Decoy Modular Battery

[Foiled Again]

Hey Guys

I've assembled a travel battery that consists of 5 pieces, each piece is nominal at 7.4V 10.5Ah (2S3P) that when interlocked together form a 10S3P pack giving me 42V 10.5 Ah 440Wh when fully charged. (ignore the lable on the battery, the 22.2V is a typo!)

The pack when assembled slides nicely into the existing Decoy enclosure. Disassembly and reassembly in less than 15mins.

Each piece is under the current airline limit of 100Wh so this setup is great for those of us that travel the world and can't leave our toy at home.

Now, the problem is I can't get it to power on the Shimano 8000. When the battery is inserted the display powers on and hangs on 'Shimano Steps' screen. I can only think there is some clever circuitry that needs some feedback from the BMS. I deliberately didn't install a BMS as it made the modular concept difficult. Has anybody else dabbled in DIY batteries or does anybody have the expertise to diagnose this problem?

 

[khorn]

Your idea is great but unfortunately the stock batteries are “intelligent” meaning that the battery packs, apart from a BMS, also have integrated electronics. Many are utilizing the “CAN bus” standard for communication with the different parts of your system. By integrating a “raw” battery without this electronic circuit you will never get it to work. If it were that simple your concept would be all over eBay right now?

karsten

 

[ImSundee]

I've been playing with the same idea in my head, to get around the 'smart' part is easy if you have a donor battery.

I'd change them connectors to XT90s, they are stronger and offer better support. hate just naked bullets like that.

Do you have the board from that battery? I see you have the case? If you have the board I can try to help you work out how to make it connect properly.

 

[silverstone]

Oh boy, I would love to do the same with a specilaized battery. I could print the case by myself, and the cells would cost around 200 bucks for a 700wh battery But then I still do not have the necessary BMS...

 

[Hugh-Jazz]

Your idea is great but unfortunately the stock batteries are “intelligent” meaning that the battery packs, apart from a BMS, also have integrated electronics. Many are utilizing the “CAN bus” standard for communication with the different parts of your system. By integrating a “raw” battery without this electronic circuit you will never get it to work. If it were that simple your concept would be all over eBay right now?

karsten

I'm not sure the STePS pack has a CAN bus connection to the battery. There is no firmware on the battery as there is with a Di2 battery.

Hey Guys

I've assembled a travel battery that consists of 5 pieces, each piece is nominal at 7.4V 10.5Ah (2S3P) that when interlocked together form a 10S3P pack giving me 42V 10.5 Ah 440Wh when fully charged. (ignore the lable on the battery, the 22.2V is a typo!)

The pack when assembled slides nicely into the existing Decoy enclosure. Disassembly and reassembly in less than 15mins.

Each piece is under the current airline limit of 100Wh so this setup is great for those of us that travel the world and can't leave our toy at home.

Now, the problem is I can't get it to power on the Shimano 8000. When the battery is inserted the display powers on and hangs on 'Shimano Steps' screen. I can only think there is some clever circuitry that needs some feedback from the BMS. I deliberately didn't install a BMS as it made the modular concept difficult. Has anybody else dabbled in DIY batteries or does anybody have the expertise to diagnose this problem?

Did you measure the output voltage on the YT pack? I've read there is a second lower voltage that is used for accessory lights and Di2? It would be at 6V or 12V.

 

[Changleen]

This is a great concept, please keep trying!

 

[Sapientiea]

Any update?