World Record A123 Battery Packs

I can say we build the best packs and BMS(Battery Management System) for Racing. Over the years I have had the great privilege to work with the best EV racers. More Nedra records are held by racing teams that have used the packs we helped build. www.nedra.com/record_holders.html"
To name a few great racers:
KillaCycle (Bill Dube) www.Killacycle.com,
White Zombie (John Wayland) www.Plasmaboyracing.com,
Lawless Ind (Shawn Lawless),http://www.paradefloats.com/pages/orangejuice2.html
2 SSIC(Michael Kadie)http://ssi-racing.com/
As techniques have gotten better the packs have changed and so has the BMS. The first KillaCycle A123 pack built use the normal nickel plated steel tabs.
It was discovered that 1 tab would get very hot with the amps that we were going to be pulling out of the cell. A second Tab was added to each series connection a single tab for parallel connections.

Below is a picture of the first pack with the second generation BMS. You will notice that each cell had to be welded up to 4 times on the ends. This was a very long process and since we have started using copper has made life alot easier. Each steel tab had to be precrimped to form when the cells were unfolded. Unfolding was a 2 man job and took many hours as the steel was not as forgiving as copper.

First KillaCycle pack built with second generation BMS 100S 8P. Side view of the first pack of A123s.
This pack was built for Shawn Lawless it uses copper instead of steel for the cell interconnects.
Video of the the pack being welded with copper. This is the same process that was used for the KillaCycle pack. A newer welding machine has been built since then and is much better.
The process that we used to build the Lawless and Killacycle packs. Note: This has now been updated and modified for more cooling and will be described latter. First is the welding of the cells into bricks of that will become rows of cells. The photo below shows a brick that has been welded.
The cells are then unfolded in the next step.
The unfolded cells are placed into a fixture that will press it tightly together.
Next the fixture is lightly secured to keep the cells held down.
A piece of wood is used along with clamps to press the cells together.
You can see the spacing as it is being pressed together
Fully compressed but not too tightly to damage cells.
Holes are now punched to allow air flow through the cells. This happens on both sides.
Closeup of the hole created.
Tabs are now cut for latter soldering to BMS.
Silicone is applied to each cell.
G10 sheet is place on the silicone glue. This provides an insulating layer as well as support for the cells.
BMS sticks are soldered to the cells.
Rows are stacked up waiting to be put into the pack.
Battery pack being assembled. The ends are soldered together to connect rows.
Assembled battery pack ready for testing.
First charge coming up all green.
Testing the packs.
Cycling the packs.
Packs equalized and fully charged ready to go racing.