Battery Bits

Had four days with a clear schedule - no rehearsals or concerts. Last weekend I performed in three concerts, the weekend before played two concerts with six rehearsals in between. That doesn't leave a lot of time to spend on the car, but this weekend I have the luxury of uninterrupted work time. It was great to get some things accomplished.

I mentioned in an earlier post that we've finalized the placement of the batteries, all in the rear. Two of the banks of batteries are just as received with sixteen modules all built up into a unit. Those we had figured out some time ago.

Since the charger is moving under the hood, that leaves a nice opening between the full banks over the transaxle. Four battery cans stacked are just the right height and will allow for a deck covering the batteries under the hatch with no loss of storage. So I built a four-pack in that configuration that should mount in the center of the battery bay.

That leaves eight modules, so after consulting with Robert, we decided to keep all the batteries together in the rear of the car. I proposed pulling out the rear seat and installing them there, but Robert made a good case for keeping the back seat and placing that group on the remaining deck behind the seat back.

Once again, four of the battery cans stacked flat was just equal to the height of the seat back above the deck, so I built an eight can module in two sections electrically tied together by one of the original flat connector straps from the Better Place pack. The strap is solid copper, plated with a silver material. It is insulated with a very tough plastic jacket (mylar maybe?) that is adhered to the strap and very hard to remove. Don't ask me how I know.

These will go over to Pro Automotive on Monday to get fitted to the car. They are built up with six inch carriage bolts in 1/8" aluminum bar stock passing through the holes in the battery cans and mounted to the aluminum sheet with metal lock nuts. It feels very secure and can be mounted by drilling and bolting the base to the battery box structure and deck. I need to bring the remaining four pack that is behind the transaxle home for the same treatment.

UPDATE April 27, 2015:

Dropped off the finished battery modules this morning. The center pack looks real nice in its new home. Robert plans to build a tray to secure the eight pack behind the rear seat. He's also working on the motor mount and Dave the machinist is preparing the coupler for installation on the motor. Things are beginning to come together.