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Discussion Starter · #1 ·
today I officially started the conversion of my 1962 Corvette on a tube chassis with C5 suspension. For the planning details see my introduction thread here

The introduction post pretty much lays out the plans and configurations so I wont repeat those in the first post but I will bring each portion up to date and fill in details here as it is built.

first off is the battery conversion from 3P to 2P. I pulled apart the first module by using a chisel to cut the battery tab spot welds away from the bus bars. this confirmed the construction was as I had imagined as well as demonstrates the way to move forward. The tabs are also welded to each other, but I do not have to separate the tabs on side opposite the terminals since they are common polarity. I will have to separate those on the other side as well as flip one of the battery packs to make the polarity common. the sketch below shows the configuration of the 6 cell (in 3 housings) groups. I was able to separate the tabs by cutting the tabs right at the weld line. this leaves enough of the tab for several reassembly methods I am considering.

initial volt measurement shows these cells are fully charged so i am being careful to avoid any unwanted connections. the +/- cell arrangement in the single plastic housing has presented a special handling challenge so i am working on a way to separate these in the initial tab removal from the bus bars.
 

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first off is the battery conversion from 3P to 2P. I pulled apart the first module by using a chisel to cut the battery tab spot welds away from the bus bars. this confirmed the construction was as I had imagined as well as demonstrates the way to move forward. The tabs are also welded to each other, but I do not have to separate the tabs on side opposite the terminals since they are common polarity. I will have to separate those on the other side as well as flip one of the battery packs to make the polarity common. the sketch below shows the configuration of the 6 cell (in 3 housings) groups. I was able to separate the tabs by cutting the tabs right at the weld line. this leaves enough of the tab for several reassembly methods I am considering.
I trust that your planned connection method will work, but it would have been nice to save more of those tabs, perhaps by punching out the welded spots instead of cutting off much of the tab.
 

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Discussion Starter · #3 ·
thanx Brian, the negative tabs are line welded and the positive ones are spot welded, so there is not much left if you take out the weld. they come off the bus bars pretty clean by being patient and careful, and making sure the chisel is sharp, but where 2 tabs are welded over top each other, they rip when I try to separate them, and I do not want to stress the tab to pouch side. on these two cases by cutting it right at the weld, I conserve the most possible, there is only about 1/8-1/4 beyond the weld. I only have to do this for the 2 tabs in the plus/minus combined pair, in all other cases I conserve the entire tab.
 

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Discussion Starter · #4 ·
pulled the 62 out from under the router where it has been stored since July 2012. I hope to get this into the working side of the shop and do some scans, although I haven't worked out the logistics of the scanning. If I cant beg, borrow or rent one, I may see if I can do it with share ware and multiple pictures.
 

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Discussion Starter · #5 ·
I got a little free time tonight so i started on the second battery. I don't have the method down perfectly for breaking the spot welds on the tabs, some pop right off, and others are fighting for every fraction. once each section is finished I remove the bus, this disconnects the groups so the other side is easier. I was clamping the battery but the plastic that the bus bars are riveted to started to move, I put it up on end and that solves the issue and makes the whole thing more stable. just for reference, this is about an hour of work.
 

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Discussion Starter · #6 ·
more work on battery disassembly. I finished the 2nd and got half way through the 3rd. I also removed the stock batteries from the bench as I want to put all the disassembled parts there. I moved my grinder next to my chair so I can sharpen often. While giving my fingers a break from the chisel, I slipped a putty knife in between one of the pouch batteries in a plus/minus frame. I get 5 of these per battery so I need to figure out how to separate one battery and flip it. I shot alcohol into the gap of the putty knife to see if it would loosen up, it did not. I can't tell from the Munro video how the batteries are held in but you can see some residue on the plate on the one they did take apart. I will have 9 spare 2 pouch frames when all is done, so I think the next step is to cut the side off the frame to see if there are mechanical tabs or if it is just adhesive.
 

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Discussion Starter · #7 · (Edited)
I did manage to get one of the cells removed. turns out the alcohol was effective on the suspected glue joint. Confirmed it is a simple rectangle of green colored glue and no thermal paste or putty. I tried a couple different solvents other than alcohol, since the alcohol is only marginally effective. So far the best has been acetone. I continued disassembling and now have 4 batteries broken down into 3 pair sets. I have some googone ordered so I will try that as well. My hope is I can dissolve the glue enough that removal does not require any prying, which I did have to do for this first one. i will segregate this set of batteries as suspect. not sure how the pouch cells react to getting bending or localized compressions.
 

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Discussion Starter · #10 ·
I completed the 6th battery and I am half way finished with the 7th. I had the idea to use stickers to mark the battery polarity, but the stickers didn't show up until this week. I will go back through all of the previous ones and mark them as I separate the groups of 3. in the breaks between hammering to rest my fingers, I am setting up a 3D scan experiment with a place to take multiple angle photos on a part. I used two florescent light reflectors to make a small chamber with a black sheet for a background. I have some LED work lights to set up and I purchased a used but VGC Nikon D5000 DSLR. which I have no idea how to use but will have to learn. this will allow me to take many varied angle pictures of a battery frame and then use some shareware software to combine them into a 3D model. I am hoping this will work. If so, I will use this process to get a 3D model of the engine bay and relevant frame sections of the 62.
 

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Discussion Starter · #11 ·
finished the 7th battery disassembly. In reviewing the fastening torque and the bolt I noticed these are shoulder bolts, so they intentionally are not applying torgued compression to the stack. Before separating these modules completely I removed all of the foam pads to determine the design clearance of the four shoulder bolts. with the foam removed I clamped the stack tight to find that there is .12"-.13" clearance. when I reformat these to 24 modules, I will design with a similar clearance extrapolated for 24 instead of 15. I also cleaned the thermal putty strips and removed them, saving them in a clean container. I am hoping I can figure out a way to reconstitute these and reapply. in any case it is in the way so needed to be removed. I also got my lighting set up for the 3D scan photo setup, but still have not set up the camera for pictures.
 

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Discussion Starter · #14 ·
thanx Remy. it is not soft anymore, I am hoping I can either kneed it, or maybe add something like alcohol to soften it temporarily. I am not sure if it is a two part that already reacted, or if it has cured in some way. I will try, as I know this is an expensive component. I don't hold a lot of hope, but no reason to throw it away without trying. The the the EV Jeep team @D&VsEVJeep have an alternative identified, I will ask again when I get to that point.
 

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Discussion Starter · #17 ·
yes I am! :) the mixed polarity ones are being a real challenge. should have held out for 4P units...... I may have a very slow process figured out, but so far I am 0 for 2
 

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Discussion Starter · #18 ·
so, bad news is the glue used on these battery slices is too aggressive and the battery pouch skin is too fragile for me to remove and flip one pouch on the mixed polarity slices. this is 1/3 of the batteries I have recovered from the 3P Mach-e batteries. the good news is, that I believe I can still use them by cutting two slices in half so that I can put a half slice on each end, this will allow me to use the mixed slices unmolested. In weighing risk reward, this is the best solution for me to use the batteries I have purchased. At this point this is my plan moving forward. I believe all of the other design for the strengthener and terminal ties will be identical, so it isnt that much of a departure. Also this allows for the future expansion to 3P if I end up wanting to go that way after using the car. packs 1 and 2 will be fully unmolested recovered slices, battery 3 will be all but 2, unmolested. I have several with one battery removed, so I will try to buy 2 new pouch cells to complete these, which would also make them unmolested. for the fourth battery I will need to use the half cells at each end and the rest would be the unmolested mixed polarity sets. I think this plan is going to be best. I will not be building these for quite a while, so if I find some more mach-e batteries for sale before I build I may just take the hit and buy enough to complete the 4 set. not what I had planned, but I will make it work.
 

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Discussion Starter · #20 ·
today I mocked up a 24 cell battery layout. I drilled the end plate and tapped it to 5/16-24NF. then after stacking 24 slices I added the opposite end plate and 4 threaded rods. I clamped the stack together and using low profile nyloc nuts I set the clearance to ~.19". this is calculated from the measurement I took on the shoulder bolts for the 15 slice stack. (.12/15)X24=.192. I plan to weld these nuts in place and cut the threaded rod flush. I am either going to add a stop on the other side or just turn the rosd in so that the end is flush to set the final height at assembly.

one thing maybe the EE's out there can answer. As I look at each feature of the assembly, I see they are taking great pains to prevent any metal from touching the plastic on the individual battery carriers and the heat sink tab on the bottom of the carriers. the shoulder bolt diameter is cleared by a good distance. I think I will grind the inner portion of these threaded rods and also maybe add shrink wrap so it is insulated from the plastic of the carriers. is this to prevent any type of voltage loss? is it feasible that there would be losses through the plastic or if the heatsinks touch metal?
 

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