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Discussion Starter #1
I feel like this topic needs a thread of its own. I have seen some safety problems, have experienced some of my own, and have heard of other possible issues. I will add more as time goes on, but these are my initial thoughts.

The LTO packs, consisting of 2 subpacks in standard configuration, contain a very large amount of stored chemical energy - when in 3 pack configuration, about 3 times a standard Insight pack. This is why we love them, but it does present significant safety risks both to the hardware and to personnel. When charged to the specified 2.7V/cell, each pack stores just under 20Ahr of capacity at 60.8V terminal voltage, or if three cells are connected nearly 20Ahr at up to 180V. This is a serious amount of energy, and quite dangerous, possibly fatally, if mishandled. Also very significant, these conversions do not have the level of safety engineering built into them that standard IMA pack has. A lot more high voltage points are exposed or nearly exposed, so the safety risk of these conversions is significantly higher than the standard IMA pack!

Don't be careless and/or cavalier. These conversions can kill you! If you aren't entirely comfortable working with high voltage, high current electrical stuff, then don't attempt these conversions. Neither I nor the site owners are responsible for any consequences of making or attempting one of these conversions. This list is offered as information only and no claim is made that it is adequate to protect either you or your car.

1. Covers. Always keep the covers installed unless you have good and immediate need to uncover them, such as segment testing or charging/discharging.
2. Interconnection strap. Always remove the interconnection strap between the two subpacks for storage or prototype work. Leave the strap off until you are satisfied that your configuration/conversion is safe. Following this precaution creates a mid pack switch much like the switch in the standard NiMH pack.
3. Terminal Spacers. Always remove the thick terminal spacers BEFORE removing the plastic covers. The spacers can easily slip out of place and short two cells together through the tap links. This will instantly blow out a tap link. The damage isn't too serious unless you intend to fit a battery balancing BCM system, such as the Orion, at some point.
4. Manual Voltage Balancing. You may want to manually balance all the cells to within a millivolt or two for manual monitoring purposes. This can be accomplished with a pair of jumper wires IF the difference is just a few millivolts. BUT, this is possible only between two different subpacks. If you try this within the same subpack, you will create a short, lots of sparks and likely damage to you pack or hurt yourself.
5. Weight. The packs weigh approximately 30 pounds each and have very little purchase to grab. This is enough weight to easily break a foot if you drop a pack. Make sure you have a good grip before you lift a pack. Make sure you know where your next support point is, such as a work bench.
6. Wiring. Don't try to connect too much stuff at one time, and don't leave unnecessary stuff hooked up. Every wire connected represents a small risk of getting it wrong. Keep the interconnection strap and the junction board switch off until you are thoroughly satisfied that your circuit is complete and correct. USE A VOLTMETER to verify that everything is working correctly and connections are correct.
7. Secure attachment. Because of the high amount of energy and high potential of accident, the packs need to be securely attached to the car unit body. I have suggested a bolt attached mounting plate or frame for this purpose, though that may also be inadequate in some collisions. Envision a frontal collision with 90 pounds of very high energy batteries unattached to anything stable. That much mass might not even be contained by a closed IPU cover. Certainly it has potential to short and burn your car to the ground. You might also be held liable for any injury to emergency personnel.
8. Configuration of center pack switch. I highly recommend that one retain the junction board on/off switch near the electrical center of the series chain of subpacks/cells. This is a strong safety measure. It is true that the switch can be installed at one electrical end of the pack, but this presents needless safety risks and doesn't really allow a semi-safe shutoff of the pack.
9. Tools. Make sure that your screwdrivers and wrenches don't create unintentional shorts or conduction paths. If you create a contact weld, there is enough energy of burn through a small wrench, or at least create so much heat that the tool can't be touched. Fires could result. Insulating your tools helps reduce this risk somewhat. Plastic tools are even safer if they can be found.
10. Safety gloves. It is a good idea to wear electrical insulating safety gloves as the pack is fully connected. In particular, be aware of standing on moist footing while working with a fully connected pack. There is a safety note on the standard pack which says that potentially fatal injury can result from handling that pack. The precaution applies doubly so to these LTO conversion packs.

This list is probably incomplete. These precautions are important, but DO NOT let this list serve as a substitute for electrical understanding and common sense. It is entirely possible that this pack can kill you if treated carelessly. It is also possible that you can create conditions which would set your on fire.
 

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I think 'Lithium safety precautions' would be a good title.
That covers all then.

Timely advice..
 

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Discussion Starter #3
I would be willing to have it adapted by some knowledgable individual to be more general, but the first 5 items are specific to the LTO packs. I'm not smart enought on the other chemistries like the A123. Won't every cell type have somewhat specific cautionary notes? For example, for A123 pouches, there is a risk of allowing tabs to touch various grounds and shorts like the containment rack. I have no pride of authorship. Certainly don't mind someone taking it and using it for other purposes.

I'm a bit surprised that we haven't seen more conversions using the A123 pouches. There certainly was a bunch of them in the U.S. a few years back. From Ian's work, we know that a large portion of the cells are still usable. Maybe Ian has all the U.S. supply stashed in his basement;)
 

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I getting ready to open up my batteries and start removing the circuit boards and testing doing an initial voltage check on each cell, but just wanted to be clear on the safety and terminology. What are the terminal spacers? And I'm guessing the interconnection strap is the metal bar that connects each sub-pack?
 

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I getting ready to open up my batteries and start removing the circuit boards and testing doing an initial voltage check on each cell, but just wanted to be clear on the safety and terminology. What are the terminal spacers? And I'm guessing the interconnection strap is the metal bar that connects each sub-pack?
Yes it's the metal busbar that connects the 2 12 cell packs. It'll take the pack from 1 60ish volt pack depending on charge level to 2 29ish volt packs. Generally, unless you have wet hands or something else abnormal it helps you get out of electrocution range, down into the burn range on a short.

As always when loosening a bar that can swing don't remove one side then the other allowing the swing. loosen but don't remove each side and then when loose removed each side so it can't swing.
 

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Discussion Starter #6
Caution: Always fish out the aluminum spacers at the 12cell terminals BEFORE removing the covers. As noted above, they can slip off their little platform while removing the covers and short to an adjacent fuseible link. If they do that, they will blow the fusible link to one of your tap screws. Only seldom can the damage be repaired, so you don't want to take the needless chance.

You can use a small pick or any sharp instrument to snag the spacer and fish it out before removing the cover.
 

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Before or after the nap?
 

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Oh, I see what is meant by terminal spacers.

So I unscrewed the small screws that attached the BMS board, but that wouldn't release it from the module. I took off the black screws thinking that would work, but it still seems stuck. Do I need to remove all the cell screws to remove the BMS board? Or is there a place to gently pry and release it?
 

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Discussion Starter #11 (Edited)
Oh, I see what is meant by terminal spacers.

So I unscrewed the small screws that attached the BMS board, but that wouldn't release it from the module. I took off the black screws thinking that would work, but it still seems stuck. Do I need to remove all the cell screws to remove the BMS board? Or is there a place to gently pry and release it?
All the stainless screws and ALL the black screws must be removed to get the BMS boards free. Sometimes a board does seem to stick a bit, but make sure All screws are out before prying slightly.

If your packs came with the CAN ID written on the covers, then make sure you write that ID on the board somewhere before it gets separated from the battery half.
 

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Oh, I see what is meant by terminal spacers.

So I unscrewed the small screws that attached the BMS board, but that wouldn't release it from the module. I took off the black screws thinking that would work, but it still seems stuck. Do I need to remove all the cell screws to remove the BMS board? Or is there a place to gently pry and release it?
You actually don't need to do the little screws, just all the black screws and all the cell screws.

You won't need the black screws since you're not using the BMS but you'll obviously need all the stainless cell screws for your balance leads. Since you're not rewiring anything the plastic tray can stay on nothing of note under that unless you were going to rewire.
 

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Discussion Starter #13
You actually don't need to do the little screws, just all the black screws and all the cell screws.
Correct. The smaller screws which go through the PC board don't have to be removed. I've done so many I don't pay much attention any more :oops:
 

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You actually don't need to do the little screws, just all the black screws and all the cell screws.

You won't need the black screws since you're not using the BMS but you'll obviously need all the stainless cell screws for your balance leads. Since you're not rewiring anything the plastic tray can stay on nothing of note under that unless you were going to rewire.
Yeah, I eventually figured out those small screws could stay in. I've gone through 4 modules and on my 8th sub-module, there was an odd green extra harness attached to the the BMS and battery. Any idea on if this is normal. I'll upload a couple pics...

85898

85899

85900
 

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the green connector and the short gold-colored compound wire was used to monitor the battery temperature in the OE configuration. At the end of the wire is a temp sensor.
 

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Discussion Starter #17
Well, I blew a fuseable link early in the game while taking off a cover. At least one other owner has done the same. If you are unlucky, the spacer, which is held in position by the opening in the cover, can slip is such a way as to short the end terminal bus to an adjacent fuseable link. If one is going to remover covers, the entire risk can be avoided by simply lifting the terminal spacers out of the covers. I guess one could reinstall the terminal bolts, but most of them have to come out anyway to get the covers off. Once all the terminal bolts are removed then removing the spacers only takes seconds. The spacers are of 3 different heights. They fit flush with the cover opening, so it is easy to keep them straight. On most packs, there is one spacer which is quite long and sticks out above the cover.
 
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