EV Trans Am

Neighbor Mike has a big Ford Expedition so we expeditioned ourselves to our local Sears Auto Center and picked up 13 Diehard Platinum P1s last Saturday. They are equivalent to the Oddysey PC1500 I was eyeing up, but about $50 less each so I’ll give them a go. The best part was customers weren’t allowed in the work area unless they had eye protection. Neighbor Mike jumped right in and helped loading, but in doing so took the only extra pair of safetly glasses they had. So I scoped out the vending machines while they loaded 650 lbs of batteries.

I did help unload and then moved them into the garage on a pallet though. I’d never heard it before but people are saying that leaving a battery on concrete will drain it. One idea I thought made sense is that the concrete remains cooler than the ambient air so the electrolyte separates at the bottom. The slight differential created eddy currents which drain the battery. I remember hearing about those at UF, but I don’t know what they are. I do know they aren’t used to build roads and were not on the PE exam.

A couple of thiings have been figured out regarding the small electric motor I purchased to run the power steering and A/C. The bolts that I used to mount the adapter plate to the transmission actually are the same thread pitch and size as the interior of the P/S pulley. However, the pulley needs to run counter clock-wise so if I used the threads it would probably unbolt itself over time. Alternatively, before the threads the pulley has a hexagonal opening and a 3/8″ punch fits perfectly into it. I assume then that a 3/8″ allen key will also, or a nut that is 3/8″ outer width.

The other trick though is that the motor shaft is reverse threaded. So what I really need is a nut that is reverse threaded and the appropriate inner diameter to mate to the motor shaft while having an outer width that is 3/8″. I don’t know that they make those so I may need to but a reverse tap and a make my own.

I haven’t heard anything from the vendor I ordered everything from earlier this month. Normally they ship very fast so I’m assuming that some of the parts are not in stock. I know the crimper I will be renting had a few days delay, but that may ship separately since it has an extra shipping charge. I’ll probably call tomorrow to see what’s going on. I also wasn’t able to order the mk2d regulators online so I asked them so send me an invoice for them separately and I want to followup there as well.

On a good note I’ve been directed to a local metal fabricator who is interested in the project and will be coming by sometime this week to look over everything. He’ll be helping with the battery racks, including the new one that will require cutting out the floor above the fuel tank and raising it about an inch. We’ll also provide an access hatch to install and maintain the batteries.

One Thursday I placed one of my final orders, I hope. This one included the charger and battery regulators, a rented bench mount crimper to make the battery cables, DC-DC convertor, and a pretty cool looking forced air cooling kit for the WarP11. I wanted to filter the air somehow and this kit makes sense to not only filter but force air into the motor. I’ll need to modify my control board layout because I think the hose will be pointed up right behind the accessory bracket, but I have to room to fit it all in.

Not sure how I will tie the power in to the cooling fan. It would be nice if it could be triggered automatically off a temperature probe, although I have a feeling that sealing the motor with the shround will block any ambient air, requiring the forced motor to be on at all times.

I figured out the wiring for the motor that will drive the power steering pump. I wanted a way to shut the motor off when PS wasn’t needed to save some amps. This would be primarily when sitting at long traffic lights, but I could also see using it on the interstate occasionally. I really depends on the amps the motor ends up drawing and if the PS pump can be cycled on and off. If it takes 5 seconds after switching the motor on for the lines to be pressurized then it’s a no-go.

My original thought was to tie into the parking brake light indicator. This comes on when the parking brake handle is engaged even a single click. There is continuity in that wire that I was going to use to trigger my relay. Turns out though I would need a normally closed relay and then the brake was engaged it would open the relay. That’s not what I bought, so considering that and the fact that the brake light is on all the time currently (when a battery is connected to the frame for testing) I opted to instead use a switch the presious owner had installed for some fancy blue light special around the radio bezel.

Here is me figuring out how everything needs to be wired with a junk motor from a cordless grass trimmer. The switch triggers the relay which can handle the amps of the motor. The switch even has a little light on it when it is on.

12V, 1200 amp battery makes 18V tiny weedwacker motor whirrrrrr!

The next step is to figure out how to mate the shaft of the motor to these threads or hex (9mm?) opening on the PS pulley. And also how to mount the motor itself to maintain a parallel connection between the two. I think I’ll sleep on it some more.

Instead of constantly thinking about the wiring song (The battery negative connects to the fuse wire, the fuse wire is connected to the funny bone, the funny bone is connected to the motor controller…) I decided I just needed to lay it out in a way that makes sense to me. Here is what I came up with – tags of paper tied to each part with a label and designation of where it goes. That way when I’m laying it out in the car I only have to think about connecting “1” to “1” and “2” to “2” instead of + and – and whatever.

I’ll use the string again once things are going in the car to determine how much cable I’ll need for that connection.

I’ve been thinking more about a charger and battery monitoring. I like the look and cost of the paktrakr, but it doesn’t link into the Manzanita I’m considering. Not too big a deal I think, I’ll just scan through the batteries before charging to make sure they’re all pretty equal so no single battery gets overcharges. But I say that now not having to check battery voltages everyday. The system that Manzanita makes costs more, but would make sure everything plays together nicely.

More research is needed, but I’d like to order it pretty soon. I like the Manzanita because it has variable everything it seems, so different battery packs, input voltages, etc don’t matter.

I ordered the wrong size lugs so I sent them back for smaller ones.  The screws for the batteries measures just over 5/16″ so I thought I needed to order the next size up – 3/8″.  Turns out the lugs, at least the ones I got, are oversized so they were 0.05″ too big.  The connections was a little sloppy so I’m going with the smaller size.

It works out well, because with the battery swap I’m going to need to use the SAE posts on top of the battery.  The new battery has both SAE terminals on top and screw post on the side.  If I want to put the batteries in rows front to back, the screws posts would not be accessible for the cable.

I also found a leak with the vacuum pump.  When I put the muffler on the o-ring slipped to the side and wasn’t sealing right.  While I had the reservior and pump off I added a pad beneath and to the side of the pump to keep it a little quieter.

Other progress was painting and bolting up the motor mounts.  I need 2 bushings and 2 more bolts and they’ll be done.  I should take some more pictures.

I’ve decided it’s better to upsize my battery from a PC1200 to a PC1500 equivalent (more later).  I should add about 60% more range (42 ah to 68 ah) with only a 11lb per battery penalty (30%).  We’re also planning on cutting into the floor above the fuel tank and hanging the batteries there instead of trying to install them from underneath.  Maintaining them would be very difficult if they were underneath due to the weight (400 lbs).  With the new setup I’ll have an access hatch to easily check and tighten terminal connections, not to mention install the batteries one at a time.

I also received a motor to drive the power steering pump.  It’s from a scooter like the Razr.  I figure if it can push up to a 180 lb kid at 10 mph (rated at 2500 RPM) it should be able to run a pump, and hopefully the A/C too.  It’s meant for 24V and it’ll be on the 12V system so we’ll see how it goes.  It was a pretty cheap buy and even looks like it will couple to the PS pump pulley pretty easily. I tested it with a 9V battery and it spun right up so I’m hopeful it’ll do well with more juice on tap.

I’m not getting much done lately. I think it’s because I’m to the point where I could do a lot. Previously I was always waiting on parts (motor before motor installation…) Now I almost have everything so I’m undecided on making the cables or finishing the battery racks or setting up the controller wiring or finishing the vacuum pump wiring, finding a motor for the power steering pump, etc.

So I’m making a list, somewhat flow chart to figure out logically what should be done before everything else. Here are some of the items I’m trying to work in.

• Complete the motor mounts, then design a battery rack for the top of the motor
• Complete the front battery rack that incorporates a mount for the power steering motor
• Measure amp draw from headlights, wipers, etc. to size DC-DC convertor
• Finalize battery layout to determine cable lengths, cut and crimp

Hopefully the mounts will be completed this weekend.  My wife had a good idea for a brace that would encircle the motor – a clamp like those used on hoses, just much bigger.  After a little looking there is a company that allows you to design a clamp any size needed.  If I use the company and it works out I’ll post more info on that.