Occasional Use Cable

[ericonline]

Has anyone tried charging the battery using the standard OUC - Occasional Use Cable? Would appreciate some info. I'm considering stretching my budget to get an i3 Rex and saving money on the EVSE by just using the standard cable with a standard 120v outlet. Thanks.

 

[jadnashuanh]

It works, in comparison to a level 2 EVSE capable of the max the i3 can handle, the 120vac unit that comes with the USA and Canadian cars could take as much as 6x longer to recharge the vehicle. It really depends on how much you drain it on a regular basis, and how long you have in between uses. Worst case, nearly dead battery, could take upwards of 19-hours to recharge with the unit verses about 3.5-4 hours for a level 2 unit. The 120vac unit supplied in the USA can source a maximum of 1.44Kwhr...the vehicle can accept as much as 7.4Kwhr, and many level 2 units can supply that. Also, the charger in the car is not as efficient using the 120vac input as the 240vac input, so that cuts it down a little bit more than the theoretical amount.

Note, when you lock the vehicle with the charge cable attached, it locks it into the socket so it cannot be removed or stolen.

I bought an Android tablet to play with the vehicle, and just tried it this morning to tell the vehicle to precondition itself prior to me leaving. It was nice getting into the vehicle. And, if it was plugged in at the time, you'd maximize your total range available, since it wouldn't have to use that power from the battery pack to do it.

 

[pokiri]

Has anyone tried charging the battery using the standard OUC - Occasional Use Cable? Would appreciate some info. I'm considering stretching my budget to get an i3 Rex and saving money on the EVSE by just using the standard cable with a standard 120v outlet. Thanks.

I'm doing that - it seems to work just fine. So far, ~600 miles in and I haven't used the REx yet, though I did once use a charger outside the home. I'm not aware of a reason not to do this, other than the obvious "it takes a long time to charge" issue.

 

[ultraturtle]

If you do not need to top off the battery every day for maximum range (a good idea to not do so, btw - the practice has the potential to wear down your battery capacity a tiny bit more quickly), you will recoup a bit less than 5 miles of EPA range per hour charging with the occasional use cable up to a SOC something over 80% where the rate begins to taper off. In other words, if you only have 12 hours to charge, you can recoup as much as 58 miles of range. If that fits your needs, you're good to go. 120v charging is a tad less efficient than 240v - that would be my only concern.

 

[Scootir]

So I have been using the OUC since I got my i3 last week. Almost a deal breaker at first - wouldn't charge from many outlets, then would start charging and quit. Couple of things helped. Changed the settings on "Charging" to start immediately and maximum. Wouldn't work on the others. Also found if you can avoid using an extension cord to plug in the OUC that seems to help as well. Since these tweaks I haven't had a single issue aside from the time it takes to recharge.

 

[sc68z28]

A 20 amp 240V ClipperCreek was only $500. http://www.clippercreek.com/store/product/charging-station-lcs-25-level-2/
It's portable, about the same size as the 120V OUC, and it will charge from 6% to full in under 5 hours. From 40% SOC to full in under 3 hours.
It was under $50. for the 30 amp breaker and other electrical components to wire up the outlet at one of my homes. The other two already had 14-30 dryer outlets I use when I'm at those locations.

Well worth it, 4 times faster charging, JMHO.

---Bill.

 

[shrikantc]

Be careful at new locations- I had a problem charging my REx with OUC at my friend's garage overnight. All indications said vehicle was charging. However charge level started at 4% and went to 5% but then came down to 3% and stayed at that level all night. Had set i3 to charge immediately and Max.
Next morning, thought I could drive it on REx to Level 2 Chg station, but car moved 10 feet and stopped. THe charge level went down to 1% as I tried to program in destination in navigation system. Had to be towed to BMW service center. they said to use reduced charging level when that happens.

Verified that it worked at reduced level. Noticed that when I increased charge level to max, heard a clicking noise from the engine bay. Looks like the on-board charger relay was engaging and dis-engaging. Likely explanation- voltage drop got excessive on max current, causing the onb0ard charger to refuse charge. However, problem is that vehicle did not alert or alarm user in any way.

BMW needs to fix this issue/Current have reported it to BMW IConcierge. Waiting for resolution.

 

[jadnashuanh]

If your supply wiring or receptacle are not up to snuff, all sorts of things can happen, or if things got wet - especially in the winter when it may be mixed with salt. Plus, do not try to use an extension cord, or if you do choose to ignore BMW's advice on that, make sure that it is one that is of high quality and has at least 14g and preferably 12G wires inside. Inside the EVSE, there is the equivalent of a GFCI, and if the wires are not of good quality or the receptacle contacts are flaky, it is more likely to shut itself off at higher currents than at lower ones. All it takes is a little resistance along the way that is imbalanced, and the unit will shut down...this is the equivalent of a GFCI and it is just doing what it is supposed to do. An imbalance in resistance along the way looks like current leaking, and it gets worse when the current is higher. This is NOT the EVSE's fault, but likely worn or loose connections, or the use of an extension cord. It's also possible that the EVSE was defective, but it's not very common.

 

[Cartman]

I use the supplied OUC through a 25 foot heavy duty extension cord daily. I forget exactly what it is rated but I did make sure it is higher than what is required on the cars medium 120v setting (might be similar to this one but mine may be better: http://www.homedepot.com/p/Husky-25-ft-14-3-Extension-Cord-HD-277-533/100650642). Up until recently I have used the default low 120v setting but just started using the medium option. I don't have access to the circuit breaker so I don't know if it is a 15 or 20 amps circuit.

With my daily driving requirements I rarely get below a 50% SOC so the OUC is more than fine for me. I am fortunate to have access to plenty of L2 (never used) and L3 public chargers if necessary.

Here are a series of pictures of the draw using the extension cord.
http://imgur.com/Ztq9BOf,DjqxZPK,pIpsQei,OwhWuKo,qP4heBq,jSUpGJV,B4cbDSl,slTbkQI#0

Just the OUC plugged in:
0.02 amps
2.6 watts
116.1 volts

Low 120v charging:
5.89 amps
677 watts
113.4 volts

Medium 120v charging:
8.64 amps
976 watts
? volts (forgot to take pic)

Edit: On second thought I may go back to the low 120v charging option since the garage door opener is on the same breaker and it could be pulling from 3 to 5 amps.

 

[i3an]

I have had no problems charging overnight on Maximum Level-1 at home using an industrial-grade 50-foot 10-guage extension cord from a sturdy 20-amp circuit with nothing else plugged in. I am usually parked up for a good 12 hours overnight with a 10-hour off-peak window, but if I am below, say, 25% SOC I might specify "charge immediately" when I pull in.
OK, one slight problem: tried to run the cord through a Kill-A-Watt meter, but that killed the charging (don't know why), so right now I have no simple way of separating out my household consumption from the i3's. Any suggestions?

 

[jadnashuanh]

A 10g extension cable should be fine as long as the ends are still in good shape. Hassle is, people often do not look at the ratings on the thing, and it can overheat or, if worn (contacts overloaded, and lost spring tension) then you'll end up with unreliable results.

Not sure why a Kill O Watt meter messes things up. I have a hard-wired EVSE and at the junction box feeding it, I installed a panel mounted volt/amp meter in line with the power lines. It has no recording capability, but does let me get an instant snapshot of what's going on (P=V*A).

 

[wayne325]

I use the supplied OUC through a 25 foot heavy duty extension cord daily. I forget exactly what it is rated but I did make sure it is higher than what is required on the cars medium 120v setting (might be similar to this one but mine may be better: http://www.homedepot.com/p/Husky-25-ft-14-3-Extension-Cord-HD-277-533/100650642). Up until recently I have used the default low 120v setting but just started using the medium option. I don't have access to the circuit breaker so I don't know if it is a 15 or 20 amps circuit.

With my daily driving requirements I rarely get below a 50% SOC so the OUC is more than fine for me. I am fortunate to have access to plenty of L2 (never used) and L3 public chargers if necessary.

You should be fine to charge the car on the high setting. A breaker will only trip if it gets too hot and that won't happen during the 8 or 10 seconds the garage door is opening or closing. Besides on the high setting at 120V I think the car is pulling about 1200W and that gives you 600W of overhead on a 15A circuit. So with the garage door operating 100% of the time and with the car on high, you won't be overloaded if you're on a 15A branch circuit.

I'm not sure I understand how people are thinking they can afford a $50k car that's going to save them tens of thousands in gasoline over the years, but they can't afford a $500 EVSE. Maybe if you have a Rex version it makes a bit more sense.

For those who have no access to a panel with spare capacity and ability to get a wire to where it's needed, clearly that's a situation where the no-EVSE approach is obvious.

Also for those who bought EVSEs during 2014, it's tax time coming up and don't forget you get a 30% federal tax credit for your EVSE equipment cost. So with that in mind, a $500 EVSE puts you out of pocket $350 after the credit.

 

[wayne325]

A 10g extension cable should be fine as long as the ends are still in good shape. Hassle is, people often do not look at the ratings on the thing, and it can overheat or, if worn (contacts overloaded, and lost spring tension) then you'll end up with unreliable results.

Not sure why a Kill O Watt meter messes things up. I have a hard-wired EVSE and at the junction box feeding it, I installed a panel mounted volt/amp meter in line with the power lines. It has no recording capability, but does let me get an instant snapshot of what's going on (P=V*A).

The 25 foot 14 ga extension cord Cartman showed is just fine given as you said all the contacts are good.

I'm seeing 14 ga at 2.525 ohms/1000 ft. Cartman's cord has 50 feet of wire (there's two conductors in the cord - carrying the current to the car and the return), I'm calculating 0.12625 ohms total for his cord. Add maybe another 50 mohms for two added connections (seems very high to me), and we've got an added 0.175-ish ohms. At 12 amps current the voltage drop from the added cord can be bounded as under about 2.0 V and probably more like 1.5V. No worries.

When you have lighter gauge wires or plug a long cord into an outlet that has already a long run from the panel, that's when things go astray.

Also if the utility is iffy then things could be not so good also. I never had problems using my OUC at high power.

 

[wayne325]

I have had no problems charging overnight on Maximum Level-1 at home using an industrial-grade 50-foot 10-guage extension cord from a sturdy 20-amp circuit with nothing else plugged in. I am usually parked up for a good 12 hours overnight with a 10-hour off-peak window, but if I am below, say, 25% SOC I might specify "charge immediately" when I pull in.
OK, one slight problem: tried to run the cord through a Kill-A-Watt meter, but that killed the charging (don't know why), so right now I have no simple way of separating out my household consumption from the i3's. Any suggestions?

Try this guy - it's Z-wave though so means a start to home automation that you go crazy with - locks, lights, motion sensors, garage door controller, thermostats,... :

http://www.amazon.com/Aeon-Labs-DSC06106-ZWUS-Z-Wave-Energy/dp/B007UZH7B8/ref=sr_1_3?ie=UTF8&qid=1425957082&sr=8-3&keywords=z-wave

I'm running an electric water heater on mine that pulls 1400W, I can't see why the EVSE isn't going to like it.

While we're at it, this one will do for 240V EVSEs - I use one of these for tracking my i3 consumption and watching what the car is doing when it charges (fascinating, really):

http://www.amazon.com/Aeon-Labs-Aeotec-Z-Wave-DSB28-ZWUS/dp/B00FKJBUX2/ref=sr_1_6?ie=UTF8&qid=1425957133&sr=8-6&keywords=z-wave+power

Also you can put your whole house on one in case you're interested.

 

[Cartman]

Wow, thanks wayne325!

I checked on the rating of my extension cord and it is actually this one: http://www.homedepot.com/p/Workforce-25-ft-16-3-Extension-Cord-AW62601/100661460
25 ft, 16 gauge, 13 amp, 125 volt, 1625 maximum watts extension cord.
I believe it's good for the medium setting but the high setting would probably be pushing it?

I don't suppose there is a way to find out if an outlet is on a 20 amp or 15 amp breaker without access to the panel.

 

[alohart]

I don't suppose there is a way to find out if an outlet is on a 20 amp or 15 amp breaker without access to the panel.

The neutral connection of a 20 amp outlet is T-shaped rather than I-shaped.

 

[jadnashuanh]

25 ft, 16 gauge, 13 amp, 125 volt, 1625 maximum watts extension cord.
I believe it's good for the medium setting but the high setting would probably be pushing it?

I would NOT use a 16g extension cord to power the OUC! Plus, I would NOT use a 2-conductor extension cord, either...you should have a ground. Yes, internal to the EVSE, it has the equivalent of a GFCI, but there's a reason why they put a 3-prong plug on the thing!

It is code compliant to use a 15A receptacle on a 20A circuit, it is not acceptable to use a 20A receptacle on a 15A circuit. Constant use items (over 3-hours continuous use) should be rated at 125% of the listed load. In the case of a 12A OUC, that's a minimum of a 15A circuit (which is why they chose 12A - in the USA, the most common receptacle is wired for a 15A circuit). P=V*A 120*12=1440W 1440W*1.25=1800W. NOte, it is not uncommon for your voltage to be higher or lower than 120vac. Say it was 127vac*12A=1524W 1524*1.25=1905W

The trip curve on CB varies depending on the intended use...almost immediate on a direct short, but it could be many minutes on an actual overload, depending on how much and how long.

A too small cord acts like a big resistance heater, potentially overheating things (do NOT coil it up! while powering things!) and can eventually cause the contacts to overheat, losing their spring tension, creating a poor connection, and get worse. This may not happen right away...but it is cumulative. Keep in mind, a nearly discharged i3 with the USA OUC may need to run nearly 20-hours to fully charge the battery back up. Those with 220vac (Europe and other parts of the world) with their OUC, they'd get about double the charging rate at the same amperage.

 

[Cartman]

jadnashuanh, it's a 3 prong grounded cord.

Based on the reading from the kill-a-watt the extension cord I am using appears to be fine for the low and even the medium 120v setting but will pick up a heavier duty version to be safe.

As a side note I used a L2 public charging station for the first time today
They suck compared to the L3's I'm used to using...can't imagine having to wait on a L2 at a public station!

 

[jadnashuanh]

A (free) L2 unit is handy if you had planned to spend some time in a place...say a movie or restaurant, or work, or extended shopping. If you just want to get on with your life, a CCS unit is highly preferred! Unfortunately, essentially none around where I live or drive.

 

[CMYK4Life]

I use the L1 cable supplied with the car at home, I did not install anything at my house.

Did the same thing with LEAF.

As long as the wiring is legit and the car is the only thing plugged into that circuit you should be OK.

Its slow, but I charge while I sleep so I dont really care.