2nd Gen Prius PHEV Conversion (Enginer plug-in lithium ion battery kit)

[Daox]

Originally Posted by Cobb

Have you considering getting a battery pack to put between your porius pack and the enginer system? I had an idea to get another honda pack, hook up the blower to run continious to keep it cool and use a set of diodes to keep power from going into it from the IMA system. This way the PHEV converter has a buffer to help the high drain of ev mode.

Yes, the thought has occured to me. I will likely never bother with it though. All of the places that I can get to while staying in EV mode I can get to as is. Some of them push me to the limie, but the frequency with which I go to those places isn't that often. So, a mod simply wouldn't be worth my time and effort. I think I'd be better off doing some more aeromods or something.

Id contact Enginer if I were you, I heard something about 100 volts and 40 amps earlier today.

I'm not sure what you are talking about.

Maybe as soon as I can post attachments Ill do a post and youtube video of my install?

You should be able to post links and attachments. I believe its just the first 10 posts that are restricted.

[Daox]

I spent a good part of the day today working on the PHEV kit. This time it had nothing to do with electronics or batteries. Today was about mounting the battery box in the trunk.





Previously, I had simply set the box in the back. This presents two problems. First off, in the event of a roll over, that box is free to play pin ball around the cabin which surely isn't good.





Second is what you see above. This is what the box covers up. If I get a flat tire with the box full of batteries and electronics its a huge pain for me to get the box out. If my wife were driving alone I'm sure she wouldn't be able to move it out of the way.

So, I had to think up something, hopefully simple, that might allow me to access the spare tire if the need ever arises. I went through a few fancy ideas that included air cylinders, a hinged system that lifted the box up. But, I finally decided on something very simple and inexpensive which was the goal. There isn't enough room for the box to simply hinge at the back corner and tilt up, the box hits the hybrid battery box which is directly forward of it. So, the box has to move towards the rear of the car while being lifted up to clear everything.





The solution I came up with was fairly simple. Add some wheels to the rear of the box to allow it not only to hinge upward, but also move rearward. So, I ran and got some 4.5" wheels from the lawn mower section of a big box store.





To mount them to the ~16ga box, I decided to weld some threaded rod to some 1/8" plate I had laying about. This will ensure that the weight of the batteries doesn't bend the box where the wheels attach.





Here is the finished assembly. There is one on each rear corner. They stick out from the box about 1/4". They are so far rearward because they have to allow the back corner to articulate without hanging up.





The Last part of the system is the lifting part of things. I think the box weighs around 200 lbs all together with everything in it, so its not light. So, to lift the box I decided for the moment to use some ratchet straps. I attach them to the hinge mounts for the hatch, and the other ends to the rear corners of the box. These allow you to lift each side up a little at a time. Once I actually get all the bits back in the box we'll see how hard it is to ratchet those things and if its too hard I'll probably weld some extensions on the handles to give more leverage. But, with the empty box the ratchet straps work great for lifting the box up and give plenty of room to get at the spare tire and tools.

However, the ratchet straps do have a very annoying flaw. Lowering the box back down is a big pain. You have to let a little slack down on one side, re-lock the ratchet strap, go to the other one, let it slack down, re-lock and back and forth and back and forth. The empty box bumbles around a little bit which isn't too nice like this. My question is, does anyone know if you can get ratchet straps (or something similar) that ratchets in both directions? This would really be ideal.

I'm still working on exactly how I'm going to attach the box to the trunk so it can't move in the event of a roll over. I'll have to find some way to add some weld nuts or something so it can be bolted down. I thought about welding in some angle in the trunk but I'd like it to remain completely removable (and OEM parts go back in) in the event that I want to pull it out for whatever reason.

[Daox]

I did some searching on mcmaster-carr and found these weld nuts. I think this style is low profile enough that it shouldn't interfere with the OEM box that goes back there.

[mrbigh]

Originally Posted by Daox

I did some searching on mcmaster-carr and found these weld nuts. I think this style is low profile enough that it shouldn't interfere with the OEM box that goes back there.

This is a great solution for some type of cargo with much lesser mass. Not to withstand, in the severity of an impact, the freedom movement of a heavy box inside of a moving vehicle.
I will explore more seriously the addition of 2 pieces of angle iron in the cargo area to retain the battery container in one solid location that will be easy to unbolt to gain access to the spare tire.
Personally, I do not care about the doughnut at all, never need it after 125K driving miles.
In the event of a long drive, I do load it behind the driver's seat, in the foot well of the rear passenger as a precaution.

[Daox]

Do you have previous experience that doubts the strength of that type of weld nut? I find it odd that you would say it won't work when I haven't even mentioned the bolt size or how many will be used to hold the box in place.

[mrbigh]

It is not the weld nut by itself, it will be the thin tin were it will be tack to. The material used to build the Prius body it is not of any heavy stock.
I have use these pen nuts in almost the same applications with very poor results.
A length of angle iron bolted through with reinforcement in the underside of the body is a much better option.
I used this method to hold the 240 Lb of extra batteries on the last 2 PHEV conversions and it's rock solid.
I'm including the first photo I could find, but tha same concept of attachment.

[Daox]

I'll take that into consideration. I think I'm still going to use those type of weld nut due to the low profile. Perhaps I'll add an additional thickness of sheet metal between them to reinforce things. However, I'm pretty sure that they will suffice. I just did a quick weighing of the components, and everything together weights about 170 lbs. That is only a bit more than myself, and much larger people are held into the car by only four M8 bolts holding the seats to that same thin tin. I would think that 6-8 bolts will be plenty. We'll see how it looks and feels when I go to install them. If it feels flimsy I'll do something to reinforce it.

[Daox]

I've finished the rest of the cycle testing on the PHEV cells. The results are below. Not a lot has changed since the previous data was shown except that multiple cycles on my strongest cell showed no improvement in capacity.

[Cobb]

Wow.... Yeah, I used the prius 2 box for a while, but found it retained soo much heat since my first install was out in the open. I still have a rather open install and everything runs cool as it can be til the heat hits 100 degrees and you park out in the open.

I think Enginer now has a sheet you can mount the parts to, the spare as well and everything is happy. Ive since done away with my spare, jack, tire iron, top half of back seat and a few other parts.

The cells, are you going to mix the best with the worse? YOu are using 32 cells grouped in groups of 2, right?

[Daox]

Yes, the pack is 16 in series 2 in parallel. I will be pairing the worst cell with the best cell, next worst with next best, so on and so forth. This is the common practice since it gives you the most balanced pack and therefore the most usable capacity.