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Smart EV battery test units ready to go

20K views 56 replies 16 participants last post by  MrCaspan 
Odyssey on the other thread says that these will definitely not work on the 453 EDs, so these are 451 only per the expert.

Here's a couple of photos of the complete units. They include everything you should need except for a laptop with a USB port and some kind of serial terminal program (available for free for every platform out there).

The black cable is J1962 ("OBD2") on one end and a DB9 ("9 pin") connector on the other end and plugs from the car's OBD2 port near the driver's right knee into the 9-pin connector on the top of the side.

The blue cable is USB-A on one end and USB-B on the other end and plugs between the computer's standard USB port ("USB-A") and the USB-B connector on the bottom left. The other circular connector is not used and not needed in this application.

You need a laptop with a standard USB port and everything should just work on either Mac, Windows, or Linux with whatever serial port program you want to use on your platform.

I figured the EDs are green, so the cases are 3D printed in a translucent green ABS. My 3D printer is a hobby grade printer. The cases are fully functional, but no one will mistake them for a commercially produced injection molded polyethylene case.

Contact my dad (@sokoloff on the forum) for more information or to order one.
 

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would love to buy one, would also love to expand to a display in real time in the car.
Built into the unit is the ability to periodically log output to the serial port (at a user-defined interval).

As an example:
Code:
log on 10
will configure the device to emit a log message every 10 seconds to the serial port.

Full documentation on the command line is here:
https://github.com/MyLab-odyssey/ED_BMSdiag/wiki/Command-Line-Interface

If you want to display on a nice little device in the car, you're into a project of some sort. I'd look towards perhaps using a phone and an app (and buying a BLE or wifi CAN dongle) or look to what some of the other EV projects that use OLED displays. I'd love to think along on such a project, but realistically, I'm not likely to find much time to dedicate to it.

LeafDD is one example I'd look towards (OLED display).
LeafSpy is another (Android phone; I wasn't able to get it to work, but I think I bought perhaps two different counterfeit ELM327s)
LeafSOC is another (uses a mobile phone LCD in a custom circuit/enclosure)
 
Also, is the firmware in them re-flashable via the usual equipment for Arduinos or the like?
Yes, it can be flashed/re-flashed using the Arduino IDE.

Odyssey's original writeup on Hackster (detailing how to build it yourself, if you're so inclined) is here.

I found the code easy to understand and modify. If you have Arduino electronics / programming skills, it's a quite simple project to DIY.
 
Thanks. I have a USB tiny, and my experience is limited to only re flashing my Arduino-based devices OpenEVSE charging station and an electric motor scooter). But I certainly have electronic soldering experience and I can always learn the software end. Maybe I'll give it a shot.
Definitely do! Lots of people can lend a hand if you get stuck, including me.

If you don't have the desire (or time) to learn about Arduino and CAN and just want the task accomplished, you can also buy them pre-assembled, so anyone has a workable path.
 
Any chance that you or your son can simply provide the .hex file and an AVRDUDE command batch file (which I can edit for the specific loading gadget and Atmel chip if needed) for flashing it?

That stuff about setting the "fuses" and the processor being permanently ruined if you mess up always sounded scary to me. You can PM me.
I would if I could, but I can't, so I won't.

If you're building on an Arduino, use the Arduino IDE (which is free as in beer)

Grab the code: mine from here (which has links to the original as well)

Connect the Arduino to your computer, select the board, open the sketch you downloaded in the previous step, and press "Upload". The IDE manages all the behind the scenes grunge (compile, package, upload, fuses, etc).

I would give you the .hex file if the Arduino IDE left it lying around, but it doesn't seem to. The IDE really is the way to get started I think. It's designed to make things easy and safe, and part of the Arduino brilliance was to make the bootloader on the chip such that it was easy to use from an IDE. Though I own some of the various physical programming devices, I've literally never used them. I just use the Arduino software IDE.

I'll help in any way I reasonably can to have other people get this working if they want to DIY. Please try the Arduino IDE first.

Even without owning the Arduino and CAN shield physical hardware, you can grab the code and IDE and make sure you can compile the code. If you get to that point and your computer has a USB port, you can be pretty certain that getting it onto the Arduino will be a yummy piece of cake.
 
Sorry for an additional post, but just for clarity on the above: you can program the Arduino using ONLY the USB port and the free Arduino software; you don't need any other equipment or software.

(There are valid reasons to want to use AVRDUDE or other programmers for other projects, but to get your feet wet and for this project to work, none of those are necessary or desirable. You will know when or if your advanced project needs more than the Arduino software; for this project, it doesn't.)
 
One important question (I think I already know the answer?)

would it be possible to read the diagnostics on an iPad (air) by running from the USB on the unit to the lightning USB on the iPad? (probably not, but thought I'd ask)
I have been thinking about this all morning and I don't think there's any way to do that.
Otherwise I have to get a (cheap) laptop just for this unit?
That does seem like a bit of a waste; if it's just something you'll do a few times a year, maybe you can park close enough to a desktop PC somewhere (or move a PC to the garage temporarily) or borrow a laptop?

If I come up with any better idea, I'll be sure to let you know, but this project kind of assumes the existence of a laptop or a garage PC.
 
I have a 2014 ED Coupe. That's a 451, right?
Yes.
Do you have any more battery test units available? I would like to order one.

I have been looking at a couple of posts. Does this unit work with a phone app?
It's designed to work with a laptop. I'm thinking about how to make a different product that would work with phones (either Bluetooth or wifi), but that's far enough away, it's over the horizon and would require different hardware.

I have another batch of 5 ready to send down to @sokoloff for testing, so if you can use a laptop, one those would work for you.
 
I'd like to buy one unit for a 451 ED3 please.
Hi Marginal,
Be happy to provide one, but the shipping costs, import duties, and time to Europe might be higher than you'd prefer.
There's another guy who sells them in Europe that you might also consider for faster delivery: https://www.eqpassion.de/shop/product/1-battery-tool/

If you'd rather wait for one from the US for whatever reason, I can look into shipping, but I'd need you to be on the hook for anything import/VAT/other European stuff that I know nothing about.
 
If you get close the point of making a deal, it's easy enough to trigger the test:
Run the car down to 35% state of charge.
Turn it off.
Let it sit for 2h15m or more (I think the threshold is 2 hours, but it's better to go a little long than be too short).
Charge it all the way up to 100% (and ideally, leave it on the charger for a couple hours past that for an unrelated reason).
Do the test. It should report "0 days since last measurement"

In addition to the great explanatory content above, one of the other measures that I look at is the delta-V, which is the millivolt difference between the highest and lowest reading cell. At/under 25mV is excellent. Under 40mV is perfectly acceptable. If a car has been sitting a long time and not exercised or never allowed to stay on the charger past 100%, I wouldn't worry much about a delta-V (dV in the report) reading of even a little over 50mV as it will likely come down as you use the car and let the car top-balance the battery cells.

These cars give excellent service from the batteries, owing to sensible engineering and keeping them cool in operation. You're not looking for "tiny cracks" in a used car purchase, but rather looking to verify that this battery is not a grossly negative outlier/lemon.
 
@jimsokoloff New here, but i put your tool together and used it on a 2015/2016 Smart and i ran the battery down to 0% and then charger it all weekend. Test says 0 days since test but comes back with a bad reliability score? Any idea what thats about? 0.676....

Happy to run the test again, just want to get a good result that's trust worthy?
That comes straight from the BMS, which is doing some kind of coulomb counting as it charges the battery and, for whatever reason, it doesn't have a high precision estimate of the capacity.

In your shoes, I'd use the car normally and give it some further moderately deep discharge/charge cycles and leave it on the charger to and past 100% (to allow the BMS to top-balance the individual cells).

If this car is new to you or had seen a period of dis-use, I could see the estimate having a high uncertainty and hopefully that will correct itself.
 
Just FYI I decided to go with the Nissan Leaf, will your tester work for other EDs?
The hardware would work on other EVs, but the software does not.

I can highly recommend "Leaf Spy" (or Leaf Spy Pro) for your new car. (My daily driver is a Leaf.)
If not if any one is in Canada I'll ship you the device for 50% the price :)
That's a good offer; USPS charges a lot to ship to Canada, so hopefully a Canadian member can make use of this. If any future inquiries come in from Canada, I'll try to send them your way first before sending USPS another $30. :D
 
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