negligible for a motorcycle, especially given the added complexity required.  From a riding standpoint, I really like the Vector system... had forgotten about that implementation.

Anyone know how much additional hardware (weight and cost) such a system would entail?  Perhaps it could be an option to go with the 2-up seat, the bikini or full fairing, ABS, etc!

As for crashing, has anyone even dropped theirs?  I really would like to know that the batteries aren't too fragile to survive a windstorm drop or a gravel low-side.  This would be a deal braker for me.

[Brammofan]

As for crashing, has anyone even dropped theirs?  I really would like to know that the batteries aren't too fragile to survive a windstorm drop or a gravel low-side.  This would be a deal braker for me.

I was putting mine on my hitch-mounted rack and it fell on me.  Bent the handlebars, broke the bar-end mirror and sprained the sh!t outta my wrist.  The bike was, for a short time, more than 90 degrees from upright.  The handlebar (and me) took the brunt of the impact, so it wasn't a particularly hard fall.  No other damage to the bike. No apparent after-effect to the batteries. 

[Richard230]

Due to the batteries that I have in my GPR-S, my motor's appetite for electricity and its less-than-optimal BMS, I have killed a number of my prismatic LiFePO4 batteries. (You know they are dead when their plastic bodies blow up like a blimp and vent noxious gas.) What has compounded my problem is that the Chinese manufacturer of my batteries has decided to no longer import the batteries due to the demand for their products in China.

That has resulted in me having to buy about 10 used batteries from various private sources who have moved on to a better electric storage system. These replacement batteries have been sent via UPS, USPS and FedEx. None of those transportation companies are noted for gentle handling of packages. In spite of that, all of my batteries have arrived without damage. So my thought is that if they can survive UPS, they likely can survive a pretty decent crash.

Brammo enclosed their batteries in tough steel boxes, unlike my batteries in my bike, which are placed in open-topped, thin, mild steel boxes that are there only to keep the batteries from falling out of the bike. Therefore, I wouldn't worry about any motorcycle crash that does not involve a lot of fire causing the batteries in an Empulse or Plus to become damaged to the point where they might pose a hazard to you or anyone else.

In any case, you know that Brammo is going to put a lot of thought and technology into their battery system to insure that their new LiPo batteries will safely survive the expected riding environment for their motorcycles.

[Vibetrippin]

I can't remember who it was, but somebody on here dropped their bike on an icy road. Since I haven't read anything about him having battery problems I imagine that his bike is performing fine.

[protomech]

@ Richard230 and protomech,

Seems like you two are in agreement that the gains from a regen system are fairly negligible for a motorcycle, especially given the added complexity required.  From a riding standpoint, I really like the Vector system... had forgotten about that implementation.

Anyone know how much additional hardware (weight and cost) such a system would entail?  Perhaps it could be an option to go with the 2-up seat, the bikini or full fairing, ABS, etc!

I don't think rear wheel regen adds much weight, it's more a matter of design time and perhaps selecting batteries that have can accept high charge rates. Maybe a few pounds if using a separate lever (vs a "twist past neutral" system using the throttle) and any additional control hardware.

A KERS is a very serious design activity. Possibly as much as the rest of the electrical system combined. It offers some very respectable performance (range improvement) when done properly, but you really have to approach the design process from the beginning knowing that you're going to double your time investment for 6% extra range or so.

To get a sense for that, look at some of the Chip Yates interviews about the KERS in his superbike, or check out this electric subaru impreza racecar and their struggles with KERS from a couple years back. Absolutely fascinating to me.
http://www.proev.com/

As for crashing, has anyone even dropped theirs?  I really would like to know that the batteries aren't too fragile to survive a windstorm drop or a gravel low-side.  This would be a deal braker for me.

Check out this crash report. Dumped the bike at low speed on ice, most of the impact absorbed by the rider's leg. Brammofan's drop while loading was probably a harder shock. No reported damage in this case, anyhow.

[oobflyer]

My 2007 Vectrix has regen braking. To use it you just twist the throttle in the opposite direction. There are no additional components for regen breaking - it's just a matter of reversing (electronically) the polarity of the voltage at the motor to turn it into a generator. On the Vectrix the motor is in the rear hub, so there is no issue of stress on the chain. I'm betting that the chain drive is the obstacle for regen braking on the Brammo bikes.

I do believe, however, that the amount of energy recovered from regen-braking is quite minimal, and even less on a bike than a car (less momentum). I'll trade my Vectrix for an Empulse right now  ;-)

[HighlanderMWC]

My Enertia has dropped twice. It was knocked over while parked and a couple months ago I went down hard enough to crack my helmet (wet railway tracks). The handlebars, saddlebags and footpeg took all the impact in both cases (and on opposite sides). No discernable effect on the batteries.

[JN2Wheels]

@ Highlander,

Glad to hear you're ok.... and thanks for taking one for the team!  The railroad track lay down sounds pretty rough, and its good to hear the batteries made it through with no problem.

The EV motorcycle is an interesting case in that the bulk of the cost of the bike is going into a permanently affixed "gas tank" with little opportunity for repair should disaster strike.  I'm sure if its a just-riding-along warranty failure, Brammo will make good.  But what happens in the case of a high speed low side where the frame, motor, and bits are ok, but something is borked with the battery or management electronics?  Huge chunk o change to replace the whole pack.  I'd like to see a crash replacement policy, where Brammo will swap out a verifiably junked battery pack thats out of warranty at cost (or close) with their new local dealers.  That way the recycling can be handled in a best case scenario. Ideally too, these retailers will have specially trained and certified Brammo techs to trouble shoot and perform the service.

Paging BrammoBrian, I'd love to hear Brammo's thoughts on crashability, crash replacement, and certified service techs.

And while I've got you here... Any reasoning or thoughts behind regen?  If future models get it, would it be and upgrade compatible with the first gen of empulse?

[Brammofan]

BrammoBrian has spoken on the issue of regen.

[JN2Wheels]

Awesome, BrammoFan.  That helps a lot!

Now, crashability, crash replacement, and certified techs?