Is my e-bike upgradable?

[andrey320]

Hello!
I ride a 2006 Izip Cruiser Enlightened. This is my original thread - http://endless-sphere.com/forums/viewtopic.php?t=270&highlight=

I will be moving in two weeks which will increase my commute to nine miles each way and add a fairly long and steep hill. At the moment, my bike does great going 15 miles/hour on flat roads. The controller overheats on hot days and on continuous uphills. After reading this thread – http://endless-sphere.com/forums/viewtopic.php?t=238&highlight=

and looking at the motor’s manufacturer’s website, I realized that there is a 36 volt version of the motor. This may open the opportunity of upgrading my bike!

Here are the specs of my bike -

Battery - NiMH EV Rated Batteries- Down Tube Concealed-24V / 9AH Pack - (20) 1.2V Rechargeable Cells

Motor - Exclusive Alloy Shell DC Brushless Geared Hub Motor (by Tongxin)

Controller - Exclusive Currie Electro Drive - 24 Volt Fully Potted (the sticker says – 300W, 24V, 15A

My goal for upgrading would be to increase top speed to 20-25 mph, and increase range to 30-40 miles. Current range is 20-25 miles(maybe longer - I've only gone 20 miles max).
Is this possible? What would be involved in this project? I am not very good with electronics, by am mechanically inclined and can follow directions. I guess the new motor, more batteries, new controller, and different gearing is what will need… don’t know the details though. Where to get the motor / controller / batteries (and what kind)? How to do the wiring? Would it be easier to build a new bike?

Here is some wiring and other tech info - http://www.tongxin.net.cn/en/download.htm

Here is a website where I can inquire about the tongxin products - http://product.globalimporter.net/china-sample/59965/Hangzhou+Zheda+Tongxin+Electric+Technology+Co,.+Ltd./1.htm

Thanks for reading and for any useful information you may provide!
Andrey

 

[Drunkskunk]

the way I see this, you have 3 weak links that have to be corrected bvefore you can hit your goals.

If your controller is already overheating on flat ground and warm days, its too small for the job already. it needs an upgrade. idealy A 48-72 volt, 20 amp would work. I don't know that a Cl-yte would work with your motor, but the smaller unit might be ideal.

The motor on these is small, meaning it isn't going to be very heat tollerant. at 24V and 300W its probably fine, but pushing it harder may fry it. my first reaction is to tell you to replace it with a BMX or C-lyte motor ... but if you were going to do that anyway, then pushing the motor harder and seeing if it would take it isn't such a bad idea. Many of these brushless motors will take a lot more voltage than they are tagged for, the killing factor is the heat. 36V might be ok though.

the Bike frame looks good. I like the stealth look. The only problem I see is that the down tube would never hold enough NiMH cells to be able to reach your goal for speed and range. to do 20+mph and double your range you're going to need a battery at least 4 times bigger. LiFe technology would do 4 times the power for the same size, but the cells would be hard to fit in that shape. Lipo has more choices in cell sizes, and is even more energy dense, but has a shorter life cycle. the biggest problem here is going to be the cost.

 

[andrey320]

Thanks for the input DrunkSkunk!
I am working on solving the current problem of overheating. A new controller is on back-order (has been for 2 months) and I have purchased two large heatsinks that I will use to "sandwich" the controller. Here is a quick question about mounting the heatsink - should I avoid direct contact with the frame?
The frame is black and gets hot quickly. I will probably use some heat resistant material to wedge between the frame and the heatsink....
Regarding the batteries, I understand that what I have now is not sufficient. How many batteries will I have to add? How do I wire them?

 

[Drunkskunk]

If you're wanting to go faster, the controller you have can't be used. Speed is a product of volatge, so a 24v controller won't work.
As for the over heating, the heatsinks attached to outside of the controller won't do much. there would be an internal heatsink the Mosfets are attached to. Idealy you would need to make this larger and put it out were the wind can blow across it. attaching your heatsinks directly to the original is an option, but not as good. the important part is to get air flowing over the heatsink.

But if its overheating now from just the summer heat and flat roads, then it may be a sign that it's at its design limit, and no amount of heatsinks will be able to keep it from frying once you add in long hills.

As for batteries, if you simply want to double your range at the speed you have now, just double the size of the battery.

 

[xyster]

If you're wanting to go faster, the controller you have can't be used. Speed is a product of volatge, so a 24v controller won't work.

Other Currie 24V controllers work fine at 36 volts. My 24v Currie works great at 36v -- and of course top speed is increased by 50%. It remains to be seen if Andrey's type of 24v controller will likewise live at higher voltages.

As for the over heating, the heatsinks attached to outside of the controller won't do much.

There was already a thread about helping Andrey's controller not cut-off due to temperature. The fins should help enough to prevent the early cut-off.

As far as batteries, I'd first try another 12v NiMH pack of the same AH capacity or higher, then if you still need more range, parallel another separate 36v pack (which because it's NiMH, will require separation for charging with its own charger). Realize that there's a fair risk 36v will kill this particular controller.

 

[andrey320]

I may actually be able to afford to risk killing this controller. What would go first, the motor or controller?
When my new one arrives (assuming it will), I may be up for the experiment of "another 12v NiMH pack of the same AH capacity or higher".
Can I just splice the wires from the new battery pack directly to the current batteries?
How do I wire up the pack?
Where/which batteries should I get?
Sorry for being such a noob...
Thank you!!

 

[xyster]

I may actually be able to afford to risk killing this controller. What would go first, the motor or controller?

If I remember right, you have a small brushless hubmotor. The controller would almost certainly die before the motor.

When my new one arrives (assuming it will), I may be up for the experiment of "another 12v NiMH pack of the same AH capacity or higher".
Can I just splice the wires from the new battery pack directly to the current batteries?How do I wire up the pack?

Basically. To wire in series cut the red (positive) wire going to the controller, then wire the part still connected to the batteries to the black (negative) wire of the new pack, and wire the red wire of the new pack into the part of the red wire you cut that's still connected to the controller. In essence, your stacking batteries end-to-end like in a flashlight, but doing it with the wires.
Series/parallel primer you should read before trying this:
http://www.batteryuniversity.com/partone-24.htm

Where/which batteries should I get?

You can actually use any type of battery you like, including lead or lithium, but I'm trying to keep my recommendations as simple as possible for now. For your 12v boost pack, either the 12v10ah or the 12v13ah packs here would work nicely -- the 13ah version would work better (much less voltage sag, and probably live longer):
http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=904
Going with the 13ah would also allow you the option later of increasing your range by replacing your internally-mounted ~9ah batteries with an external 24v13ah pack -- though you'd probably have to mount the 13ah batteries on the outside of your bike somewhere, as you'll obviously have to with the 12v "boost" pack you're thinking about.
If the extra expense is a major issue for you, you could use a much less expensive, but much heavier 12v 14-18ah SLA instead, charging it with it's own 12v SLA charger. This would also be a good way to test your system at the higher voltage before investing in expensive NiMH or lithium batteries. SLA batteries and chargers:
http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=775
http://electricrider.com/batteries/index.htm

Sorry for being such a noob...
Thank you!!

No prob. We're all noobs at most things.

 

[andrey320]

Great info xyster!
I will work on putting the heatsinks on today and will see how the bike does on the new ride to work in two weeks. I know it will not provide sufficient power to go up the hill, but hopefully it will not shut down.
What can I expect from adding the extra 12V?

 

[xyster]

What can I expect from adding the extra 12V?

1) Because voltage would be increased by 50% (24v --> 36v), top speed will be increased by 50% too (e.g. 16 mph --> 24 mph).

2) Because power (like to climb hills and to accelerate faster) is the product of volts and amps (watts (power) = volts X amps), you'll be able to climb hills you couldn't climb before, and you'll accelerate from a stop faster too. Without knowing the maximum slope of this hill in your way, it's not possible to know if a 50% increase will be enough -- but at least it'll mean you won't have to pedal as hard.

3) Because total battery capacity would be increased by 50%, so long as you go the same speed you're used to going (say 16mph), your range will increase by 50% too (e.g. from 10 miles --> 15 miles). If you use this added power to go faster than you did when you measured your range with just the original pack, then your range could actually decrease -- going just a little bit faster requires a lot more power because of increased wind resistance.

4) If you use the extra power to go faster or accelerate quicker, then because your controller and motor is handling more power, both will get hotter. A motor or controller that becomes too hot to hold your hand on, is a motor or controller on the edge of being fried. If you don't use the extra power (like by going the same speed you do now), then the motor and controller should get no hotter at 36v than at 24v, and you'll gain that extended range.

 

[albie]

I got a EZIP (which is really an IZIP) Trailz... its a full steel frame and i had BiGH help upgrading the bike recently...

Got a set of 12V 17aH SLA batteries and built a pack running at 36v 17aH. This will work with the bike till I organise a set of lipo batteries. The only problem i have now is the charger but I have my setup from a 36v scooter so I'll just check out what wiring I have on that thing.

here is the setup of what it is now... currently the top speed i've got on the bike is 35km/h on the flat and 25km/h while hill climbing.

The Currie Tech motor... crappo 200w motor!!!

Messy wiring... has been cleaned up after the photo was taken...

This is the fastest I've gotten it going down hill....

More piccies here

 

[BiGH]

Welcome Albie!

nice setup there

Glad those batteries are workin out 4 ya hope u ride 2 work each day this week!

 

[albie]

i can't ride it to work tommorow because i have to sort out the charger wiring (which will involve a visit to Jaycar in the city at lunchies)....

but I can start riding it again on tuesday! woo hoo!!!

 

[safe]

I think your best bet is like what has been said. Increase the voltage to 36 volts and change your controller so that it can handle the extra voltage. Be careful with your choice in amp limit for the controller however. In the chart I'm assuming that you use the same amp limit, but to be really careful you might even want to go a little lower. Look at how the heat just goes off the charts at low rpms... that's your biggest fear... low rpm full throttle situations like a really steep hill will launch the inside temperature of your motor up really high. With some knowledge and self control you can ride such a machine and be careful not to hold the low rpm situation for too long. (but it opens the door for potential abuse) You can prevent overheating by pedaling harder and backing off the throttle.

You will be making your bike no longer "idiot proof".

 

[albie]

The controller on the 2007 range is already rated at 36v.

You can buy the 36v SLA pack from currietech as well as the 24v SLA Pack.

If you were going to keep the setup that comes with the bike then it is a good idea to change the controller, but the setup thats currently on the bike won't be staying for long (possibly a few months) because I'll be going to a Hub motor setup.