Supercharge Your Master Pro With This Hardware & Software Hack

[Marty Backe]

A huge shoutout to Bill, AKA @Freestyler, for his help in making my Master Pro the best long range wheel I'll ever own. And you too can have the same capability.

But really, don't do any of this unless you are experienced and understand what you're getting yourself into 
 

 

[RagingGrandpa]

"Custom charging board from Roger" - that is bypassing the following safety features:

1. Cell fault charge-stop.
2. Charging port overcurrent protection.

#2 has another line of defense which you mentioned: the fuse will blow.
But it means hardware damage, if you make a small mistake such as letting a key or screw or anything else conductive fall down into the gap near the charging ports. Something the BMS would normally prevent harmlessly. 

#1 concerns me greatly.

Consider an in-range cell imbalance situation:

• Due to defects, age, or other issues, assume one pair of cells is at 4.0V, and other 31 pairs are balanced perfectly at 3.5V.
• The EUC is operating normally, and before your next long ride, you recharge overnight.
• During the night, the voltage rises to the charger's setpoint of 134.4V. But this forces a cell pair to exceed 4.6V, beginning internal cell damage.
• The pack beepers begin sounding due to this overvoltage, but the recharging continues because charge-stop has been bypassed. If the EUC is unattended, this can continue indefinitely. 

Also consider a mis-adjusted charger situation: 

• With a manually-adjustable charger (such as the server power supply which is becoming popular), assume the setpoint voltage is accidentally moved to its maximum of 140V. 
• The EUC is operating normally, and before your next long ride, you recharge overnight.
• The EUC begins recharging normally. During the constant-current stage of charging, the voltage is automatically regulated to not exceed the selected current e.g.: 7 amps. 
• During the night, once the cell voltages rise above 4.25V/cell, the pack beepers begin sounding, but the recharging continues because charge-stop has been bypassed.
• Recharging continues until 4.37V/cell, causing cell stress and continuing to dissipate excess heat for as long as the charger remains connected. 

 

@Marty Backe do you think this is a safe modification?
 

Edited March 27, 2023 by RagingGrandpa

[Cerbera]

I don't wanna speak for him of course, but in his video on the subject Marty is very careful to point out that this is a mod most Master owners won't do, and should only be done by those who seriously know and appreciate what additional risks they allow by fitting this. Its exclusively for range junkies who know what they are doing !

In my case for example, there is simply no need to do this - I never get anywhere near the maximum range of my wheel, so if I am a volt down when I start I couldn't care that much about it...

[Marty Backe]

13 hours ago, RagingGrandpa said:

"Custom charging board from Roger" - that is bypassing the following safety features:

1. Cell fault charge-stop.
2. Charging port overcurrent protection.

#2 has another line of defense which you mentioned: the fuse will blow.
But it means hardware damage, if you make a small mistake such as letting a key or screw or anything else conductive fall down into the gap near the charging ports. Something the BMS would normally prevent harmlessly. 

#1 concerns me greatly.

Consider an in-range cell imbalance situation:

• Due to defects, age, or other issues, assume one pair of cells is at 4.0V, and other 31 pairs are balanced perfectly at 3.5V.
• The EUC is operating normally, and before your next long ride, you recharge overnight.
• During the night, the voltage rises to the charger's setpoint of 134.4V. But this forces a cell pair to exceed 4.6V, beginning internal cell damage.
• The pack beepers begin sounding due to this overvoltage, but the recharging continues because charge-stop has been bypassed. If the EUC is unattended, this can continue indefinitely. 

Also consider a mis-adjusted charger situation: 

• With a manually-adjustable charger (such as the server power supply which is becoming popular), assume the setpoint voltage is accidentally moved to its maximum of 140V. 
• The EUC is operating normally, and before your next long ride, you recharge overnight.
• The EUC begins recharging normally. During the constant-current stage of charging, the voltage is automatically regulated to not exceed the selected current e.g.: 7 amps. 
• During the night, once the cell voltages rise above 4.25V/cell, the pack beepers begin sounding, but the recharging continues because charge-stop has been bypassed.
• Recharging continues until 4.37V/cell, causing cell stress and continuing to dissipate excess heat for as long as the charger remains connected. 

 

@Marty Backe do you think this is a safe modification?
 

Up until VERY recently all Gotway/Begode wheels operated like my modded Master Pro. So no, I'm not worried. I monitor my wheels and am attuned to their behavior.

I never fast charge over night. I use stock chargers. My fast chargers are only used if I need to charge a wheel while I'm impatiently waiting.

This is an extremely dangerous modification and should only be done by savvy EUC owners, as I stated in the video.

I'm providing information and assume that my viewers are smart and understand the risks and proceed accordingly.

12 hours ago, Cerbera said:

I don't wanna speak for him of course, but in his video on the subject Marty is very careful to point out that this is a mod most Master owners won't do, and should only be done by those who seriously know and appreciate what additional risks they allow by fitting this. Its exclusively for range junkies who know what they are doing !

In my case for example, there is simply no need to do this - I never get anywhere near the maximum range of my wheel, so if I am a volt down when I start I couldn't care that much about it...

Tiny correction. This is for the Master Pro not Master.

Thanks for your support 

[RagingGrandpa]

5 hours ago, Marty Backe said:

Up until VERY recently all Gotway/Begode wheels operated like my modded Master Pro.

No...
Before Master was released, Gotway packs contained the charge shutoff and port protection circuit inside each battery pack. 

Master changed this, because its packs aren't just in parallel with eachother. With Master, MasterP, T4, EX30, each pack contains the cell voltage monitoring, but then communicates with a new, single PCB outside the battery packs (the 'charging board') via the white wire. 
This new charging board contains the shutoff function. You bypassed it.

The result is:
A Nikola from 2022 will automatically stop recharging, if any of its 96 cells exceeds 4.25V. 
Your modded MasterP will not.
 

(I appreciate and enjoy your content Marty! I just want to be clear about the safety features involved here.)

[alcatraz]

12 hours ago, RagingGrandpa said:

No...
Before Master was released, Gotway packs contained the charge shutoff and port protection circuit inside each battery pack. 

Master changed this, because its packs aren't just in parallel with eachother. With Master, MasterP, T4, EX30, each pack contains the cell voltage monitoring, but then communicates with a new, single PCB outside the battery packs (the 'charging board') via the white wire. 
This new charging board contains the shutoff function. You bypassed it.

The result is:
A Nikola from 2022 will automatically stop recharging, if any of its 96 cells exceeds 4.25V. 
Your modded MasterP will not.
 

(I appreciate and enjoy your content Marty! I just want to be clear about the safety features involved here.)

Is it sure that the individual packs don't also have some sort of overcharge protection (that can interrupt its charging) apart from just signaling to the external charge board?

[RagingGrandpa]

12 hours ago, alcatraz said:

Is it sure that the individual packs don't also have some sort of overcharge protection

Each pack contains a shutoff device (4 FETs in parallel), but it has not been demonstrated whether it is used for anything more than overcurrent protection at the pack level. 
Bear in mind: this is not the same as the shutoff device in 'classic gotway' BMS: because this Master pack shutoff is interrupting the main output from the pack. The Master BMS does not have a separate recharging input (like classic gotway BMS had), because in Masters that function has been relocated to the charging port board. Master packs recharge "through the main output." It's the first time Gotway has used this approach. 

Marty's video suggests that the packs do not shut themselves off based on voltage: because his MasterP pack alarms were sounding (due to undervoltage) and yet the packs still accepted recharging through their main connection (with the charging port board bypassed).

 

I encourage anyone curious enough about it, to prove it.
Overvoltage shutoff could be demonstrated easily by a competent battery hobbyist, and does not require exotic tools.

The method could be:

1. Disconnect one pack from the EUC, and remove the heatshrink to expose the pack BMS.
2. Recharge the whole pack to 4.1V/cell. 
3. Recharge a single cell group to 4.2V/cell.
4. Resume charging of the whole pack, while monitoring voltage at the overcharged cell group. Continue charging until the cell group reaches 4.3V, or until the pack shuts off. 
5. If the pack does not shut off with cells at 4.3V, let the pack rest open-circuit for a few hours, to bleed away the 4.3V cell group with its balancing resistors. Or, discharge that group into a load manually.

And since he's the person producing the bypass mod product, we should request that Roger take the time to do this demonstration  

 

(I would be glad to volunteer to conduct this demonstration also, if provided access to a suitable pack.)

https://ecodrift.ru/2022/08/30/begode-master-razbiraem-3-yuyu-inkarnatsiyu/

Edited March 29, 2023 by RagingGrandpa

[Marty Backe]

On 3/28/2023 at 6:55 AM, RagingGrandpa said:

No...
Before Master was released, Gotway packs contained the charge shutoff and port protection circuit inside each battery pack. 

Master changed this, because its packs aren't just in parallel with eachother. With Master, MasterP, T4, EX30, each pack contains the cell voltage monitoring, but then communicates with a new, single PCB outside the battery packs (the 'charging board') via the white wire. 
This new charging board contains the shutoff function. You bypassed it.

The result is:
A Nikola from 2022 will automatically stop recharging, if any of its 96 cells exceeds 4.25V. 
Your modded MasterP will not.
 

(I appreciate and enjoy your content Marty! I just want to be clear about the safety features involved here.)

Do you know this for an absolute fact? That the BMS that is attached to each battery pack will NOT stop charging when the voltage is exceeded.

[RagingGrandpa]

What we know:

• Master-style packs have no separate charging input. ('Classic' packs did.)
• Master-style packs are used with an external charging-shutoff FET in the charging port board. ('Classic' packs had no external board for charging.)
• Master-style packs remain 'active' and allow discharge and recharging, when the BMS alarm is sounding. (Marty demonstrated it by overdischarging and then recharging his MasterP pack, without removing the pack shrinkwrap.) 

What remains to be demonstrated is: 

• Do Master-style packs disable themselves when there is single-cell overvoltage, including when the charging port board is removed or bypassed?
  (The method to demonstrate it is above, awaiting execution from a suitable volunteer.)

.02