Review of the Newest MP4

[Kauaikit]

Hello all….yes, I'm a new member and eager to try out the newest MP4 (sine-wave controller) on one of my older EVG PE (Police Edition) ebikes.

The 26" rim version, along with the dash and PAS setup is on it's way from China to S. CA.

Anyone have any advice or reviews of this hub yet for MAX performance?   

I've reviewed Gary's (Ca) excellent youtube video, though I'd like to know the upper most performance (60v) from this newest hub from GM.

Thanks.

Kit (kauaikit)

12/1/14

Installed the MP4 hub with grip throttle (factory out of thumb's) and LED display. Fairly straight forward. Installed two 22.2v/8ah (12s2p @ 50.4v/8ah) Nano tech batteries in the original EVG bike battery box.

It works as designed. Very quiet up to around 25mph.

I'm used to higher speeds, so have ordered a 14s5p Samsung 25r pack from China. I'll keep the voltage @60v and see if I can get the claimed 28mph level speed. Now working on installing the PAS to test on how that functions, though I've always been a throttle guy.

I've too ordered a second MP4 hub kit, though am having the Factory setup the sine wave controller for higher speed, though with less torque. This should be interesting to test.

KB

[GM Canada]

Hello, I have not been in the forum for a while but trying to solve an issue for someone has brought me here so I thought I would read a few posts.

Thank you for your positive comments on my video.

First: Who is claiming it will go 28 MPH. This is something I have not seen.

Second: running it with a 60 volt battery is risky. Its not designed for that. Any spike over 60 volts will likely fry the controller instantly.

I'm not trying to be negative, just pointing out a reality from previous experience.

Gary

[Bikemad]

Running it with a 60 volt battery is risky. Its not designed for that. Any spike over 60 volts will likely fry the controller instantly.

I'm not trying to be negative, just pointing out a reality from previous experience.

Don't worry Gary, he's not using a 60V battery, he's planning on using a 14 cell LiPo pack, which is only 51.8V nominal and 58.8V maximum, that's only 0.4V higher than the 48V GM LiFePO₄ packs which are charged up to 58.4V.

Over the last five and a bit years I have run all of my GM hubmotors on a 14 cell LiPo pack without damaging any of the controllers. (Except for the tweaked controller that I managed to blow up after extracting over 97 Amps from it.)



Alan
 

[Kauaikit]

Hello Gary….my current interest in the latest Chinese manufactured Golden Motor MP4 is their upgrade to a internal sine-wave controller. I'm experienced with the now BK USA Wavecrest Tidalforce ebikes (2005) using the same tech though having a 7 phase motor. I have 8 of these bikes. These are over engineered NASA quality electric hubs. They originally used a 36v/8ah NiMH front battery hub source. Mine are upgraded to use 46.2v Lithium Poly battery packs, which is the max voltage allowed.

So, with a small investment I decided to try out a complete Golden Motor Magic Pie 4 "kit". As you know, it works well and is dead silent. A Chinese TF or even a poor mans BionX model D?!?   

I've installed this first MP4 on an older EVG PE (Police edition) ebike (BK 2004) which I've retained the original controller to power the great front 35 watt front light, rear LED light, original left hand brake handle to power the rear LED brake light function, and too the horn!

Test riding this MP4 power ebike, a few days ago, with a charged 51.5v (NanoTech 22.2v/8ah x 2) battery pack got me a level speed of 27mph/43.2kph (195lbs). I using both the GM BAC-601 and a Cateye Enduro 8 bike computer. Getting 28mph/45kph from a charged 58.8v battery pack shouldn't be a problem. Currently I decided on having a 14s5p (58.8v/12.5ah) battery pack made up to fit into the original EVG ebike battery case, that slides in the side compartment. This shouldn't be an issue, since the MP4 sine wave controller has 63v caps installed. I've attempted to get the GM R&D department to update to higher voltage caps & Mosfets, but….

I'm eager to still install the PAS setup, as I just received my BB tool, and test the 1-5 settings.

I just received a second MP4 rear 26" "kit" that I had the GM R&D Department rewind for higher top end speed, though lower torque. I'll be testing this unit as soon as it stops raining here in S. California! I'm being told it will get an "off road" speed of 34mph/55kph with a 48v battery. Lets see? 

Gary, I've watched your videos and understand your a bit conservative in your speeds you like to ride. The last four years I've been riding street ebikes, I safely go to 31.5mph/50.4kph on level ground, though cruise around 25mph/40kph on my TF ebikes. I have a regular "cardio" 12 mile loop I ride 2/3 times a week. It's 6 miles up hill and then 6 miles downhill. And I've safely gone 40mph/64kph pedaling hard (53t-11t) on the Tidalforce bikes on a slight downhill.

Currently I have 31 ebikes in the collection and am looking for a low cost upgrade, and higher silent speeds, with the MP4 hubs. There is only one Company in Utah that can or will service the TF ebikes. The EVG ebikes use a heizmann brushed geared hub that is a bit noisy. Though I can go to 22mph/35.2kph using a charged 50.4v/8ah lithium battery pack. This is too slow for me. I have 17 of these ebikes.

I'd be curious to get your feedback on trying a 2wd dually MP4 setup for speed and performance on the street and even MTB trails.

Kit

[Kauaikit]

Hello Allan….so, when are you going to attempt a 15s (63v) lithium battery pack, maybe only charge to 61.5/62v to test the limit of the MP controllers? 

I'm thinking the current MP4 sine wave controller should handle it just fine.

BTW, what level speeds are you getting on your MP ebikes using 14s?

Kit 

[Bikemad]

Hello Allan….so, when are you going to attempt a 15s (63v) lithium battery pack, maybe only charge to 61.5/62v to test the limit of the MP controllers? 

I'm thinking the current MP4 sine wave controller should handle it just fine.

BTW, what level speeds are you getting on your MP ebikes using 14s?

Hi Kit,

I have tried 15s in the past but the voltage was too high for the controller to work. When the voltage eventually dropped below the High Voltage Limit  on the controller (below 60.5V if I remember correctly) the motor would work fine.

Unfortunately my last remaining 14s LiPo pack is getting on a bit and the packs are starting to swell, but I can't really complain as they had a lot of use during the last 5 years. I now get a large voltage drop on some cells under load and the pack is therefore unable to deliver the high current that it used to supply. 

The majority of my rides are purely for walking the dog through grass fields and bumpy lanes, my dog is now over eight years old, so I rarely exceed 15 mph.



As I live in a very hilly area, torque is far more important to me than top speed.

My rides are typically two or three miles long, so I tend to use a small lightweight 8s LiPo pack comprising of two 4s hard case Turnigy 5000mA packs in series, but even these are beginning to bulge slightly.
I managed to pop one of the hard case packs last week during one of my wheelie sessions while the dog.
I noticed the power had dropped significantly and when I removed pack for charging, I found this very disturbing sight:









And this is what it now looks like after undergoing some experimental LiPo-suction:







These hard case packs are only just 2½ years old and have never been overloaded or more than 80% discharged, yet all four of the packs that I have are now bulging. 

I haven't tried 15s on the MP4, perhaps I will give it a go one day just to see what happens.

Alan
 

[GM Canada]

I'd be curious to get your feedback on trying a 2wd dually MP4 setup for speed and performance on the street and even MTB trails.

Kit

If you have followed my posts and videos you can see I have built many two wheel drives, even a three wheel drive.

I have thought about two wheel drive mp4 but to be honest it really does not seem necessary. The power is far more than I need and I have zero fear of controller failure. I do ride a long isolated trail home from work and I can actually be miles from the nearest road at times so I always liked the confidence of two motors if one failed. But the reliability factor has increased by leaps and bounds and Im really enjoying that fact. The only Issue I have is I stocked up on a lot of mp4 controllers at release time just incase and now they just sit there.

Gary

[GM Canada]

Awesome picture of your dog!

[Bikemad]

Awesome picture of your dog!

That's because she's an awesome dog! 

Unfortunately she doesn't always stay quite that clean, as she cannot resist wallowing in muddy puddles:




Alan
 

[Kauaikit]

Alan…I've been using the HK Nano Tech 22.2v/8ah & 18.5v/8ah batteries for years on the Tidalforce ebikes. The engineers @ Wavecrest Labs decided to be very conservative and max the voltage @ 46.2v. So I combine one 22.2v & one 18.5v batteries in series for a 46.2v/8ah (charged) battery, then parallel a similar pack for a 46.2v/16ah 10lb brick. Works great, though I tend to puff a cell or two within 6 months. My level performance is 31.5mph/50.4kph (195lbs) level, and 37+mph/59.2kph on a slight downhill pedaling (53t-11t). The Tidalforce 7 phase internal sine wave controller hubs are amp hogs!  :-)

I've been using 2 of the 22.2v/8ah batteries for a 50.4v/8ah battery to test the MP4's. I'm waiting for my 14s5p Samsung 18650 cell pack to be finished, though I thought of trying a 15s/5p pack but only charge to 60v (4.0 cell), instead of the max 63v, to eek out one more volt. Which too is why I'm curious on the max voltage the newest MP4 sine wave controller will take. Which you say is 60.5v, right?

My goal is to match the American manufactured TF performance with a lower cost Chinese substitute. :-)

I'll be testing my second MP4 (HS "CA Special") today, though it's been setup by Golden Motor for higher speed performance but expected lower torque (50nm vs 70nm).

Would you be curious on the test results, though it's only using a 50.4/8ah battery pack?

Kit
S.CA

[Bikemad]

Which too is why I'm curious on the max voltage the newest MP4 sine wave controller will take. Which you say is 60.5v, right?

No, the 60.5V limit was on the earlier controllers (MPII and MPIII).

The MP4 vector controller can have the overvoltage protection set using the USB lead and it can be programmed for up to 65V maximum, but the default setting is 62V for the 48V battery.
The two large capacitors are marked 80V, one of the smaller ones is rated 63V and two others are rated 25V. But as I cannot access the tracks on the PCB, I don't know whether the smaller capacitors are subjected to full battery voltage or not.

I'm guessing it may be feasible to set the maximum to 65V and then use a 15S LiPo pack fully charged to 63V without experiencing any problems, but I haven't tried it yet.

It's a pity that the Nominal voltage can only be set to 24V, 36V or 48V, as it would be nice to be able to set it correctly for different LiPo packs (29.6V for 8s and 51.8V for 14S etc.).

I'll be testing my second MP4 (HS "CA Special") today, though it's been setup by Golden Motor for higher speed performance but expected lower torque (50nm vs 70nm).

Would you be curious on the test results, though it's only using a 50.4/8ah battery pack?

It would good to know how much faster the MP4 is with the modified windings, which I guess has been reconfigured as delta instead of star (Y).

I wonder how long it will be before we start seeing 12 or 24FET controllers connected to motors via 6 phase wires which would be able to automatically switch between Delta and Star (electronically) dependant upon the speed and load of the motor. This combined with a built in high power variable voltage step-up inverter would allow much higher top speeds to be achieved using lower voltage batteries.


Alan
 

[Kauaikit]

Alan…please give me an email address, as my iPhone tends to take photos too big to attach here. You may enjoy reading todays results.

Kit
kauaikit@earthlink.net

[Bikemad]

My email address should be underneath my avatar, but I have just PM'd you just in case you can't see it on your iPhone.

Is it by any chance a photo of a speeding ticket?

Alan
 

[Morgen 3Eman]

Hi Folks,

Damn, Alan, that winding switching idea is a great idea.  It effectively gives the motor an equivalent of a two speed transmission, with higher torque in one setup, and higher speed on the other.  GM would be crazy not to use this scheme. I gotta draw out a schematic for doing the switching. 

Brilliant work, dude.

TTFN,
Dennis

[Supchrgamx]

sounds like laminations more than y delta

Laurence