A forum for Vectrix riders to post their experiences regarding regen braking.
How much difference does it make under real world conditions?
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I tried to establish how much difference regen braking makes.
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The test course:
34km total return. Little traffic.
About 13.5km at 80km/h with multiple up and downhill parts, overall staying at the same elevation level. Undulating up and down by probably 20-30m repeatedly.
Occasional braking is needed on this part due to several tight bends at the bottom of undulations and sometimes because the scooter coasts faster than 80km/h.
This is followed by a continuously steep uphill part of 3.5km length with 200m height increase and 60km/h speed limit.
Turn around at that point and return to starting point.
A lot of breaking is needed on the downhill 3.5km to stay at the speed limit and make it around the bends.
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Results:
Using regen braking throughout the ride the remaining battery charge was 6/17th, 128V, 36dC battery temperature. EST RANGE displayed: 22km
The scooter felt like it still had full power at the end, going up the last hill at 80km/h at less than full throttle. My estimate for remaining range: between 3 and 5km left.
Ambient temperature: 21.3dC at bottom, 19.3dC at top.
Using no regen braking at all (same route) the remaining battery charge was 5/17th, 125V, 36dC battery temperature. EST RANGE displayed: 15km.
The scooter had enough power to climb the last hill at 80km/h but at full throttle only, and the battery warning light and “buSVLt” appeared briefly on the display.
My estimate for remaining range: None.
Ambient temperature: 20.5dC at bottom, 18.7dC at top.
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Problems potentially causing bias:
Whilst the battery was charged fully each time, the first run was started just after charging was complete (charger had just started the EC=End of Charge cycle in which the fans are running but no charging happens.
The battery voltage was 144V and battery temperature was 27dC.
The second ride was done with the battery having been fully charged the evening before. I tried to give it a “top-up” charge just before leaving, but the charger turned itself off after just a few minutes.
The battery voltage was 141V and battery temperature was 27dC.
The road was wet in some places during the second ride and I might have gone around corners a little slower.
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Overall this result is consistent with my previous experiences – regen braking does add a little bit of range, in this case about 12%.
This is very significant for my circumstances because my commute is right at the limit of my Vectrix range.
I’ll try out the effect of avoiding regen braking during my usual commute, but might run into trouble with insufficient range to get back and up the driveway.
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I just repeated the same trip without regen braking.
I changed the riding position to "normal", ie. bum against the bump in the middle of the seat.
The previous two rides had been done with knees almost against the dashboard in chopper style. This is a lot quieter because the wind does not hit the helmet but I do not yet know how much difference it makes to the range. At 187cm height I am just looking over the edge of the windscreen that way.
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This time the battery was charged the evening before, and I turned the charger back on for a top up just before the ride. This increased the battery Voltage from 42V to 44V and the battery temperature was 23dC.
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Ambient temperature : 23.4dC.
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The road was dry and I was able to take most bends at 80km/h, so there was a little less breaking than last time and therefore less accelerating.
Driving style: Aggressive but within the speed limit.
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At the end of the ride the remaining battery charge was 5/17th, 126V, 35dC battery temperature.
EST RANGE displayed: 17km.
The scooter had enough power to climb the last hill at 80km/h at a little less than full throttle, and neither battery warning light nor “buSVLt” appeared this time on the display.
My estimate for remaining range: 1-2km.
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I just repeated the same trip with regen braking.
Riding position again "normal", ie. bum against the bump in the middle of the seat.
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This time the battery was charged continuously since the last regen braking test ride until it changed to "EC"= End of Charge mode.
Battery voltage: 47V and 30dC.
The recharging took 3hrs and 20min and used 3.9kWh.
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Ambient temperature : 23.5dC.
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The road was largely dry and I was again able to take most bends at 80km/h, so there was little breaking like last time and therefore less accelerating.
Driving style: Aggressive but within the speed limit.
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At the end of the ride the remaining battery charge was 6/17th, 128V, 38dC battery temperature.
EST RANGE displayed: 22km. Exactly the same as for the first regen braking ride except for a slight difference in battery temperature.
The scooter had enough power to climb the last hill at 80km/h at less than full throttle, no warning lamps, it felt like it still had full power.
My estimate for remaining range: 4-5km.
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All up the problem remains that the initial voltage is different between both test rides, although I am not sure if it matters.
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Starting with 147V or 144V did not make an obvious difference between the two rides with regen braking.
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Starting with 144V vs. 142V for the two rides without regen braking might have made a difference.
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It appears to me that the effect of regen braking is not large enough to make it easily detectable amongst the variables that the real world conditions keep shuffling.
(These are road and traffic conditions, ambient temperature, wind, battery voltage and temperature and rider behavior, tire pressure etc. etc.)
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To be relatively certain about the effect a larger number of rides is needed.
This I can only do as part of my usual commute, which strongly increases the influence that traffic volumes have on the results.
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I have already done many commutes using regen braking almost exclusively, and because I usually make it home with full power but very little range left, I should be able to determine if it makes a real world difference.
After all, that test ride I just did four times is not what I would usually be doing - it's just for fun when I have some time!
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If regen braking is adding between 5-12% range, then I should frequently arrive home from my commute with less than full power if I do not use regen braking.
I shall try that out...
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I'll continue this particular discussion about one of the effects of regen braking here because it is more likely to be found under this heading than in the original post at:
http://visforvoltage.org/forum/3372-vectrix-loopholes
I tried to make this happen on purpose to figure out what actually happens:
It is not loss of contact with the ground but locking of the rear wheel that turns off the regen braking until the throttle has been returned to the zero position. (Maybe that's what you meant, anyway)
I have rarely experienced locking of the rear wheel by regen braking alone (and only on slippery, downhill slopes at very slow speed), it is a bit like rear-wheel ABS, but the rear wheel locks easily if the rear disk breaks are used on top of regen braking.
It's the same as if your wheels lock on snow or ice with normal brakes: You have to let go of the brakes in order to get the wheel spinning again and to regain some control and braking action.
On slippery ground, with full regen braking applied, just a touch of rear disk brake can lock your wheel. The more or less natural reaction is then to let go of your disk break, expecting to be back in ABS-like regen braking mode, but you instantaneously find yourself in free-wheeling mode instead.
I try to avoid using the rear disk during regen braking.
Whenever the road surface is a bit dodgy I only use the disks, they are excellent and give much better fine control than the regen braking.
Any motorbike instructor would tell you that you should always use both front and rear brakes simultaneously.
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The regen brake could actually be used as a rear wheel ABS:
I found a spot with a lot of gravel on the ground to test this out on flat ground and found the following:
If the rear disk brake is not used at all then the rear wheel only rarely locks despite full regen braking, even when the front wheel locks up temporarily (almost causing a crash...)
The effect of full regen braking in the context of maximal possible use of the front disk appears to be very close to what you could achieve by using both disks together, without regen braking.
I found earlier that it is (just) possible to get the front wheel to lock up on a good road surface when breaking extremely hard during practice runs.
Adding hard font disk breaking to full regen braking on good road surface at about 40km/h did not cause any problems.
The fastest and safest way to turn a standard regen braking situation into a full emergency breaking might be to add the front break and leave regen brake applied and leave the rear disk alone.
Letting go of the regen brake first might lead to a short delay to efficient braking, and adding rear disk to regen and front disk braking is very likely to lock your rear wheel.
I have not yet tested this at high speed - it might behave differently.
See also parts of http://visforvoltage.org/forum/2924-honda-goldwing-sp1 for more thoughts on regen braking.
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I can't say I've experienced the free wheel after bump too much. But I will say in my limited experience with snow and the vectrix that the regen braking is strange.
As for the regen to emergency braking, this is the thing that makes me the most uncomfortable.
For me its an comfortable transition either way.
1. to release and grab both
2. to keep the throttle full back, and some how pull that front brake lever.
I guess I've developed a probably bad habbit of in emergencies clawing my index finger around the lever and maintaining regen. Its the fastest way for me I've learned.
http://www.qsl.net/n5mya/aero.html
If it can be of some help: I've acquired the habit to first release the throttle then grab it after lowering the wrist as to be with the fingers aligned with the front brake while applying regen braking, this is much quicker done than explained :). But I second your thoughts, it is difficult to use both regen and front brake at the same time.
Whilst re-reading the above posts I found some errors:
That was supposed to be 142V to 144V. There is another similar error further down the thread somewhere.
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This is incorrect. There is a small amount of current going into the battery during "tr", just enough to keep the voltage up whilst the battery is being cooled down for one hour.
I did not know this before I build the RETAMPI.
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This information may be used entirely at your own risk.
There is always a way if there is no other way!
I am seriously considering swapping the brakes to opposite sides. Assuming that there is adequate hosing, I would only need to detach and swap the two brake hoses at the reservoirs.
Bicycles have always placed the front brake on the left and rear brake on the right. Motorcycles move the front brake to the right so the non throttle left hand can operate the clutch. Vectrix ain't got no clutch, so in my opinion, with the fairly significant rear braking effect of the regen throttle, the front brake (which typically bears the majority of bike stopping power anyway should be on the left.
No, not anywhere I (have) live(ed).
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
But you live in Australia. Everyone knows that everything is upside down in Australia! HAHA!!! :-)
Here in the US, where we drive on the RIGHT side of the road, bicycle controls have always been left-front, right-rear.
Hmmmm...try it. You might just like it!! :-)
P.S. - I tried Vegamite once. That stuff is horrible! HAHA!! :-)
Here is a previously posted video showing the RETAMPI on the Vectux during a full throttle acceleration, followed by a full-regen-throttle-deceleration, followed by a full throttle acceleration.
All on fairly flat ground, with about 107kg payload and with a relatively full battery.
The RETAMPI is calibrated to show "-100" when the maximum possible amps flow out of the battery. I do not know what the actual amperage is.
It might be: 20000W(=peak motor power as advertised)/125V (=nominal battery voltage) = 160A.
That's unreliable, though. The peak amps are probably a fair bit lower, but who knows?
What is more reliable - and relevant to the regen topic of this thread - is that the RETAMPI also shows the power going into the battery during regen braking, as a positive number, and also as a percentage of the maximum amperage observed during full acceleration.
So, if you are keen, you can calculate all sorts of things from the information in the video, like C/x charging ratios!
The RETAMPI is measuring the current which is going through the main positive battery cable, so the measured regen current (percentage) is not the entirety of what is produced by the motor/regen system, but only what is actually flowing into the battery.
How much of this is likely to be turned into heat, and how much into recoverable battery charge - I leave that for others to asses (for now)!
Also, there might be an amount of electrical charge going into capacitors; that would be in addition to the current (percentage) measured by the RETAMPI. This might possibly be used during the next acceleration or be fed into the battery later.
Any suggestions for an experimental setup to clarify these (and any other questions you might have) will be considered!
Mr. Mik
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I think a way to calibrate the batteries charging rate using brake regeneration would be to find a hill long and steep enough so when you go down it would generate a quantitatable charge but that might involve having to truck the scooter up the hill a number of times.
Also I was wondering what provision is engineered into it to prevent overcharging when the battery is fully charged as in a situation like the above test, the only thing I can think of is if the motor controller has a variable reverse motor while going forward mode in addition to its other modes. What I mean is when your backing up the scooter the motor is running in reverse so it might also be able to do that when going forward in order to use electricity instead of generating it. If this is true then the regeneration feature of brake regeneration may not occur when the battery is fully charged so you could go further if you use your regular brakes initially.
I'm sure it's not my imagination, but I do think that the regen brake is more effective when the batteries are not full up.
The start of my commute is Immediately downhill, and it seems there's not that much braking resistance. Then after a few miles, it's better. I have deduced from this that there must be some sort of flow control for the amps going back to the battery. Anyone else noticed this varience?
Simon
Howdy,
I've definitely experienced reduced regen braking effectiveness after a full charge. The batteries can't take max regen when they are full, the controller likely limits the regen current as you said to prevent overvoltage and damage to the controller and batteries.
(When the batteries can't accept all the current it simply raises the bus voltage that could simply fry the controller or at the very least heat up the batteries; pushed to the extreme, excess voltage would release hydrogen gas that would build up and increase cell pressure and temperature and bad things would follow...)
I use regen braking almost exclusively but I blend front and regen braking for the last bit to reach a complete stop or during hard braking. I've had the rear lock up once for a couple of meters on wet pavement while braking to a stoplight on a downhill but I can't remember if I lost regen completely once the tire regained grip. Since the wheel locked up while decelerating and just before I reached a complete stop it's hard to judge since most of the braking effectiveness is on the front wheel and at low speed regen doesn't do much either.
07 Vectrix, Vego 600 mod.48V 800W, Arcade Alu E-Cycle 24VSachs Hub
Of course there is. Like any other charging system on any other vehicle, the output of the alternator/generator/or in this case reversed polarized motor must be regulated to prevent damage to the system. In our case, this is likely controlled by the controller itself, rather than a stand alone regulator as most vehicles use.
The only real "variance" I can notice with regen is directly related to how hard I twist the throttle back. My run everday starts with a half mile descent to the main highway, and I can't tell any difference on the regen decel strength between a morning run down and a lunch time run down. Although I'm certain that my morning run regen does nothing to charge the already full battery, it still makes more sense to me than heating up and wearing out brake parts, which has always been a major issue with all my other vehicles since I moved up on this hill (warped rotors, rapid pad wear, etc).
I have learned lots in the last year which makes it clearer to me that there are some serious problems with the Regen Effect Measurements I attempted in the above posts.
As already mentioned earlier on, during the EC part of charging there is some actual current flow into the battery. The voltage increases by 1-2V compared to the end of CC part. How much difference that makes, I do not know.
Something else I did not know about back then is the high self discharge rate of NiMH cell, particularly in the first 24hrs. So I basically do not know what those test results mean, because the self discharge rate might have been equal to, or different to the charge amount missed during the abandoned EC charge part.
And I never did the planned commuting without regen, because 2 weeks after the first regen tests the motor controller fried and Vectrix canceled my warranty. It took me 3 weeks to repair the motor controller myself, but 9 days later it was frying again. After another 3 days I managed to fix it properly; that was followed by another blown fuse 12 days later, which I sourced and replaced within 2 days.
And then I finally had some time to read up more about batteries. And as a result I canceled the plans to deliberately run out of charge for testing purposes.
In short: I don't know how much the regen really adds to the range, but it is so little that it is not easily measured with accuracy.
I guess the commonly quoted 5% range increase under good conditions might be right, and that means 2km extra range for me, 2km I don't have to push!
This information may be used entirely at your own risk.
There is always a way if there is no other way!
I happened to look down at my gauges while braking the other day and actually saw a bar added to my charge - I'm sure that it had just disappeared and the regen braking put back just enough voltage to add the bar back - but it was cool to see :)
Yes, it was a nice sight here also, when I drove down to the garage in the 2nd basement.
The way I see it, regardless of the amount of charge input, it is the GREEN way to slow the bike down.
These bikes are all about saving engergy and reducing maintenance costs and materials. Regen saves brake pad wear and tear and actually puts something back into the battery as a bonus. Therefore, regardless of it's real world charging benefits, it is a "Green" braking system. And in that sense, it is an absolutely wonderful alternative to brake pads! :-) (although conventional brakes do make an excellent backup source! ;-)
And AS brakes, they worked better then I expected, really!
I got used to them after after about 1 km, its so obvious to have them!
If you think about it: most of the energy to propel your vehicle is demanded when you accelerate. mass x speed = energy
You need about the same energy to stop that mass, and for 100 years, we converted into friction = heat that got lost entirely.
I know it's technically not simple to regenerate energy from braking, but it proves that efficienty was absolutely not important until now..
It's crazy really!
"doing nothin = doing nothing wrong" is invalid when the subject is environment
Bit of an old thread, but I thought I'd share my experiences from today.
I plugged in mid morning to charge with 4 bars remaining, not really expecting to use the Vectrix until late afternoon.
A few hours later I decided to go for a ride. The charge process was a few minutes in to the final 1 hour equalisation. I noticed the voltage was at 149V just before switching to the final stage and changed to 148V shortly before I unplugged. My normal level is 146-147V after a complete cycle. After switching on and pulling away, it was at this point I found regen braking was almost non existent! I realised then that the battery must be at maximum voltage and couldn't accept even a small trickle charge from the regen braking. After I had used some energy, everything was back to normal.
I have a quick question regarding this post for the EV experts in this forum (i.e. X Vectrix). I have noticed that at the end of a complete charge as of lately my voltage is only 140-142V. Is this a software limited problem that has been discussed prior re: needing to do the discharge cycles so the charger knows how much charge to put back in, or does this mean my pack has lost some capacity? Thanks for any advice/clarification.
Adam - Denver, CO
2007 Vectrix VX-1 charged with the power of the sun = zero carbon footprint
rewski
This is a tricky question to answer directly. Every battery pack is slightly different so the final voltage on any one pack is not a great indicator of health w/o knowing a complete history of the pack. The internal impedance of the pack has alot to do with the charging voltage and final voltage. Also, this voltage is sort of a floating voltage, as soon as you load it down the voltage will fall to the working voltage (again depending on the internal impedance this could be 6-10 volts lower). So with this in mind I wouldnt pay too much attention to the final voltage per se, but do take note of any change in final voltage over time. And yes, a change in final voltage could simply be that the gauge and pack are slightly out of sync, especially if you have been doing many shallow discharge/charge cycles. A discharge to icon should even it out again.
The main concern is AmpHrs out of the pack. If you getting consistent range (and consistent is used loosely here) then dont worry about the voltage. A periodic discharge to icon can help maintain the consistency.
Notes from other posts:
You may notice a weak regen immediately after a good full charge as the voltage during regen is limited. But as was noted it doesnt take long to knock off that top of charge and get back to full regen power. A couple good accelerations will do it.
yeh don't worry about this as the batts are full to the brim and .
if you try to shoe hord any more energy in somthing will give so take it easy man ..
I had a two year check up in June this year (just to make sure there were no nasty out-of-warranty frights waiting for me... The tech chaps said that both sets of pads looked effectively new. I make full use of regen, mainly from high speed to junctions, but I suspect 5-10% extra mileage is about right.
So I save on the cost of brake pads. I had a eureka moment earlier today though - with all this rear wheel braking going on, it probably explains why I only get 3000 miles from a rear tyre (6000 from the front).
Swings and Roundabouts!
Cheers,
Brian