Fiat 500 Forum banner

500e Pre-Purchase Checklist. 12/5/23 Important Update: Check parked with HVAC off (item 1)

10K views 26 replies 7 participants last post by  Electric Tire Shredder 
#1 · (Edited)
There's no engine, transmission, belts, clutch, fuel pump, injectors, turbo, timing belt/chain, starter or alternator to worry about.

Even the brakes last over 100k miles since they only activate below 7mph because above that it's all "regenerative" motor-braking.

You do want to check some standard things, like tires, lights, wipers, locks, windows, etc. & there are 4 non-standard things to check, all of which are relatively cheap or easy to fix or work around, except this first one:

1) Check for a rare-but-serious weak cell with the free AlfaOBD "demo" app.

READ FOOTNOTE*

Practice at home first, like this (click to enlarge):
Computer Rectangle Screenshot Line Font

Next time you open the app it goes straight to step 6, so when you get to the car just:
  • Turn the key 1 click.
  • Hit the "OFF" button on HVAC.
  • Plug in the reader (socket by the hood release).
  • Connect to your device.
  • Do 6 thru 10 as above.
Then scroll down until you see this, without the blue box I added:
Font Parallel Electric blue Number Circle

Parked unplugged with HVAC off it should be under 10mV difference, all the way down to about 30% charge.

Even better to also check for under 20mV difference at 20% & under 30mV at 10%.

If not, either walk away or try the non-OBD test below, or charge to 100% to activate the "balancing" cycle, & check again. If there's less difference, but still more than 10mV, drive it down to 98% & take it to 100% again.

If it keeps getting better, & a few full charges gets it below 10mV at 30%, it just means the difference was caused by to the prior owner avoiding full charge, not by a weak cell.

If the seller won't let you use OBD:
-Tell them to call you when it's down around half-charge. Then starting at 50% or less, reset a trip gauge (wiper stalk end) & make sure it only drops about 30% in 30 miles.
-That's at moderate temp, city traffic or steady 55mph, HVAC off, & not too many uphills with stops on the way back down cuz there's no regen below 7mph.
-A trip gauge that was reset after any harsh low-efficiency test-driving should be about 4mi/kWh. If it's 10% less due to cold or hills then 10% less miles to drop 30% is okay.

All the rest are usually relatively cheap or easy to fix or work around:

2)
See if it charges from the OEM cord AND a "level 2" unit like on a dealer's wall, or test drive to a public station found on plugshare.com
If not, it's sometimes just a temporary minor glitch**.

Use a $9 Amazon "outlet ground tester" to check any outlets you plan to use but note that an extension cord works: 25' max on 14ga, 50' max on 12ga, 100' max on 10ga. Ideally, replace any original 80-cent "residential grade" outlet with a $3.50 "commercial grade" unit.

3) Get $400 off to cover a dealership copy if it doesn't have 2 keys like it came with originally, that each work in the door slot AND start the car with the other one outside (out of transponder range). Work-around: Get cheap copies, tape the OEM one inside the steering column cover, & use the copies to unlock/drive/lock with the door slot, but note the alarm won't arm. That avoids about $1500+towing by preventing the loss of your only transponder key (click here for explanation).

4) Get $1500 off to cover dealership repair if there's a crack or bent pin in the orange part inside the filler flap. DIY is currently $60, as shown in this Facebook vid (click here) using a slightly different part on eBay:
  1. Click "shop by category"
  2. Under "motors" click "parts & accessories"
  3. Click "car & truck parts & accessories"
  4. Scroll down & click "electric, hybrid & PHEV specific parts"
  5. Type "j1772 socket" in the search field & look for this part:
Camera accessory Auto part Font Gadget Automotive wheel system


* A cheap Bluetooth reader like a Veepeak VP11, or $17 eBay Konnwei KW902 works for this, but if you plan to buy a 500e, they won't prevent stalling (click here & see item 4). Anyway, @Iceman advises against cheapies (post #6 here) AND @fast_dave recommends against wireless (post #2 here)....

So ideally you want a $45 OBDLink.com SX (click here) or $54 EX (incl. 10% off by signing up to free newsletter) & use a laptop or ~$10 OTG adapter in an Android that's been checked with the free "USB OTG Checker" app. Connecting may require selecting "OBDLink USB":
Product Font Screenshot Software Technology

Android above. Windows below.
Product Rectangle Slope Font Parallel


The AlfaOBD app is Android/Windows only, so if you & all your friends only have iPhone/iPad/Mac, you can use a $30 Amazon Android. No service needed, just download the app on Wi-Fi, but before you buy one, if you're using a recommended SX or EX device, check that it's OTG compatible.

**
  • Check the plug & its orange socket for damage & bent or corroded connectors.
  • Deactivate the charge timer in the car’s menu. It can default itself to “active”.
  • Turn the car off for 3 minutes & back on.
  • Reboot the charger via reset button, unplug/replug, or circuit-breaker off/on.
  • Try a different charger.
  • Leave the car on when plugging in (especially if the battery pack is below -14F)
  • Hold the button down on the plug until it's fully inserted.
  • Try the OEM cord. It can reset some charge errors:
Product Communication Device Gadget Material property Rectangle
 
See less See more
6
#2 · (Edited)
For comparison, this is from a pack with a bad cell:

At full charge, 17mV imbalance (about 10mV more than it should be):

Max Cell Voltage: 4111 mV
Min Cell Voltage: 4094 mV

At low charge, 231mV imbalance:

Max Cell Voltage: 3486 mV
Min Cell Voltage: 3255 mV

If you scroll further down the OBD readout it shows individual cell voltages.
Here's that same bad-cell pack as above, at full charge:

51: 4110 mV
52: 4108 mV
53: 4094 mV < Small imbalance. (but still about double what's normal)
54: 4103 mV
55: 4103 mV

Here's the same pack, at low charge:

51: 3437 mV
52: 3381 mV
53: 3255 mV < Big imbalance.
54: 3315 mV
55: 3384 mV
 
#3 ·
You mention "commercial outlet"? what do you mean by that? In my garage, I have a tesla charger, so I can use this adapter https://www.amazon.com/Lectron-Charging-Compatible-Connectors-Destination/dp/B09DCTJCTV.

on the opposite side of the garage which is a bit more inconvenient I have a J1772 juicebox.

Are you saying I should just use the 110V cord that comes with the car overnight?

And when not home, what's the best place to charge it? chargepoint stations? Do I risk the reset that you mention above when charging it from 220V? So far no issues on the juicebox.

Problem is my 110 outlet already has.a fridge and water heater plugged into that socket/circuit. I might call the electrician to run another plug tapping off the 220v that the tesla is running off of which is in the better spot. Or even have them run another 220 I suppose, but that does seem like overkill.
 
#4 ·
#11 ·
Thanks! I'm only using this specifically to check the battery levels as per your wonderful pre-purchase checklist, not to modify anything.

No risks of breaking anything that way right? I've already verified AlfaOBD can see and talk to the adapter via WiFi on my Android phone. It might be an unreliable connection but I'm fine with that as long as I don't brick an ECU just trying to read the battery state!
 
#12 ·
I'm pretty sure that the only way to brick it (temporarily) with AlfaOBD is with "active diagnostics" (contactor enable, proxy align, coolant/brake bleeding, etc.) & those are deactivated in the free AlfaOBD app.

One of my points that may apply is that if you need to buy an OBD device to do a pre-purchase test, you should consider that if you do purchase a 500e you should buy the OBD gear that you're going to want on hand as a 500e owner.
 
#13 ·
... but me & many other owners have had no issues from checking battery levels hundreds of times with $17 wireless dongles.

That $17 turned out to be fully wasted since it wouldn't do a proxy align when my miles started flashing, AND then I learned that I shouldn't have done that with the $140 wireless dongle I bought just to do it :rolleyes:. Now I need a $41 OBDLink SX cable. Learn from my mistakes.
 
#17 ·
Just fyi: The Sept 13, 2018 U69 date that shows for all of us at Mopar.com is when the customer satisfaction notice was issued, not the date it was completed on the car.

Also, as this is the pre-purchase thread, U69 completion is no guarantee against battery damage, so that's what a potential buyer needs to check. As long as there's no damage, you can get U69 done later, so it's on the post-purchase list here: Post-Purchase Preparation. 6/15/23 Update: No Wireless...
 
#18 ·
Just fyi: The Sept 13, 2018 U69 date that shows for all of us at Mopar.com is when the customer satisfaction notice was issued, not the date it was completed on the car.

Also, as this is the pre-purchase thread, U69 completion is no guarantee against battery damage, so that's what a potential buyer needs to check. As long as there's no damage, you can get U69 done later, so it's on the post-purchase list here: Post-Purchase Preparation. 6/15/23 Update: No Wireless...
Is there any way to do a non-OBD battery status/health check (reset trip gauge, drive, make sure it doesn't go down more than ~4mi/kWh) above 50% charge?
 
#22 ·
Yes, ":oops:".

That's why you HAVE to do a driving test below 50%.

Even worse for an OBD imbalance test which can look fine all the way down to 31% & then spike like crazy.

& those are both MAXIMUM test levels. It's MUCH better to drive it to below 30%, &/or check for under 20mV at 20% & under 30mV at 10%.
 
#23 ·
“A trip gauge that was reset after any harsh low-efficiency test-driving should be about 4mi/kWh. If it's 10% less due to cold or hills then 10% less miles to drop 30% is okay.”

I don’t see mi/kWh on my trip computer. Or does kWh correspond to a certain amount of battery percentage?
 
#25 · (Edited)
"1%/mi below 50%" is really just for if you can't check the imbalance.

However, you now know that to fix breakdowns you need AlfaOBD on a device that's always charged up in the car. So you can ignore the 1%/mi test, & just check imbalance, in P with everything off but the key.

If I were to rank the effectiveness of the tests from most effective to least effective it would look like this:
  1. <30mV at ~10%
  2. <20mV at ~20%
  3. <10mV at ~30%
  4. 1%/mi, below 50%
 
#27 ·
Any 1 of those tests is effective enough if it FAILS, indicating 1 or more weak cells* & therefore reduced range.

What I meant was if it passes 1 of the less effective tests, its health is less certain than if it passes the more effective tests.

* or it might just need to be taken to 100% a few times to balance them & then see if it passes the test(s).
 
Top