Monday, July 23, 2007

Hauling Lead and Confusing Connections

Tonight was an evening of heavy lifting. These high-capacity 8-volt golf-cart batteries are 70 pounds apiece. I'll definitely take some ibuprofen before tomorrow.

Here are the batteries in the front box.

The fuel compartment box...

And the rear box.

I pre-laid out these batteries on the floor to guestimate what the connections between the terminals were. I couldn't find a good solution with the copper bars supplied by ElectroAuto, so I just took my best guess and gave it a shot. I've got an e-mail into ElectroAuto for some connection diagrams, but haven't received the files yet.

Here is the battery strap designed for these kind of batteries. I got this battery strap at a Yamaha golf cart dealer. The advantage is that it attaches easily to the battery at the loading loops on the edge. The downside is that you can't use the strap for "edge" batteries. Note how close the loading loops are to the edges of the battery on either side of the filler caps. I was able to load most of the batteries with this strap away from an edge and then slide the battery into position.

For the edge batteries, the other battery strap I had contained two large loops which I could hook around some bolts threaded through the battery terminals. I didn't like to use this because I felt it put undue stress on the terminals.

A modification of the prior strap is basically what is suggested in the DC kit instructions. I used bolts, washers and nuts to create my own special battery strap which could quickly slide into a set of battery terminals and lift it. Again, I tried to use this strap on as few batteries as possible because I was concerned about applying too much tilt force to the "L" terminals.

Okay, onto the copper battery interconnects. It turns out that the only copper interconnect that fit right out of the kit bag was the completely flat bar with two holes. All other bars had to be re-bent in a vise to fit properly around the terminals.

Here's a picture of the front battery box with the short interconnects temporarily in place. I forgot to get 5/16" stainless steel flat washers to properly connect these copper bars (whoops, back to the hardware store). Note the large interconnect missing from the two battery terminals in the center of the box. These are for the front box fusible link, shown later.

Temporary links for middle box.

Temporary links for the rear box. Note the very far link in a reverse "S" shape. I found a funny shaped link in the kit, but could simply not get it to fit anywhere in the system. Out of impatience, I bent the link to fit the terminal spacing around the far corner of the battery box.

Also note the missing fusible link near the center of the pack and the long vertical link not really connecting the lower right two batteries. I might have to add long stainless bolts because this piece of copper just isn't long enough to get to the terminals and still fit around the filler caps.

Here are the supplied fusible links. I'm rather confused by them because they have 1/4" holes instead of 5/16" holes like the rest of the copper bars in the system. The bars also don't seem to fit anywhere in the whole battery system nicely, so something is awry with where these go. I'm guessing I'll end of bending them to fit the remaining terminals in the battery boxes, but I'd sure like to know what the designers intended.

We're getting closer. Time to go back to the hardware store for stainless washers and bolts to finish installing the interconnect. Goodnight.


Ross Cunniff said...

I've thought personally that I'm going to have to remove some of the speed caps and replace them with regular screw-on caps - both for battery interference as well as for middle-rack cover interference (the hold-down cylinders don't mesh properly with the speed caps in my kit)...

Joe said...

I saw on the C2EC2T video; that it was recommended that flexible cables be used between the batteries, to better support the movement of the car and batteries. Since you’re having so much fun bending the provided ones into shape; are you planning on upgrading?

TimK said...

Hi Ross and Joe,

Do you know where I can get non speed-caps for specific instances? I figured these would be custom from US Battery.

I'm probably going to stick with the copper bars for the moment and see how it goes. They're much smaller and simpler to maintain. We'll see...

Cheers, Tim

Ross Cunniff said...

I have not yet started looking for regular screw caps. Thought I might wander down to my local battery store to see what they have...