Installing the Potbox

The Belktronix system tries to make installing the potbox a no-brainer by allowing the user to put it right under the accelerator pedal. For the Civic, this works out quite well.


Here are the heavy-duty Velcro pieces that come with the Belktronix kit. The intent is to put the "hook" side of the Velcro on the rear side of the potbox and simply stick it to the rug under the pedal.


I found that the rug moved around quite a bit, so I wasn't comfortable sticking the potbox directly to the rug. In the above photo, I've cut away the rug and the rubber pad underneath the rug to expose the firewall metal under the accelerator. I want to line up the bulge on the backside of the accelerator pedal with the plunger on the potbox. There's a seam with a right edge and bottom edge shown in the photo above. Mark a horizontal line 3/8" above the bottom edge of the seam, and align the potbox with it and the right edge of the seam.


Clearance is tight, so I added the "hook" sid of the Velcro to the backside of the potbox between the assembly bolts.


To get the "fuzzy" side of the Velcro to line up on the firewall, I just pressed the fuzzy Velcro onto the "hook" Velcro attached to the potbox and just pressed the whole assembly into place under the pedal. Again, the bottom edge is 3/8" above the bottom seam and the right edge lines up with the right seam.


Here's the potbox installed with the bump of the pedal resting on the plunger. There are also some small "L" brackets in the kit that I could also use to mount the potbox to the firewall, but I'll try the Velcro version first and see if it sticks (pun intended).


With the potbox mounted, I need to find a way to route the potbox wires into the engine compartment. After hunting around, I found this 25mm plug on the passenger side under the glove compartment. The picture above shows the plug (red arrow) from the engine compartment side. I'm guessing a 1" grommet would do just fine here. I could have drilled a 1" hole in the firewall, but I think this is cleaner.


Since we're on the topic of routing cables, I thought about how to route the high-current battery cables from the front engine compartment to the rear battery rack area. It turns out that there are also two 25 mm plugs (the ones we used to align the front bolts) in the rear area that line up neatly with the ends of the batteries. I figure I can route the cables under the car and tie-wrap them to various brake lines down there and they will come up through these holes (with grommets added) to attach to the batteries.

The next step will be to figure out how to attach the vacuum pump or extend the engine wiring harness to reach all the places we need it to.

Onward!

Installing the Powdercoated Racks

The past two days have been productive. I went to Class Act to pick up the powder-coated angle-iron and installed most of it.


Here are the powder-coated pieces all nicely wrapped up to prevent damage.


Here are the pieces unwrapped. Yep, all 39 pieces are there and in good condition.


I started by installing the rear battery rack. The two cross pieces of angle-iron sit on top of the two square tubes. The bolt going down through the angle iron sits several inches away from the end. I taped the bottom face of a box wrench and inserted a nylock nut (see picture above) so that I could tighten the bolt into the nut.


Here is the rear battery rack installed, without the wood insert. I cut 10" pieces of 5/16" all-thread for the hold-downs and installed them. I had difficulty installing the two pieces of all-thread between the shock-towers due to lack of clearance under the angle-iron for the nylock nuts. I had to use two thinner "jam" nuts in order to install these last two all-thread pieces.


Here's the rear rack with the batteries on top of the wood plank and hold-downs installed. I still have to devise a system to hold down the extra battery on the right, but I think there are off-the-shelf automotive solutions for this.


The next step was installing the rear motor mount plate and bracket to the driver-side engine mount. I bolted the rear plate on with 5/16" bolts (threads had red loctite) and lock-washers. With the plate on, I could use the engine hoist to raise the whole assembly into place. After bolting in the transmission on the passenger side, I bolted together the bracket on the driver-side. All in all, I'm pretty happy with how it blends in with the black chassis of the car.


Here's the motor/transmission assembly fully installed. I have a portion of the original engine wiring harness plugged in to get a feel for what I'll have to deal with electrically. I'll add more pictures in the future after I figure out how to tap into this.


Here are the firewall-rack angle-iron pieces installed. Are are some dry details about what I used to hold it together:

• 6mm bolts (20 mm long) with lock washers hold up the vertical bars to the shock towers
• 3/8"-16 bolts, 1" long with nylock nuts hold the left and right angle-iron supports to the vertical bars
• 5/16"-18 bolts, 3/4" long hold the four horizontal angle-iron pieces to the driver-side support.
  
• On the passenger side, the horizontal pieces are bolted in with 5/16"-18 bolts (3/4" long) only on the two middle pieces.
  
• The rear-most and front-most horizontal pieces are bolted to the passenger-side support with 5/16" all-thread, 10" long, which also serves as hold-down support.
• The front-most and rear-most horizontal pieces have 5/16" holes 27" in from the passenger side. I inserted 5/16" all-thread to serve as hold-down support and to attach the control-board support that juts out towards the viewer in the picture.
• The remaining control-board piece that points toward the viewer in the center of the picture is held up by two 5/16"-18 countersunk flathead bolts 3/4" long with nylock nuts on the bottom. These have to be countersunk because the top surface needs to be flush with the angle iron to support the batteries.

Here is a top view of the front rack installed with hold-downs in place. I also used 5/16" all-thread 10" long for this. I probably should have used 9 1/2" long pieces. The driver-side all-thread closest to the grille has very little clearance, so I had to screw it downward in order to fit the small nut on the top (as opposed to wingnuts on the remaining three corners). Note: for some reason, Blogger is acting up and magically rotated the bottom picture. It is horizontal for easier viewing on my hard-drive.

Next up: installing the potbox

Battery Monitoring Parts

I received several more critical items in the mail this past week.


Here are several components from the Belktronix battery monitoring system. In the upper left is the "batmon" unit (one for each battery) that monitors each battery. The black/white wire coming out of the top is a temperature sensor which adjusts the final shunt voltage based on the environment. The green LED turns on when the resistive shunt (lower left in the photo) kicks in to balance out the batteries. The red LED turns on when the battery voltage sags down to about 10.7 volts or so. This is far more effective than just monitoring the total voltage of the pack because the system has undervoltage protection for each individual battery.

Bryan at Belktronix came up with a great way to connect these modules together. There are four green snap-in connectors for each Batmon board that allow easy connection and disconnection for the individual functions:

• shunt resistor
• 12V connection to the local battery
• signals in parallel with each Batmon to indicate shunt active
• signals in parallel with each Batmon that an undervoltage has ocurred.

The plastic bag in the upper right contains all the plastic mounting hardware for each batmon. These are standard tie-wrap holders with sticky bottoms. The "IsoBatmon" circuit in the lower right corner of the picture electrically isolates the signals from all the Batmon boards from the rest of the system for safety.

At this point, I'm only waiting for the charging/DC-DC system from Belktronix, which should arrive in a few weeks.


The other two parts I received from KTA-services were a 500-amp Ferruz-Shawmut fuse and a heavy-duty Airpax circuit breaker. Theoretically, I should only need one of these, but I'll put both in the high-current cabling for safety in case something shorts out. I plan the mount the circuit breaker under the parking brake like Bob Bath did in his CivicWithACord project.

On another bright note: I received a call from the powder-coating shop on Tuesday letting me know that they had already finished the job. I'll be going to get the finished parts tomorrow morning and seeing how far I can get with assembly.

I'm exciting to have all the parts needed to make significant progress. Let's see how much I can get done this weekend.

Sending Pieces off to Powder-Coat

Last night I disassembled all the battery racks and gathered the pieces in the living room to get ready for powder-coating.


Here are all the steel angle-iron and bar-stock pieces in their approximate battery rack groups (39 pieces in all). I put them in the plastic bin to the left and drove them over to Class Act Powder Coating for powder-coating. For $100 they're going to sandblast all the paint and oxidation off and coat the pieces with epoxy to prevent rust and acid damage.

While it may not seem like much, the above picture represents several months of trial-and-error design work to fit twleve group-31 batteries into the limited space of the Honda Civic. I'm looking forward to the mechanical design being finished so I can focus on the electrical design, which is much more up my alley.

Here's the rundown of pieces:

Rear Rack:
2 square tubes
2 angle irons (notches on outside)
2 angle hold-downs with notches
2 bar hold-downs

Front Rack:
2 short angle irons
2 long angle irons
2 bars
1 short wide angle iron
2 angle hold-downs
2 bar hold downs

Firewall Rack:
4 short bars (notches start at driver, clockwise)
2 side angle iron
4 horizontal angle iron
2 support angle iron
2 side hold-down bars
2 angle hold-downs
2 hold-down spacers

Motor Mount:
1 heavy short angle iron
1 end plate

Happy Halloween everyone!
Tim

Making the Battery Hold-Downs

I cut several pieces of metal for the battery hold-downs. The construction details are as follows:

All angle iron and barstock is 1/8" thick and 3/4" wide.

Front rack:
2 pieces of angle iron, 27 1/2" long with holes
2 pieces of iron bar, 7 1/16" long with holes

Trunk rack:
2 pieces of angle iron, 36" long , with notches described here
2 pieces of iron bar, 13 3/16" long with holes

Firewall rack:
2 pieces of angle iron, 27 1/2" long with holes
2 pieces of angle iron, 26" long (no holes)
2 pieces of iron bar, 14 1/16" long with holes

All items listed above "with holes" have a 11/64" hole drilled in each end, centered from side to side and 3/8" in from the end.

This description is terse as I'm trying to get the whole pile of steel out the door today for powder-coating. I'm an electrical engineer by training, so I'll be happy to get all this metalwork out of the way.

Redesigning the Firewall Rack

After redesigning the firewall battery rack with rotated batteries, I wrote down some installation instructions. For the past two days, I've been following my own instructions to see how well they work out.


Here are the four 1" x 3/16" x 5.5" bars that will be mounted to the shock towers


With the bars mounted to the shock towers, I cut the left and right angle iron supports. I bolted the rear end through the 2 3/4" piece of 1" galvanized pipe and used a clamp to hold the front to the bars on the shock towers.


Here's a similar view of the supporting angle-iron, but on the driver-side. Note that I had to carve out a much larger notch out of the rear motor mount to accomodate the supporting angle iron. I also had to cut an angled piece off the back of the supporting angle iron to not interfere with the brake lines under the brake-fluid reservoir.


After measuring the distance between the two side pieces, I cut four horizontal pieces of angle iron, measured the proper distance between them to fit the Lifeline batteries and clamped them in place.


Same structure but on the passenger side. The rear-most horizontal bar has a curved piece cut out of it to avoid touching the brake lines. With all pieces clamped in place, I could now draw through the holes in the horizontal bars to the underlying metal to properly drill bolt holes.


After marking and the holes on the left and right supports as well as the bars mounted to the shock towers, I disassembled the structure, drilled the holes and bolted it back together. With the structure bolted together, I now added the two angle-iron pieces on the right that jut out towards you. These are just clamped in place so I can mark holes on the angle-iron pieces.


With the marked holes drilled on the rightmost angle-iron supports, I bolted the far right one on. These supports that jut out towards the front of the car will hold a platform for all the electronics.


Here's a final test to make sure the batteries fit in and I still have hood clearance. With the batteries in, I was able to close the hood easily without any interference. Yay! It took me awhile to get this solution to work.

Next up: making the hold-downs for the front and firewall battery racks.

Cutting the Battery Hold-downs for the Rear Rack

The upper edge of the LifeLine batteries has some protrusions that the battery hold downs must fit around. I'm using 3/4" angle iron to hold down the batteries in the rear trunk. To make the hold-downs work for the life-line batteries, I used the metal cutoff grinding blade to make several adjacent cuts, thereby making a much wider unified cut.


In order to notch out the 3/4" angle iron, I made one cut on the right and several vertical cuts (1/8" wide each) on the left side of the notch. I could then wiggle my sabre saw blad into the wider cut on the left and finish cutting out the notch.


Here's one of the rear hold-downs almost complete. I've used my sabre saw to cut the notches on the left and just have two left, including the unfinished one shown in the picture.

These pieces of angle iron seem fairly ridgid, so I think this scheme will work out reasonably well.