Begode Master 134V 2400WH Suspension

[Freeforester]

Certainly a refreshing difference to Kevin’s S20 teardown experience, the video above makes it look extremely simple by comparison. We’ll have to see whether the potential for wicking into the battery boxes is a real ‘thing’, but it certainly looks like it could steal a March on the S22.

[The Brahan Seer]

1 hour ago, Freeforester said:

 We’ll have to see whether the potential for wicking into the battery boxes is a real ‘thing’,

Nothing liquid electrical tape can't fix.

[Rawnei]

2 hours ago, The Brahan Seer said:

Nothing liquid electrical tape can't fix.

Is there an advantage to using that compared to alkoxy silicone?

[Freeforester]

 

 

[The Brahan Seer]

33 minutes ago, Rawnei said:

Is there an advantage to using that compared to alkoxy silicone?

I imagine cost and curing time is a lot less, Liquid electrical tape is usually just rubber based depending on the brand.  Usually waterproof and can tolerate the voltage. I've not used Loctite SI 5145 or equivalent alkoxy silicone. Though I imagine they will have higher ratings and tolerate higher voltages. 

[Rawnei]

1 minute ago, The Brahan Seer said:

I imagine cost and curing time is a lot less, Liquid electrical tape is usually just rubber based depending on the brand.  Usually waterproof and can tolerate the voltage. I've not used Loctite SI 5145 or equivalent alkoxy silicone. Though I imagine they will have higher ratings and tolerate higher voltages. 

Over here we're used to using Casco silicone that we buy locally, it's not super expensive but at the same time it comes in a pretty small tube so probably more expensive by volume. So both should be ok for this application I think, use whichever of those two you have at hand.

[Tawpie]

Keep in mind I haven't seen a video of the battery box being disassembled, but take care not to make a seal that is "too good". You do want some 'blow-out' protection in case a bad cell or some other issue either causes a venting or thermal runaway, and changes in atmospheric pressure will want relief (thinking about altitude more than barometric pressure). Perhaps there's another pressure relief vent? Given that the battery box is plastic, in a real fire it should melt through quickly enough to provide a pressure outlet.

[That Guy]

12 hours ago, The Brahan Seer said:

Reading comments and watching the E-rides vlog see @Freeforester link above. They are saying 2 Master Wheels HS and HT, this is the HT version with Max Top speed 50MPH, this corresponds with @BleepBloopBlop theory too. Will be interesting to know if this is true or not.

Would Master HS be OTT (Over The Top)? :-) Here is the recent top speed testing by Alien Rides:

 

[stephen]

I'm really liking the master

[TantasStarke]

1 hour ago, stephen said:

I'm really liking the master

The speed it hits and seeing videos from Chance Hinz really makes me want one more and more, I just really wish it had a larger battery. I have an insane amount of range anxiety

[meepmeepmayer]

3 minutes ago, TantasStarke said:

I have an insane amount of range anxiety

I have range anxiety and price anxiety and need to decide between the two (Master or EX20S)

[redfoxdude]

Ah! 🤩 I had the opportunity to hop on one very briefly. Smooth suspension, with that characteristic GotWay power delivery. I'm weary of describing it this way because it's really it's own thing, but... kinda like a V11 in terms of smoothness (small bump compliance is stellar!), kinda like an S18 with rebound dampening and response to bigger stuff, no pogo. However, I'm not doing big jumps in my usual riding, just up and down curbs, potholes, and some stairs when I'm feeling extra adventurous. The 80mm is more than adequate. Big jumps though, I could understand wanting the S20/22. That thing feels even wider and significantly less comfortable to me, though. (I'm very picky with ergonomics because my short legs, ha!)
It is tall and wide, especially for someone with short legs like me, but the huge pedals make it very doable. I can get my feet wide enough to straighten my knees and still be fully on the pedals. I'd probably do some custom padding to shim out the stance like Law talked about in his video.
Being really used to nimble tires like the H666, the CST 186 and I didn't get along. It's just as @mrelwood described in his review some time back. I wish I was more comfortable with the way it handled so I could have been more playful with it. I did take it up to around 27mph over some speed bumps and it was very smooth, but unfortunately I wasn't comfortable enough with the tire to push any further. Not my wheel after all.
The trolley handle does indeed need to be improved, you really shouldn't lift with it - it's just not strong enough to take the full weight.
I think the shock it comes with is not too shabby! It would be fun to find a nicer shock with volume spacers to play with spring rates though. I'm not sure I'm understanding why some folks want to put a coil shock in to address bottoming out - a more progressive air shock with lower air volume would work to reduce bottom outs, while a coil has a linear spring rate. Wouldn't that cause more bottom outs? I haven't played with coil shocks though, so I may be misunderstanding something.
Now the wait for my preorder is gonna be harder though, since I know exactly what I'm waiting for 

Edited April 21, 2022 by redfoxdude

[Tawpie]

Ray Rokni's first look has an interesting tidbit... each of the 4 battery packs measures 30.x volts… ~1/4 of the full 134V (the batteries aren't fully charged in the video). So they're doing part of the series stacking in the "top" (power board or motherboard). Is that unusual for BG? I believe KS split their third 'pack' on the S18 between two bundles, but it seems like BG has always had "full voltage" packs. Am I ignorant or is this a new thing for BG?

There is a wad of grey pucky goobered on the fiberglas sleeve into the battery case on this wheel (hopefully all the way round, but not certain that'll defeat the wick), but only a grommet where it goes into the top housing (probably ok, gravity is our friend... just don't get it wet and store it upside down or on its nose!)

 

Edited April 21, 2022 by Tawpie

[RoosterFeet]

On 4/15/2022 at 12:38 PM, Vanturion said:

Something to bear in mind when you are doing these comparisons is there is a significant performance difference between generations of Samsung 50E and 50E2 cells. I don't know if all new Samsung cells coming in the master come as 50E2 or if the charts you are using are of 50E or 50E2, but here's one test showing the difference:

 

So the 50E2 = would be a decent amount less voltage sag and more range over the older 50E.

source

I'm not sure if this is known by now, but I emailed eWheels about what generation of Samsung 50E batteries the Begode Master will ship with. It looks like eWheels will use "the newer variant" for the Master, which makes me believe they are the 50E2. That said, I'm a complete newbie with battery tech and still undecided which cell is the best for everyday riding.

 

 

[alcatraz]

30 minutes ago, Tawpie said:

Ray Rokni's first look has an interesting tidbit... each of the 4 battery packs measures 30.x volts… ~1/4 of the full 134V (the batteries aren't fully charged in the video). So they're doing part of the series stacking in the "top" (power board or motherboard). Is that unusual for BG? I believe KS split their third 'pack' on the S18 between two bundles, but it seems like BG has always had "full voltage" packs. Am I ignorant or is this a new thing for BG?

There is a wad of grey pucky goobered on the fiberglas sleeve into the battery case on this wheel (hopefully all the way round, but not certain that'll defeat the wick), but only a grommet where it goes into the top housing (probably ok, gravity is our friend... just don't get it wet and store it upside down or on its nose!)

 

Really? Wow! That certainly changes things.

So it's four 8S BMSs connected in series.

That PCB must contain some sort of overcharge protection then.

None of the packs should receive more than 33.6v and by using a 134.4v charger you have a tricky double hiarchy. 

It's almost like the PCB is a 4Sx33.4v BMS and then the packs are 8Sx4.2v BMSs. Five BMS?

[alcatraz]

What happens when a module cuts off charging before the other modules?

Won't 134.4v land on the other three modules?

How did they design this?

[Tawpie]

1 minute ago, alcatraz said:

What happens when a module cuts off charging before the other modules?

If it were me, I'd step down the charger voltage to a bit over 33.6V and feed each pack separately (disconnect the series connection). That way I could put a 33.6V BMS in each pack. I'd need to noodle on it for a while though—how are things connected/disconnected etc., especially at power up.

 

[alcatraz]

7 minutes ago, Tawpie said:

If it were me, I'd step down the charger voltage to a bit over 33.6V and feed each pack separately (disconnect the series connection). That way I could put a 33.6V BMS in each pack. I'd need to noodle on it for a while though—how are things connected/disconnected etc., especially at power up.

 

That's great for charging but maybe risky for discharging, and impractically big. The mechanism that switches back and forth between modules needs to be super reliable and heavy duty.

[Tawpie]

4 minutes ago, alcatraz said:

The mechanism that switches back and forth between modules needs to be super reliable and heavy duty

Yeah, it does. Has some potential benefits though. I need their schematic 

[mrelwood]

55 minutes ago, alcatraz said:

What happens when a module cuts off charging before the other modules?

Won't 134.4v land on the other three modules?

How did they design this?

Even if it were a dummy fixed series connection, once one pack bails out, no electricity flows in any of the packs.

While we might expect it to have an intricate pack charging and health monitoring system, I have a hunch that  GW would’ve only gone to fulfill slightly less than the bare minimum expected…

Then again, regular packs don’t have monitoring in the midst of the series connections either, so a dummy fixed connection just might suffice.

 Others are switching to individual cell group monitoring though, I hope GW joins the masses sooner than later.

[alcatraz]

23 minutes ago, mrelwood said:

Even if it were a dummy fixed series connection, once one pack bails out, no electricity flows in any of the packs.

While we might expect it to have an intricate pack charging and health monitoring system, I have a hunch that  GW would’ve only gone to fulfill slightly less than the bare minimum expected…

Then again, regular packs don’t have monitoring in the midst of the series connections either, so a dummy fixed connection just might suffice.

 Others are switching to individual cell group monitoring though, I hope GW joins the masses sooner than later.

Right!

One critisizm I've seen before (if memory serves) about serial connecting bms', is that when one bms disconnects charging, that mosfet/relay has the entire voltage of the charger at its pins.

So a 33.4v 8S bms cutting off the charge loop will have 134.4v across its little cutoff transistor. They're never designed for such a thing.

I guess you could design a bms specifically for use in series with really beefed up charging circuits that are rated for those voltages. Then it should work, shouldn't it?

[meepmeepmayer]

Huh that is a weird battery configuration. Should we be worried? Why would they build it like this in the first place? (Other than being cheap with low voltage BMSes instead of one proper one... only cause I can come up with.)

[Mango]

Very impressive build quality and materials.

2022 wheel of the year.

[mrelwood]

5 hours ago, alcatraz said:

Right!

One critisizm I've seen before (if memory serves) about serial connecting bms', is that when one bms disconnects charging, that mosfet/relay has the entire voltage of the charger at its pins.

So a 33.4v 8S bms cutting off the charge loop will have 134.4v across its little cutoff transistor. They're never designed for such a thing.

I might figure the thing in my head very differently than it is in reality, but if the packs are truly hardwired in series and they are charged from the BMS output…

If one BMS cuts out, it only has 33.6V or slightly more at the cutoff transistor. If for example the topmost pack cuts out, it’s cutoff transistor sees the charger positive (134.4V) on one end, and the positive of the second pack in the other. And the second pack positive voltage is charger negative (= 0V) + pack 1 voltage + pack 2 voltage + pack 3 voltage = about 100.8V.
134.4 - 100.8 = 33.6V.

But again, I could be thinking about a completely different circuit here.

[alcatraz]

1 minute ago, mrelwood said:

I might figure the thing in my head very differently than it is in reality, but if the packs are truly hardwired in series and they are charged from the BMS output…

If one BMS cuts out, it only has 33.6V or slightly more at the cutoff transistor. If for example the topmost pack cuts out, it’s cutoff transistor sees the charger positive (134.4V) on one end, and the positive of the second pack in the other. And the second pack positive voltage is charger negative (= 0V) + pack 1 voltage + pack 2 voltage + pack 3 voltage = about 100.8V.
134.4 - 100.8 = 33.6V.

But again, I could be thinking about a completely different circuit here.

I know it isn't intuitive but a guy demonstrated it in a youtube video with a multimeter. Maybe it's between ground and the charge input. I forgot. I'll post the video when I find it.