Question about watts Currie eZip *Resolved*

[neiltoe]

I currently have a 24v 250w Currie Skyline. I was looking for a replacement mounting bracket at thesuperkids online store and seen a 24v 450w replacement with the mounting bracket. It appears the wiring harness is the same so I am tempted to just go this route. My question is how much difference in performance does 200w make? Also would a 200w difference cause damage or even work without changing anything else on my bike? I can use a little more power to climb hills as 250w always shuts off if I do not peddle soon enough if I am in twist and go.

I have swapped up to 450w. The motor mounted up and worked just fine. The original controller did not deliver anymore power so a new controller is necessary. 200w is a significant improvement for torque on this bike.

 

[dnmun]

usually when a brand advertises a 200W 24V motor and a 36V 250W motor then they are the same motor but have different battery voltages so the total power in watts that the bike can use is higher for the higher voltage model. so they change the rating. you should investigate to see if that is the case which means you could just add the extra 12V to your system and then use it as a 450W version.

or instead of spending more currie money on SLA, go to 48V lifepo4 until you can burn up that motor and then buy a stronger motor, and so on and and so on....

but i am not familiar with this motor or bike in particular. someone else may opine.

 

[docnjoj]

Drkangel does a lot of experiments with these motors and bikes. Worth a look for his stuff on this forum. I had the 450 version but I do not know if it is the same motor as the 250 watt. I had it running up to 54 volts, but very carefully and with a temp thermometer glued inside the windings. Very powerful (MY18Z) if I remember but very noisy. There is a quieter one now with helical gears.
otherDoc

 

[neiltoe]

Thanks for the replies. I guess my answer is not really worth it. I have to say I am constantly reading on this forum and getting more ideas but more unsure on what would work best for me.

 

[winkinatcha]

Hey Mate,

Just to give you a quick bit of background so you know I know, I build e-bikes in Aus, and sell base conversion kits and e-bikes that are compliant with AUS e-bike laws (250w) but are upgradeable power wise in two stages, first by upping the batery voltage, and then by upping the current... blah blah blah... main point is I ride a A LOT on the lower power end of the scale and have a lot of 'sperience in the 250 to 1500w area ON THE SAME BIKE...

An extra 250 watts (from 200 to 450), assuming your bike is already solid at 250w does not require any bike changes...

You will notice the difference enourmously... at 450 w you will find that you probably dont NEED to pedal, except to maintain speed, and effectively your bike will be able to carry you home unassisted, though you might find that means even though it is still hauling you up hills, it might only be at 4 mph... but it will still be hauling you, without you having to put in any effort.

One of my favourite power levels is 36 volts at around 350-400watts... I can keep up with/pass most lycras (fit(ish) cyclists on good bikes) and run at reasonable speed, with my input seemingly being about the same as the motor's... note, I LIKE to pedal...

Joe.

 

[neiltoe]

Hey Mate,

Just to give you a quick bit of background so you know I know, I build e-bikes in Aus, and sell base conversion kits and e-bikes that are compliant with AUS e-bike laws (250w) but are upgradeable power wise in two stages, first by upping the batery voltage, and then by upping the current... blah blah blah... main point is I ride a A LOT on the lower power end of the scale and have a lot of 'sperience in the 250 to 1500w area ON THE SAME BIKE...

An extra 250 watts (from 200 to 450), assuming your bike is already solid at 250w does not require any bike changes...

You will notice the difference enourmously... at 450 w you will find that you probably dont NEED to pedal, except to maintain speed, and effectively your bike will be able to carry you home unassisted, though you might find that means even though it is still hauling you up hills, it might only be at 4 mph... but it will still be hauling you, without you having to put in any effort.

One of my favourite power levels is 36 volts at around 350-400watts... I can keep up with/pass most lycras (fit(ish) cyclists on good bikes) and run at reasonable speed, with my input seemingly being about the same as the motor's... note, I LIKE to pedal...

Joe.

Thanks for the in depth answer that was what I was thinking but have no basis to believe it. Now that you say from your experience 200w difference is significant I will order it and install. What I am hoping for the most is it to quit shutting off. I believe it is an overheating protection but it is awfully annoying since the on/off switch is not that easy to get to while sitting.

 

[dogman dan]

I'm not familiar with those motors either, but in general it works like this.

There is a motor, and it may operate fine in a wide wattage range, say 250w- 800w, or 400w-1500w. So the motor may be built a bit more robust in the higher wattage motor. It might have stronger or wider magnets for example.

But what wattage that motor operates on depends on the controller. If you have a seperate controller, then if you upgrade the motor the wattage won't change or won't change much. Same controller will continue to put out just 250w.

If the motor has a controller built into it, then the 450w one will be stronger, because it has a stronger controller. If you post links to stuff you are asking about, we can look at the link and make better guesses.

Overheating motors is a big problem here in the desert. Eventually, you may want to spring for a larger brushless hubmotor and the larger battery to run it. Expensive yes, but I have not had big problems running direct drive hubmotors on 1000w. I melt a motor or even two a year, but that's at 3000w off road.

Winter is coming. Almost time for fiesta!

 

[dogman dan]

Maybe you need this,

http://www.thesuperkids.com/24vo35ampize.html

rather than the motor. The motors may be identical for all I know. So maybe you just need a more powerful controller to increase the watts. Bear in mind though, that 35 amps can be hard on small batteries. Do you have lithium or lead? Lead can actually stand more amps than a tiny inexpensive lithium.

You might want to go back to your original post and edit it. Change the title, and reask your question.

Ask what the difference is between those two specific motors. Use currie in the title, so currie experts will notice the thread.

 

[TylerDurden]

Ja, Currie supplied a 450W version with different windings. More copper = more motor.

As Dogman points out, the motor alone may not get you the lift you crave. The controller seems to cut you off at higher power.

But rest assured, a cheap 500W brushed controller and the proposed motor will feel very different.

Don't use the bigger controller with the small motor, or the magic-smoke may come out of the motor on the big hill.

 

[neiltoe]

Thanks again everyone for the answers. Yes the desert might be a huge contributing factor. No I don't want magic smoke. Damn I was hoping for a cheap fix.

After I posted I did a little tune up cleaned up the rear end a little realigned everything and got a little improvement from that. I have Lithium battery pack and the controller is rated 250w. So it would probably not do much after all. I have over time learned to avoid wot. It does help prevent most shut offs. But when I do hit a grade it is a mandatory I peddle or I have to turn it off and on. I don't mind peddling when it is exercise/recreation. But when I am commuting to work I would prefer to stay as low cardio as possible so I don't go in to work soaked in sweat.

I love the concept of an electric bike but got to say this is not an easy upgrade for a novice. You can settle on an upgrade plan and then research yourself right out of it. I really wish this was easier to do and not so much guess work when you don't really understand the specifics.

 

[ecowheelz]

We've been dealing with Currie for the past 4 years...

I'm pretty sure Currie downgraded all their Li-Ion powered bikes to 250W (instead of the 450W motors used on the SLA bikes) because of the negative impact the higher current draw has on Li-Ion batteries. Since we haven't switched one of these motors out, I'm not 100% sure, but I think it should work (unless the BMS in the battery has some type of cutout prevention). The issue is, you're likely to shorten your battery life by using the higher wattage motor.

I'm not a technical expert, but I think the lower C-rating of the Li-Ion battery limits how powerful of a motor can be used. It might work OK, but it will limit the life of the battery...

 

[neiltoe]

We've been dealing with Currie for the past 4 years...

I'm pretty sure Currie downgraded all their Li-Ion powered bikes to 250W (instead of the 450W motors used on the SLA bikes) because of the negative impact the higher current draw has on Li-Ion batteries. Since we haven't switched one of these motors out, I'm not 100% sure, but I think it should work (unless the BMS in the battery has some type of cutout prevention). The issue is, you're likely to shorten your battery life by using the higher wattage motor.

I'm not a technical expert, but I think the lower C-rating of the Li-Ion battery limits how powerful of a motor can be used. It might work OK, but it will limit the life of the battery...

Thanks for the information. With daily use of my bike for the last 4 months my battery is already starting to fade.

 

[dogman dan]

That could mean all the shutoffs are actually the battery bms shutting off to save the battery. Unfortunately, the cost tempts the manufacturer to try to make the battery as small as it can possibly be.

Once in the situation where you need a bigger motor, bigger controller, and bigger battery, I'd have to say a start over with a much more powerfull direct drive hubmotor and a much larger battery might be your best bet. Costs about $800-$1200 though, but you get a bike with true ability to replace a car. 20-30 mile range, up to 15 miles range at 30 mph.

But if your distances are not that long, just a better (larger so it won't cut out) battery for your current bike might do the trick. The risk of melting may not be that much. What's your normal ride? Los Lunas is not all that big. Do you need to ride to Belen or buque much?

 

[ddk]

negative impact?
li-on batteries*???
I think you're confusing battery chemistry with a piss-poor bms

*exception-battery packs made from way under-sized cells

 

[docnjoj]

negative impact?
li-on batteries*???
I think you're confusing battery chemistry with a piss-poor bms

*exception-battery packs made from way under-sized cells

Unfortunately Curry did just that ddk. The two batteries that they sell are 6 ah that come with the bikes and 9.6ah is the "big" one. Probably not great cells either.
otherDoc

 

[neiltoe]

That could mean all the shutoffs are actually the battery bms shutting off to save the battery. Unfortunately, the cost tempts the manufacturer to try to make the battery as small as it can possibly be.

Once in the situation where you need a bigger motor, bigger controller, and bigger battery, I'd have to say a start over with a much more powerfull direct drive hubmotor and a much larger battery might be your best bet. Costs about $800-$1200 though, but you get a bike with true ability to replace a car. 20-30 mile range, up to 15 miles range at 30 mph.

But if your distances are not that long, just a better (larger so it won't cut out) battery for your current bike might do the trick. The risk of melting may not be that much. What's your normal ride? Los Lunas is not all that big. Do you need to ride to Belen or buque much?

I wonder how complicated it would be to re-use the battery shell with something more respectable? I only travel in a 5 miles radius. I don't have the patience to charge for 4-6 hours anywhere other than home. Since there is the Railrunner I am tempted to venture further for just a day away from LL. But that hasn't happened but it could. I really like the cadence assist it is a huge factor when it comes to exercise. If I didn't have it I wouldn't ride off of scooter style riding.

 

[ecowheelz]

negative impact?
li-on batteries*???
I think you're confusing battery chemistry with a piss-poor bms

*exception-battery packs made from way under-sized cells

Actually, the C-rating of the cells will have a BIG IMPACT on how the cells peform over time. If they have a low C-rating, they can't handle higher power systems as well. That's one of the reasons these bikes have a 250W motor instead of 450W used on their SLA bikes. As mentioned, I'm not a technical expert, but I'm sure someone like Ypedal could clarify why the c-rating will impact the performance of the cells under higher amp draw...

Unfortunately Curry did just that ddk. The two batteries that they sell are 6 ah that come with the bikes and 9.6ah is the "big" one. Probably not great cells either.
otherDoc

The 6.4AH and 9.6AH batteries you're referring to are not options for this bike (the EZIP Skyline). They're sold as upgrade packs for the RMB (rack mounted battery) bikes Currie sells like the Trailz, Via Lento, Vibe, etc. And acually, these ar VERY HIGH QUALITY cells with a 3-year warranty. They're LiFePo4 cells produced by K2 Technologies in Utah. The EZIP Skyline, on the other hand, probably has lower quality cells. Not sure about the specifics, but it's a 10AH battery...

 

[docnjoj]

They may be very high quality cells but the 6 amp pack is certainly undersized for most of us. While you may be right about the quality I am always sceptical of ready made E-Bike batteries for ready to ride bikes. I hope I am wrong, because the market seems to be opening up to these higher quality bikes for folks who don't want to tinker much but just ride or commute. We will see.
otherDoc

 

[neiltoe]

I just want to do a follow up to my situation. I recently made the mistake of bending my rear rim beyond repair. I do use my bike as a daily commuter and am still just a noob. I chose to stick with Currie products until I really understand all this.

So I purchased the whole dyi kit from Currie. Overpriced and underpowered with SLA. All I really needed was the rear rim but I couldn't pass up the opportunity to go 450w over the 250w. I installed the rim and did the motor swap with all my existing components. I still got the cut off. This was no surprise as I suspected it was the controller that was doing it. After fine tuning the wheel so it was aligned properly (not really an easy task). I decided to do a controller swap. My original setup has PAS and dual brake cut off switches. The new controller has no connectors for these features. I still went ahead and setup with the new controller and the only things I kept original were the throttle and the battery.

So I took it on its maiden voyage. I took the bike to my daily nemesis the interstate overpass. I was surprised I went up at 9mph without any cut off or assist by peddle. Now I was impressed!. But the battery consumption has went up. So I added the SLA battery that came with the kit. My bike has increased in weight significantly now. But with 2 batteries my power indicator is a little more useful. I am only experiencing power sag when it is nearly dead. I am happy so far with the results.

So in summary...

My Currie Skyline is now 15mph consistent on level to a small grade. I can pull up hill grades I couldn't before. It does NOT ever cut off anymore. It has gained a lot of weight. But now I feel a little more confident venturing into areas I knew I couldn't go before. I now need to find a way to improve the batteries on my bike. The Lithium battery I got originally far exceeds the power output of the SLA battery I just got. But in tandem they really fill my power demands for my short commute.