Another Chevy Volt Lithium thread

If repinning JST-XH 9p connectors. No special tool is needed.
A pocket screwdriver will push down the metal release.
Look at the release before inserting. Pry it up slightly with a razor blade. Tug to see if it locks.
The larger atx connectors are near impossible, even with tool. IMO

Made a little progress. It’s been stupid hot here, and my shop is an uninsulated metal building (AKA oven), so I’ve only been working for a couple hours in the evening.

Warning: Some (a lot?) of this stuff is dangerous, I’m not the smartest man in the world, so hopefully if I say or do something stupid, someone smarter than me will correct me and we can all learn from it… but if they don’t, and you die, tell your widow ahead of time it wasn’t my fault. I also don’t know how this differs from other models of gem car. Also a lot of these pictures are “mid process”, and may not be finalized, use common sense where applicable.

Started by cutting the battery liquid cooling channels off. I made a mistake on the first one, and didn’t drill the rod support channels before cutting the old ones off. I also got a little crazy with the cheese whiz and cut too far into the case. fortunately, didn’t get too close to the lithium cells, but that was stupid.

Oops… too close. Don’t be stupid like me. Cut it a little wide, and keep your insurance agent happy.

Doing it right this time. I drilled 2 new holes at the bottom to support the battery pack. I used a 3/16 12" drill bit from Home depot. My drill press only has a 4" throw, so I measured from a reference point on both sides of the pack, and drilled 4" on each side, and then drilled by hand to meet in the middle (the pack is just under 10" if I remember right). By drilling from both sides, you also help eliminate the risk of your bit wandering and getting way off course. any misalignment will probably get pulled towards the center where your two holes meet (as long as you’re not way off). The case is also not solid plastic, so the walls around where I drilled, help keep things aligned as well.

After drilling from both sides in my drill press, I finished the middle by hand. everything lined up great.

I also drilled through the little hooks/supports on the side, which I intentionally didn’t cut off during the sawzall phase, since I thought the battery pack could use some support in the center. Again 3/16" was perfect.

I used a partially extended box cutter blade to clean out the shavings which were stick in between the case pieces.

Destroyer of worlds.

Much better this time. It’s a little wider, but the only place this pack wouldn’t easily fit is the #6 battery spot in the front, and I think with some creative massaging, it would have fit there. The one I cut “too close” fit in the #6 spot fine.

I installed the voltage spoofer from @Inwo. The connector was very easy to disassemble, and insert his spoofer in line. Just needed a screwdriver, no special tools. Once you remove the connector from the controller, you can use the screwdriver, to release some tabs to pull the red portion away from the connector, which allows you to pull the number 1 wire out, and replace it with the voltage spoof. The wire numbers are labelled on the connector. #1 is upper left.

Voltage spoof in place

Since I got worried about front suspension ride comfort, I tried putting both batteries up front. To do that, I ran a new cable (5ft long, 1 gauge) from the front, for the B- to the controller. (seen above). My local auto parts store had a proper crimper for putting the terminal on it, and they crimped it for me (no charge, other than materials). I then repurposed the original “B4 to B5” cable and the “B1 to controller” cable that runs from under the seat, and used those to put the disconnect inline without having to move the disconnect (at least for my test - I wasn’t sure if that would be smart long term since it was such a long run? Any thoughts from smarter people?). I used the original “B6 to Fuse” cable for B+. This all worked, but it was very tight, and I wasn’t overly happy with the way the B+ cable/terminal was basically touching the firewall. It was protected by rubber, but I didn’t like it, and wanted a better solution if I were to keep it long term. There may have been enough slack to pull some of that cable through to the front, but still would have been tight. Same with the “B4 to B5” cable. But it doesn’t matter, because after my test ride, I realized those two lighter batteries didn’t provide the right comfort I wanted, and would need to either add ballast or change suspension (like everyone else said before me… duh… Maybe I should have listened?). With the two batteries up front, it was close, but not quite what I wanted.

BUT! BOY HOWDY WAS IT FAST! And it turned like a dream. It was like a whole new car. In all fairness my old batteries were pretty worn out. but wow. Batteries came to me well balanced at 94v (total). The voltage spoof worked great. Nothing exploded.

I moved the batteries under the seat, which seems like a better fit, and also allows me to add another 2 batteries if I decide to do that, without having to get funky with the BMS wiring harness. No pictures of new battery location.

Next thing to figure out was how to mount the new Delta Q Charger. It was a lot wider and taller than my Quickcharge. It’s also a LOT lighter, and it’s not as deep. The width was the main problem, which means there is very little clearance between the controller on one side, and the main contactor, and the DC/DC converter on the other. There’s roughly 3/8" on each side clearance. I also had to offset it from the mounting place with some 1" spacers.

The existing bolts weren’t long enough, so I had to remove them. Easy enough right? I’m not sure if all cars are this way, or if my car was assembled on a friday at 4:30, but the bolts on the aluminum plate wouldn’t be removed without unmounting the aluminum plate. I left one of the self tapping screws in (upper left corner, attached to controller), and removed the other self tappers. I hate removing and re using self tappers, especially in soft metal like aluminum. So be careful with this, and don’t over tighten when you put it back together. I used supported the DC/DC converter end with a 2x4 to keep the whole thing from dropping and and breaking wires, etc.

2.5" grade 8 1/4" bolts installed in the bottom two existing holes, which 1" spacers. (I had to hog it out a little since I think it was a metric, or maybe machine screw size). I had to drill a new 1/4" hole in the DQ Charger to fit the existing holes in the gem car plate. I also drilled two new holes in the top of the Gem car plate. It barely fits without having to drill into the support frame behind the plate (which I didn’t want to do), but it does work. I had to cut away the plastic and rubber dust guard behind the gem car plate just a little bit to fit the nut for the bolts.

Installed and happy. The DQ is very light compared to Quickcharge, so I don’t think the 1" spacers will be a problem at all.

Clearances. My hope is that because the Charger won’t be getting used/hot at the same time as the controller and DC/DC converter, these tight clearances will be ok. I also have no idea how hot the DQ gets. Any input on that?


That’s where I’m at as of right now. Next I’m going to actually hook up the charger, and test/hookup the BMS. Critique/questions welcome.

The charger needs the white wire connected to B- to charge.
Either directly, or from the bms.
Don’t connect bms until you understand the balance lead order of the 3 plugs.

On a hot summer day in central Texas my DQ gets hot enough while charging my Volt pack that the charger goes into Thermal Protection mode. I plug the charger into a timer INWO suggested so it cycles to charge 30 minutes, then off 20 minutes. Allows DQ cool down so it doesn’t trip. Your DQ mount has the cooling fins stacked vertically and they may not get much air flow for cooling. May or may not be a problem - something to keep an eye on.

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Does anyone have any pictures or suggestions for shunt mount? Should I just zip tie it to the aluminum frame somewhere like in the picture below? There’s no insulation material and no mounting brackets on the shunt.


Also, I need to extend the white wire from @Inwos one wire charger controller from Bms under seat to charger under dash. Can I use 20g wire to extend it?

Thanks!

Yes, any small wire will work.
I mount one end to the b- terminal of volt module. One end support is enough if the cable connecting to it is secure.
Insulated stand-offs work nice. I can find a link.
It must me fully insulated from frame and everything except B-.

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My Delta Q charger has an 8 pin connector. I’ve gathered from @Inwo that the white wire turns the charger on and off, so I’ll be using that, but what do the other wires do? Should I be using any of them, or at least run wire for future applications? For the life of me I can’t find anything explaining it on DQ’s site, their “manuals” read more like sales brochures.

https://www.google.com/url?sa=t&source=web&rct=j&url=http://static1.1.sqspcdn.com/static/f/497536/23990781/1385952140963/QuiQ%2BInstallation%2BManual%2B2011.PDF%3Ftoken%3DXjoIgNtnv8MyNImcpdYSHwU1gGE%3D&ved=2ahUKEwjn1si7l6DcAhUI0oMKHVCxD04QFjABegQIABAB&usg=AOvVaw3os9lUdwL3SZIzvycRySRC

Well, now I feel like a dufus. Thanks again @Inwo

I used a mount similar to this picture Grant sent me, it made from UHMW poly.

image

@Inwo the doc you linked has pin 1 (white wire) as a temp sensor (+). Does your custom bms wire use the temp sensor to shut down the charger?

Do I need a b- wire going into pin 2? Tried plugging into ac for first time and charger showed some led lights I couldn’t catch and then shut off.

With lithium firmware in charger, wht wire becomes “enable”.
Connecting it to B- or temp-, turns on charger.
Wht wire from bms-24 led, controls charger when connected.

Pin 8 is the Gem green interlock wire on the ones I’ve checked. Use with caution. It can blow internal fuse.

So then if I’m not using an interlock, all I need is bms plugged into pin 1 (temp sensor +) on above picture. No need for pin 2?

[quote=“TJelecD, post:31, topic:13973”]edit, read charger manual, and yes it needs a b- connection to pin2. Leaving this here for future reference.
[/quote]

No, pin 2 is B-.
Pin 1 is enable.
Connect 1 to 2 to enable charger.

I thought pin 1 of the charger went to the charge controller port on the bms? Isn’t that what cable #7 is for on my Labeled picture earlier in thread?

Yes.
Or jump 1 and 2 to test charger.
If led from bms is on, it will start charger when plugged in.

Yes, but only through led wire.
If led is lit, charger will function.
Led out inhibits charger.

Ok. Thanks. That solved it. I had it hooked up correctly but the bms was shutting off the charger because I don’t have current sensor setup yet. Jumping pin 1 to 2 on charger turned it on.

It should work without current sensor.
If led is not on, see what setting has it off.
First setting is most important. If any cell is over set point it turns charger off.
Watch cell voltages if bms is not controlling charger.
Easy to damage a cell going over 4.2v.

It definitely wouldn’t turn on the charger when the Current sensor was disconnected. I connected the current sensor tonight, and it worked as expected.

Also, I ran into something that I’m curious about. I have the factory disconnect switch between my two batteries. Tonight, with the BMS connected, after charging the batteries for a little while, I unplugged from the wall, then flipped the battery disconnect switch off, so I could start doing some wiring cleanup under the dash before buttoning everything back up. However, when I checked voltage B- to B+ I was getting 90v! I looked at the BMS, and the only cell that was showing no voltage was the cell that was the one that had been the highest (4.1v, the rest were around 4.0v). I switched the bms from “batt” to “ext”, and was still getting 90v. It wasn’t until I unplugged the BMS wiring harness that I dropped down to 0v B- to B+

So does that mean that the BMS was keeping voltage in the system, so it could discharge the highest voltage cell to try to balance the system? I’m not really sure how the balancing works.

Also, presumably this could be dangerous to people, since you think you’ve disconnected the batteries. Maybe dangerous for the car too, since the controller thinks it has voltage, it would presumably power the motor, but I’m guessing that would likely damage the BMS/wiring?

Very short test drive with everything in place went well. Only drove about 1/2 mile from Shop to house :slight_smile: I’ll take it for another spin tomorrow.