VCU Internals (Gen1)

[Foss]

Posting some pictures of a VCU which failed on me. I never knew there was a secondary battery within the VCU which I believe was the culprit just judging by the voltage readings.

2x 32 micro sd cards
1x sim

EG25-G GB-256-SGNS is a module from Quectel, a company specializing in cellular and IoT modules. This specific module is a 4G LTE Cat 4 module designed for IoT and M2M applications.

 

[AL_V]

Not great to see micro SD cards, those things are not the most durable of creations...

 

[doates625]

Nice tear down. This stimulated by EE brain. Thank you sir.

 

[Foss]

Nice tear down. This stimulated by EE brain. Thank you sir.

No problem man, I figured you are dealing with the negative temperatures like I am. You may want to keep the VCU warm as well seeing this battery establishes a heart beat to the main battery. If this CMOS battery dies you will not be able to turn the bike on, even if the main battery is healthy.

And to reiterate in past posts in other threads, this is another reason why we do not hard shutdown the bike for storage. Soft turnoffs are best practice (blinking red light). I’ll keep preaching it lol.

 

[doates625]

No problem man, I figured you are dealing with the negative temperatures like I am. You may want to keep the VCU warm as well seeing this battery establishes a heart beat to the main battery. If this CMOS battery dies you will not be able to turn the bike on, even if the main battery is healthy.

And to reiterate in past posts in other threads, this is another reason why we do not hard shutdown the bike for storage. Soft turnoffs are best practice (blinking red light). I’ll keep preaching it lol.

Keep preaching. I am new to this thread and was unaware. I have been doing hard shutdown to minimize phantom drain and will reverse this practice. Can you link to threads where this is discussed further? I'm curious about the other reasons.

 

[Foss]

Keep preaching. I am new to this thread and was unaware. I have been doing hard shutdown to minimize phantom drain and will reverse this practice. Can you link to threads where this is discussed further? I'm curious about the other reasons.

I have not posted this response here until now for the community. Hopefully this shed light to the importance of a soft or hibernated state of sleeping the bike. It was not mentioned in the email there is a CMOS battery which is also critical to the stability of how the main battery communicates to the VCU. I don’t want to use words like shutdown or turn off.

And once lithium batteries are depleted it is nearly impossible to regain a pulse.

I can further study this battery and do not mind finding a replacement part somewhere in the ether of the web.

 

[Foss]

To add, you can actually re-use this SIM card in other devices with success. But I am sure it will leave a footprint behind for which device heartbeats in at that time to T-Mobile. That’s if this is being monitored?

 

[LTJ]

Wow, that is good to know. I've been doing a complete shut down to store the bike because of battery drawing. I'll now store it in standby mode with the battery between 30% and 50%.