Ebike voltage issues

Deano2609

New Member
Region
United Kingdom
Hi I have a problem with my ebike conversion just bought a 1000w 29" 48v wheel kit from g-volt it keeps cutting out in pas and throttle when I put pressure on pedles either trying to go faster or going up hills , it seems to go up over 1200w really quickly then cutting out , but if I try and keep it under 1000w it stays on , can't climb hills at all , I have I 48v battery 10ah which is only about 6 months old , is my battery not powerful enough as the supplier keeps telling me . But its been like this since I've had it only a month ago , its got a sw900 display but has never worked properly the pas levels 1,2 don't do anything 3 does a bit 4 nothing and 5 goes like a rocket ,but stopping and starting, I've been told the display needs a kt controller to work properly but this hasn't any ideas many thanks
 

harryS

Well-Known Member
I agree with the kit seller. Your 10AH battery sounds too small, and it was too small when new. Most 10AH batteries can't run a 1000W motor. They can't supply the steady 25-30A you need for hills or throttle. A few small AH packs will, but they were designed with high current cells, and are priced accordingly/

Your SW900 display won't work with a KT controller. The KT guys put some effort into having a nice gradual pedal assist. A lot of other controller makers don't care. I have an SW900 and associated controller that works exactly like you describe. Pile of junk in my opinion, and it's sitting in my junk box.
 

Deano2609

New Member
Region
United Kingdom
Thanks for your reply I thought my battery was under powerd, what type and power would you suggest for a new battery, also display that would work better many thanks
 

AguassissiM

Well-Known Member
@Deano2609

Welcome to the forum hope you`ll enjoy your stay.

Which controller do you have, or post a picture of the label.

As the capacity of your battery is not up to par to be your daily source of power you can try to make some changes within your display unit to tweak the parameters to get some use of it, have a look here and see if it will be helpful :
or here:
you can always keep this one as spare once you get a new one.

The replacement battery as far as capacity goes it will depend on how much you can or are willing to spend, as @harryS has mentioned the more AH the more expensive it will be.
48 volt 17 to 25 AH in general is what you should be looking at since they are good performers and reasonably priced.
Unless you can afford one that is 35AH and have room on your bike to mount it but that is just overkill in my opinion.
There is a member here on this forum @Jenny Mao that sells brand new batteries made just for your application at very reasonable price, send her a message and see if she can build one for you.
 

Deano2609

New Member
Region
United Kingdom
Thanks for the reply my my motor is a brushless gearless 1000w and I'll send pics of controller and my display is the sw900 as you know I've been into settings and modified it a little but pas doesn't really work properly but obviously my biggest issue is the voltage loss many thanks
 

Attachments

  • 20211121_120208.jpg
    20211121_120208.jpg
    139.1 KB · Views: 60

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Agree. The "cutting out" is most likely the fault of the battery.

Looking at that tag, while it may not be the best available, that controller SHOULD be up for the task of supplying power for your motor.

No clue what you have going on with the different issues within the PAS levels.

Last, from a performance perspective while getting moving from a stop and climbing small hills, I would describe a 1000w direct drive hub as gutless. A 500w geared hub will leave something like that in the dust behind it - AND - use less power doing it.
 

Deano2609

New Member
Region
United Kingdom
Yes I've just changed from a geared 350w motor and had two of them in just over a year and seemed not to last and on advice whent for a 1000w gearless supposedly last longer if someone could give me any advice about may be a better controller and display that would work together well many thanks
 

AguassissiM

Well-Known Member
Can you explain : ""keeps cutting out in pas and throttle when I put pressure on peddles"", are you sure you did not criss-cross these 2 connections and the output of the controller matches the input of the components,
ie : positive negative sense wire match?
Do you have a decent multi-meter and do you know how to use it (some fox do not have one or care to learn how to use it correctly).
 

Deano2609

New Member
Region
United Kingdom
Yes all connections correct I'm an electrician, in full power 2 seconds of pedling and wattage goes straight up to well over 1200w and cuts out if I keep it below 1000w it stays in but obviously cutting out all the time going up a hill, because it constantly goes above that putting pressure on pedals , also with throttle hopefully changing battery should resolve this
 

AguassissiM

Well-Known Member
@Deano2609
I`m sorry for doubting your ability to use a multi meter, and now i am the amateur...

""in full power 2 seconds of pedling and wattage goes straight up to well over 1200w"" this suggest to me that the settings in the display unit may not be adjustable or not adjusted correctly, please keep in mind that i have been known to be wrong on several occasions however i`m still not afraid to admit it.
Here is a brief explanation of the display parameters, your parameters may differ some by not having all the options included.
If you like check your configuration vs this guide and see if it helps any.
Always write down all the parameters that are present before changing them.

I forgot where i got this from but it helped me out a lot when i was making my first steps treble shooting my new configuration, thanks go to the original poster.

Look at your P07 P09 P10 P11 P12 P13 .....

Menu Operation


Press UP + DOWN buttons to enter configuration menu. Parameter PXX, beginning with P01, will show on screen in the SPEED section. Parameter value will show in the bottom right of the display, in the ODO section.

Use Up and DOWN buttons to change value of parameter.

Short press M button to select next parameter.

Long press M button to save current parameter.

When in configuration menu, press UP + DOWN to save parameters and exit configuration menu.

After 10 seconds of inactivity, configuration will automatically be saved and exited.


P01 Backlight Brightness
1-3, Higher is brighter.
Brightness of the display in low light (night).


P02 Unit of Measurement
0 for Kilometers, 1 for Miles
Sets the displayed unit of measurement for odometer and speed.


P03 Battery/Controller Voltage
24/36/48 volts.
Sets battery voltage. This should match the output of your battery. Used to calibrate battery level indicator.


P04 Inactivity Timeout
0-60 minutes, 0 disables inactivity timeout.
Automatically sets display/controller to sleep after a given time of inactivity.


P05 PAS Levels
0 or 1
0 = 3 Levels, 1 = 5 Levels
Sets of the number of Pedal Assist System (PAS) levels available. More levels = finer control over amount of assistance given by the motor.


P06 Wheel Size
Diameter In Inches, Precision 0.1
Sets the wheel size of the bicycle in inches. Correct wheel size is required for accurate speed and odometer function.


P07 Motor Speed Magnet Type
0-100
Set to 47 for direct drive motor, 86 for geared motor


P08 Speed Limiter
0-100 km/h, 100 for unlimited
Shuts off motor when using PAS and above set speed limit. This parameter's value is always in km/h, so a mph limit must first be converted to km/h first!


P09 Throttle Response
0 for instant throttle, 1 for delayed throttle
Sets whether pressing throttle and motor beginning to spin is instant, or whether there is a delay between the actions.


P10 Throttle Mode
0 = PAS Only, 1 = Throttle Only, 2 = Both PAS and Throttle
Sets which sensors are used for throttle control.


P11 PAS Sensitivity
1-24, Higher = more sensitive
Sets how sensitive PAS is to movement of the pedals.


P12 PAS Start Strength
0-5, Higher = more assistance
Amount of assistance given when you start pedalling.


P13 PAS Magnet Type
5, 8, 12. Determined by magnets (dots) on PAS ring.
Sets PAS ring magnet type as determined by the number of magnets on the ring.


P14 Controller Current Limit
1-20 Amps, some versions of sw900/controller allow higher values.
Sets the current (amp) limit of your controller. Setting this value to something higher than your controller or motor can handle may cause damage!


P15 Not Implemented
This parameter is unused


P16 Odometer (ODO) Reset
Press and hold UP button for 5 seconds to reset ODO counter to zero. Some versions of SW900 do not contain this parameter.


P17 Motor Wattage/Display Option
250-1000 Watts
Some versions of SW900 use this parameter to switch between displaying battery voltage and wattage.
Sets the wattage of the motor. Some versions of SW900 do not contain this parameter.

Here is another video walk thru the settings:
 
Last edited:

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Yes I've just changed from a geared 350w motor and had two of them in just over a year and seemed not to last and on advice whent for a 1000w gearless supposedly last longer if someone could give me any advice about may be a better controller and display that would work together well many thanks
If you feed a 350 watt motor a steady diet of 1000 watts, common sense says you're going to (melt) go through them....

I agree with the "advice" you were given that going to a 1000 watt drive will cure that situation, but the downside with a direct drive is the big performance loss. Now if you had gone with a 1000w geared hub, pretty safe bet it would hold up and would likely be in a completely different league when it came to performance.

A 35a KT controller with a KT display will work together for sure, and likely do a much better job while doing that. However, that 1000w direct drive hub is STILL going to be gutless.

The right advice, if you have performance in mind, is to go with a more powerful geared hub drive, something in the 500w-750w range (even one of your original 350w hubs). Then set your controller up to limit the amount of power available to the motor to no more than the motor can handle safely. Alternatively, you can feed a 500-750w geared hub all the power you have available - IF - you have the presence of mind/discipline to limit the occasions you do that to just a few seconds - to prevent overheating them. Otherwise, you're going to be right back where you started, with a burnt out motor....
 

Deano2609

New Member
Region
United Kingdom
Thanks for your advice the 350w motors that I had were on different displays and controllers this 1000w kit came all together from g-volt as it is now ,without the battery so was hoping that my old battery would last for a while until I could replace it but it doesn't seem like the case , do you think I should change controller and display at the same time as battery many thanks
 

Deano2609

New Member
Region
United Kingdom
The p14 controller current limit is set at 26a the speed magnet is set at 46 which I've not changed
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
That's a loaded question. Because the direct drive motors can keep themselves cooled down so well (as compared to mid drives and geared hubs), they lend themselves well to performance holics who like to feed them 40 to 60 amps at 60-72 volts. Those are going to need some pretty special (expensive) controllers and batteries. At that point, you can no longer describe the direct drive hub as "gutless".

I don't know what kind of performance level you are looking for, or what your budget is. As far as the battery is concerned there's a lot to them. It's not just about amp hours, though that's clearly pretty important. Amp hours is about your range. You would think that would be easy right? The more the merrier? It's not, because that range is equal to the batteries weight. Lugging around extra battery weight in the form of range you never need/use is a bad plan - not to mention a waste of money.

A battery needs to be able to supply enough amperage too. This seems to be where your battery is suffering. This is about the battery cells used within the battery pack. I'm not going to get in to all that, other than to say you need to pay attention to the different cells used to build packs. Watch the available amperage rating as well as the amp hour (ah) ratings....
 

Deano2609

New Member
Region
United Kingdom
I'm not really looking for a massive amount of performance I just really only need about 25 miles in one go . And not large hills , but I thought if I'm changing battery and looking to spend about £300 on battery and I thought I may as well change controller and maybe display, but I can't seem to find a 35a controller that's not from China and will take ages to come any ideas , mainly because I have just paid £400 on motor many thanks
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
KT35a controllers and the LCD3 display can be had together for 100 dollars or so from a LOT of different sources here stateside. Not all come from China... Try Google and ebay. If you have any waterproof ends watch what you are doing! KT sells controllers using many different wiring formats...
 

Deano2609

New Member
Region
United Kingdom
I have seem some in United States but I'm in the United Kingdom I need to have a really good look , I think I would rather change the lot to match the motor .
 

Deano2609

New Member
Region
United Kingdom
At the moment I'm really struggling with what battery to get so many and weather to change controller and display as well dose anyone have any ideas or links to equipment many thanks
 

harryS

Well-Known Member
Pedal assist is really an afterthought when you have a 26 amp controller, I would suggest disconnecting the assist sensor, and riding it as a throttle bike. If you want to ride slow, it should easy to feather in about 100-150W with throttle. You could change the controller and set it to deliver 500W, but why do that now, Your resources should be allocated toward a dependable battery.

Anything that is low cost will kill itself trying to supply the 26A your controller demands. Look for a supplier that is honest enough to tell you how many amps their product can supply.

Unfortunately, this is the problem with high power kits. The motor/wheel is often dirt cheap, but you have to spend for the battery,

I've bought several UPP batteries. They use chinese cells, but these are rated for 30A continuous.

Go onto the UK Pedelecs forum for their advice on vendors.
 
Last edited: