1000watt ebay hub motor

[dmcke]

Hi guys, I've recently purchased a 1000watt 48v hub motor from ebay and I've been trying it out in the streets around my house so far. Now, I don't have a cycle analyst but I do have a hobbyking watt meter running inline to keep an eye on things. I'm worried about the temperature of my motor after a 20 min run as its quite hot, almost too hot too touch. Watt meter shows that I'm pulling 50 amps under hard acceleration and roughly 20 amps once I'm up to speed. Speed is topping out at 33kmh. I'm running two high C rate 6s lipos in series so voltage is holding up fine under load. Does this all sound about like what I should expect?

Cheers,
Daniel

 

[DAND214]

Hi Daniel,
jow about a little more info.

Wheel size, controller, weight, hills, top speed.

Where are you located? That seems to help a lot of us as to know where you are playing.

Too hot to touch, is how hot? BURN ya or just uncomfortable to hold your hand onit?

Only 2 6s packs is kinda small if you are pulling high amps, yeah I know they can take it but how far are you pushing the voltage?

Is it sluggest off the line or peppy?

Dan

 

[skeetab5780]

Lift your hub wheel off the ground and turn the throttle to 100%(WOT) and check the watt meter readings of the "no load full speed" if you are drawing more than 2amps you might have the wrong motor wiring combos.

 

[dmcke]

Hi Dan,

Here's some more info for you then. Wheel size is 26". Controller is the standard "silver box" controller that seems to come with these motors from eBay. Sadly that's all the information I can give you on the controller. The batteries are a little small, yes but are coping fine for now at least until my next 2 packs turn up to get me up to 10ah. Best I can give you for hills is the height difference reading that my GPS gives me, which says a difference of 4m from memory. I would say almost the entire trip is relatively flat ground, just the hill at the beginning that contributes to most of the 4m. I'm located in Capalaba QLD and I'm running around a little park behind our local bunnings at the moment. Nice and far from the road so I don't get myself into any trouble. Weight wise, my ride is 25kg and I'm about 85kg so lets say less than 120kg by the time I have all of my batteries. Its worth mentioning that this isn't a bike, its a trike and is electric only, no pedal assist.

I'll go give the wheel a no load test now.

Thanks,
Daniel

 

[dmcke]

Okay so I'm getting .7 of an amp wot with no load. Bike computer says the speed is 43kmh.
Any other suggestions?

Daniel

 

[wesnewell]

How about a link to the ebay kit you bought. 33kph sounds pretty slow for a 48V 1000W motor kit running 12s lipo. Until I looked it up, I had no clue where Capalaba QLD was btw.
Welcome to ES****Do this before your first post or now (it's retroactive)*****
Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. Once done, your location will appear in every post so you won't have people asking where you are ever again. This will help people help you. Example: Wylie, TX, USA. or just USA, but country as a minimum, and country is the most important. There are many cities with the same name all over the world. Without knowing what country you are in it's hard to make any recommendations. Thank you.

 

[dmcke]

Thanks for the tip, I've updated my profile. I should have been more specific when I told you anyway, so my mistake. Here's a link to the map of the park I ride around: https://www.google.com.au/maps/@-27.5228128,153.1866428,17z
Here's a link to the ebay page for my motor kit. http://www.ebay.com.au/itm/SPECIAL-...pt=AU_Cycling_New_&hash=item2a2e07ad71&_uhb=1 Please note however that the motor doesn't look like the one in the picture on the add, I'll go and take a photo of mine in case someone recognizes it. Does it make a difference that this is a front wheel motor kit, maybe they "de-tune" them a bit so you don't rip the forks off your bike?
And yeah I thought 33kmh seemed a bit slow. At first I thought it was my cheap $8 bike computer, but the GPS on my phone agrees definitely only 33kmh, even on a slight down hill!

- Daniel

 

[wesnewell]

Their ad states a top speed of 55kph, which sounds reasonable. Your controller may be speed limited. Usually 2 wires connected together, but I've heard of it being done inside the controller. It sure as heck shouldn't be getting too hot to touch only going 33kph on fairly level ground, and it shouldn't need 20A to do that either. Something isn't right, but I don't know what it is. Check that the wheel turns freely and the brakes aren't to tight.

 

[dmcke]

Wheel's turning fine and brakes definitely aren't rubbing. The only thing I can think of about the heat issue is that the last run I made, I was going quite slowly maybe 10kph max. I was watching the amp meter and It was reporting that things were running very efficiently at that speed (200-300 Watts on relatively flat ground) to maintain that speed. Does running slow heat these motors up more than normal?
This internal speed limit thing sounds interesting? Is there a way I might be able to remove it? I'm pretty sure there isn't any wires connected to each other on the outside of the controller at least.
My current measurements may well be out too, I've heard these Amp meter's aren't know for their accuracy.

- Daniel

 

[dmcke]

Actually, Scratch that. I've just had a closer look at the controller, and in the messy bundle of wires, there is in-fact a read wire which joins back to itself! Does this sound like a speed limit wire to you guys?
My batteries are almost re-charged now so I'll take it out later tonight for a run and see if that solves the problem!

- Daniel

 

[dmcke]

No luck. That wire seems to be an ignition switch type wire. Nothing happens unless its connected. Its worth noting that when I spin my wheel up unloaded with freshly charged batteries, its more 49kmh. It still doesn't manage any more than 33kmh when I'm riding it though.

- Daniel

 

[dogman dan]

Well, I was thinking you might weigh twice what you say.

I agree, 20 amps cruising should be getting you about 40-45 kph. 33 kph should not pull so much.

But a pretty warm motor is not so unusual. Almost too hot to touch is common, and not harmful. But it does sound like it's getting that hot faster than is typical. Pulling 50 amps to start up will make a lot of heat. It almost sounds like the controller is too powerful.

Which leaves, how much load is this? On hills, take them full throttle. below 25 kph on steep hills will cause inefficient running, high battery use, and lots of motor heat. But slow on the flat should run cool. At full speed, a trike will pull more wind drag, but it sounds like it's pulling a lot of amps even for that.

Is there a sun shade on it or something? I just keep wondering what we're missing. Something sounds wonky.

 

[dmcke]

Yeah I agree, it just doesn't seem right from what I've seen everyone else getting out of their motors. I've got a mate with one of these on his trike and he's managing just over 50kmh. Plus he's gotta weigh at least 20kg's more than I do. I'm only a pretty small guy, and I'm definitely 85 as I checked it today before I posted haha. I've only done full throttle up hills, as I've heard that less than that can cause problems. I haven't noticed the motor being hot before this last run, but I'd checked immediately after the run other times. This was about 10 minutes after the run, and it was too hot to hold my hand on for more than a few seconds, which is the test we use on our model plane motors. I'll take it for a ride soon and confirm that it is actually pulling 20a on flat ground, just incase it was a slight up hill when I checked.

- Daniel

 

[dogman dan]

How long a run that time it got hot? I'm assuming pretty short, assuming a 5 ah pack. One thing, after you park, a motor will get hotter, since the cover is no longer in the wind. There will be a temp spike for 5 min or so. Then it will start to cool more.

If you hand didn't sizzle, then it's still in the fairly normal temp, for some operating conditions. it should be getting noticeably warm if you run at 20 amps for 15k.

 

[dmcke]

It is a 5ah pack at the moment, soon to be 10. It was a slow run however so managed probably half an hour of on and off use. My hand certainly didn't sizzle, so maybe it is a normal temperature. I just thought that may have been a clue as to the low top speed. I'll go and get a few more readings now.

- Daniel

 

[dmcke]

Okay so I just got back from my test.
Obviously on my initial test's I didn't pay close enough attention to the Amp meter (it was mounted on top of the battery behind me initially which may be why).
On flat ground, the Amp's eventually settle down to about 16-17 which translated to about 33kmh when the pack was fully charged. After a few minutes of use, the highest top speed I was able to achieve was 30 at still around about the same amps.
Under hard acceleration I saw peaks of up to 57 Amps, however they didn't last for long before backing off to around 25 Amps as my speed increased to a point where my top speed was reached.
Its now been 5 or so minutes since my ride and my motor is a nice warm temperature to warm my hands up on (Air temp is about 13 Degree's C here at the moment).
I traveled roughly 4km and used about 3AH worth of battery.

Does this help make things any clearer?

Cheers,
Daniel

 

[dmcke]

Here's a photo of the motor in-case someone recognizes it.(I can't find a picture of one with the same pattern anywhere!)

And here's a photo to show you that there's nothing crazy and draggy on it apart from me.

Brakes definitely aren't dragging as I adjusted them right before leaving to make sure they were set properly.
The two rear wheels have good bearings in them and are turning very smoothly and easily.

Any other suggestions would be great!

- Daniel

 

[wesnewell]

Your no load speed of 43kph calcs out to a 350rpm motor. I'm guessing you got a 48V 500W motor (350rpm @48V rating is typical for these) or a very slow wind 1000W motor. If it's a slow wind 1000W motor, it should accelerate to top speed in seconds. 50A from a dead start is a lot of amps. Try swapping controllers with your friend and see what happens. That will tell you a lot since he gets 50+kph.

 

[dmcke]

My no load rpm did increase a little on a fresh battery. I got to 49kmh right after a charge. Theres one thing I can think of that didn't worry me at the time, but is kind of making sense now is that the label on the controller had been crossed out in permenant ink and re labeled as 48v 1000 watts. At the time I figured it just had the wrong label on it? And they hadn't been bothered fixing it but now I'm suspicious.
I've emailed the seller asking for advice and he told me my battery voltage is too low. He said to try Sealed lead acid batteries for more voltage. Am I right in thinking that's rubbish? A fully charged SLA may be a slightly higher voltage but surely that isn't enough to get me going faster? Any advice on how to deal with the seller?

Cheers,
- Daniel

 

[wesnewell]

It's rubbish. I ran sla for a couple of weeks, and fully charged was only ~54V. Your lipo only charges to 50.4V, but there's not near as much sag in it under load compared to sla, which will sag considerably lower. I didn't mention it before, but radial lacing a 26" wheel is nuts. Even if it's a 36v controller, that would not make any difference in speed since the voltage controls that. I think he just shipped you the wrong motor. Is your friends motor identical to yours? Althouhg that won't matter much as the 500W and 1000W version of the ones I had looked identical on the outside.

 

[dmcke]

That's what I thought. From what I've seen of SLA's, they aren't likely to deal well with the current this motor is using. Not to mention that the extra 4v at full charge still wont get the motor going up to around 470rpm unloaded which seems to be roughly what others report their motors do.
I haven't yet actually seen this guys trike apart from 1 picture so its a bit hard to know. I can tell you that his motor is black and has silver rings around it, like all the generic pictures of these motors on ebay.
I rubbed at the label a bit this afternoon to reveal that faintly underneath the dodgy permanent marker cross out, the controller actually says : 36v, 500 watt.
This can't be correct though as my 48v batteries haven't smoked it yet, right?
I'm still waiting on further response from him. He seems to reply very quickly at night, but not during the day at all.

Thanks for all the help so far!
- Daniel

 

[Rodney64]

Daniel

Where are you measuring your amps, Battery amps are normally a 1/3 of phase amps. If you want you can purchase the cycle
analyst with an inline shunt. http://www.ebikes.ca/product-info/grin-products/cycle-analyst.html


Glow worm cycles also sell CAs as well as inline shunts.

http://glowwormbicycles.com.au/store/e-bike-parts-and-accessories/ebikesca-item/cycle-analyst-version-3-ca3-dps


These type of kits normally only have a 15 to 20 amp controller so im assuming yourre monitoring phase amps.

 

[dmcke]

I have absolutely no idea how to measure phase amps? Would this involve running a current meter on one of the motor output wires? My amp meter is currently inline between the battery and the controller. I thought these controllers were meant to be current limited too, but I'm definitely getting peaks of 57 amps on the input side of the controller.
I love the idea of the cycle analyst but sadly its out of my price range at the moment as I still need to purchase the second half of my battery pack.
I know it all seems a bit weird, and I assure you my measurements are accurate and I'm just as confused as you guys are.

- Daniel

 

[dmcke]

So the controller I have appears to be compatible with both 36V and 48V. My 57 amp peaks are only for a very short time (less than a second) and from what I can tell, the rest of the time my current is under 30 amps. Maybe these controllers allow a short high current burst in order to help acceleration?
Still sounds like the motor I've been sent is too small doesn't it?

- Daniel

 

[Rodney64]

No the motors ok. I have a 1000 watt kit and In The past 500 watt kits.

All that changes is extra voltage 36 to 48 volts and 15 to 20'amp controller. Amps times voltage determines the final watts.

My 36 volt kit was approximately 32'km per hour
My 48 volt kit 55 volt off charge was 40 odd kmh.

12s is 50.4 but not a lot in it in reduced speed.

When you buy kits off eBay your aren't guaranteed what Rpm motor that you're going to get.

Faster RPM is going to make more heat.