Excelsior/Strong GTS Cromotor Build

Joined
Apr 15, 2011
Messages
330
Location
Paris France
I am about to venture into lithium polymers for my second bike. I have never dealt with this type of battery before. From following posts on here I know it can be very dangerous and you must watch the voltage when charging and other factors. The reason for the switch from LiFePO4 to Lithium Polymers is $$$. I do not want to spend over $1500 for a pack alone.

I currently have a nice 58V 11.5Ah LiFePO4 A123 triangle pack on my first bike, pretty easy to manage.

For the 2nd build bike I wanted suspension, 150mm dropouts and a place to put lots of batteries. I came across this type of bike here on ES, its a ISD EXCELSIOR. I believe ES member Brentis has a few named Strong GTS. I got lucky and found one here in Paris for 100€.
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I am 215lbs 5ft 11", riding mainly on level flat streets. I want to be able to hit speeds 45mph+ and have some good torque.
So, I bought myself one of these, a Cromotor.
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Here are the main parts I need, to get her running:
Controller, thinking of Cellman's 24 fet 4110, 36-75V Infineon Controller, but not sure if this will be powerful enough to handle the volts & amps I need to hit 45mph + ??
Torque arms, already on the list for Doc's new batch.
LiPo batteries, I have no idea what brand, volts & Ah and Size to get.
BMS, not sure?
LiPo charger, powersupply and anything else I would need for these batteries.
Cycle Analyst

I'm sure I am missing more items regarding the battery setup. The bike will need new front forks and better brakes. I have the new rims and tires for her.

The picture with the mock up battery box, the dimensions are 400mm L x 100mm W x 150mm H, so I am not sure how many & what type of LiPo's I can fit there.

So, to sum this up, I need some help with LiPo's, Charging items and Controller. Any advice is deeply appreciated. Thanks for listening.

Pete
 
pucksterpete said:
BMS, not sure?
Depends greatly on how you intend to use the system. If you use RC LiPo packs or a similar chemistry (laptop LiCO, various NMC, etc), you could use a pack-level LVC via the CA, and cell-level protection via Methods' protecton kit, which is basically a last-resort cutoff to prevent damage or fire (not an everyday LVC; for that you ahve to use the pack-level CA or soemthing else, like cell-monitor alarms, etc).

I dunno of a truly reliable BMS for any chemistry, at least not that's avaialbel to us. Some are "good enough" as long as you're also checking everything, but I don't ahvea ny recommendatiosn.

The picture with the mock up battery box, the dimensions are 400mm L x 100mm W x 150mm H, so I am not sure how many & what type of LiPo's I can fit there.
First thing to do is determine how many Wh you need to get the range you're after. Then what sustained Watts you need to keep the speeds you want to go, including up hills and stuff. Then what voltage you need to reach the speeds you're after with the motor you've got. If the motor you have is in the ebike.ca simulator, you can determine some fo that there.

That will tell you a lot about what batteries you can use, and help you narrow down the selections, and determine how large the pack is going to have to be.

Then to figure out which types of packs in what physical arrangment, you could do some CAD (cardboard-aided-design) with little boxes made just a little larger than the measurements they give for various pack sizes (at least a couple mm larger in each direction). Fit them all up in various ways until you've got one that works in your avaialble space, including the wiring (whcih is a significant amount of space!). If you have old cables from other things like power cords or speaker wires you can use those on the ends of the boxes to simulate the wires in your space.


BTW, it looks like your inspector is working overtime; she(?) looks really tired. Or...like mine, she's got that "oh, ghod, not ANOTHER bike part!" look. :lol:
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What a handy ready made ebike frame!

Where did you get yours from, I've done a search but can't seem to find any for sale anywhere.....


Kudos
 
I was wondering what battery config you have?
20S Lipo 13.5Ah consisting of 6x 10S 4.5Ah bricks.

Make of batteries, Volts & Amps?
Zippy 10S Lipo 20C packs from Hobby King. 37V nominal, 41.90V hot of charger (HOC), capable of minimally 90A discharge per brick. With three of them in parallel (13.5Ah), it means the lipos can discharge up to 270A.

Where did you buy them from and roughly how much?
HobbyKing at around 105 USD per brick. One can not buy them anymore. I would now recommend 5S 8Ah bricks like these. More cables, but you limit the possibility of a bad cell costing you the whole 10S pack.

I have never fooled with LiPos and want to learn and figure out what I need for a high 72V or more pack. Currently on my first bike I have a 52V 11.5Ah A123 LiFePO4 pack from Cellman. Those packs are expensive once I get into the 72V range and beyond.
You will need a good 10S charger, some good 5S high capacity lipo packs, a way to break the pack down to 10S to balance charge it once in a while, and a way to keep track of individual cell voltage before and after charging. You also need to be sure to set your LVC on your bike so that you not overdischarge while riding.

I would suggest starting with 8x 5S 8Ah bricks. First parallel pairs of 5S bricks into 5S 16Ah. Then put these in series to create 20S 16Ah. This is probably more than 10kg of lipo, so you need to seriously think about how to carry that on your bike in a safe way.
 
pucksterpete said:
Controller, thinking of Cellman's 24 fet 4110, 36-75V Infineon Controller, but not sure if this will be powerful enough to handle the volts & amps I need to hit 45mph + ??

Just to stop your dreams. You will just get 45mph with a cromotor 20S lipo setup. At 20S HOC (4.20V cell level) I get to 45mph/74kmh on the flat for a couple of minutes. You will need higher voltage to maintain those speeds as voltage drops. Think 24S with 4110 FETs or 30S with 4115 FETs.
 
Amberwolf Wrote
Depends greatly on how you intend to use the system. If you use RC LiPo packs or a similar chemistry (laptop LiCO, various NMC, etc), you could use a pack-level LVC via the CA, and cell-level protection via Methods' protecton kit, which is basically a last-resort cutoff to prevent damage or fire (not an everyday LVC; for that you ahve to use the pack-level CA or soemthing else, like cell-monitor alarms, etc).
I plan on running RC LiPos, I currently us the LVC setting on the CA for my other bike. Going through the CA with LVC set is only for the total volts in the pack, correct? Then I would still need cell-level protection like you mentioned above?

If I can get 15 to 20 miles on a full charge when not running it hard all the time, but still have the capability to hit 45mph +, that is what I am after.

I wish I knew of a simulator that was for the Cromotor, haven't found it yet.

Thanks Amberwolf
 
kudos said:
What a handy ready made ebike frame!

Where did you get yours from, I've done a search but can't seem to find any for sale anywhere.....


Kudos

I found the bike on http://www.leboncoin.fr/ and selected the region I live in Ile-de-France, got lucky and did a search for Solex, then came across the bike. The seller had put solex as one of his tag words in his ad.

There is an ad for another one, http://www.leboncoin.fr/velos/414803216.htm, it looks much newer, but no price
Goodluck
 
Subject: Excelsior/Strong GTS Cromotor Build

hjns said:
I was wondering what battery config you have?
20S Lipo 13.5Ah consisting of 6x 10S 4.5Ah bricks.

Make of batteries, Volts & Amps?
Zippy 10S Lipo 20C packs from Hobby King. 37V nominal, 41.90V hot of charger (HOC), capable of minimally 90A discharge per brick. With three of them in parallel (13.5Ah), it means the lipos can discharge up to 270A.

Hi Henk,

I had question about your config for your batter pack set up. Let me see if I understand this correctly.

You have 6 of these Zippy 10S 4.5Ah batteries, which are 37V each. You wired 3 of them in Parallel to get the 13.5 Ah and the other 3 are wired in Series? Are all the packs wired together?

I was told before you either wire them in Series for more volts or Parallel for more Ah. I'm sorry for all the questions, I am a big Noob with batteries and trying to understand all this.

Regarding the Turnigy nano-tech 8000mAh 5S 25~50C Lipo Pack, If I ran 5 of these packs in series I would have 92.5V Nominal and only 8Ah, correct?

I am trying to have at least 15Ah to 20Ah and over the 90V range.

Thanks Again,

Pete
 
--- Disclaimer ---

As your questions show that you indeed have no experience with Lipo, I would actually recommend NOT using them!
A 10S lipo pack can be dangerous and create a fire if treated wrongly!

--- End disclaimer ---




I have 10S 1P 4.5Ah 37V nominal 42V HOC bricks. This means that every brick has been built up from 10 individual cells, and these have been put in series. Every cell has a capacity of 4.5Ah (4500mAh). Therefore, this 10S pack has a capacity of 4.5Ah as well. There are two big main wires, and there are 11 balancing wires.

I then put three of these in parallel. I have paralleled them at both main wires and balancing wires. One big mesh of wires. This creates a 10S 3P pack, with a capacity of 13.5Ah. All individual cells are balanced with their counterparts via the balancing wires. So cell 1 of pack 1 is paralleled with cell 1 of pack 2 and cell 1 of pack 3. And so forth.

Then those paralleled 3 were put in series with another pack of paralleled 3. In series using only the main big wires. That makes for 20S 3P 13.5Ah.

For charging, I break down the packs into a 10S 6P 27Ah pack. I started with balance-charging every day, and voltage checking before and after every charge. After more than a year observing how the pack behaves, I can afford to balance charge only once a month. However, you need to know your packs very well before you do that.
 
Welcome aboard the sphere Pete. :mrgreen:

Nice to see another one of these Strong frames being used. Congrats on your purchase.
I didnt see the o.g. battery box in your pics. Do you still have it?
No biggie if not, it is actually not a very efficient use of the available space of the frame.
Build your own around the required battery.


pucksterpete said:
Amberwolf Wrote
Depends greatly on how you intend to use the system. If you use RC LiPo packs or a similar chemistry (laptop LiCO, various NMC, etc), you could use a pack-level LVC via the CA, and cell-level protection via Methods' protecton kit, which is basically a last-resort cutoff to prevent damage or fire (not an everyday LVC; for that you ahve to use the pack-level CA or soemthing else, like cell-monitor alarms, etc).


I wish I knew of a simulator that was for the Cromotor, haven't found it yet.

The Cromotor has been modeled on the ebikes.ca simulator. It is listed as noname 5004
Cromo2.JPG

Assuming you are using 26" wheels you'll need @ least 24s lipo.
Do you really need 70+kph? or is that more of want thing.
70+kph on this frame is fast. I wouldnt want to do it with stock components.
A quality fork and shock will certainly help, but this still is a bicycle style frame. Not a moped/scoot.
I admire your desires though.

So 24s lipo should get you above your target speed on a full charge, voltage wise.
You dont list any distance requirement so I assume this is a play bike.
At full speed you will be burning roughly 75wh/mile.
88.8v10ah pack is roughly 888wh. so maybe 10 miles of WOT.

Sound good? I would want to double that for a commuter bike. That is starting to get heavy though.

Best of luck to ya on the build. I'm going to subscribe and watch your progress. Id love a cromotor for my bike.

ps.

What's pucksterpete? You a hockey fan?
 
which free-wheel are you going to use for the cromotor ?

my motor is being delivered this week, so I really need to order one asap... could really do with a link so show me what I need (hint hint)

(still a bit new to all this bike stuff)
 
My frame only fit a single speed. So I went single speed 14T gear with an elongated BMX ss chain, normal rear derailleur fixed in place to accommodate the rear suspension, and front 52T gear. I can keep up pedalling with my motor up to 35kmh....
 
Hi Pete !

If you plan on running 45mph in Paris, forget this idea immediatly. You will be caught by the cops (if you are lucky) or this may finished badly... 35mph is the maximum I would run on this frame (even with mine) on town. Still very fast. People don't except you to come so fast remember :)

If I were you I'd buy a good quality fork like that http://www.troc-velo.com/peripherique-fourche-foxshox-f100-rl-1-1-826722.htm with hydro brakes

15s3p or 18s3p should give you a 20mph range if you don't run too much Amp.
 
knighty said:
which free-wheel are you going to use for the cromotor ?

my motor is being delivered this week, so I really need to order one asap... could really do with a link so show me what I need (hint hint)

(still a bit new to all this bike stuff)

Hey Knighty,

Not sure yet, more than likely it will be a single 14T. I will have to wait once I get Doc's torque arms in and see what kind of space I have left.

Pete
 
Brentis said:
Welcome aboard the sphere Pete. :mrgreen:

Nice to see another one of these Strong frames being used. Congrats on your purchase.
I didnt see the o.g. battery box in your pics. Do you still have it?
No biggie if not, it is actually not a very efficient use of the available space of the frame.
Build your own around the required battery.

Yep, The guy selling the bike kept the battery, for he bought another Strong.

Amberwolf Wrote
Depends greatly on how you intend to use the system. If you use RC LiPo packs or a similar chemistry (laptop LiCO, various NMC, etc), you could use a pack-level LVC via the CA, and cell-level protection via Methods' protecton kit, which is basically a last-resort cutoff to prevent damage or fire (not an everyday LVC; for that you ahve to use the pack-level CA or soemthing else, like cell-monitor alarms, etc).

Pucksterpete Wrote
I wish I knew of a simulator that was for the Cromotor, haven't found it yet.


Brentis said:
The Cromotor has been modeled on the ebikes.ca simulator. It is listed as noname 5004


Thanks for this, I wonder why they don't just change the name on the list to cromotor?

Brentis said:
Assuming you are using 26" wheels you'll need @ least 24s lipo.
Do you really need 70+kph? or is that more of want thing.
70+kph on this frame is fast. I wouldnt want to do it with stock components.
A quality fork and shock will certainly help, but this still is a bicycle style frame. Not a moped/scoot.
I admire your desires though.

More of a desire. Before getting into electric bikes, I had one of those small little 66cc gas engines on a mtb, and was hitting over 40mph on it. The noise, too many moving parts and not being able to ride it everywhere without the hassle made me try an electric setup. Getting something from Hyena has been good, but I need more speed. I agree the stock componets are not the best, a new fork, shock and brakes are on the list.

Brentis said:
So 24s lipo should get you above your target speed on a full charge, voltage wise.
You dont list any distance requirement so I assume this is a play bike.
At full speed you will be burning roughly 75wh/mile.
88.8v10ah pack is roughly 888wh. so maybe 10 miles of WOT.

That doesn't sound too bad, WOT all the time na. But let's say I wanted to add more Ah's, how would I go about this? Buy the same type of LiPo's I have currently in my pack and just reconfigure them in a different paralleled order?

Brentis said:
ps.

What's pucksterpete? You a hockey fan?

Oh yes, I have played since I was young boy and when I lived back in the States I played for a men's team called the Pucksters. That's where the name came into play. You being from Ontario, you have to be a hockey fan! Games start this Saturday, short season, but it will give me something to watch over here in France. Thanks for info and tips.

Pete
 
+1

Be careful with this frame at high speeds. Also, you really really want to consider using either a CAv2 with "current-throttle" or a CAv3 with "power-throttle" implemented. If you connect 20S lipo to the controller, and connect a normal ebike throttle directly to the controller, your throttle will be soo darn sensitive that you will wheelie in no time. At 40mph, that's killing.

Start thinking about how to make the throttle less sensitive, and still be able to accelerate like crazy.
 
hjns said:
+1

Also, you really really want to consider using either a CAv2 with "current-throttle" or a CAv3 with "power-throttle" implemented. If you connect 20S lipo to the controller, and connect a normal ebike throttle directly to the controller, your throttle will be soo darn sensitive that you will wheelie in no time. At 40mph, that's killing.

Start thinking about how to make the throttle less sensitive, and still be able to accelerate like crazy.

This is what I had in mind, not sure if it works this way. I plan on getting another CAv2 like I have now, A 24 fet 4110, 36-75V 90V Max Infineon Controller from Cellman and I already have one of his 1/2 twist throttles with 3 speed switch setting, like I use now.

From what I understand, If I use one of Cellman's Controllers and Throttles with the 3 speed switch setting (like I do now) that controls the sensitivity of the throttle, the 3 speed switch is already set for 30%, 70% & 100% from what I was told.

Does this sound about right?

Pete
 
Well, no better way than learning from experience. Start with what you have in mind (aka the 3 speed thing without "current-throttle") and then come back and tell us if you like it. In my case, even in the lowest speed setting, my throttle would be non responding in the first 25% rotation, then an extremely sensitive 10% with lots of increase in speed, and then 50% low sensitivity throttle, followed by a non responding (aka no change in full throttle) remaining part.

Using a CAv3 you can actually influence the way the throttle behaves. Start reading on that one before you buy another CA.
 
Would a A 24 fet 4110, 36-75V 90V Max Infineon Controller, be on the right path for this build or must I go bigger?

Pete
 
LSBW,

I saw that. Brentis's & your pics where in mind and when I came across the bike on a French like Craigslist, I jumped on it. For 100€, the frame is solid and with the more than 150mm dropouts I know the Cromotor would fit. How is your build going as of late? Thanks for the info on the 18FET. Your up Toronto, you a Leaf fan?

Pete
 
What pretty pictures. Do you think there is enough room for 6 or 7 spd freewheel?

Did you DP420 those Doc Torque arms in yet? Its Good to see your build, thanks

Pete
 
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