How much power can my kit handle?

[MikeFairbanks]

I have the 9c motor and 22amp controller.

What can that system handle in terms of voltage and AH?

Can it handle 60v without burning up?

 

[neptronix]

There are dozens of people who have hopped up the 9C on here. This is one of the most common motors to hot rod due to it's low cost. I suggest you check out the ebike photos & video section. You will not have a hard time finding an answer, or getting some ideas.

http://endless-sphere.com/forums/viewforum.php?f=6

 

[amberwolf]

I'm running the old curved-sided 9C 2807 on heavy CB2 at 2KW, 58.3V peak battery pack, and 40A (battery-side) controller seeing 60A short peaks, 40A long bursts, and 7-20A continuous. It's ventilated, but doesn't need to be at this power level. It barely gets warm even on the windings.

I intend to run it eventually at much higher levels, for harder/faster acceleration to get to my 20MPH speed much quicker, once I have the old Methods' 100V/100A 18FET working with it, and can add the other part of my pack tha'ts waiting for this, in series for ~90V-ish. Should be interesting to see if I can do tire burnouts with it this way.... (without doing motor or controller burnouts!)

 

[MadRhino]

I have the 9c motor and 22amp controller.

What can that system handle in terms of voltage and AH?

Can it handle 60v without burning up?

The motor will handle high voltage without mods
It will need phase wire upgrade, and cooling to feed high Amps

You kit can't handle much power, it is limited by controller and batteries.
The motor itself, is capable of a lot of power with little mods.

 

[dogman dan]

The stock controller can take up to 63v of fully charged actual voltage. The caps are 63v. So that's 48v nominal.

Ping 48v 15 ah comes off the charger at 59-60v, but runs at 56v once the surface charge is taken off.

14s RC lipo comes off the charger at 59v, and would drop at least a volt fairly quick

Some run 15s RC lipo, which comes off the charger right about 63v, taking it right to the theoretical limit.

Many just run 44v nominal 12s RC lipo for the eaiser switching to paralell 6s charging with RC chargers. That's well in the safe zone, at 50v fully charged.

48v lead you are used to, of course you know that voltage. Likely your charger stops about 54-56v.

But you will stop having lead sag with any lithium, so you will definitely notice more speed the latter part of the ride with lithium.

For your short ride, a 12s 10 ah pack would get you to school and back handily. Or a similarly sized in wh cellman pack.

60v nominal you will need a new controller for. 1500 w with a 72v 20 amp controller is not a problem for the stock unmodified motor. That would see you hitting 35 mph. With your short ride, even the 40 mph club 72v 40 amp controller would not be very likely to melt your motor in less than 8 miles.

 

[SamTexas]

I have a 9C 2807 and a 40A controller from ebike.ca. I have run it on 21s (88.2V max) and had no problem reaching 40mph on flat terrain, that's around 2,200W. I can run that combo at 30mph (1,000W) for hours continously w/o worrying about heat issues. The 500W rating of the 9C 2807 is a joke.

 

[MikeFairbanks]

I really didn't want to upgrade anything other than the battery. I'd prefer to keep the 22 amp controller and all that's with it, but just get a new battery.

Most likely I'll get the Ping 48/15ah. I know my system can handle that, but can it handle this:

http://www.pingbattery.com/servlet/the-18/60v-10ah-lifepo4-lithium/Detail

60v, 12ah Ping.


I don't want more top end speed (my current 29mph is enough), but I would like more off-the-line pickup for when I come out of turns.

I'm also thinking of, yet again, changing builds. I love my single speed with the coaster brake and front v-brake, but the tires are so narrow that it freaks me out at anything over 20mph.

I'm thinking of picking up a brand new Mongoose Blackcomb in the next town for 100 bucks and using that as an ebike while making my current e-bike a fitness bike (since it's single speed and rides unreal). Yesterday, while on a recreational ride, I was bummed that the bike had a motor on it because it's so smooth and fun to pedal, but at 29mph it's way too intimidating.

I keep racking up bikes.

 

[neptronix]

You need more amps.
On 48v you will be starving this wind for amps at 22A.
On 36v, more amps helps a lot too. It does not starve for amps like on 48v, BUT hill climbing performance is particularly poor as the motor drops in speed due to lack of amps to maintain speed.

I ran that motor on 57v/56A. Got it hot, it performed like crap once it got hot, but I never managed to melt it down.
Double / triple the power of stock.

Going from 22A to 36A made a huge difference in acceleration.

If this is an ampedbikes, cell_man kit, or an otherwise non-programmable 9FET controller, it can be modded for more amps as such. I found 28-29A to be pretty safe for that controller.

 

[dogman dan]

60v ping will come off the charger way above the 63v caps theoretical max. So you'd need a new 72v controller to go with it.

The blackcomb is a great bike to convert, but not ideal with a front motor. Cheap alloy fork on it. But it's what you need if cheap enough priced, to become the dirt bike you've craved. Grab one of methods last 2810 motors, and it will make a good dirt ride on 48v and your stock controller.

But for the dirt bike, you want lipo. No good place to carry a ping on the Y frame of a blackcomb. Put one on the back, and it will handle horrible. I know this for sure.

You could solder the shunt for more amps. But if you do that, and have a ping, you might wear out the ping faster. If you go lipo, then mod away on the controller if you like.

 

[MikeFairbanks]

I have some good steel suspension forks gathering dust in the garage. I can fit those to the blackcomb if needed for the front hub motor. They handle the motor really well.

I don't want to make any changes to my setup other than a new battery.

I suppose I could do the 48 volt, 10ah battery from Ping.

 

[neptronix]

I have some good steel suspension forks gathering dust in the garage. I can fit those to the blackcomb if needed for the front hub motor. They handle the motor really well.

I don't want to make any changes to my setup other than a new battery.

I suppose I could do the 48 volt, 10ah battery from Ping.

Mike, you kinda make me tear my hair out when i read your posts. You ask for advice, then get all sorts of hi-quality advice from people with good experience, and just ignore it.

I'm not sure why you ask for advice.

 

[MikeFairbanks]

I don't ignore it. I'm just thinking out loud, trying to get more feedback.

Heck, if I had ignored everyone's advice I wouldn't have built two e-bikes by now.

I was on bikeforums.net and all the threads were troubleshooting threads, so I began to wonder if ebikes were even real or if they were just hobbies of hope.

Endless Sphere rocks. Anything I know (which isn't much, because I absorb slowly) is from Endless Sphere.


Here's an analogy of the way I think:

As a surfer, only a new board overrules a new wetsuit in the stoke department.

A new wetsuit is awesome, and it works much like my brain.


When you get a new wetsuit and jump into cold water, it takes a long, long time for the water to soak in. Once the wetsuit is finally saturated, it holds that water in extremely well, and the layer of water rises in temperature to match your body. Then, as cold water continues to wash over your new suit, it can't penetrate well because the outer skin keeps a good barrier. You stay warm and toasty. I had a brand new 4/3 (4mm body, 3mm arms and legs) suit and took it out in water that was 54 degrees F. It felt like Hawaii.

Fast forward a year, and the wetsuit soaks up water much faster. But it also has a difficult time holding that warm water in and, therefore, you get cold quickly. It's less effective.


My mind is like a new wetsuit. It absorbs information very slowly (most info just washes right over it), but what gets in stays in pretty much forever.

I still don't have my mind wrapped around electricity very well, so I really don't understand the difference between a 48volt battery with 10ah and a 48 volt battery with 15ah, with the exception that I know it will have more range.

That's all I know.

I also understand the basic bit about SLA having a lower lifespan, that it drops off as it wears down (like a person would when at play) and of course it's heavier.


What seems like simple math to one person is confusing to another.

Now, when it comes to photography or surfing I can honestly claim being an expert...not just a hobbyist or someone who knows a lot...but an expert. Obviously there's more to learn in those fields as well, but I know it. What seems easy to me might not seem simple to others.

 

[MikeFairbanks]

You need more amps.

Going from 22A to 36A made a huge difference in acceleration.

I had to read this a few times to get it, but I think I do now. Acceleration and hill-climbing is weaker with a 22amp controller because it's maxing out under strain, but by upgrading the controller I'm maintaining speed under more strain, but keeping the same overall top speed.

Is that correct?

So, essentially I could save money by purchasing Ping's 36 volt, 15ah battery (which would give me considerably more range than what I currently have), and then purchase a 36 amp controller and have a lot more bottom-end power while maintaining about 24mph.

Is that about right? I think I'm getting it.

See, it's not the top end that bothers me. My setup goes 29.2mph, but I only do that occasionally just to measure speed. I'm very uncomfortable at that speed in what I normally wear (shorts or pants and a t-shirt plus helmet). I'm not going to get all geared out.

But by getting a higher amp controller and getting a 36 volt Lifepo4 I should be able to get up to speed quickly and climb hills better.

 

[neptronix]

Mike, you listened. And i am happy.
Your way to greater acceleration is, as in the picture, a few blobs of solder on your current controller away

You can adjust yours upwards to 30A safely, just soldering the shunt.

http://ebikes.ca/simulator/

Go play with this ---^
Your motor should be a 2807.
Set the controller to custom, and 22a. Don't worry about the resistance.
Set the grade to 3%, or higher according to whatever conditions you have.

Now set the controller to custom 30a. You'll notice that the speed on a hill is faster.
Try 40A, it might go even faster up that hill.

Now, try that with a 0% grade and you will notice that the maximum torque goes up.
Yep, you are putting more amps into the motor and thus it will generate more torque.
Now ideally i would run 35-45 amps on that motor, but if you're looking for just a bit more power, then the shunt mod will give that to you.

An upgrade would be a 12FET infineon, capable of doing bursts of 50-60A. That would make some torque all right....

As for a battery, the 15AH ping should be a huge improvement over what you have ( SLA ? ) You'll get less voltage sag, the battery will last longer, and it will be a hell of a lot lighter too.

The 15AH pings should not be pushed over 30 amps. Your motor will not draw over 30A continuously, so that's ok, but if you have a lot of hills, it will want 30A continuous and you will really want a 20AH ping to handle the load.

Hope that made sense.
Do the shunt mod now as pictured, get a battery later.

And yes, pretty much every other ebike forum on the net is a total joke. I can't read those forums with a straight face.

 

[MikeFairbanks]

Seriously, just adding a little solder to that one part will give it more power? I totally don't understand how that's possible. Does it allow more current to get through because it's thicker? Your diagram seems to show extra solder in a lopsided manner. Trippy. That's all it takes to boost it, eh?

 

[neptronix]

https://www.google.com/search?sourc....,cf.osb&fp=909331469ac07cad&biw=1280&bih=711

A shunt is basically a resistive element that determines how much current the controller can flow in most common BLDC controllers. Yes, you literally add solder, and you thusly change the resistance value - the resistance drops.

Doesn't matter how or where you put it really. Just be careful and add a little tiny bit, measure the amps, add more.. measure.. etc. This is when a GT Power analyzer, turnigy watt meter, or cycle analyst comes in handy ( if you don't have one already, shame on you ;D )

This is a very old trick and common method of hopping up controllers, before the forums collectively figured out how to program the infineon controllers, this is how people got more power. Your controller is not gonna be programmable if you bought a commercial kit like that.

Seriously, just adding a little solder to that one part will give it more power? I totally don't understand how that's possible. Does it allow more current to get through because it's thicker? Your diagram seems to show extra solder in a lopsided manner. Trippy. That's all it takes to boost it, eh?

 

[MikeFairbanks]

Alright, I have most of it down (and have been reading the ES tutorials...stickies....on power).

I now have a firm grasp on volts (top-end speed).

Watts (total power possible.... amps times volts).

Amps: How much power can be drawn from the battery to reach top speed (torque).

AH: battery capacity (and I think, but am not sure, that it has no bearing on torque or speed). I also understand now that forcing power from an SLA battery too quickly cuts the rated AH in half.

Watt hours is still a little tricky for me. I'm struggling to understand that.


So, basically, the only difference between a ping that's 48 volt and 10 AH and 48 volt, 15AH is capacity and nothing else. The way to get up to top speed quicker isn't AH. It's how many amps can be drawn at one time (which rests in the controller).


So, I think I get it now (except watt hours).

 

[DAND214]

So, basically, the only difference between a ping that's 48 volt and 10 AH and 48 volt, 15AH is capacity and nothing else. The way to get up to top speed quicker isn't AH. It's how many amps can be drawn at one time (which rests in the controller).

On a Ping you need more AH to be able to draw the amos out of the battery faster. A 2c pack at 10AH is straining wher the 15AH will deliver the power easier.

this would be differant if you were using LiPo and a 30 amp controller. A 12s1p of 5AH zippy's would get to speed faster than the 10AH ping and be under no excess strain.

Higher AH allows for less voltage sag and extends life cycles.

Dan

 

[dogman dan]

I don't see your problem being so much that you don't listen. It's that you don't make up your mind what you want.

I'm a lot the same, so it took me 4 years to build enough ebikes to be able to do it all. Always limited funds. Race bike, cargo bike, fast commuter, dirt bike. The ones I built trying to combine functions barely get ridden at all. The specialty rides are so much better at what they do.

Once you grasp watts and watthours better, it becomes easier to compare things when they are not the same voltage.

36v is different from 48v, because watts is amps times volts. so increase volts and you get more power in watts. increase amps, and you again get more power.

But the bottom line is how many watts. 72v x 10 amps won't have more power than 36v at 20 amps. both are 720 watts.


There are some rules of thumb, they are imperfect because if the equation is still not much power, you still have no power.

But in general, more amps increases the torque avaliable, while top speed may increase only slightly.

More volts, gives the motor a faster no load speed, so usually your under load speed also increases. Generally total wattage increases, so torque may be better too. But with the v increase, if you don't also increase amps you may still have a fairly sluggish take off.

Both rules run into a limiting factor, if the power is still relatively low.

The most popular upgrade is to increase both. Double volts to 72, and double amps to 40, and you get both. Along with a big ol EV grin.

But here is the rub. If you want to merely increase range, then get a 48v 15 ah or 36v 20 ah ping. You'll get range in the 20-35 mile ballpark depending on the speed you ride.

But if you want more performance, then you need a battery who's discharge rate will allow a lot of amps to flow without damaging the battery. I don't recomend a 10 ah pingbattery with a large dd motor and 22 amp controller because the ping is limited to 2c discharge rate. That means every time you pull a 30 amp spike with that 22 amp controller you just exceeded that batteries comfy discharge rate by 10 amps! Not a real good idea.

So if you want to add some amps to your ride, you really need to start out with a battery that can provide it. Look at getting a cellman battery, or an RC lipo setup. If you just want to take long weekend expeditions on your ebike, then get a 48v 15 ah ping. Bear in mind one thing, you will have a big perfromance increase with just a ping because the weight will be less than half, and you will see only a couple volts of sag. So you may be happy enough with a stock controller on a 48v 15 ah ping.

FWIW, I did do a shunt solder on a controller and ran it at my first death race on a 48v 15 ah ping. The ping hated it. I was pulling a lot of 35 amp spikes leaving each corner. By the end of the race I'd used ony 5 ah of capacity, but the battery was sagging like crazy, and took about two days to finaly balance when I went to recharge it. It was a new, but broken in properly battery, and I very nearly wrecked it in 10 miles of riding.

So don't solder your shunt if you get a ping.

Given that you want more, I recomend you go RC lipo, or A123's. RC lipo will allow a lot of flexibility in the controller you use. You'll love your bike if you have 18s lipo, and run a 72v 20 amp lyens 9 fet. I wouldn't recomend more power than that, (1500w) for front hub. you'll have about 35 mph. If you start with a 12s pack, your costs can be as low as $250 for 12s 5 ah plus a tolerable charger. And you can go right ahead and solder that shunt. Then with small expenditures from time to time, 12s 10 ah, the controller for 72v, then finally more ah to have 18s 10 ah. Or, taking a different tack, stay at 12s, but get yourself a Mac 10T and go dirt riding on that mongoose.

But you can dip your toe into lipo for just a hundred for some 5 ah packs, and $150 for a mid range charger.

 

[Tom L]

Seriously, just adding a little solder to that one part will give it more power? I totally don't understand how that's possible. Does it allow more current to get through because it's thicker? Your diagram seems to show extra solder in a lopsided manner. Trippy. That's all it takes to boost it, eh?

That one little part is a current shunt. It is a very low value resistor capable of carrying a lot of current. Your controller measures the voltage across it as current passes through it. Your controller uses this voltage to determine when the current limit has been reached.

By adding a little solder you lower the resistance of the shunt and it takes more current through it to reach the same voltage as an unmodified shunt would (V = I*R) . Hence your controller will supply more current.

 

[MikeFairbanks]

Thanks guys. Then I have it pretty much worked out that I'll go 15ah and just leave things stock or maybe buy a new controller. I might even just go to 36 volts, 15ah and upgrade controllers. It was only torque I was after and now I understand. Top end speed, in my case, won't get me to work faster. My longest straightaway is only about 200 yards. My average straightaway is about fifty feet or so. That makes it a lot of fun, but on SLA it makes turning tougher (because of weight) and momentum is not easy to keep when constantly turning, which is why bottom-end Is far more important here than top end. Plus, 20mph is our legal limit on the MUP (multi-use paths)

I think I'll film my ride again. It's pretty fun. You guys would love riding here. You can ride all day and not have to deal with any traffic. Just 125 miles of six- foot-wide asphalt (and in some places eight to ten feet wide) with nothing but electric vehicles. Winding paths, tree canopy, little bridges (the cute, arched kind but without the trolls), tunnels under the highways, and no harassment from the fuzz. Just good, fun riding and tons of eateries and watering holes along the way. We have two lakes to ride around (the path skirts the lakes) and we even have a new dirt mountain bike loop that can be accessed from the paved paths. And for the adventurous, a free bmx track that is regularly used for regional competition.

 

[neptronix]

So don't solder your shunt if you get a ping.

It's fine to add more amps you're running a ping within it's limits. He's talking about a 15AH ping minimum which can discharge 30A.. bump the current up to 25-28A and you are well within the limit of the battery.

20AH would perform better on the same amps of course, very minimal voltage sag. peak amp draw is 40A, so that's when a new controller would be justified.. one that could pull 30-35A out of the battery

Remember, these are peak amps, not constant on a motor like this. When you are on the flats at your top speed, you'll be drawing the same 15-20 amps constantly.

 

[shock]

Seriously, your still using lead-acid?? People still use this for things other than starting gas engines?? I'm confused!

Run the max voltage of lithium battery you can afford, and your system can handle, because High voltage, low current setups need smaller wires than low voltage high current setups. It's more efficient. That's why homes run 110/220v. If it were lower voltage the entire house would have to be wired in 4 gauge

 

[MikeFairbanks]

Yeah, I still have lead acid.

On the trike at work it'll always be lead acid for a couple reasons: 1. The school won't buy a 500 dollar battery. 2. It's a Worksman Industrial Trike. It can handle 500 pounds. Plus, it doesn't go much faster than 10mph anyway. Sure, it can go 20 on the 36 volt, 14ah batteries it's currently running, but in the hallways of the school I don't go much faster than light jogging speed. I don't want to hit anyone. I'll probably drop it to 24 volts, 14ah. I can get each of those for about 30-40 bucks here in town at batteries plus. That's cheap and easy.

On the bike I have 48 volt, 9ah SLA. The pack is 22 pounds. Sure, it's a chunk and it's weak, but I'm going to use it up until it's dead. It totally gets me to work and back fine. It meets my needs. My wants can wait.

Through Nep, Dogman and others, I finally understand all of it (volts x amps = watts, etc.). It's now making sense.

I've narrowed my battery (will buy it in a couple months) choice to a Ping 36 volt, 15ah or possibly the 48/15ah. I'll probably do 36. Might even get 20ah. I'll replace the controller as well.

But I won't do it until a few months from now because I have some serious expenses coming up (sick kid...many medical trips coming up).

 

[Drunkskunk]

Don't downgrade your battery to 36 volts, you'll be unhappy wiht it.

right now with your 48 volts, your controller can put out 1000 watts (48 volts X 22 amps, its limit)
If you downgrade to 36 volts, you'll have only 800 watts for torque ( 36 volts X 22 amps)
So your speed and torque will be rediuced. Your best option is to go with a 48v 15a Ping, or something similar from Cell_man.