eWheels contracts outside company for custom battery packs

[alcatraz]

Samsung 50E discharge/temp curve:

Measured capacity 4722mAh @5A

@15A discharge rate the cells reach critical temperature after ~10min.

 

Molicel P42a discharge/temp curve:

Measured capacity 3924mAh @5A

@30A discharge rate the cells reach critical temperature after ~6min.

The P42a are about twice as powerful than the 50E. Heavy riders, performance riders, crazy about torque riders, climbing, or just overall obsessed with safety (more so than range) might prioritize the P42a.

[alcatraz]

The 2400Wh has ~20% more range than the 2000Wh. (based on lab measurements)

[enaon]

27 minutes ago, alcatraz said:

Samsung 50E discharge/temp curve:

 

this graph is not correct, it is for the 50e, the ones we use are the 50e 2, they are more like the 50g. 

Edited March 15, 2022 by enaon

[alcatraz]

Ok. That's interesting.

That's a capacity measurement. It doesn't mention cell temperature. Higher capacity doesn't always mean a greater discharge rate.

The Begode Master is possibly going to pull more current from the battery pack than most other wheels so people shouldn't underestimate the importance of high discharge cells, considering the Master's only got a 4P cell configuration.

[onkeldanuel]

10 minutes ago, alcatraz said:

Ok. That's interesting.

That's a capacity measurement. It doesn't mention cell temperature. Higher capacity doesn't always mean a greater discharge rate.

The Begode Master is possibly going to pull more current from the battery pack than most other wheels so people shouldn't underestimate the importance of high discharge cells, considering the Master's only got a 4P cell configuration.

Not to Sure, because Higher Voltage means less Amps for same Power and compared to a 100v wheel there could be less importance/relavance to high discharge or sag , especially with 2400 wh ....

 

I think on a RS 100V 1800wh its far more relevant than on a 134v 2400wh

Probably the most relevance is at really high Speed usage, since a c38 is not that efficient at high rpm and needs more Amps in that Window above lets say 60 kmph++

Edited March 15, 2022 by onkeldanuel

[alcatraz]

3 minutes ago, onkeldanuel said:

Not to Sure, because Higher Voltage means less Amps for same Power and compared to a 100v wheel there could be less importance/relavance to high discharge or sag , especially with 2400 wh ....

That's true. You can push more watts at a lower current. But you're assuming that watts = torque. I'm not so sure about that.

[onkeldanuel]

Since its the very same c38 Motor it should be same wattage needed for same Torque, dont know what other variables could be there tbh aside efficiency perhaps and Ofc more total weight of the wheel, but its only 8kg

Edited March 15, 2022 by onkeldanuel

[goatman]

i dont really care what the total capacity is at the end of the test, 2.5v

im more interested in the LVC of the controller, whether its 3.3v/3.2v/3.0v and then look at the capacity given at the voltage cut off at max amps

is that the 50e or 50g that hits 3.3v at 10amps for 2500/2700 mah

p42a at 3.3v at 20 amps gives about 2700mah but at 10 amp discharge its good for 3250mah

it just means youll have more fun longer with a p42a but wont go quite as far as a 50e/g

[enaon]

I still don't see the point f having a 45A continuus discharge capable cell. The molicel m50a looks more appropriate. 4x20 is 80amps ,X136 is ~11KW sustained, way more than what the rest of the system can handle. 

I also do not understand why using a molicel will take the cost up, unless they are using clones of samsung/lg batteries now. Molicel and samsung/lg have very similar prices. 

https://eu.nkon.nl/rechargeable/li-ion/21700-20700-size.htm

Actually, a moli p42a is a bit cheaper than the lg 50t. 
https://eu.nkon.nl/rechargeable/li-ion/21700-20700-size/molicel-21700a-4200mah-30a.html

https://eu.nkon.nl/rechargeable/li-ion/21700-20700-size/lg-inr21700-m50-5000mah-7-3a.html

Edited March 16, 2022 by enaon

[alcatraz]

The P42a aren't 45A cells if you look at the lab tests. 

They can almost do 30A, for sure 25A continuously. (@20C amb temp)

The 50E can do 10A. (50G appear to barely pass the 15A test).

So by looking at the results:

50E are 10A cells.

P42a are 25A cells.

50G are 15A cells.

50E2, I haven't found a discharge test on these with temperature.

Edited March 16, 2022 by alcatraz

[goatman]

the problem with the 50e or m50 is they arent 10amp cells, they are 1C-5amp cells if you want any longevity out of the packs

theyre not traction batteries

 

a 4p pack, 4x5amps is 20 amps

at 136v thats 5320 watts

at 100v (dead battery) 2000 watts

i was also wondering why they would be charging more for a different battery when they are basically the same price unless they were getting crap batteries,for dirt cheap

i was pretty gung ho for the s20 til i saw m50, they lost a sale

id like to see a range test by speedy feet, identical wheel but 2 different battery cell packs 50e/p42a, he rides hard in cooler temperatures

 

[alcatraz]

You make many good points goatman. (typo: you mean 2688w @20A)

Longevity is important but still secondary to heat. It's pretty scary to see the temperature rise to 70C on the cells at relatively mediocre discharge rates.

Imagine a heavy rider climbing on the Master 50E, on a warm day. I wonder if the wheel will monitor cell temperatures.

[alcatraz]

There's also the question of voltage sag. There will be A LOT of it in a high power 4P system with high capacity cells.

[xorbe]

EUC Addict's website expired, now all those incomplete forum posts with (Read More) that drove traffic to his site are dead.

[Rawnei]

I went with Samsung 40T LiTech assembly for my Master order but I'm still curious how much better the assembly would be, it wasn't an easy choice to make as it costs more but ewheels and now more suppliers choosing them as a partner must have some merit?

[RagingGrandpa]

On 4/28/2022 at 9:48 AM, Rawnei said:

I'm still curious how much better the assembly would be

Regarding the feature list Jason provided in September 2021: 

• Imported Korean 50E cells (Molicel P42a will be offered as an option later)
  (No difference: multiple cell choices are available from Gotway now)
   
• BMS with short protection 
  (No difference: Gotway BMS have output shutoff now)
   
• Depending on the application, 30-40A physical fuses designed to work, not this 120A nonsense... 
  This is good.
  <edit: Master added fuses in the intermediate PCB now> 
   
• 5x temperature probes
  This is new and good.
  <edit: Master added 2 temp sensors per pack now> 
   
• with buzzers to alert at a 65°C level & shut-off when the temps exceed 75°C
  This is new and good.
  But I'm not sure which LiTech EUC's get these buzzers. They weren't visible in the photos of the SherMax LiTech packs, for example. 
  <edit: Master added a buzzer in each pack now> 
   
• Voltage differential management for packs of unequel voltage, no balance lead required! 
  (This is a different way to achieve the same thing, not much difference)
   
• Improved cell holds & upgraded (thicker) nickel strips 
  This is good.
   
• Automated weld production methods for consistent quality 
  (Gotway also uses automated machines for strip welding. We would need to know more about both company's process controls to declare a winner here.)
   
• Capacity & stress-testing processes  
  (We would need to know more about this to say anything)
   
• Certification program planned in the next 3-6 months  
  (I haven't seen an announcement of the certification result: @Jason McNeil could comment further) 

.02
 

Edited June 24, 2022 by RagingGrandpa
(added info for new GW Master and its new generation of BMS PCBs)

[Rawnei]

2 minutes ago, RagingGrandpa said:

Regarding the feature list Jason provided in September 2021: 

• Imported Korean 50E cells (Molicel P42a will be offered as an option later)
  (No difference: multiple cell choices are available from Gotway now)
   
• BMS with short protection 
  (No difference: Gotway BMS have output shutoff now)
   
• Depending on the application, 30-40A physical fuses designed to work, not this 120A nonsense... 
  This is good.
   
• 5x temperature probes
  This is new and good.
   
• with buzzers to alert at a 65°C level & shut-off when the temps exceed 75°C
  This is new and good.
  But I'm not sure which LiTech EUC's get these buzzers. They weren't visible in the photos of the SherMax LiTech packs, for example.
   
• Voltage differential management for packs of unequel voltage, no balance lead required! 
  (This is a different way to achieve the same thing, not much difference)
   
• Improved cell holds & upgraded (thicker) nickel strips 
  This is good.
   
• Automated weld production methods for consistent quality 
  (Gotway also uses automated machines for strip welding. We would need to know more about both company's process controls to declare a winner here.)
   
• Capacity & stress-testing processes  
  (We would need to know more about this to say anything)
   
• Certification program planned in the next 3-6 months  
  (I haven't seen an announcement of the certification result: @Jason McNeil could comment further) 

.02

Those are the features that ewheels specifically asked for, I asked my resellers (not ewheels) what the difference are in terms of the Master if you go LiTech batteries and they said no difference other than the assembly of the packs which means I'm paying €120/$126 for hopefully higher quality assembly.

[RagingGrandpa]

3 hours ago, supercurio said:

Okay I had a call with LiTech / Henry (boss) about that and got some info worth sharing:

• LiTech packs for Master will use LiTech BMS instead of Begode's BMS.
• LiTech BMS for Master are not available yet but should be in a couple weeks.
• LiTech reviewed the Master pack/BMS from Begode and found the same shortcomings as previous designs.
  They anticipate the same issues coming as last generation, maybe fine in the beginning, then not 😬
• No Smart BMS for Master packs yet, maybe later.
• Smart BMS functionality still in the works for 100.8V packs
• LiTech (like eWheels @Jason McNeil) wants really bad to get the BMS talk to the mainboard, so I'm guessing it's still not the case on the Master.

 

[supercurio]

More info gathered in the process:

From Dylan Chen via Alibaba:

Quote

We have our own bms factory named BesTech, which is well-known in global.

All we do is customize, all according to customer requirements.

Optional communication protocol Canbus, MODbus, Rs485/232, UART and Bluetooth.

We are in battery business around 18 years.

Their BMS brand is http://www.bestechpower.com/

[RagingGrandpa]

More surprising info with LiTech packs for Gotways... the fuses seem too small and blow early  

Which seems to match the LiTech test video. These fuses should pass 30A forever; but instead overheat and melt if 30A is sustained. 

Situation:
Local ~200lb buddy has an eWheels RS C38 w/ LiTech 50E packs.
100 miles into ownership, we're riding offroad, and come upon a soft muddy spot blocking our trail. 
Light rider on MSX (no fuses) chugs his way through.
Me (~170lb) on MSP (no fuses), same thing - a 10 second struggle, then complete. 
RS rider gets only 5 seconds into pushing through mud, and the fuses blew. 
He had a sad but short walk out; glad we weren't in a remote area.
We presumed it was a board failure, but later discovered the EUC worked perfectly normally when a replacement fuse was installed.

I realize that mud clogging the tire and motor leads to a high-load condition, but with modern controllers I would want to see the controller be able to sustain its output until the controller alarms are reached (and here, they weren't). 

Also interesting that Sherman uses a larger-size bolted fuse, also at 60A total (30A per pack), and no nuisance blows have been reported yet. 
Normally I would think a 60A-total melting fuse rating sounds great (because they shouldn't melt until at least 125% of rating), but perhaps with these tiny mini-AT fuses, it's not enough for all riding types.

.02

[meepmeepmayer]

2022 isn't the year for EUC hardware companies, is it? 

[WillieP]

Good for eWheels!  Glad to see they are doing what they can to place safety high on the priority list!!