Getting the Lifecycle BMS to Market

[PJD]

I talked to Bob Mcree by phone this past Saturday regarding the status of the Lifecycle Battery Management System.

He said that, with some updates to the documentation, kits for the verson without the status LED's could be available this week.

But, Bob also strongly implied that he had limited time and resources for the project, as he had intended for Gary/TPPacks to take over the manufacturing and selling of completed units or kits. With Gary deciding to get out of the venture, I think the time has come for some people to contact Bob and move this project forward.

I would take the initiative if I had more technical background, or can find someone that does.

Ideas?

 

[fechter]

Bob and Gary have done quite a bit evolving the design of the system.
silicium designed a similar BMS and reports it is working nicely for him.
The full schematics for both are posted on the forum.

I might approach the design a bit differently in a few areas, but either way, once you nail the design down and establish functionality and reliability, then it's a matter of production.

There are several ways to go about this. One is to get someplace like Express PCB to make just the board, then buy the parts yourself and solder them in. This is very time consuming, and not a job I would want to do. OK for one unit, but I wouldn't want to make dozens.
This would be a good approach for a DIY kit.

Another approach is to find a place that can completely assemble the boards based on the established design. They take care of getting the parts and do all the assembly. For large scale production, surface mounted parts would be much more attractive. This would allow for a smaller board and probably save a considerable amount of money. Surface mount is not so good for DIY assembly. Testing the board is another job that you could farm out or do yourself. It wouldn't be too hard to build a test jig and test every board.

Designing a BMS that would appeal to the R/C crowd as well as the EV crowd might be one way to increase volume. A modular design that allows you to stack elements to get the desired amount of cells might be cool.

The problem with using outsourced assembly is you need large volumes to get the price down to a reasonable level, which means there is a considerable risk involved and you need a bunch of money up front. What if there's still a bug in the design? What if you make 100 of them and can't sell all of them?

To start with, you can use their board layout and bill of materials (parts list) to get a quote from an electronics fabricator. I'd be curious to see how much it would cost fully assembled. It stops being an engineering project and become a business venture at some point. This really takes someone who is good a business, and that would probably not be an engineer :wink:

Anybody want to start a company?

 

[Toorbough ULL-Zeveigh]

I might approach the design a bit differently in a few areas,

dish, girlfriend!

 

[PJD]

There are several ways to go about this. One is to get someplace like Express PCB to make just the board, then buy the parts yourself and solder them in.

I know this is a rank beginner question, but how is this usually done? Do you just send the board maker a schematic and some general desired dimensions for the board and the board maker figures out the traces and layers? Or do you have to send them a detailed, dimensioned, drawing of the desired board?

 

[Dr. Shock]

Anyone heard of Megasquirt diy fuel injection systems? They used to have things set up so that you'd buy the board and a couple of programmed chips from them and then on their site they had all the parts listed with Digi-key parts numbers, and somehow you just had to click a button and you were on Digi-key's website, with all the parts already in your cart. I'm guessing Digi-key has someone who helps you do this. There were a lot more parts on the Megasquirt board than on the bms, so it should be even simpler.


Eventually, Megasquirt got enough of a following so that 3d party suppliers sold pre-assembled boards over the internet.

 

[fechter]

I know this is a rank beginner question, but how is this usually done? Do you just send the board maker a schematic and some general desired dimensions for the board and the board maker figures out the traces and layers? Or do you have to send them a detailed, dimensioned, drawing of the desired board?

They have some nice board layout softare you use. You have to do the board layout yourself. Once you have it, you send them the file and they make the board.

 

[rkosiorek]

one of the manufacturing issues is the setup of all of the pots that control each individual cell cutoff voltage. tediuos when you have to do 16 pots per board.

I have quite a few LiFePO4 cells that will be in packs soon and i was intending to use the Lifecycle design. so i too would like to find out who is taking over. I have been waiting for the boards for 4 packs for quite a while.

rick

 

[PJD]

Yes, I have sixteen, 40AH thunderskys sitting on the bench waiting on this product.

I'll call Bob tomorrow to see if he is would like someone to take over having the latest version of the PC board made, and kits assembled.

I agree, that this BMS may be strictly a DIY kit for a while.