MCM5 100V Mod Possibilities

[Asphalt]

With Begode's new design direction moving towards heavy, suspension wheels, the probability of a lightweight (<40lbs), high-performance MCM6 seems pretty low.

Conversion of the MCM5 from 84V to 100V may be an appealing modification for those that want more power in a lightweight form factor.

I am not an expert in these types of mods, so I'm hoping that the community can help guide the process.

 

Control Boards

Since the MCM5 has a side-mounted control board, possible 100V replacements may include:

• Nikola Plus 100V
• MSX 100V
• MSP 100V
• RS 100V
• EXN 100V
• Monster V3 100V (build exists)

While these are all side-mounted, there may be other factors that limit their usage in the MCM5

• dimensions (ability to fit inside the MCM5)
• orientation (long side oriented vertically or horizontally)

 

Batteries

Let's look at possible 24s battery pack configurations. Many of these will be excluded due to the battery pack being unable to fit inside the shell. Another consideration is the pack's continuous discharge rate (CDR), a measure of the pack's ability to provide enough current when demanded by the control board. We should also consider voltage sag as the battery is depleted. With a small volume inside the MCM5 shell, it is best to go with "high performance" cells over "high capacity" cells to reduce sag.

24s3p NCR18650GA (10A)

• 24s * 3p * 3.7V * 3.5Ah = 932 Wh
• 30A CDR
• Unknown if it will fit inside shell

24s3p LG M50LT (14.4A)

• 24s * 3p * 3.7V * 5.0Ah = 1332Wh
• 43.2A CDR
• Unlikely to fit inside shell

24s2p LG M50LT (14.4A)

• 24s * 2p * 3.7V * 5.0Ah = 888Wh
• 28.8A CDR

24s2p Molicel P42A (45A)

• 24s * 2p * 3.7V * 4.2Ah = 746Wh
• 90A CDR

24s2p Molicel P45B (45A)

• 24s * 2p * 3.7V * 4.5Ah = 800Wh
• 90A CDR

 

Firmware

Since we're taking a control board from a much larger wheel, the speed needs to be recalculated for the smaller diameter.

Hoping @Freestyler can provide some information on updating Begode firmware to recalibrate speed.

 

If anyone has done this mod, or can help point out other considerations that were missed, please add to this discussion.

[Ben Kim]

The mcm5 shell is specifically designed for a 20s3p pack, the easiest way to boost it to 100v would be to add a 4s3p in series to the existing pack, with the appropriate balance wire. Not sure what connector it is, maybe a Jtag? 
 

regarding board placement, I believe there is enough space inside the shell to fit a larger 100v board in it.  You may have to cut the shell in order to clear the heat sink but not that difficult. you will also have to orient the board correctly. 
 

the motor wires will need new bullet connectors as the mcm5 motor uses different ones. 
 

I’d also add some additional cooling since 100v boards do run a bit hotter, and the nikola board should work best (my opinion) 

I did a ton of research into making this work, however I found a 100v 1230wh MSX which fit this niche (48 lb, 40ish mph top speed) which ended my brainstorming for this project. 

Edited November 15, 2022 by Ben Kim

[Denny Paul]

less cells in parallel means molicels, or some similar high discharge cell, would be the easy pick for pushing faster speeds. 

also, you'd want to bump up the tire size probably. the 14"x 2.5 can be quite unstable just by hitting a pothole or a tree root growing under the asphalt. 

Probably these reasons are why there's not much to be gained in a 100v+ mcm5, as much as I would like to see one. The wheel is already pretty close to as good as it can get for what it is. 

[Asphalt]

2 hours ago, Ben Kim said:

The mcm5 shell is specifically designed for a 20s3p pack, the easiest way to boost it to 100v would be to add a 4s3p in series to the existing pack, with the appropriate balance wire. Not sure what connector it is, maybe a Jtag? 

...

I did a ton of research into making this work, however I found a 100v 1230wh MSX which fit this niche (48 lb, 40ish mph top speed) which ended my brainstorming for this project. 

The MCM5 800Wh comes with 20s3p consisting of 18650 cells.
Will 21700 cells in 20s3p fit in the same space?

Good tip on the bullet connectors.

I can get a local battery pack builder to customize the groupings. Might even install a smart BMS if there's room.

Hoping to keep the final weight under 40lbs, so keeping the 2.5-inch tire and will probably try 24s2p Molicel P42a for 20km of fun.

For this wheel, I'm more worried about weight than range, but still want to be able to hold 50 km/h.

[thendless]

FYI you can fit 40 18650 cells in the space currently occupied by the 20s1p pack. You have to mount the BMS in the location above where all the cables are though. I am actually working on this pack right now with a smart BMS.

[Freestyler]

@DhuXn Did the 100v mcm5 mod using the monster v3 controller. I only changed the reported speed.

@Vanyayak Did a 100v mten4 mod using the stock mten4 84v controller! I altered the mten4 firmware to support 100v.

 

Maybe they can provide more info on their projects.

Edited November 16, 2022 by Freestyler

[Asphalt]

6 hours ago, Freestyler said:

@Vanyayak Did a 100v mten4 mod using the stock mten4 84v controller! I altered the mten4 firmware to support 100v.

Wow, I didn't even know that was possible!
Do you think it would be possible to alter MCM5 v2 firmware to mod the 84v controller to support 100v?

I'm guessing this isn't the smartest idea, since the electronic components weren't engineered to support 100v, but it would save the cost of a new control board and remove the work of shell modification to fit.

@Vanyayak have you had any issues running 100v on the 84v mTen4 controller?

[Asphalt]

16 hours ago, thendless said:

FYI you can fit 40 18650 cells in the space currently occupied by the 20s1p pack. You have to mount the BMS in the location above where all the cables are though. I am actually working on this pack right now with a smart BMS.

Would love to see some photos or video of your progress.
Did you have to modify the shell at all?
Which smart BMS did you choose?

[thendless]

I did some digging and here is what I found:

 

Things to note:

-Monster V3 black board is used

-24s2p 21700 pack with a distributed arrangement. 20S2P on the Top and 4s2p on the side. BMS is a standard 24s 30-50A I'm guessing. Not sure what cells used.

-the new motherboard appears to have been placed in the original 20s1p location and the 4s2p and bms are in the original mobo location. The handle has been removed as well. Looks like there is space to keep it there but I'm guessing the width of the 20s2p pack gets in the way.

-Ride video is only 16 minutes and has a temperature rise from 31.5C to 67.5C. There is clearly not sufficient cooling for the Monster V3 black board. Comments from the owner mentioned a hole was cut for the heatsink. Not sure if that ride video has that implemented or not

-User mentioned 75kmh free spin and 60kmh max

Edited November 16, 2022 by thendless

[thendless]

6 hours ago, Asphalt said:

Would love to see some photos or video of your progress.
Did you have to modify the shell at all?
Which smart BMS did you choose?

No modifications required to the shell for what im doing. I am using the Jiabaida SP22S003A 40A BMS. It fits perfectly in the space above the 20s1p pack and is only 10mm thick.

[Vanyayak]

On 11/16/2022 at 6:54 PM, Asphalt said:

@Vanyayak have you had any issues running 100v on the 84v mTen4 controller?

No problems at all, it is factory-hardware-ready for that case.
As for MCM5 - mosfets and capacitors change will be needed.

Edited November 19, 2022 by Vanyayak

[Asphalt]

1 hour ago, Vanyayak said:

No problems at all, it is factory-hardware-ready for that case.
As for MCM5 - mosfets and capacitors change will be needed.

Factory-ready? I wonder how long it will be until Begode officially releases a 100v mTen4?

This brings back some hope that Begode will release a 100v MCM6.

@Vanyayakwhat is the free-spin speed of the 100v mTen4?

[Vanyayak]

1 hour ago, Asphalt said:

Factory-ready? I wonder how long it will be until Begode officially releases a 100v mTen4?

This brings back some hope that Begode will release a 100v MCM6.

@Vanyayakwhat is the free-spin speed of the 100v mTen4?

yup, no onboard changes whatsoever to work with 24S. I think eventually they will
freespin is 70-73 km/h

[blox1130]

It's possible to use a vesc controller although I don't know any rated for 100v. The closest I see is the ubox by spintend which has built in accelerometer. Advantages include ability to program the controller to very specific values. I know I've used some VESC controllers made by flipsky that are rated for 84v and ive pushed them up to 110v during regen. However, I didn't use that in a self balance vehicle so who knows if that's safe lol.

[Asphalt]

On 11/19/2022 at 9:50 AM, Vanyayak said:

yup, no onboard changes whatsoever to work with 24S. I think eventually they will
freespin is 70-73 km/h

A 100v mTen4 might be even more appealing than a 100V MCM5, for a lightweight, low range, pocket rocket!

So many questions:
Do you have a write-up or photos of it?
How much does it weigh?
Was there sufficient room for the 24S battery pack?
Did you have to do any shell modifications?
How stable is it at high speed?
How fast have you ridden it?

[roghaj]

On 11/19/2022 at 9:50 AM, Vanyayak said:

yup, no onboard changes whatsoever to work with 24S. I think eventually they will
freespin is 70-73 km/h

Did you use an external battery or fit one inside?  I am going to test this firmware with an external battery first.  Just wanted advice as to the pack layout.  I hate thinking for myself.

Thanks

RogerEUC

[thendless]

Just an update to this thread. I was able to get a hold of an old 100v Nikola board a few months ago and decided to embark on doing a ton of upgrades for my MCM5.

-Added bumpers and kickstands

-Inmotion spiked pedals with bumpers

-Replaced all the wood screws with machine screws and knurled inserts

-Added 3d printed reinforcements on the pedal hanger areas

-Added rubber gasket/sheet between the pedal hanger and shell

-Added some metal brackets to provide the shell with more structural rigidity on the front and back sides 

-Removed bluetooth module, speaker and stock fan

-Removal of charger port and usb port so that I could have additional battery space.

-Replaced stock fan with a blower style fan running all the time 

-Added Voltmeter on top

-Cut a hole to accommodate the motherboard heatsink 

-Addition of XT60 connector under the handle for charging

-Total 1332Wh - 2 Distributed battery packs: Pack 1: 24S2P, Pack 2, 24S1P. Went with 2 battery packs as I want redundancy. Smart BMS with thermal temperature probe

-Total weight: 46 lbs

 

Future upgrades:

-3 inch tire

-96 or 144 LED strip

 

What can I say about 100v MCM5? I have only tested it out for about 30km but it feels like its at another level compared to 84v. I reached 55kmh without beeping and was able to sustain 50 no issue. The torque also feels increased. The only thing is I think a 3" tire is needed now because it does get a little sketchy over 50kmh with the 2.5" tire. That being said I did get acclimated to it and will test it for a while before i swap over. I must say If the wheel is able to perform this well after doing this hackjob I am betting the MCM6 will next level. 

[Denny Paul]

On 3/13/2023 at 2:37 PM, thendless said:

What can I say about 100v MCM5? I have only tested it out for about 30km but it feels like its at another level compared to 84v. I reached 55kmh without beeping and was able to sustain 50 no issue. The torque also feels increased. The only thing is I think a 3" tire is needed now because it does get a little sketchy over 50kmh with the 2.5" tire. That being said I did get acclimated to it and will test it for a while before i swap over. I must say If the wheel is able to perform this well after doing this hackjob I am betting the MCM6 will next level. 

I wish I had the guts to try what you've done. Can't wait for a legit 100v mcm5-like wheel to come out.

The 3" tire makes a massive difference. There's a thread on it for the mcm5 in the tires sections somewhere. Just takes some cutting of the shell after dropping the motor out. I used to feel sketched out around when the beeps kicked in on the stock wheel. Now, after having a 3" tire I feel super stable at the beeps; in fact I'd be happy if I could get another +10mph out of it.

Since your 100v wheel is capable of that, that's the next mod i'd do for your souped up mcm5.

Enjoy it!

[cegli]

On 11/16/2022 at 2:37 PM, thendless said:

No modifications required to the shell for what im doing. I am using the Jiabaida SP22S003A 40A BMS. It fits perfectly in the space above the 20s1p pack and is only 10mm thick.

Very cool mod! 

One question (for safety).  I tried to look up the BMS above, and found a datasheet for the SP22S003 (can't find the A, but maybe that's because it's just Rev A?).  It says it's for a Li-Poly batteries, with a max voltage of 3.7V, min 2.2V.  Here's the Jiabaida's datasheet page.  With time, I'd expect this might cause a battery fire from too deep of discharge plus not using "pre-charge" at low voltage, and you wouldn't get your full range.

If you ended up using a different BMS, what one did you use?  I'm curious about reliable BMS's for EUCs.  Worried about a cheap one cutting off the output and dropping me on my face.

[Timwheel]

On 3/13/2023 at 10:37 PM, thendless said:

Just an update to this thread. I was able to get a hold of an old 100v Nikola board a few months ago and decided to embark on doing a ton of upgrades for my MCM5.

-Added bumpers and kickstands

-Inmotion spiked pedals with bumpers

-Replaced all the wood screws with machine screws and knurled inserts

-Added 3d printed reinforcements on the pedal hanger areas

-Added rubber gasket/sheet between the pedal hanger and shell

-Added some metal brackets to provide the shell with more structural rigidity on the front and back sides 

-Removed bluetooth module, speaker and stock fan

-Removal of charger port and usb port so that I could have additional battery space.

-Replaced stock fan with a blower style fan running all the time 

-Added Voltmeter on top

-Cut a hole to accommodate the motherboard heatsink 

-Addition of XT60 connector under the handle for charging

-Total 1332Wh - 2 Distributed battery packs: Pack 1: 24S2P, Pack 2, 24S1P. Went with 2 battery packs as I want redundancy. Smart BMS with thermal temperature probe

-Total weight: 46 lbs

 

Future upgrades:

-3 inch tire

-96 or 144 LED strip

 

What can I say about 100v MCM5? I have only tested it out for about 30km but it feels like its at another level compared to 84v. I reached 55kmh without beeping and was able to sustain 50 no issue. The torque also feels increased. The only thing is I think a 3" tire is needed now because it does get a little sketchy over 50kmh with the 2.5" tire. That being said I did get acclimated to it and will test it for a while before i swap over. I must say If the wheel is able to perform this well after doing this hackjob I am betting the MCM6 will next level. 

I would actually kill for a wheel like that... Did you document the process ?

Thanks

[thendless]

19 hours ago, cegli said:

Very cool mod! 

One question (for safety).  I tried to look up the BMS above, and found a datasheet for the SP22S003 (can't find the A, but maybe that's because it's just Rev A?).  It says it's for a Li-Poly batteries, with a max voltage of 3.7V, min 2.2V.  Here's the Jiabaida's datasheet page.  With time, I'd expect this might cause a battery fire from too deep of discharge plus not using "pre-charge" at low voltage, and you wouldn't get your full range.

If you ended up using a different BMS, what one did you use?  I'm curious about reliable BMS's for EUCs.  Worried about a cheap one cutting off the output and dropping me on my face.

This is the BMS i mentioned in that post: https://www.aliexpress.com/item/1005004675668215.html?spm=a2g0o.order_list.order_list_main.21.52b51802jIVy1h Just FYI that is for 84V only, I was originally going to replace the 20s1P pack with a 20s2P one but plans changed when I aquired the nikola board.

8 hours ago, Timwheel said:

I would actually kill for a wheel like that... Did you document the process ?

Thanks

I have some photos but no real documentation. If you have questions I can try to answer. 

Edited March 16, 2023 by thendless

[cegli]

1 hour ago, thendless said:

This is the BMS i mentioned in that post: https://www.aliexpress.com/item/1005004675668215.html?spm=a2g0o.order_list.order_list_main.21.52b51802jIVy1h Just FYI that is for 84V only, I was originally going to replace the 20s1P pack with a 20s2P one but plans changed when I aquired the nikola board.

Ah, gotcha.  Seems they're pretty loose with their part numbers!  Looks like it'd be a good fit for a 22S or lower pack.  I've saved the link for potential future projects.  Do you have any pictures of the battery arrangement inside?  What BMS did you end up with for 24S?  I'd love to see more pictures of the internals!

[Asphalt]

15 hours ago, cegli said:

What BMS did you end up with for 24S?  I'd love to see more pictures of the internals!

If you were willing to pay more, and didn't want a smart BMS, you could try the Nikola BMS
https://www.aliexpress.com/item/1005003520971435.html
Although at 261.2 x 144.1 mm, it would be a tight squeeze.

Here's a link to the 100V Nikola control board:
https://www.aliexpress.com/item/32898618042.html

[thendless]

19 hours ago, cegli said:

Ah, gotcha.  Seems they're pretty loose with their part numbers!  Looks like it'd be a good fit for a 22S or lower pack.  I've saved the link for potential future projects.  Do you have any pictures of the battery arrangement inside?  What BMS did you end up with for 24S?  I'd love to see more pictures of the internals!

You can find these BMSs on aliexpress. Multiple sellers sell the same ones. https://www.aliexpress.com/item/1005001630814863.html?spm=a2g0o.productlist.main.1.6dbe4e793MAfRX&algo_pvid=68d966f0-dd64-4620-a113-ee5e008f13eb&algo_exp_id=68d966f0-dd64-4620-a113-ee5e008f13eb-0&pdp_ext_f={"sku_id"%3A"12000028697901577"}&pdp_npi=3%40dis!CAD!94.73!78.62!!!!!%4021224cdb16790667886004222d070a!12000028697901577!sea!CA!118719529&curPageLogUid=FROfi7jCbFlx

[thendless]

4 hours ago, Asphalt said:

If you were willing to pay more, and didn't want a smart BMS, you could try the Nikola BMS
https://www.aliexpress.com/item/1005003520971435.html
Although at 261.2 x 144.1 mm, it would be a tight squeeze.

Here's a link to the 100V Nikola control board:
https://www.aliexpress.com/item/32898618042.html

I would not recommend using any of those gotway BMSs for this type of job. While they are super thin they are designed with a certain arrangement which likely will not work on the small shell. With the space constraints of the MCM5 you have to be creative with cell arrangement and distributed packs are mandatory.