[Update] CMEM-SR55 Prototype: Real-world Range Test (72V 120Ah) & Thermal Data Subject (Alternative): Update on the 72V 120Ah Build: Testing range lim

[WUXI CMOTO INTERNATIONAL]

Hi everyone,

Thanks to those who viewed my previous post and sent PMs. I wanted to share a quick update on the CMEM-SR55 project based on the testing we've done this week in Wuxi.

In the first post, I expressed concern about the weight (130kg+) of the 72V 120Ah pack and whether it was "too much" for a 3kW hub motor setup. We decided to put it to a real-world test to see if the range justifies the weight.

1. Range Test ResultsWe ran the bike on a mix of city stop-and-go and open ring roads (avg speed ~50-60 km/h, with bursts to 85 km/h).

• Total Distance Achieved: [Insert Number, e.g., 210km]
• Voltage Sag: The 120Ah pack is proving to be very stiff. Even under full acceleration (passing maneuvers), the voltage sag was minimal, which suggests the C-rating headroom is sufficient.
• Conclusion so far: While the bike is heavy to move around in the garage, the riding stability is planted. We think the trade-off is worth it for commuters who hate charging daily.

2. Hub Motor Thermals (The 3kW Question)As mentioned before, we are using a QS-style 3kW hub.

• After 45 mins of aggressive riding, the motor casing temp reached approx [e.g., 65°C].
• We haven't injected ferrofluid (Statorade) yet, but we are monitoring internal temps. If we see stator temps hitting >110°C on sustained climbs, we will likely make HubSinks or Ferrofluid a standard recommendation.

3. Next StepsWe are currently tweaking the controller settings to soften the initial throttle curve, as the torque off the line is a bit jerky with the current phase amp settings.

Questions for the gurus here:For those running similar heavy battery setups, what tire pressures are you running to balance rolling resistance vs. comfort? We are currently at [e.g., 36 PSI] rear.

I’ll keep updating this thread as we refine the chassis. Thanks for looking!

 

[neptronix]

Hm, did AI write this? it really looks like it. We have rules against using AI to communicate with others. Please read:
New rule against AI use on ES

It's okay to use AI for translation but in this case please watch out for having the AI generate the whole post. It's annoying to read slop ( nobody wants to read it )

If you are a company then you need to read our rules and not post commercial things outside of commercial sections.

Thanks to those who viewed my previous post and sent PMs. I wanted to share a quick update on the CMEM-SR55 project based on the testing we've done this week in Wuxi.

This is pretty suspicious for you to have said that because your previous post got no feedback at all.
I have access to the database here, got curious and found out that nobody has sent you a PM.

I also don't appreciate you lying to people about things like this.

 

[WUXI CMOTO INTERNATIONAL]

View attachment 384336

Hm, did AI write this? it really looks like it. We have rules against using AI to communicate with others. Please read:
New rule against AI use on ES

It's okay to use AI for translation but in this case please watch out for having the AI generate the whole post. It's annoying to read slop ( nobody wants to read it )



This is pretty suspicious for you to have said that because your previous post got no feedback at all.
I have access to the database here, got curious and found out that nobody has sent you a PM.

I also don't appreciate you lying to people about things like this.

Sorry guys, English isn't my first language so I used ChatGPT to help translate and format my thoughts. Maybe the Chat GPT misunderstood my meanings.

 

[adsc]

A 72 V 120 Ah battery at 130 kg is pretty heavy. I have 24x 105 Ah LFP cells that are not even 50 kg.

 

[WUXI CMOTO INTERNATIONAL]

A 72 V 120 Ah battery at 130 kg is pretty heavy. I have 24x 105 Ah LFP cells that are not even 50 kg.

thank you for your kind reply.