For some reason, I have been unable to send private messages for months. They just remain in my Outbox unsent. So I will reply to you publicly. Hope you don't mind.
Alohart - thought I'd say 'hi.' Monday AM I expect to hand over the money for my first i3 (or ANY EV) after a near-miss with a Leaf a week ago. Rebounding with the i3 will, I expect, not leave me looking over my shoulder - the leaf felt comfortable, intuitive, and boring, as I'd expected, but someone bought it out from under me so it's history regardless.
We're up in the back of Palolo, in Honolulu. I'm a nearing-retirement engineer who loves to get hands into projects, but with less tolerance now for open-ended ones (since they're essentially cluttering up my existence at this point.) Do you do much work on your i3 yourself?
Since you clearly have extensive history on the site, and I've not yet stumbled on (or been able to search out, even) certain themes in posts that would probably interest me, I hope I can ask a few questions. And, with your perspective, if you think this deserves posting to start off, I can do so - just LMK.
1) With a 2017, what maintenance tasks can I do on my own without offending the pack warranty (or any other about which I don't know anything, yet?)
2) Any basic must-haves like code-reader, apps, etc, per your long experience?
3) I've got nothing other than the stock level 1 charger available (and that might be entirely sufficient, honestly, since we don't go anywhere) but I'd assumed that I'd be able to do something as simple as wiring an adapter 'whip' to fit a 240V extension cord to end in a charging plug. It's #10, IIRC, heavy enough for some of the welding I do occasionally...but that Simple Plan doesn't square with the cost of some of the nice wall-mounted rigs, at $400 and up. What makes those worth their cost?
That's more than enough for now. Hope you've got time for this...but if not, no worries.
If possible, avoid buying a REx. The REx system has been a source of problems that don't exist in a BEV. The 94 Ah battery pack in a 2017 - 2018 i3 BEV provides sufficient range to travel round-trip anywhere on Oʻahu, so why bother with the additional complexity, maintenance, and weight (+300 lb.) of a REx? Instead, buy a 2017 or later BEV.
A problem with the REx system might explain the yellow triangle and exclamation point which is called a check control symbol. That indicates the presence of some sort of warning that can be displayed in iDrive. The seller should know how to do this. Hopefully, the Check Engine light wasn't on as well. Some REx warnings are transitory and tend to go away on their own, but others indicate a real problem that needs to be fixed. These can be expensive to fix, and not all fixes are easily done by the owner. I'm guessing that the seller hasn't used the REx recently (a likely situation on Oʻahu) and the REx engine needs to start itself which it does if it hasn't been used within something like 60 days. It won't do this periodic startup unless the charge level is below 75%.
I bought a 2014 BEV new. The only maintenance that I performed was after the 4-year scheduled maintenance that was included with the purchase, and that was changing the brake fluid and checking the cabin filters which looked new after <13k miles driven total, so I didn't replace them. BMW recommends changing the brake fluid every 2 years, but I replaced it with some Bosch extended life (3-year) brake fluid, so I don't plan to replace it until 3 years have passed. With a REx, an engine oil filter and oil change is recommended every year. I don't miss ICE maintenance chores like these, and with a REx not necessary for most who live on Oʻahu, why add to your maintenance chores?
I installed and licensed the BimmerCode app which can modify settings to change behaviors. For instance, I eliminated all the legal warning screens that must be dismissed every time an i3 is started. I disabled seat belt warning messages and sounds because my wife and I always wear seat belts. I changed the default driving mode from Comfort to Eco Pro because that's what I prefer. I've made a number of other changes as well, so BimmerCode has been well worth its license fee plus the cost of an OBD to WiFi (or Bluetooth) adapter. Had I not wasted money on a Foxwell NT520 PRO+ diagnostic trouble code (DTC) reader, I would also have licensed BimmerLink which uses the same OBD adapter as BimmerCode.
Any work you could reasonably do on an i3 should not affect its battery pack warranty.
Your Level 1 EVSE (120 V) might work well enough for you since you don't drive much. It pulls 10 A when the Level 1 charge rate setting is set to "Max" in iDrive. That can stress a corroded 120 V 15 A outlet and any extension cord that you might use, so the first time you charge, touch the outlet and plug(s) after an hour or so to ensure that they're not overheating. It might be worth replacing the outlet with a commercial quality outlet because outlets corrode pretty rapidly in Oʻahu's salty, humid climate, especially back in Palolo. You would have the option of using your 240 V welding outlet if you need to charge faster, but you'd need to buy a Level 2 (208-240 V) EVSE. Charging is slightly more efficient at 240 V vs. 120 V, so more of the charging power would be used to charge the battery pack rather than be lost as waste heat. Not worth buying a Level 2 EVSE if charging with Level 1 is sufficient.
I'm traveling in Europe for 3 months now, so I can't stop by to discuss anything with you until I return at the end of September. Meanwhile, the 2019 i3 BEV we bought to replace our 2014 (needed a bit more range to avoid having to charge en route returning to Hawaii Kai from the North Shore) is asleep in storage.