Design and Fabrication of A123 Pouch cell case

[Mike Dabrowski 2000]

Been hearing from some of our members that have a strong fabrication background, so lets put our heads together to design an enclosure that is safe, and environmentally controlled so we can use the pack in the cold New England weather, as well as the hot south west.
The wish list: feel free to add or suggest modifications to this list.

1. needs to use the relay interconnect board from a standard pack.
(Dimensioned drawings)

2. needs to mount with the same 4 bolts at the stock pack
(drawing of mounting surfaces and their 3D relationships)

3. would be nice if the two computer boards also mounted in the same position as on the stock pack. (drawing of their present location, relitive to the cover and the pack mounting bosses)

4. may need heating system in the colder climates
Determine temperature change response time (thermal mass)

5. may need cooling system in the hot climates
(test cell temperature rise under real world current conditions)

6. BMS for top balancing with charger, Peters has given us a good starting point, but I want to take it further with cell level voltage monitoring and reporting.
Will use
EVILbus | CasaDelGato Systems
as a model.
More good info.
http://www.evdl.org/lib/index.html

7. I have a design and soon prototype of a 3A booster for the grid chargers. This will work with the GCIM1, GCMI, and the GCO1. Parts will be in hand second week of July.
The design could produce a 30A version with fully adjustable constant current from 0 to 30A at 12 to 250VDC.

8. Battery case wants to protect the cells and have additional electrical safeties in response to an accident

9. stuff We have not though of
10. Stuff we have not thought of before doing the drawings and thermal efforts

[retepsnikrep]

Originally Posted by Mike Dabrowski 2000

6. BMS for top balancing with charger, Peters has given us a good starting point, but I want to take it further with cell level voltage monitoring and reporting.
Will use
EVILbus | CasaDelGato Systems
as a model.
More good info.
EVDL Library

7. I have a design and soon prototype of a 3A booster for the grid chargers. This will work with the GCIM1, GCMI, and the GCO1. Parts will be in hand second week of July.
The design could produce a 30A version with fully adjustable constant current from 0 to 30A at 12 to 250VDC.

Not quite sure where we are going with all this now

My BMS does individual cell voltage monitoring and reporting

If you are also going to design a BMS etc for the system there seems little point in me doing a huge amount of work on a modified pcb for my own BMS or all in one pcb for the system and the associated software if only half a dozen people may want one and it will be binned in six months?

I'm more than happy though to hand over the A123 torch to you, as I have stacks to do here and the Civic HCH1 has just arrived at my house today

The charger mod is good news and 3A is quite adequate for gentle charging of the A123 cells overnight.

[Mike Dabrowski 2000]

The BMS you have designed is good for the Insight pack, but I want a more modular system, that can be used on the many other configurations that may fall out of this.
Not ready to put down any specifics yet, as I have yet to get my hands on a cell, and need to get fully up to speed on what your BMS can do.
The combined BMS,BCM fooler circuit you have at is probably a good way for people to go that want an good solution, and may in fact be what I will end up with, just not ready to say for sure till I understand what you have in more detail.


My brain is deep in Grid Charger Labview monitor mode, as I try to get the final details of that worked out.

[retepsnikrep]

Originally Posted by Mike Dabrowski 2000

At this point it is only an initial statement of how I see this unfolding, and don't want to get pinned down to anything yet.

OK I will wait and see what you decide to do before I do any more work on pcb's or a combined interceptor/fooler/bms/charger controller software etc etc.

The Mini BCM interceptor I mentioned earlier will be availabe as a seperate pcb shortly anyway. The BCM fooler is already available.

V0.04 of the OBDIIC&C code and IMAC&C for the Civic HCH1 beckons anyway and as you know time for everything is like rocking horse poo.

[Rush]

Now is the time for all good men to....

[rayholan]

Originally Posted by Rush

I'm not sure what is going on here...

Mike - While your product may be valid, it does not solve a problem that is here and present today. And the way you have presented it, it seems to be a long term project and sounds complicated...

Peter - Please finish your pcb's, I think that they answer a very valid bump in the Insight road. I am sure that there is a market for your system and it will not be 'binned'.

Sorry to be so direct, but I, for one, think that Peters A123 boards are a very viable product and want them.

It might help the community to get a clear statement comparing and contrasting what Peter and Mike are discussing. I, for one, am a bit lost in the technical details and would welcome a simple summary so I and other Insight owners could distinguish the two paths being proposed. My hunch is that they both have merit but one approach might suit one owner's taste better than the other. Great to have choices. Grateful to have a couple of brainy and generous chaps like Peter and Mike (and others on this site) to blaze the trail.

[Calpod]

From the looks of it Peter's would be a system that will have to be put together and it would be for those that can make up the boards, and Mike's would be a "turn Key" systems.

Please Peter, Mike, correct me if this is not the case.....

[retepsnikrep]

I have no problem with the design and build of a case etc or if Mike/others want's to do his/there own system and offer it for sale. It's a free country

I think the projects are very similiar. Both involve a number of A123 cells fitted in place of a standard OEM pack and modification of the Insight system to make it work.

Mike's involves design and build of a new case and all the non insight electronics, bms etc etc. He is also looking ahead at other cars. I have no doubt it will be a finely honed work of art.

Mine involves using an old battery case and updating my pcb's/software to make assembly a tad easier. It's rough and ready and aimed squarely at the G1 Insight.

I'm going to wait a bit now and see where Mike's idea goes.
Once he is upto speed with where we are we can discuss.
I'm happy to offer my support and knowledge to a better collective system.

I'll tinker with my own pcb ideas in the meantime as time permits. I was proposing through hole parts and self assembly pcb's but only yesterday I was speaking to one of my UK Electronic Gurus who aside from delivering the HCH1 Civic is putting me in contact with an SMT pcb assembly expert in the UK. I'll see how that pans out.

[Mike Dabrowski 2000]

If you guys want to get going quickly, both Peter and I are busy, and what Peter is doing will work just fine.

I will design what I want for my car, and share the design as Peter has.
Two options are always better than one, so people that want to get moving on this quickly should be sending Peter some money, and signing up for the system.

The main purpose of this thread is to discuss the design of a custom pack, that is not a hacked up regular battery case, and that has environmental extremes of hot and cold taken care of.
I have several configurations in mind as well as some V-boost concepts that I want to try and want the BMS to be integrated into the pack at the 12-48V pack level, with a different form factorthan Peters design.

The large 25 cell BMS that Peter has will not meet that requirement for me, and will restrict my freedom to mount the BMS different from what Peter has done.
I have no desire for Peter to stop on his design just because I will be doing something differently.

[Rush]

Now is the time for all good men to...