noob question about controller and battery

[tomtom123]

Was thinking of getting the yescomusa kit, which from what i read has a 25a controller. I'm also of getting bmsbattery 48v 10ah which has continuous discharge of 15a and max short discharge 30a. i would be going probably around 80% throttle should i should be pulling like 20a continuous from the controller so would this damage the battery? Should i invest in a lower amp controller to keep my battery lifespan longer? Or is whatever i said earlier completely wrong and my understanding of things completely off? Thanks in advance!

 

[wesnewell]

Unless they've recently changed, all yescomusa kits come with 30A controllers. If you want to pull less amps, you can always cut one of the shunts in the controller. The one with 2 shunts (12fet that comes with 500W kits) would then be 15A. The one with 3 shunts (15fet that comes with 1000W kits) would then be 20A. You won't loose a lot of speed accept on hills and acceleration will be slower if you lower the amps.
http://endless-sphere.com/forums/viewtopic.php?f=3&t=49638

 

[tomtom123]

Unless they've recently changed, all yescomusa kits come with 30A controllers. If you want to pull less amps, you can always cut one of the shunts in the controller. The one with 2 shunts (12fet that comes with 500W kits) would then be 15A. The one with 3 shunts (15fet that comes with 1000W kits) would then be 20A. You won't loose a lot of speed accept on hills and acceleration will be slower if you lower the amps.
http://endless-sphere.com/forums/viewtopic.php?f=3&t=49638

but the effects of 30a controller on a 15a continous battery is what? does it damage the battery or just drains it faster?

 

[Drunkskunk]

but the effects of 30a controller on a 15a continous battery is what? does it damage the battery or just drains it faster?

Yep, it damages it quickly. You need the battery's continous rating to be at least equil to the controller's rating (or modifed rating, as wesnewell was describing how to do), although Its better for the battery if you can have a higher rating than the controller. For example, I would want a battery with at least a 30 amp continous rating if I had a 25 amp peak controller. That would ensure that I never pushed the battery to it's limits, and should give it the longest life.

 

[tomtom123]

but the effects of 30a controller on a 15a continous battery is what? does it damage the battery or just drains it faster?

Yep, it damages it quickly. You need the battery's continous rating to be at least equil to the controller's rating (or modifed rating, as wesnewell was describing how to do), although Its better for the battery if you can have a higher rating than the controller. For example, I would want a battery with at least a 30 amp continous rating if I had a 25 amp peak controller. That would ensure that I never pushed the battery to it's limits, and should give it the longest life.

Is this motor and the controller 30A also? since it listed as 500w 12 mosfets


http://www.bmsbattery.com/ebike-kits/348-bafang-350watts500watts-bpm-motor-e-bike-kit.html

 

[wesnewell]

No way of telling without actually having the specs or testing it. After you add shipping the price will be a lot higher too. That's a small geared motor.

 

[tomtom123]

No way of telling without actually having the specs or testing it. After you add shipping the price will be a lot higher too. That's a small geared motor.

Actually its only expensive for the shipping if you only buy one item at a time but if you buy multiple its in bulk like I will, like battery, torque arms, controllers and etc, it pretty cheap overall.


And regarding the size of the motor, yea in was wondering about the power of that motor since it looks pretty small. But multiple people on in this forum say its pretty powerful, reaching same speeds as.the.yescomusa

 

[tomtom123]

the controller for the motor seems to be the KU123 500W. But i have no idea how many amps that puts out, even after google searches, anyone know?

 

[wesnewell]

And regarding the size of the motor, yea in was wondering about the power of that motor since it looks pretty small. But multiple people on in this forum say its pretty powerful, reaching same speeds as.the.yescomusa

They're blowing smoke. The same thing that motor would do if you tried to put the controller and battery pack I use on my yescomusa motor on that motor.

 

[e-beach]

Was thinking of getting the yescomusa kit, which from what i read has a 25a controller. I'm also of getting bmsbattery 48v 10ah which has continuous discharge of 15a and max short discharge 30a.

Could you post the specs and link of the battery you are thinking about getting?

BMS battery claims to have a "48V 9Ah 38120S LiFePO4 Battery 16 Cells EBike Battery Pack" 10c, 30-60a discharge for 246.60 before shipping.

(1Pcs 48V 9Ah LiFePO4 Battery 16pcs 9Ah 10C 38120S Cells ebike battery pack with BMS.)

http://www.bmsbattery.com/packs/559-48v-10ah-38120-lifepo4-battery-16-cells-ebike-battery-pack.html

 

[tomtom123]

Was thinking of getting the yescomusa kit, which from what i read has a 25a controller. I'm also of getting bmsbattery 48v 10ah which has continuous discharge of 15a and max short discharge 30a.

Could you post the specs and link of the battery you are thinking about getting?

BMS battery claims to have a "48V 9Ah 38120S LiFePO4 Battery 16 Cells EBike Battery Pack" 10c, 30-60a discharge for 246.60 before shipping.

(1Pcs 48V 9Ah LiFePO4 Battery 16pcs 9Ah 10C 38120S Cells ebike battery pack with BMS.)

http://www.bmsbattery.com/packs/559-48v-10ah-38120-lifepo4-battery-16-cells-ebike-battery-pack.html

This is the one i'm gettting. http://www.bmsbattery.com/48v/496-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

But yea i noticed while browsing other batteries like the 12ah version, you can choose between 15/30a and the 30-60a options, but this battery does not have that option, weird...

ANd as for the controller amps, i pmed some dude on youtube how had a video of the bafang 500w and he states that the default controller is 30-35amps.

 

[d8veh]

The 12 aH on with optional high power BMShasheadway cells, so is relatively heavy and more expensive. The 15aH shrink-tube on is much lighter, smaller, and more capacity:
http://www.bmsbattery.com/48v/248-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

the 20aH one is the same weight and price as the Headway pack, but you can go a lot further.

 

[dogman dan]

Before you buy multiples, I highly recommend you do a very complete test of the combination first. Like 1000 miles minimum.

For the typical bike batteries generally available, 10 ah is too small for 20-30 amps controllers. The damage can be severe. You can go from expecting 500-1000 cycles, to one cell up and croaking on you in 10 cycles, or just having all of them lasting at best half what you expected.

And yeah, I did it to a pack, so I know it the hard way. Seems to be the way I learn things.

One ah per amp of controller, -5 is one way to think of it. For 15 amps controller, 10 amps will do. For 20 amps controller, 15 amps will do.

This does not apply to higher c rate batteries, like A123's, or 20c lico. But for all battery c rate claims, cutting the stated c rate in half is good policy. Then do your calculations based on half the c rate they claim.

 

[tomtom123]

Before you buy multiples, I highly recommend you do a very complete test of the combination first. Like 1000 miles minimum.

For the typical bike batteries generally available, 10 ah is too small for 20-30 amps controllers. The damage can be severe. You can go from expecting 500-1000 cycles, to one cell up and croaking on you in 10 cycles, or just having all of them lasting at best half what you expected.

And yeah, I did it to a pack, so I know it the hard way. Seems to be the way I learn things.

One ah per amp of controller, -5 is one way to think of it. For 15 amps controller, 10 amps will do. For 20 amps controller, 15 amps will do.

This does not apply to higher c rate batteries, like A123's, or 20c lico. But for all battery c rate claims, cutting the stated c rate in half is good policy. Then do your calculations based on half the c rate they claim.

but like wesnell states, i can just do a "shunt mod" but "cutting" some wires and limit the amps? what is the shunt mod? i did some searches and there was no cutting of wired involved, only soldering metal strips on the PCB.

Also, can anyone direct me to a good 15 amp controllers that will work with the bafang or the yescomusa wheel? i'd buy one just in case. Thanks for the help, if i wasn't curious and hadn't ask, i would have bought a battery with lower discharge current than the controller and things would have be horrible.

 

[dnmun]

buy a cycle analyst if you wanna limit your current. you need one anyway.

 

[e-beach]

OK, my 2¢ and IMHO on the Yescomusa kit because that is what I have,

Both my Yescomusa kits came with controllers that pulled 30-33 amps WOT. It depended on the meter that I was using at the moment. At 33 amps, I am guessing the meter was a bit off and I was pulling closer to 30 amps.

So, if you get a Yescomusa kit, you will need a battery and BMS that can handle 30a continuous or risk killing your battery. Instead of buying the cheapest battery/bms setup, I recommend spending another $20 or so for the one that can do the job and will last.

If you really want to get the cheaper battery/BMS set-up, then you could spend another $155.00 plus shipping on a "Stand Alone CA" and use it for limiting your current. Be aware that you will also be limiting you performance, ie lowering your acceleration and top end speed, but your slower speeds will allow for a distance increase due to lowering of watt hour consumption.

Going slower = going farther.

The Cycle Analyst is a nice piece of equipment, but in some circles considered a luxury item. Properly set up, it can make your e-bike life much easier. Just park your bike in a place where the thieves can't steal it because the last time I checked it was not detachable and needed to stay on the bike.

In regards to shunt modification, if you want to open your brand new controller and cut out a thick piece of wire , their-by permanently limiting the amp draw instead of leaving it in and potentially adjustable with a CA, or a 3 speed switch, just so you can go slower and not ruin and under powered battery/bms setup, well,.......here is a picture of what a shunt in a Yescomusa controller looks like so you can think about cutting up your new controller instead of getting a proper battery and BMS set-up.

(BTW, most shunt mods around ES increase the size of the shunt to go faster.....)

 

[tomtom123]

buy a cycle analyst if you wanna limit your current. you need one anyway.

Cyclist ANalyst is too pricey for my taste.
i Hear that this can also limit the current from the controller http://www.bmsbattery.com/controller/548-s-led770-e-bike-led-meter.html
according to this video http://www.youtube.com/watch?v=8HRnNuF0rSI


also i'm thinking of getting the yesomusa 1000w motor instead of the bafang 500w and i'm getting th BMSbattery 48v 12ah at 30-60a option:
http://www.bmsbattery.com/packs/153-48v-12ah-38140-lifepo4-battery-16-cells-ebike-battery-pack.html

everything seems good? Also that LCD meter above should work for the yescomusa motor right?
THanks in Advance!

 

[e-beach]

Before you go for that battery find out what the C-rating is. 12ah with a 30 amp controller on a 2c battery could still kill your battery.

 

[wesnewell]

also i'm thinking of getting the yesomusa 1000w motor instead of the bafang 500w and i'm getting th BMSbattery 48v 12ah at 30-60a option:
http://www.bmsbattery.com/packs/153-48v-12ah-38140-lifepo4-battery-16-cells-ebike-battery-pack.html

everything seems good? Also that LCD meter above should work for the yescomusa motor right?
THanks in Advance!

Forget the meter, you don't need it. That battery with 10C rated cells will work fine with a controller up to 60A. The cells are rated for 120A, but I wouldn't pull that from them. No sweat with a 30-50A controller.

 

[tomtom123]

also i'm thinking of getting the yesomusa 1000w motor instead of the bafang 500w and i'm getting th BMSbattery 48v 12ah at 30-60a option:
http://www.bmsbattery.com/packs/153-48v-12ah-38140-lifepo4-battery-16-cells-ebike-battery-pack.html

everything seems good? Also that LCD meter above should work for the yescomusa motor right?
THanks in Advance!

Forget the meter, you don't need it. That battery with 10C rated cells will work fine with a controller up to 60A. The cells are rated for 120A, but I wouldn't pull that from them. No sweat with a 30-50A controller.

There's no yescomusa kit for a 700c bike right? i' m thinking of getting a road bike instead of a mountain bike for city riding

 

[wesnewell]

I think all they sell are 26", but you can get the same thing in 700C from other places. And I just noticed that they raised the price on their website by $50 to $339. You can still get get the lower price on ebay. Leafbike has pretty much the same kit in 700C.

 

[d8veh]

The words in the video about the LCD are a little misleading. AFAIK you can't limit current. All the LCDs that I've tried work more or less the same. The PAS levels limit power, but only on the PAS. The throttle remains unlimited. When he spoke later about limiting the throttle, he meant you can limit the speed, but you still get full current when hill-climbing slowly.

 

[tomtom123]

The words in the video about the LCD are a little misleading. AFAIK you can't limit current. All the LCDs that I've tried work more or less the same. The PAS levels limit power, but only on the PAS. The throttle remains unlimited. When he spoke later about limiting the throttle, he meant you can limit the speed, but you still get full current when hill-climbing slowly.

i see, i guess i'm going with the 1000w motor yesomusa motor then. makes no sense to me why they have a 30a controller default with a 500w motor... i wish they had a 1000w bafang

 

[dogman dan]

Figure it out. 500w ratings on motors means under nearly any conditions, the motor can take 500w continuously.

But if you are not loading up the motor too much, not too slow rpm for the winding selection, then you keep the motor in the efficient range of operation. In the faster rpm more efficient range, the motor can easily take 1500w, and many run 3000w for less lengthy rides.

The big dd motors can take a lot more than 500w if you don't make too many of your watts into heat. The more overvolted you are, the more careful you have to be while riding of course. Ride carefull, and the motor can take plenty of watts.

BUT back to the winding. The 1000w 48v yes kit is a great choice when you want cheap speed. It gets it by having a fast winding, which means it takes off like a snail from a stop sign. Unless you whack it with more amps. So the 30 amps controller makes up for that. And makes heat at every stop sign. It's a very bad choice for inner city riding.

This will frock you well and good riding in a big city, where battery range is concerned. There is a great solution for having 30 mph and great efficiency on stop and go that extends your range.

Em3ev's Direct drive motor, choose the slower one. Then run it with a 72v controller that is CA compatible. Depending on your battery choice, use a 20 amps controller, or a 40 amps controller if you have a battery good enough. Even on the 20 amps controller, you will have great giddy up from the stops, and plenty of watts to hit 30 mph. Very nimble, which saves your life riding in the city.

Over on the other thread, you are looking at the BPM, That one (faster wind) with a 48v 30 amps controller will also be very nimble, go fast and not need 72v.

Don't get the yes kit, other than as an experiment to find out for yourself what I say about range in stop and go riding is true. You won't win by making a motor hot.

 

[tomtom123]

Figure it out. 500w ratings on motors means under nearly any conditions, the motor can take 500w continuously.

But if you are not loading up the motor too much, not too slow rpm for the winding selection, then you keep the motor in the efficient range of operation. In the faster rpm more efficient range, the motor can easily take 1500w, and many run 3000w for less lengthy rides.

The big dd motors can take a lot more than 500w if you don't make too many of your watts into heat. The more overvolted you are, the more careful you have to be while riding of course. Ride carefull, and the motor can take plenty of watts.

BUT back to the winding. The 1000w 48v yes kit is a great choice when you want cheap speed. It gets it by having a fast winding, which means it takes off like a snail from a stop sign. Unless you whack it with more amps. So the 30 amps controller makes up for that. And makes heat at every stop sign. It's a very bad choice for inner city riding.

This will frock you well and good riding in a big city, where battery range is concerned. There is a great solution for having 30 mph and great efficiency on stop and go that extends your range.

Em3ev's Direct drive motor, choose the slower one. Then run it with a 72v controller that is CA compatible. Depending on your battery choice, use a 20 amps controller, or a 40 amps controller if you have a battery good enough. Even on the 20 amps controller, you will have great giddy up from the stops, and plenty of watts to hit 30 mph. Very nimble, which saves your life riding in the city.

Over on the other thread, you are looking at the BPM, That one (faster wind) with a 48v 30 amps controller will also be very nimble, go fast and not need 72v.

Don't get the yes kit, other than as an experiment to find out for yourself what I say about range in stop and go riding is true. You won't win by making a motor hot.

Thanks for the insight, i'll consider it. Man if only i had unlimited money lol, i could try out a bunch of motors for myself lol, but's that's life lol.