16 Gauge okay?

Still 11 days to go before my FFE is built, but I've finally decided to stick with the trickle charger for now. 7k miles per year means an average of 19 per day and level 2 would be an expensive luxury at this point. Eventually, I'll have a 220 line put in and would probably opt for something like the Siemans, which looks solid but as of now, totally unnecessary.

The car would be garaged by 6pm and I can even set it to charge late evening and it probably won't require more than 5 hours to top off.

However, I'll need to run an extension to plug it in. Supposedly 16 Gauge wire is rated at 13 amps, not 15. Can I use 16 Gauge or ***must*** I go to 14 Gauge???

Thanks!

I wouldn't scrimp on that. I would suggest any extensions be rated 20 A minimum. If you are talking about an actual extension cord (rather than extending your household wiring), get a good quality one. The connectors themselves tend to be weak points that develop resistance and overheat.

And yes, 220 charging for you would be nice but not necessary due to your low mileage. One of our Volts charges every day from a 110 V outlet, no problem.

michael said:

I wouldn't scrimp on that. I would suggest any extensions be rated 20 A minimum. If you are talking about an actual extension cord (rather than extending your household wiring), get a good quality one. The connectors themselves tend to be weak points that develop resistance and overheat.

And yes, 220 charging for you would be nice but not necessary due to your low mileage. One of our Volts charges every day from a 110 V outlet, no problem.

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20 amps equates to 12 gauge from what I can see. Okay, thanks for the feedback. I'll try to find a 12 gauge.

You have to distinguish between house wiring (NEC) and extension cords when you are talking current limits. Household (USA) outlets for 120V with standard plugs are wired on either 15A or 20A circuits. Assuming copper wires, 15A requires 14 ga, 20A requires 12 ga. NEC rules generally require continuous loads to be no more than 80% of the circuit breaker rating, so 12A and 16A respectively.

Extension cords can generally be two gauges smaller or so without overheating--it is the voltage drop that becomes a problem. The Ford convenience charger that comes with the car draws about 12 amps max so that it can (just barely) safely be used on any household circuit. The charger itself actually uses 16 ga wires for the power feed to the car, so a 16 ga extension isn't necessarily a problem.

However, I ended up installing a Level 2 EVSE sooner rather than later because I wasn't comfortable running my 15A garage circuit at max continuous load for 15 hours straight. I replaced the worn outlet because it the plug was loose and the outlet got warm, but even then I was losing about 5% of my voltage. It's harder to sleep knowing you have an electrical circuit in your house going non-stop at max load. Installing the EVSE was easier than rewiring my garage in 12 ga wire.

How long does your extension cord need to be? The convenience cord is about 18 feet long. If you need to do this, I'd recommend getting a NEW heavy duty cord and making sure the plugs on either ends are nice and tight--then check them after a few hours to make sure they aren't getting too hot. It would be best if you didn't have to plug and unplug them every time you charge. If the cord is more than 20 feet long, you really want to try and find a 14 gauge cord to avoid voltage drop. If this is for indoor use, you might even want to consider making your own cord with heavy duty connectors--that way you can also make it just as long as needed.

The FFE only charges at 12A on 120V The ampacity of an extension cord also should be 20% higher than the load your putting on it (Per NEC the load should be no more than 80% of what the circuit is rated for). That is why the FFE only charges at 12A. 12A is 80% of 15A which is what most 120V circuits are rated for. This handy chart may be helpful 14ga. "should" be sufficient however many consumer grade extension cords aren't made to the quality shown in the referenced chart. I agree with what has been recommended I'd look for a high quality 12ga extension cord if you must use one. The manual explicitly says you shouldn't use extension cords. I assume this is because the likely fire that would result from using some cheap Walmart extension cord. Most extension cords indicate their ampacity on the packaging. If the one you are looking at buying doesn't list this that is a RED FLAG to move along and pick another cord that does list it's rating. Just make sure whatever you get is rated at a minimum of 15A. 20A as recommended above would be an excellent choice I'll also throw out that it would be a good idea to feel the cord near the connectors from time to time. If you notice the cord getting hot, it's time for a new cord before you have a fire.

Depending on your climate, the use of "Go Times" can be very convenient to have your car preconditioned using power from the grid. This only works when hooked to a 240V EVSE.

The ampacity of an extension cord also should be 20% higher than the load your putting on it (Per NEC the load should be no more than 80% of what the circuit is rated for)

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Once the juice comes out of the wall, the NEC is (mostly) irrelevant. I agree some reserve capacity is good, but the NEC rules are very specific as to what they apply to. The ampacity of common 120V household circuits is very specific to those types of circuits and all others use different ampacity charts, most of which allow more current for a given conductor. The 80% rule is actually based on the specifications of the circuit breakers themselves, not the wiring.

You aren't too likely to find a 12 ga extension cord--although I suppose they exist--and it seems pointless to insist on connecting your 14 ga house wiring to your 16 ga EVSE wiring with a 12 ga extension cord. It reminds me of the the guys selling the multi-thousand dollar speaker wires....

Thanks for the feedback.

The 18 feet for the Ford cord may work but I'm going to get a 12 gauge 25 foot just in case. It can't hurt to have it around anyway.

I have three outlets in the garage but the closest one is on the wrong side, which means I would have to run the Ford cord resting on the car (no thanks!) or back the FFE into the garage. So, the outlet in the back of the garage may be the better way to go. Not quite sure that outlet is close enough.

Re lvl 2, I would need a 220 line. I've asked my friend Russ, but I have to wait for him to free up time. He's a workaholic but recently had a stroke and other issues, so I don't want to press him. Of course, that would be ideal and I'd get a lvl 2 ASAP. Meanwhile, the lease is three years so it'll be three years before I can consider a Tesla. :lol:

12/3 cords are easy to find. Amazon has quite a few

12/3 cords are easy to find. Amazon has quite a few

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You're right. After I posted that I checked out of curiosity. Even Lowes and HD have them. Now, for the $64K question....why do they all state that they are rated for 15 amps???

Been using this for over a year on a daily basis. No noticeable heat generation in the cord, plug, or sockets.

http://www.harborfreight.com/50-ft-x-12-gauge-triple-tap-extension-cord-with-indicator-light-61953.html



The 14 and 16 gauge extensions that I have all heat up quite noticeably when charging, some more than others.

zebracadabra - If you have an older home (mine was built in the early 1990s), you might want to spend the half hour or so it takes to replace the wall receptacle you'll be using. Mine burned out after about a year of daily charging. BTW, I'm still on Level 1 at home using the OEM EVSEs, so based on your use case I suspect you'll be fine without a Level 2 EVSE.

Thanks, replies much appreciated.

The cord that comes with the FFE might be long enough. It'll be close for sure.

Is there a problem leaving the cord plugged into an outlet 24/7???

Obviously, it won't be charging all the time, probably no more than 5-6 hours actually.

Is there a problem leaving the cord plugged into an outlet 24/7???

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No, that is how I used mine until I got the L2 EVSE. It draws about 3 watts when not it use, IIRC.

zebracadabra said:

Is there a problem leaving the cord plugged into an outlet 24/7???

Obviously, it won't be charging all the time, probably no more than 5-6 hours actually.

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I had issues early leaving the EVSE plugged in all the time, after a day or two the 12v battery would discharge low enough that it wouldn't start. I had to charge the 12v battery with my external 12v battery charger then.

But for the past few months I have unplugged after the car is fully charged (within a few hours after) and haven't had that issue anymore. I have a small 12v port voltmeter plugged in the accessory port all the time to monitor the 12v battery voltage just in case.

Others with FFEs haven't had this issue, but I'd advise you to measure the 12v battery level if you plan to leave it plugged in for several days straight.

NightHawk said:

zebracadabra said:

Is there a problem leaving the cord plugged into an outlet 24/7???

Obviously, it won't be charging all the time, probably no more than 5-6 hours actually.

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I had issues early leaving the EVSE plugged in all the time, after a day or two the 12v battery would discharge low enough that it wouldn't start. I had to charge the 12v battery with my external 12v battery charger then.

But for the past few months I have unplugged after the car is fully charged (within a few hours after) and haven't had that issue anymore. I have a small 12v port voltmeter plugged in the accessory port all the time to monitor the 12v battery voltage just in case.

Others with FFEs haven't had this issue, but I'd advise you to measure the 12v battery level if you plan to leave it plugged in for several days straight.

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I don't mean leaving the FFE hooked up 24/7, just talking about having the charging cord hooked up to an outlet 24/7. I plan on removing the cord from the car when topped off but due to its position in the garage, it would be far easier for me to leave the cord plugged into the 110 v outlet.

I've left the L1 EVSE from my Volt plugged into the wall since I got the car 15 months ago, no issues. I suspect the unit that comes with our FFE would fare just as well.

I contemplated leaving another of the L1 EVSEs plugged in 24/7 but I can't work up the courage to leave home in one of the BEVs without having an EVSE in the trunk.

zebracadabra said:

I don't mean leaving the FFE hooked up 24/7, just talking about having the charging cord hooked up to an outlet 24/7. I plan on removing the cord from the car when topped off but due to its position in the garage, it would be far easier for me to leave the cord plugged into the 110 v outlet.

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That should be fine, considering the Ford supplied 110V/12A EVSE is apparently covered by the longer 8 year/100,000mile warranty.