Shunt mod or new controller?

I don't want to increase my top speed. I want faster acceleration and Hill climbing.

Considering doing a shunt mod but the controller that came with my bike is not easy to open so getting a new controller might be a simpler solution but I have a few questions.

Could I buy a controller that would already have the affect of shunt moding my original?

Do the controller specs need to exactly match my bike? For example my bike is 48v 600watt. Could I get a 48v 800watt controller to replace it?

Also the connections might not match up. Is it common to have to adapt the connectors?

Neither. You need a higher voltage for more speed.

John in CR said:

Neither. You need a higher voltage for more speed.

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The first sentence in my post says I DON'T want more speed.

if you buy another controller then the chance are you will have to work out the new wiring , but its not that much of a problem to do. a jump from a 600W to 800W will be fine but stick with a 48v controller if you dont want to alter the speeds and buy the same type of controller i.e sensored/sensorless .
buying a higher power controller is essentially doing a shunt mod .
Trouble with doing a shunt mod unless you have done one before is people tend to go for a extrem mod then this normally pops the controller.

gwhy! said:

if you buy another controller then the chance are you will have to work out the new wiring , but its not that much of a problem to do. a jump from a 600W to 800W will be fine but stick with a 48v controller if you dont want to alter the speeds and buy the same type of controller i.e sensored/sensorless .
buying a higher power controller is essentially doing a shunt mod .
Trouble with doing a shunt mod unless you have done one before is people tend to go for a extrem mod then this normally pops the controller.

Click to expand...

Great. Thank you so what aspect of the new controller would equal the shunt mod? Is it the extra wattage?

1. Yes, it just needs a higher max amps than the one you have now.
2. No. It just needs to be a 48V controller with higher max amps. Wattage is for continuous operation. I'd suggest a 48V 1000W or higher with a 40-50A max output assuming your battery pack is capable of that.
3. Yes.

The wattage rating on controllers doesn't mean much. What's more important is the maximum current it allows. Then you would know what effect a new one would have since torque is more or less directly proportional to current.

Some controllers are potted, so shunt mods are impossible on them. I found that most controllers can manage with 25% of the shunt soldered. I've sometimes gone up to 30%, but I've had some get warm like that. However much you solder, you have to think about how everything is dealing with the extra power. It's one thing to use the extra torque for a short steep hill-climb, but most controllers will get too hot if you run them continuously at their maximum, even before soldering the shunt.

Why not use the opportunity to get a better controller, like a nice LCD, more features, better PAS, sinewave, etc? There's always a couple of connectors to change, but that's no big deal.

d8veh said:

The wattage rating on controllers doesn't mean much. What's more important is the maximum current it allows. Then you would know what effect a new one would have since torque is more or less directly proportional to current.

Some controllers are potted, so shunt mods are impossible on them. I found that most controllers can manage with 25% of the shunt soldered. I've sometimes gone up to 30%, but I've had some get warm like that. However much you solder, you have to think about how everything is dealing with the extra power. It's one thing to use the extra torque for a short steep hill-climb, but most controllers will get too hot if you run them continuously at their maximum, even before soldering the shunt.

Why not use the opportunity to get a better controller, like a nice LCD, more features, better PAS, sinewave, etc? There's always a couple of connectors to change, but that's no big deal.

Click to expand...

This is the first time I've heard of an LCD controller. You mean like LCD display? Where does the display come from? Where does it go?

EDIT

So I have decided to upgrade the controller. I am having a hard time figuring out what would be a compatible controller. Perhaps someone here can find the kindness in his/her heart to help me.

What I have below is the wire diagram for my bike.


I have most of it figured out but in the next picture I have circled two areas that confuse me. the first is the green circle, I think that's the throttle but the throttle connecters I see on other controllers have only 3 wires, this one has 4. Why? The red circles shows something with a 48v written on it. I have no idea what that is, anybody know? Also the DC converter doesn't seem to be in the diagram

The 4th wire (yellow) will be battery voltage for a battery meter of some sort. Throttles often have battery indicator LEDs on them, which this wire powers.

Your controller is a 18A one, so you should look for one about 22A, which will give you 22% more torque.

The 48v wire is just a supply line for lights and other 48v things.

What's that at the bottom of the drawing, where there's two longish words that begin with T and M? I can't read it.

Another thing: The drawing says phase angle 60 deg. Some controllers are 120 deg only. Some can work with both. You need to be sure about what your new one can do.

To continue to use your other parts, such as the lcd, you will need to get a different controller from the same people, one also intended for use with the same stuff in your kit.

I'd say, if that cannot be done, try the shunt mod, But just a tiny bit of solder, to give it 5 amps more.

d8veh said:

The 4th wire (yellow) will be battery voltage for a battery meter of some sort. Throttles often have battery indicator LEDs on them, which this wire powers.

Your controller is a 18A one, so you should look for one about 22A, which will give you 22% more torque.

The 48v wire is just a supply line for lights and other 48v things.

What's that at the bottom of the drawing, where there's two longish words that begin with T and M? I can't read it.

Another thing: The drawing says phase angle 60 deg. Some controllers are 120 deg only. Some can work with both. You need to be sure about what your new one can do.

Click to expand...

That other thing is not something my bike came with. Some sort of option I guess. I have the connectors but nothing is plugged into them. My best guess is, it's an anti theft mechanism.

dogman dan said:

To continue to use your other parts, such as the lcd, you will need to get a different controller from the same people, one also intended for use with the same stuff in your kit.

I'd say, if that cannot be done, try the shunt mod, But just a tiny bit of solder, to give it 5 amps more.

Click to expand...

Wow, really? That stinks. In order to shunt mod this, I'll have to CUT open the controller. The only parts I must have functioning are the turn singles, break lights and headlight.

Are you sure it needs cutting open? The one in the diagrams don't. They show typical construction. An alloy tubular housing everything lives inside. Closed by an end plate each end that is held by 4 screws. One plate has the wires exit through it. The other comes off easy and often exposes the shunt without further disassembly.


P.S
This don't look like an ebike to me. It's a motorcycle isn't it? 70kmh clocks and indicators

friendly1uk said:

Are you sure it needs cutting open? The one in the diagrams don't. They show typical construction. An alloy tubular housing everything lives inside. Closed by an end plate each end that is held by 4 screws. One plate has the wires exit through it. The other comes off easy and often exposes the shunt without further disassembly.


P.S
This don't look like an ebike to me. It's a motorcycle isn't it? 70kmh clocks and indicators

Click to expand...

Your right it looks like a typical controller, the ends do unscrew an come off but the board is stuck inside. Glued in or locked down somehow. I can cannot get it out. I would have to cut the top of the box off I think. The shunt is not visible from then end I can open.

And you are half right about this bike. It's not the typical electric bicycle configuration. It's an scooter style bike. Though the speedometer goes up to 70kmh, It's only capable of going about 30kmh.

since we do not have a picture of your controller there is no way to offer advice on how to open it. usually the heat sink is screwed to the side of the case. no way to know on yours.

https://dl.dropboxusercontent.com/u/14602150/IMG_20150126_113720.jpg
https://dl.dropboxusercontent.com/u/14602150/IMG_20150126_113732.jpg
https://dl.dropboxusercontent.com/u/14602150/IMG_20150126_113743.jpg

Finally got the board out. Turned out it was wedged in very tightly. It took a wood block and a hammer to knock it out.

Hows it looking in there?

I regret not taking pictures while it was open. It looked really clean and new inside. There was some kind of spring bracket that held the fets against the side of the case. That made it really hard to put back together.

The mod is done. I'll post again after a test ride.

OK now I have not fully tested the bike yet. I plugged everything back in but something weird happens...

So when I turn the the key to ON there is a single, fairly loud, click sound from the controller. Also one of the cables twitch when I turn the key. What's going on? I am afraid to continue until I learn more.

UPDATE, so the wheel does not spin freely, even when the battery is not connected and I try to use the pedal or just turn it with my hand there is a lot of resistance for some reason.

UPDATE 2. where I opened the controller again and it's clear that the a FET or two overheated and probably went bad.

I would just buy a new controller but the wheel being hard to turn makes me worried. Even with the controller and battery removed the bike is not ridable because the wheel barely moves. Now I have heard of hub motors needing to be programmed or something. Maybe I screwed up the timing or what but why would it have problems even when no power is connected? This makes no sense to me.

UPDATE 3. Um so I went to go move the bike because I'm am defeated for today. I was conviced I had to buy a new hub motor but now the wheel is spinning freely again. I don't get it.

please help

PS. I am thinking of buying the 1000W version of this http://www.ebay.com/itm/Electric-Bicycle-Brushless-DC-Motor-Controller-24V-36V-48V-eBike-350W-500W-1000W-/271745932184?pt=LH_DefaultDomain_0&var=&hash=item3f4551db98

If you have any short circuit on the phase wires, the motor will be difficult to turn. The short circuit could be directly in the wires or through the MOSFETS in the controller. If it went away without disconnectingvanything, it's probably in the wires.

d8veh said:

If you have any short circuit on the phase wires, the motor will be difficult to turn. The short circuit could be directly in the wires or through the MOSFETS in the controller. If it went away without disconnectingvanything, it's probably in the wires.

Click to expand...

Likely the problem. Did the motor just retain some electrical charge or something and that's why the wheel remained difficult to turn for a while after I disconnected the power?

No. It can't retain any charge. More likely, the phase wires were touching somewhere and now they're not. You need yo investigate.