[lordmundi]

Father-son Porsche 924S EV Conversion Part 12 - Getting ready for a real battery!

This video was filmed well before our last video was released so the knowledge we have gained since then doesn't show up in the video. But, the latest theory on the transmission noise from the last video is that running it without axles will vibrate/rattle and isn't really advised. In this video we prepare our space to receive our Chevy Volt battery that we purchased and also wire up a few other odds and ends. Also, you get to see our cool ESP32 widget intro animation!

 

[lordmundi]

Father-son Porsche 924S EV Conversion Part 13 - Our Chevy Volt battery arrives!

This video was filmed as we took our first look at the Chevy Volt battery we purchased. The good news? The battery appears to be healthy (and this is somewhat expected since the Chevy Volt packs are known to be very well taken care of and not charged or discharged to extremes). Onward with our new battery!

 

[remy_martian]

That's a live, open HV battery pack.

Nitrile gloves can have pinholes and wearing shorts and shortsleeve shirts (I assume your clothing is 100% cotton - if not, it will melt and stick to your skin, transferring latent heat to a burn) in the event of an arcflash, is a bad idea.

You got away with it, but if the next person who watched your video doesn't, the lawyers could come knocking.

That pack can still be deadly with the contactors off, so make sure younger kids or your son's friends can't get near it. Surprising they didn't ship with the cover over the battery, as it risks shipping handlers.

Also get yourself a clipon meter lead - very very bad idea to bridge your arms across a high voltage you're measuring. Only one hand should ever touch a live circuit or power source, NEVER both. You're again demonstrating this to anyone that views your video....people with no technical clue want shortcuts to not paying $5/gallon for fuel and that means copying what they see in Youtube videos.

Sorry to be a nanny in all this, but it seems like you don't know this stuff.

 

[Zieg]

Good stuff. 3.9v seems just a bit high for long term storage FYI, so if you figure it's going to be a while you might want to let them run down a bit closer to 3.7 during testing. I couldn't really find an exact recommended storage voltage for this exact battery, but that seems to be a reasonably safe number. Are you planning to do water cooling? Via the OEM radiator or something smaller?

 

[lordmundi]

Good stuff. 3.9v seems just a bit high for long term storage FYI, so if you figure it's going to be a while you might want to let them run down a bit closer to 3.7 during testing. I couldn't really find an exact recommended storage voltage for this exact battery, but that seems to be a reasonably safe number. Are you planning to do water cooling? Via the OEM radiator or something smaller?

so, we haven't done anything yet on that front, but the expectation is that we will use the existing cooling solution and add a pump and then eventually figure out how to control the built-in heater.

 

[lordmundi]

Father-son Porsche 924S EV Conversion Part 14 - Thunderstruck MCU and BMS

Now that we have our battery pack in the shop, the next step is to get all of the BMS wired up and the BMS controller and charger all integrated into our testbed. We're learning! And Charlie is learning to solder and crimp.

 

[lordmundi]

Father-son Porsche 924S EV Conversion - Part 15 - Mount Options for Bosch Pump

Just a quick video of a side topic about how we can mount our Bosch coolant pump but use something a little better-looking than a metal strap. These aluminum mounts are super cool, but all of them are too big. I decided to 3d print a spacer to fill the gap and it came out ok. Here is the Bosch pump we are using: https://www.amazon.com/gp/product/B0049PLFGK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

And I've went through comments and ordered parts that people have suggested. I don't know if ours is just different than the others or what, but at least one commenter had the same experience as me, where I eventually found a plug that is close to the correct size, but I have to cut away the plastic on one side.

 

[lordmundi]

Father-son Porsche 924S EV Conversion Part 16 - BMS Wiring Complete

That's a ton of wires! But all of the BMS wires we need for our Chevy Volt Gen 2 battery pack are now in place and tested and everything appears to be working with our Thunderstruck MCU.

In our next video I'll go through the details on the contactor/relay assembly and how we are able to drive the various contactors. But if you are looking for the two Mouser part numbers for those two connectors that have the signals going into and out of the Chevy Volt Gen 2 module, they are at the end of this video.

 

[Zieg]

Hmm, one thought about the fuse.. That front module is 24s which is one satellite's worth of cells, so if you put it between there and the rest of the pack, you would still have the ability to pull it and make the pack voltage slightly lower for safety's sake, without blowing the bms (I think).

 

[lordmundi]

Hmm, one thought about the fuse.. That front module is 24s which is one satellite's worth of cells, so if you put it between there and the rest of the pack, you would still have the ability to pull it and make the pack voltage slightly lower for safety's sake, without blowing the bms (I think).

You and I think alike. That is exactly where we currently have it. The videos aren't fully caught up to where we are at the moment. But that is exactly where we moved the fuse to. Really appreciate the input!

 

[lordmundi]

Father-son Porsche 924S EV Conversion - Part 17 - Chevy Volt Gen 2 Contactors

Now that we have a battery that we can use and monitor with the BMS, we need to figure out if we can reuse the nice contactors that the Chevy Volt provides in its relay module. One really great thing about them is that they are serviceable!

Quick aside, if you haven't watched the complete teardown and rebuild of the Chevy Volt Gen 2 "Battery Relay Assembly" done by WeberAuto, you should definitely, absolutely, check it out. You can see it starting around the 1:25:00 timestamp in their "2018 Chevrolet Volt Battery Deep Dive" video on Youtube.

In this video I want to explore what happens when we provide 12V to the pins for the contactors and the precharge resistor relay to make sure I understand what is going on before we attempt to use them. I'm hoping this might help someone else that wants to investigate reusing this Battery Relay Assembly from the Volt.

 

[Functional Artist]

Your guys progress is looking pretty good
&
a big SHOUT OUT to Jr
...great job dude!

Maybe could you guys post some nice clear pics of the service manual pages, that you discuss in the videos?

Suggestion: (extra credit)
Make copies of some of them pages
...so, you can write notes, draw on them &/or even highlight the relevant passages
...& on the diagrams too (while preserving the original)
...& then, using them in future posts & videos to help illustrate & explain what's going on

Doing it this way, gives current & future readers more info that's clearer & easier to understand

Also,
I have found that on an extended project (like a complicated EV conversion)
...or after doing several projects, it's very convenient to be able go back & re-read your (own) posts
...& re-remember (or refresh) your memory as to how &/or why you did something

&
Even years later, for maintenance &/or troubleshooting issues

 

[lordmundi]

so, you can write notes, draw on them &/or even highlight the relevant passages

yep... we've been doing that from early on. That binder you see me picking up isn't the service manual for the Volt... it is our "Service Manual". My son made the cover art for it. And inside we print out the user manual for each thing we are using and for these Volt components we just print out the pages we are using from the service manual because it is huge. And we write in it, highlight stuff, note the wire colors we are using, etc. I'm hopeful that these videos and his service manual will be something he can look at fondly (and with utility!) long after I'm gone.