QS273 5T with Sabvoton 200A - good setup or 3T better?

[nccbster]

Hello,
I have found information that the QS273 5T works well with the 150A controller, but will the 200A be too much for a 5T motor?
The battery will be 72V 70Ah EVE Chinese.
I would like to have good low end torque, but am not sure if the heat will be too much with the 5T and 200 amps and if I am better off with the 3.5T?

 

[Eastwood]

Go with the 5T winding if you’re looking for torque. I would recommend getting the QS205 compared to the QS 273 if you’re only using 150 A. The 273 is real heavy and not necessary for something under 200 A. I have 2 different qs205’s and they’re both pushed up to 200 amps.

Oh and you can definitely run 200 A with a 5T, I have a 5.5 T and a 6T with a 250 amp controller. Although I normally keep the amps around 160 with no heat issues. That being said if you’re running that power continuously you could have some heat buildup but if you’re only looking for higher power in short burst the QS205 is what you’re looking for. The 273 is about 25 pounds heavier than the QS205 so it’s really not necessary unless you’re running massive current. You have to think about how much weight you’re pushing compared to horsepower ratio with the QS 273. If you were running 300 A or something like that I would say get the QS 273 but not at 150 A it’s pointless to add all that extra weight.

You mentioned you were getting a 70 amp hour battery? Do you have a link? A lot of these Chinese companies make false claims on the specs of the batteries. 70ah sound suspicious unless you’re spending a few thousand dollars on the battery.

Here’s a video of me doing a hole shot with the QS205 at 150 DC amps. This motor is a 6T winding, QS205 v3Ti

https://youtube.com/shorts/oDLMKu5hdIQ?feature=share

Also you can check out my build thread in my signature it might be helpful to you if you’re building an Enduro frame.

 

[nccbster]

I am not building it, I want to order a ready build from alibaba.
They claim to have a 70ah 72V battery, total price of the bike around 3400 USD.
The frame is custom, pretty wide, total weight would be about 100kg / 220 lbs.
Controller is 200A - Sabvoton 72200, peak 450 amps, the given top speeds are with a 2.5T winding, but I would like to order a different build with 5T, because I am more interested in torque.
I want to have a maximum range with high torque and offroad capability, ofcourse this type of weight is in the enduro bike territory, but the biggest motor and power is simply very desirable.

https://czboneng.en.alibaba.com/minisiteentrance.html?spm=a2700.details.cordpanyb.2.7733413auqGFZW&from=detail&productId=1600387364437

 

[E-HP]

You should find out exactly what the battery pack is made of. Assuming 18650 cells, 72Ah would be 20P to 28P depending on the cells used (2500mAh to 3500mAh per cell) or 400 to 560 cells. At $5 per cell, that's $2000 to $2800 for the cells alone. That's without the BMS and other components for construction. If the cells are generic (assuming 5A continuos discharge, 2500mAh), and in a 28P configuration, the pack would only be good for around 140A continuous, so short of 200A, so you would need even more generic cells.

It would be difficult to sell an ebike for $3400 if $3000 of that is in the battery, so that's where the corners will certainly be cut.

 

[amberwolf]

The frame is custom, pretty wide,

Doesn't really look custom. Looks like the typical "eeb" / "enduro" frame. Lots of threads about bikes built with those (prebuilt and DIY) if you want to read about them and various possible problems.

I want to have a maximum range

Maximum range of how far? At what speed, under what specific conditions?

Without specifying those, then if you are already picking a specific bike, I can only tell you that to get the maximum range out of whatever bike you get, you have to go as slow as possible, accelerate as gently as possible, and avoid slopes or hills or headwinds, and ride only on smoothly paved roads. That's how to get the maximum range out of any specific setup you're already "stuck with".

But if you have a specific range you must achieve, you need to choose a system, especially battery, that is capable of that, and to do that you must know what conditions you will ride under, on what terrain, including the slopes and lengths of hills you'll be on, and at what speed, and total system + rider weight.

with high torque and offroad capability, ofcourse this type of weight is in the enduro bike territory, but the biggest motor and power is simply very desirable.

How much power / torque you get depends on the speed you are at, and the higher the max speed (higher the kV of the motor, meaning the lower number of turns), the lower the torque will be, for the same setup otherwise.

If you want a lot of torque, go with the highest winding count motor, and the highest *phase current* controller you can get, with the *best battery quality*.

A system you need for high torque, within a small budget, may be pretty limited in it's top speed. So you will need to decide which is more important, and determine the conditions you need to do each one under, to see what compromise you can make.

Note that if the battery can't handle the load you put on it, the bike wont' do what you want. The battery is the heart of the system, the most important and the most expensive part, so if you skimp on that, your system won't do what you want (or not for very long as the battery is overstressed and begins to age quickly).


I recommend going to the http://ebikes.ca/tools/simulator.html and playing around with that to see how this all works, before you spend a lot of money on something that may not do what you need it to.

 

[Eastwood]

I am not building it, I want to order a ready build from alibaba.
They claim to have a 70ah 72V battery, total price of the bike around 3400 USD.
The frame is custom, pretty wide, total weight would be about 100kg / 220 lbs.
Controller is 200A - Sabvoton 72200, peak 450 amps, the given top speeds are with a 2.5T winding, but I would like to order a different build with 5T, because I am more interested in torque.
I want to have a maximum range with high torque and offroad capability, ofcourse this type of weight is in the enduro bike territory, but the biggest motor and power is simply very desirable.

https://czboneng.en.alibaba.com/minisiteentrance.html?spm=a2700.details.cordpanyb.2.7733413auqGFZW&from=detail&productId=1600387364437

Yeah 220 pounds is too much weight for that power. So you’re basically at motorcycle weight with moped power. I’m not sure if you plan on any off-road use but you could forget it with that QS 273. Especially if it has a Chinese rim and you ride off road you’re guaranteed to bend it eventually. Even my QS205 feels heavy off road when I hit rocks roots etc.
but yeah you’re probably using this for commuting purposes so on the street it’s not as big of a deal but you’re still stuck with too much weight and not enough power.

 

[nccbster]

These are the alleged cells:

https://m.alibaba.com/product/1600451025603/EVE-18650-3-6v-2500mah-lithium.html?__detailProductImg=https%3A%2F%2Fs.alicdn.com%2F%40sc04%2Fkf%2FH921b2bef8824424aae2b0e8319b140d9j.jpg_200x200.jpg

20p, if the specs are correct - continious discharge 7,5A, so in total 210 amps
3,6 usd / piece presumable price - 20x28x3,6=2016 usd
About 1400 left for the other components, should be plausible?
My other option is to order the bike without a battery and buy a good one on my own, but I have no idea what kind, types of connectors, bms?

 

[nccbster]

Actually the seller quoted a price of 2200 without the battery, so roughly 1200 USD for the battery.
They also offer optional samsung or panasonic cells, but not for this model.
Also they offer a 12000w model, which is with a 150A Sabvoton, so i guess that they know the difference between 150 and 200A, its not just claims.
Although, they claim a lifespan of 400 cycles for the batteries, which seems pretty low to me.

 

[E-HP]

Actually the seller quoted a price of 2200 without the battery, so roughly 1200 USD for the battery.
They also offer optional samsung or panasonic cells, but not for this model.
Also they offer a 12000w model, which is with a 150A Sabvoton, so i guess that they know the difference between 150 and 200A, its not just claims.
Although, they claim a lifespan of 400 cycles for the batteries, which seems pretty low to me.

72V 72Ah battery for $1200

The cell specs from your link actually say 30A Max continuos discharge Why pay extra for something like Samsung 25R with its measly 20A max continuos for twice the price, right? Especially when they actually say their cells aren't fake.

Ordering the battery separately from a known builder would be the safest bet for the most important component of your bike.

 

[gobi]

Op, pls run away from this deal, all cuz of the batt, not sure if they tell you what is in it and how it was made, the risks are too high in my suggestion, maybe you can buy from a reputable seller who gives full disclosure about the cells used and construction.

 

[ebiken00b]

Sorry to necro this. Its 2.5 yrs later and similar deals are still on ABB - are they more sensible now, as battery costs have gone down?

 

[thebes]

Sorry to necro this. Its 2.5 yrs later and similar deals are still on ABB - are they more sensible now, as battery costs have gone down?

Nothing much has changed, still are and will be firebombs as there's no incentive to build something to a higher degree of quality. Why build a safe, reliable product just to have no one buy it since it costs 2x of the competition?

 

[99zip99]

You buy from China and they can easy just walk away. As warranty what warranty it's hard enough to get a warranty if the guy is the United States but saying that there are many vendors that do back their products.