Qulbix raptor efficiency?

lawsie

10 mW
Joined
Feb 2, 2014
Messages
25
Location
Sydney
Hi all

I recently got my raptor 165 up and running and have been riding it to and from work.
It's running a crown tc80 with a 72v 18f 60a crystalyte controller (thanks to Jay from hyena for everything). The battery is a 25ah lithium ion that charges to 88v and I am using 26 inch wheel's.
Overall I am happy with how it rides but I thought it might be more efficient. Taking it easy on the way to work I am averaging 34km/h and getting 42wh per km. On the way home I decided to up the speed and this only saw a slight increase to 45wh per km. On both these trips I pedalled when accelerating as well.
Initially I thought I must be throttle happy but now that I have been riding for a week I can't figure out why riding flatout only uses a few watt hours more then taking it easy.
For the 30km trip I am using around 1400wh. Does this sound excessive?
The CA set at a 70a limit if that helps at all

Any help is appreciated as I am fairly new electric bikes coming from dirt bikes.

Thanks
 
Maybe youre simply to slow......

The efficiency will drop when you lower the rpm to much.

Dont know the TC80 well, but thats a fact for all motors.
So, when you drive just a little bit faster, the efficiency will rise and you consume not significant more energy.
Maybe the TC65 would be better for your driving profile?

42wh per km is way to much, i think even when youre not in the efficiency "sweet spot" its to much.

When i stop pedaling and drive about 30-34km/h, i consume up to 14-16wh/km and i have a geared middrive, a direct drive should be more, or alt least the same efficient.
 
Thanks for the reply.
Yes you are correct that the slower speeds were not really helping the efficency as I had hoped. I can't seem to get it below 40wh per km no matter how I ride. My average speed today was 32km/h and I used 43wh per km.

I will admit the raptor is a heavy beast but I have seen others on here getting around 25wh per km with slightly different set ups when cruising.
The tc65 maybe a better option but I'm thinking something could be changed within the controller or CA to provide better economy

Thanks
 
Lawsie, something is definitely off there, you should only be seeing half those figures even with knobbies on the road. I take it it's nothing mechanical like dragging brakes ? Did you happen to feel the motor to see if it was warm ? I would expect it would be quite hot pulling that sort of load over 30km.

I'd say it's artifical though and it's something misreading in your CA. It could be your rShunt value (should be 1.0) tyre rolling diametre (measure yours to be sure but should default to 26" which should be near enough) or the pole count is wrong (should be 23) . I normally pre-set all these things but didn't get to in your case because of a few of the changes we did with the battery etc. We'll get to the bottom of it either way :)

In the mean time, to prove that it's artificial give it a full charge and then do your commute in the same fashion as you have been doing. Is it 30ks return or one way ? If return do it for 2 days without charging or if one way then ride home as well without recharging. You should easily get 60km range riding easily as you are doing. If it's a wacky CA setting you'll supposedly use 2800whr for the return trip which is much more than the battery holds. I'm willing to bet you'll get home without the BMS cutting out. If not, and it does cut out then I apologize in advance for the return hard slog :lol:
 
Hi mate

What should the low voltage be set at as it is at 39v?

Its a 30km return trip.
The motor was fairly hot this afternoon. I will try and go for a ride at about 15km/h and see what power she chews.
According to the stats I have used 84ah to ride 151km

I just checked all the CA settings and they are the correct values as you suggested.
Before I rode it I set the tyre diameter so that is also alright.

Thanks for all the help
 
lawsie said:
Hi mate

What should the low voltage be set at as it is at 39v?

Its a 30km return trip.
The motor was fairly hot this afternoon. I will try and go for a ride at about 15km/h and see what power she chews.
According to the stats I have used 84ah to ride 151km

I just checked all the CA settings and they are the correct values as you suggested.
Before I rode it I set the tyre diameter so that is also alright.

Thanks for all the help

With your low voltage cut off providing your pack is a 21s pack it will charge to 88.2. Easy way to calculate is your cells at full charge would be 4.2 and at the lowest 3.5 vt. You can go lower but this may shorten your pack life. 21s and 3.5Volt=73.5 volt which would be your low voltage cut off.

I find a good speed is 30kmh. On the CA look at the watts when peddling, if you're putting in effort youre watts will be low if you're crusing on the at 23-30k with watts around 50-200. Give it throttle and it'll go over 1000. Try to keep watts low.
 
Don't forget this is li-ion Rod and not lipo. While they both charge to 4.2v li-ion discharges down to 2.75v to get full capacity rather than 3.0v. They also have a little more sag to less than nominal voltage for more of the discharge so limiting to 3.5v/cell average will actually cost you quite a bit of range. Obviously the old rule applies that limiting discharge to 80% where possible will maximize pack life but it's certainly save to go under 3.5v/cell average with li-ion. I'd recommend a CA LVC of around 65v for a 21S pack. In perfect conditions (which we'd never see in the real world with every cell discharging evenly) the BMS technically wouldn't trip until <58v.

Lawsie, how is it going now ? Still the same high load ? If you're rolling along at say 30km/hr on a flat road how much power is it drawing ? Up a hill this will pull a bit more but on the flat on a sealed road it should only sip power.

Schlafmutze's suggestion to check the halls and phase wires is a good one though typically you'll know all about it if one of these isn't connecting properly as it won't be running smoothly. No damage to the wiring when your mate crashed it recently ? Check around the axle exit and make sure the wiring is cable tied tightly to the frame, there's very little clearance here. If the shop who fitted hasn't secured the wiring tightly the heads of the rotor bolts can clip the wiring and wear through the insulation in short order.
 
Just to give you some figures, Im running a H40 motor in the slow wind on a 21s 9.75Amp battery in Samsungs 20R Cells and if i travel at 30kmh on flat road my CA is telling me im using around 250 to 280 Watts of power and even lower if there is no wind, I find that the wind can push that upto 600 watts at times with around about 15 to 25kmh headwind.

So at 30 kmh my little 9.75 Amp Battery can get me around 45 to 50 km on a battery.

My original LVC was set at 70 volts which equals 3.33 volts per cell but i found i was only pulling around 6.5 amps before lvc would cut in, Now i have dropped it to 65 Volts and im seeing around 8.5 amps being used for about 60 kms of travelling before my lvc cuts in.

I know these are different motors but hopefully my motor being a 40mm wide stator can give you some type of refference as my bike can hit 65km/h but most of my riding is around the 25 to 35 km/h mark.
 
I bet that your brakes are dragging
 
Brakes are all good. I can pedal the bike at 25km/h fairly easily with no drag. With the wheels off the ground the only drag is that of the motor.

I haven't had a chance to ride it again due to rain but at a steady 45km/hr it was using between 1500-2500w. Its actually pretty hard to hold it steady with small bumps causing me to turn the throttle ever so slightly.
I have had the wheel off a few times to check and everything looks ok. Unplugged and reconnected all wires etc.

After the 30km trip i'm pretty sure it was around 72-75v

I will update when in get a chance to ride it again.
I will also record all the CA settings and post them up as someone might recognize anything that doesn't look right.

Thanks for all the help
 
I get this with 2.5" dh tires on. Seems absolutely fine to me. Maybe try some hookworms?
 
I also changed battery configuration. 48v is much closer to your speed so not loosing as much heat in your controller. Or change to a 24" wheel. Basically if you were at full throttle at full spped. Ie 20mph. You would be more efficient
 
I've just been out for a ride and at 45kms an hour I'm drawing around 1000 to 2000 watts. The issues at these speeds is peddling input is minimal. At 30kph then my watts are around 150 to 500 but if I'm peddling then they can be under 100.

I see its shit weather in Sydney today so you probably wont be able to try it. My phasor has the 2.5 Schumph drive so peddling at 45 is achievable. Maybe you have mentioned your crank set up. What exactly are you running to be able to pedal at 45kmh. My Raptor set up is only good for 30kph peddling which has the 48 tooth on the front and 11-32 rear.
 
Hi again. Well it looks like the problem was once again my right hand. Coming from a motorcycle background I seem to be riding it like one.

I did some tests tonight to compare figures and at 20km/h I was at about 450w with no pedalling. At 35kh/h I was pulling 650w. At 45km/h I was getting about 1250w. Pedalling at the slower speeds halved the consumption.
Rod I can only pedal at a max of 35km/h before I can't keep up. I have a 36t front with a shimano 7 speed. I must have typed something wrong earlier.

I then rode as I would normally ride and bingo. I wasn't seeing anything under 1500w. The majority of the time it was up around the 2500w mark

I apologize for my lack of experience and thank you all for the wealth of knowledge and suggestions.

Cheers
 
Ah, I'm very happy to hear this!
I've been thinking about it the last few days and arrived at the conclusion if you are still seeing these figures despite everything else it must be a shorted winding and I was going to have to cough up a heap for a replacement motor for you! Good to hear it's just your wrist, I can adjust that problem for you too with just a splint and some rubber bands :lol:

As for your pedalling and gearing, I'd look at swapping out your chain ring for something like a 42 tooth. If you dont already have a 11t top cog on the back switch out your freewheel for a DNP or similar that offers this will allow you to pedal along a bit more casually at those sorts of speeds. Pedaling comfortably at ~40km/hr is the sweet spot for commuting IMO and should allow for you to see power consumption definitely on the low side of 1000w. If you're going to ride it daily on the street it might be worth swapping the tyres over to something a little less knobby, that would be costing you a little efficiency too.
 
Lawsie as Jay mentioned the 11 tooth freewheel is a good option.http://glowwormbicycles.com.au/store/e-bike-parts-and-accessories/freewheels/dnp-epoch-screw-freewheel-7-speed-11-28t-ebikes

Good to see that you have it worked out. I had a similar problem as well a couple of years back working it all out.
 
Thanks for the link to the freewheel. It sounds perfect

I rode to work again today and managed to get consumption down to 1000wh for the 30km trip.
I still averaged 35km/h but modified the way I rode (obviously I still couldn't help my self on a few dirt sections as my top speed was 68km/h). I may have to find something that can limit the power but still allow the higher speed for cruising if that possible.

Reading a few older threads has helped as others seem to have had some trouble when they have come from a motorcycle background.
Ebikes definitely require a different style riding when effiency is needed. At one point I was sitting on 45km/h and sipping just 850w which blew my mind compared to what I was seeing.

I also rode past a highway patrol car while pedalling and he didn't look twice which was a surprise.

I'm thinking I may need another ebike for no other reason than I want one. Hmmm what should I get?
 
Yeah the CA is great for adjusting how you ride and getting the most from your pack. That said with a big 25ah unit you should go for hours if you exercise some right wrist restraint. You must have been tearing it up before to see those figures :lol:

Let's tee up a time to drop in next time you're out this way, I have a throttle mod I can do for you which will tame the beast on demand and do what you're after. In the mean time have a play with the CA to limit the speed or current for your commutes to make it less frisky.

If you really want another ebike and you're commuting regularly on the raptor I'd lock it up for the week and build a dedicated commuter with slicker tyres like crazy bobs. Maybe a light XC full suspension. You'll see an efficiency boost and it'll be lighter and more subtle in public. Though it's good to hear you had no trouble with the hwp. As usual the key is to ride responsibly and you'll have no issues
 
I believe it was just the way I was hitting the throttle out of corners etc. The motorcycle rider in me always seems to accelerate hard out of corners and from a dead stop.

The throttle mod sounds perfect for my poorly controlled right wrist. I would probably halve my consumption.

The raptor is still impressing me. I'm yet to get some bolts to mount the moto seat to the frame but I think that will make it handle even better on some of the long wavey trails I ride. I will definitely need a harder rear spring as 70km/h and washed out fire trails are pushing the weak 350lb spring. I may need to get a go-pro.

Don't worry jay the stock knobby tyre looks like a slick with only 180km on the clock. I need a harder compound to with stand the beating.

I nearly think I couldn't go back to a normal bike with a motor as it wouldn't be enough. The raptor feels perfect.
If only quilbix designed a slicker frame for those that only want to commute.

Thanks
 
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