original level 1 charge 'box' - better if used with 240VAC?

[808Pants]

The original level 1 factory 'charger' (maybe 'EVSE,' though I'd be tempted to refer to is as a 'wall-wart') indicates compatibility with 120/240VAC, despite being fitted with an Edison (standard USA 120VAC three-prong) plug. If I were to adapt to supply it with 240VAC, is it still restricted to...what, 13-16 amps or thereabouts? I'd suspect so because the 14AWG cable would already be operating at about max ampacity, right?

So assuming there's no point in doing the above, I'm shopping for a level 2 EVSE. But where I live, there's no 'civilization' very near where I have to park. So I'm gonna have to extend any level 2 EVSE that I might buy, from the stock length of around 25' total, to about 80' total (eg via a 55' extension to one side or the other).

I've learned that the cable on the downstream side of the 'box' is not common (carries three larger current-carrying conductors of around 9-10AWG [metric], plus two smaller signal-carrying wires at about 18 gauge, which I believe tell the interface box when to stop flow of current). Extending the supply side isn't optimal, since at simplest, it means a 240VAC "extension cord" (with connections that aren't exactly weatherproof) out in the elements. (I'm also game to make a permanent weatherproof splice to the supply-side of the box, just by cutting off the plug and permanently splicing the box's input to my extension, but I'm not crazy about doing that, either, since I occasionally would use such an extension-cord for other applications if it had standard plug/receptacle on each end.)

Anyway, I take it that one way or another, I should anticipate my highest current at 32A...which means especially with my 55' run, 10AWG isn't quite large enough for this 240VAC extension. I'd love to hear experience to the contrary, though...anyone?

Thanks - Dave

 

[eNate]

What country are you in, Dave?

Watts is voltage x amps. The stock EVSEs have come in 8, 10, and I believe 12 amp varieties. Doubling the voltage doubles the watts while the current remains constant.

Better yet, charging at 240 volts is about 10% more efficient on the i3 than 120 volts, so you get a bet better than double the charging speed.

I personally haven't tried plugging my BMW-issued EVSE into a 240 receptical yet, but I do have other dual-voltage EVSEs that work this way, including one from Volkswagen.

 

[808Pants]

What country are you in, Dave?

Watts is voltage x amps. The stock EVSEs have come in 8, 10, and I believe 12 amp varieties. Doubling the voltage doubles the watts while the current remains constant.

Better yet, charging at 240 volts is about 10% more efficient on the i3 than 120 volts, so you get a bet better than double the charging speed.

I personally haven't tried plugging my BMW-issued EVSE into a 240 receptical yet, but I do have other dual-voltage EVSEs that work this way, including one from Volkswagen.

Nate, I'm in Honolulu, which is more or less the USA.

I realized I needn't have spent as much time thinking about this (always the case) vs looking up the actual EVSE specs, which eventually led me to this description:

Charge your BMW plug-in hybrid electric vehicle (PHEV) quicker with the BMW TurboCord Charger. This dual-voltage charger is able to charge at both 120V and 240V thanks to a detachable faceplate. With the TurboCord you are able perform level 1 charging via your standard 120V outlet and level 2 charging (3.6kW) via a NEMA 6-20 240V outlet. Charge your vehicle up to 3 times faster with the TurboCord than a standard level 1 charger.
Part #
61442448670

https://www.shopbmwusa.com/PRODUCT/5755/BMW-TURBOCORD-CHARGER

So I won't get 7.2kW charging rate with my existing (factory) box, but I can certainly live with the 3.6kW upgrade - all for the cost of a converted-to-240VAC-use, 100' 10- or 12AWG extension cord, and the adapters to get me to the EVSE box...or maybe I'll actually spring for that OEM faceplate adapter if I can find one on ebay.

Whatever it ends up being, I'm going to have to weatherize it somehow - not sure how that's going to go yet.

 

[eNate]

Oh, awesome, I forgot about those units.

Was asking about country because the stock EVSEs in the US have only come listed at 120 volts, and there's some discussion (and suspicion) they're dual voltage, just not marked. Some say No, they've checked, and they're 120 only. But I forgot about the Turbo Cords.

 

[alohart]

What are the specs listed on the label of your original BMW charging cord? The one included with our 2014 i3 is listed as 12 A @ 120 V and with our 2019 i3, 10 A @ 120 V. Neither works with 240 V. BMW did offer the dual-voltage Turbocord as an extra-cost option in later years. I believe that it charges at a maximum of 16 A.

When we sold our 2014 i3, I included the 2019 i3's charging cord and kept the 2014 i3's charging cord because of its higher charging power. An i3 owner in one of the Facebook i3 groups claims that the 2014 i3 charging cord can be modified to become a dual-voltage 12 A charging cord using the procedure in this video. I plan to investigate this claim with our 2014 i3 charging cord.

We live in Hawaii Kai. Unless one's business involves driving an i3, it's not easy to drive very far each day on Oahu. In 2013 when we owned a Mitsubishi i-MiEV, we installed 16 A 120 V and 16 A 208 V (commercial power) charging circuits in our condo parking space. At 12 A @ 120 V, our 2014 i3 charging cord adds ~5 miles of range per hour of charging. So if we were to charge for 10 hours every night, we would have added 50 miles of range which would be sufficient for us on most days. You might find that this is sufficient for your needs.

We are enrolled in HECo's Residential Time of Use rate schedule which provides the least expensive electricity between 9 AM and 5 PM daily (currently, 30.5¢/kWh compared with the Residential rate of 44.5¢/kWh). So we could charge a maximum of only 8 hours during the lowest-cost period, during some of which we would be driving on errands. This makes charging with our 120 V charging cord marginal, so I always charge at 16 A @ 208 V, ~15 miles of range added per hour, which is always sufficient for our needs. Should we need to charge faster, a HECo DC fast charger is about ½ mile from our apartment, but I have never needed to use it.

Extension cables between an EVSE and an EV are quite expensive due to their complexity and the expensive J1772 plug and port on the ends of the cable. Ideally, you could bury a 240 V supply cable of sufficient gauge and terminate it above ground in a waterproof enclosure near where you park. You could then plug in your EVSE inside this waterproof enclosure.

Another option would be to replace the supply cable on your EVSE with a cable long enough to reach your 240 V receptacle. You'd have to open the EVSE case to replace its supply cable to maintain the waterproof integrity of the EVSE case.

Or you might be able to find a waterproof enclosure in which you could plug your existing EVSE supply cable to the end of a long extension cord of sufficient gauge.

 

[808Pants]

What are the specs listed on the label of your original BMW charging cord? The one included with our 2014 i3 is listed as 12 A @ 120 V and with our 2019 i3, 10 A @ 120 V. Neither works with 240 V. BMW did offer the dual-voltage Turbocord as an extra-cost option in later years. I believe that it charges at a maximum of 16 A.

When we sold our 2014 i3, I included the 2019 i3's charging cord and kept the 2014 i3's charging cord because of its higher charging power. An i3 owner in one of the Facebook i3 groups claims that the 2014 i3 charging cord can be modified to become a dual-voltage 12 A charging cord using the procedure in this video. I plan to investigate this claim with our 2014 i3 charging cord.

Hey Art! Thanks for another of your standard copiously-detailed replies.

Sounds like my EVSE is somewhere between the two you're describing (photos below). Specs are ambiguous, indicating "120-240 volts," but then also show "12/16 amps," which wouldn't naturally correspond to the two voltages just stated.

I may have misunderstood your intent, but in my case, there's no obvious way to get into the case (I'd do it in a heartbeat) to rewire, in order to make it more friendly to cord-swapping. But OTOH it doesn't seem like this is even required, since the factory 'slide on' adapter plate (which I don't have), to convert from 120VAC to 20A/240VAC, apparently is nothing but a wire-to-wire 'conversion' - I mean, it just "plugs in" to the standard Edison plug on the EVSE, so there's no possibility of any added connections to the internals. More investigation needed, but I'd guess it's set up to deliver each high leg of the 240VAC to what were the 120V hot/neutral (flat prongs), with the former ground prong repurposed to a neutral, in the 240VAC adaptation. A lot of 'devices' I own are labeled a dual-voltage compatible, regardless whether they come with a 120V/Edison plug or otherwise, and I suspect that's the case here. I've got a call in to BMW's tech support (specifically for charging, apparently?) toll-free line...we will see if they return my message about this. If it's not an arm and a leg, I'd buy that adapter plate just to see whether that's all it is...but then I might not ever even use it if that's the case.
https://photos.app.goo.gl/VN87JAFfMYKkrFmW9

We live in Hawaii Kai. Unless one's business involves driving an i3, it's not easy to drive very far each day on Oahu. In 2013 when we owned a Mitsubishi i-MiEV, we installed 16 A 120 V and 16 A 208 V (commercial power) charging circuits in our condo parking space. At 12 A @ 120 V, our 2014 i3 charging cord adds ~5 miles of range per hour of charging. So if we were to charge for 10 hours every night, we would have added 50 miles of range which would be sufficient for us on most days. You might find that this is sufficient for your needs.

I'd actually be OK with snail-rate charging if it weren't for the severe clunkiness of my current band-aid hardware: the 50' cord is about 10' too short to accommodate without being on the stretch, and it gets a bit too warm near the AC receptacle for my taste, plus it's not well sheltered where it happened to be. That also means the EVSE-to-extension-cord joint is out in the weather, and how long can my ghetto-shrink-wrap waterproofing be expected to last? :shock: What you mentioned below about TOU metering is also now (or about to be) applicable here, so having to leave charging on for more than 9AM to 5PM isn't optimal. Then there are the comments I've seen elsewhere about it being more efficient to charge at 240V (still don't get why that is, but I've seen it enough to believe it).

We are enrolled in HECo's Residential Time of Use rate schedule which provides the least expensive electricity between 9 AM and 5 PM daily (currently, 30.5¢/kWh compared with the Residential rate of 44.5¢/kWh). So we could charge a maximum of only 8 hours during the lowest-cost period, during some of which we would be driving on errands. This makes charging with our 120 V charging cord marginal, so I always charge at 16 A @ 208 V, ~15 miles of range added per hour, which is always sufficient for our needs. Should we need to charge faster, a HECo DC fast charger is about ½ mile from our apartment, but I have never needed to use it.

Extension cables between an EVSE and an EV are quite expensive due to their complexity and the expensive J1772 plug and port on the ends of the cable. Ideally, you could bury a 240 V supply cable of sufficient gauge and terminate it above ground in a waterproof enclosure near where you park. You could then plug in your EVSE inside this waterproof enclosure.

Another option would be to replace the supply cable on your EVSE with a cable long enough to reach your 240 V receptacle. You'd have to open the EVSE case to replace its supply cable to maintain the waterproof integrity of the EVSE case.

Or you might be able to find a waterproof enclosure in which you could plug your existing EVSE supply cable to the end of a long extension cord of sufficient gauge.

Yes, I'm thinking along the lines of the last item you mentioned. Our steep unretained (soil and rock) frontage is in a constant state of movement, and until I get to that magical day when I've got approved plans for something like a massive retaining-wall, I won't have anything even close to a permanent 'surface' to which I'd be able to install anything between the house and the road. A small, rounded-off plastic enclosure, like a tiny Pelican case, would be about right.

 

[3pete]

Sounds like my EVSE is somewhere between the two you're describing (photos below). Specs are ambiguous, indicating "120-240 volts," but then also show "12/16 amps," which wouldn't naturally correspond to the two voltages just stated.

I may have misunderstood your intent, but in my case, there's no obvious way to get into the case (I'd do it in a heartbeat) to rewire, in order to make it more friendly to cord-swapping. But OTOH it doesn't seem like this is even required, since the factory 'slide on' adapter plate (which I don't have), to convert from 120VAC to 20A/240VAC, apparently is nothing but a wire-to-wire 'conversion' - I mean, it just "plugs in" to the standard Edison plug on the EVSE, so there's no possibility of any added connections to the internals. More investigation needed, but I'd guess it's set up to deliver each high leg of the 240VAC to what were the 120V hot/neutral (flat prongs), with the former ground prong repurposed to a neutral, in the 240VAC adaptation. A lot of 'devices' I own are labeled a dual-voltage compatible, regardless whether they come with a 120V/Edison plug or otherwise, and I suspect that's the case here. I've got a call in to BMW's tech support (specifically for charging, apparently?) toll-free line...we will see if they return my message about this. If it's not an arm and a leg, I'd buy that adapter plate just to see whether that's all it is...but then I might not ever even use it if that's the case.
https://photos.app.goo.gl/VN87JAFfMYKkrFmW9

Your photos do indeed indicate you have the TurboCord, part # 61442448670. That isn't the original EVSE the car came with but is probably a better EVSE to have. However, there also may be a recall on it: https://static.nhtsa.gov/odi/rcl/2018/RCRIT-18V652-7122.pdf

You're right in how it works though, so you should be able to get a pretty decent charge rate out of it at 240v and 16amps if you can get the adapter and run it at full speed. Otherwise, even 240 @12 should be pretty helpful.

 

[3pete]

An i3 owner in one of the Facebook i3 groups claims that the 2014 i3 charging cord can be modified to become a dual-voltage 12 A charging cord using the procedure in this video. I plan to investigate this claim with our 2014 i3 charging cord.

For what it's worth, I opened up the EVSE that came with my 2014, model # 7644239-03 and it does look to be functionally the same as that video. The circuit board model # matches (1007-0016 REV 2.7) and components and wiring appear very similar if not identical.

One difference is the transformer in his which is visible at 3:30 in the video, covered in blue tape. Inside mine is a "Triad VPP36-070" transformer. He mentions the transformer is the reason you can't just plug the existing wiring into 240 (because it'd double the voltage to the EVSE's "brain") but I'm not sure if the VPP36-070 has the same issue or not.

 

[eNate]

...Specs are ambiguous, indicating "120-240 volts," but then also show "12/16 amps," which wouldn't naturally correspond to the two voltages just stated.

...More investigation needed, but I'd guess it's set up to deliver each high leg of the 240VAC to what were the 120V hot/neutral (flat prongs), with the former ground prong repurposed to a neutral, in the 240VAC adaptation. ...

The wiring is a bit simpler.

The ground remains a ground. The 120 volt neutral is repurposed as the 2nd hot to make the 240. This no-neutral arrangement is conventional, and most (many?) wall-munted EVSE don't use neutrals, either.

The amperage disparity you're seeing is most likely a safety concession. At 120 volts, they want this to work on any common receptacle, and 15 amps is the lowest common denominator.

However with a 240 volt circuit, they're making the assumption that the circuit will be rated for at least 20 amps.

The warmness you're feeling, since it's localized to one end of the current, it due to resistance at the plug/receptacle. Replace the receptacle and/or clean the plug, and that should cease being a problem if it's truly "too hot" – although a little warmth is to be expected.

As for efficiency, I've measured the i3 and have actually found there's a significant difference between 12 amps and 16 amps at 120 – nearly 10% IIRC (I posted my results on this forum, not finding the post). But the 120 to 240 volt gain is picked by when the inverter converts the incoming voltage to 400 volts, there are lower losses associated with stepping up the higher incoming voltage.

 

[808Pants]

Nate,

Thanks, good stuff. I can't see going too far wrong by wiring my own adapter as you covered (flat prongs = 240V, ground remains ground) there's this annoying image that comes to mind of... burning resin & carbon-fiber... I was hoping to find a standard DVM test method to probe the pins at the J1772 after doing my supply-power extension-cord modification, but the apparent need for a 1kHz +/-12V signal to trick the EVSE into switching on would take more than what I've got on hand. But just seeing the pinout makes me think there's not much to go wrong.

The EVSE in this case was designed and built by Aerovironment, which apparently was bought up by Webasto (huh? the sunroof guys are that big?) So I got in touch with them, holding out hope for a simple technical confirmation from Webasto, eg a schematic etc of the adapter, just to be 100% sure on the pin-to-pin connections within. Disappointingly, they turned my tech-help inquiry around as a sales-pitch for the adapter, claiming proprietary information as to the arrangement of the innards - you know, deep technical secrets that make america great and all. My final email explaining that even if I bought one, I wouldn't actually USE the thing beyond ohming it from pin to pin went unanswered. I'm pretty sure it'd be well over $100 by the time I paid for courier costs if I caved to their sales-pitch (Hawaii sucks for anything other than USPS) so...that was that.

My current plan is to procure 80' of #10/3 SO or similar extension-cord stock, lop one end off, directly solder/heat-shrink the three conductors to the Edison male pins at the EVSE (later to be epoxy-potted for weathertightness), and put a NEMA 6-20 male on the other end. I do wish there was an obvious way to crack the EVSE case open for a 'cleaner' splice, by removing the Edison plug entirely, but...nope.