Best charger for a 90-mile commute

[vrpratt]

I'm a recent Bolt owner with a slightly nonstandard situation that most EVSE's don't seem ideal for so I thought I'd ask around here.

Stanford's main campus is next to Palo Alto and its Hopkins Marine Station campus is 90 miles away in Pacific Grove, right next to the Monterey Bay Aquarium. I work at both campuses, with a residence adjacent to each so I can stay several days at each without no hassle. Amongst battery electric vehicles the Bolt is the first affordable one that is viable for that commute. (The Tesla Model 3 would be equally suitable but when will they be available?)

Currently I pack GM's standard-issue 120 volt EVSE in the trunk and simply top up at each end. However I'm finding this a bit limiting, so I'm going to install an NEMA 14-50 socket at each end powered by 240 volts via a 40 amp breaker. In both garages I'll be locating the two sockets about six feet from the car.

GM's standard issue EVSE has a rather bulky long cable that I won't be needing in this Level 2 situation. This motivates the following question.

Who offers a 32 amp EVSE connecting an NEMA 14-50 socket to a J1772 socket with the shortest cable?

On non-commute trips I'm happy to pack a 25' or whatever 6-gauge extension cord, but I don't need that taking up space for my regular commute.

 

[redpoint5]

Should be a simple matter to simply cut the cable to any length you desire and solder on new connectors. I wouldn't make cable length be my driving factor when selecting an EVSE.

 

[devbolt]

Should be a simple matter to simply cut the cable to any length you desire and solder on new connectors. I wouldn't make cable length be my driving factor when selecting an EVSE.

You do not want to be cutting the cable and soldering new connections on. That's just asking for trouble..

 

[devbolt]

You can turn the 120V cordset that came with the Bolt into a dual-voltage 120V/240V unit by way of an adapter that goes on the wall plug end of the EVSE that you could then plug into the 14-50 outlet. This would double your power for about $60. Max amperage is still limited to 12A.

Finding a commercial portable unit with a short cord will be difficult. They all seem to be 20-feet or more in length. You can make your own EVSE with a custom cord length. The OpenEVSE folks sell a complete assembled unit available in 18 and 24 feet cord lengths for $599.

 

[LeftieBiker]

Clipper Creek will sell you an appropriate charging station, and if it's one with different plug options, will install the plug you need at the factory. I suggest you look at those. US made, with a 3 year warranty.

 

[sparkyps]

You can turn the 120V cordset that came with the Bolt into a dual-voltage 120V/240V unit by way of an adapter that goes on the wall plug end of the EVSE that you could then plug into the 14-50 outlet. This would double your power for about $60. Max amperage is still limited to 12A.

Finding a commercial portable unit with a short cord will be difficult. They all seem to be 20-feet or more in length. You can make your own EVSE with a custom cord length. The OpenEVSE folks sell a complete assembled unit available in 18 and 24 feet cord lengths for $599.

That would be the approach I'd recommend as well, he needs a portable charger that he can use in either location and the 10 miles/hr using a 240V outlet with an adapter with his current EVSE would be perfect for his 90 mile one-way trips. Easy to get 80 miles of range during the work day and another 100+ miles overnight. Simple and inexpensive.

He'd probably even be fine running it at 8A, that would still get him 60% more range/hr than he is currently getting. 12 hours to get his range back from his trip. Even a drive 90 miles, plug-in and work 8 hours, drive back 90 miles, charge over-night works pretty good at 8A. 4 hours of driving, 20 hours of plugging in gets you about 150 miles of range minus 180 miles of driving a day. That would get you through the week easily. Easier on the EVSE to run at 8A.

 

[vrpratt]

the 10 miles/hr using a 240V outlet with an adapter with his current EVSE would be perfect for his 90 mile one-way trips.

Wait, what? Are we talking about the same thing? My "current EVSE" (the one that came with the car) is labeled 120V, 60 Hz, 12A, and the owner's manual says nothing to the contrary. Are you saying it's perfectly happy with 240V???

Actually I can believe this provided the controller is universal (most electronics these days seems to be), and the contactor only switches when no current is flowing , and the controller doesn't check for AC overvoltage (say over 140V). But then why recommend 8A? If the contactor is rated at 12A and switches at 0A then how much better would 8A at 240V be than 12A? The point of the 8A option is to protect the house wiring, not the EVSE.

I would have thought if 240V were possible with the standard-issue EVSE I would have seen it mentioned somewhere by now. It's not like I haven't been reading about the Bolt's charging options.

Who's tried it so far? If ten people tried it and their houses are still intact and their EVSEs aren't overheating I'd be willing to give it a go.

But as a practical matter this is moot anyway. Concerning the "90 mile one-way trips", it's nice to be able to get around when I get there, and I'd like to be sure that I could drive 200 miles in a day if need be. If my schedule gets so crazy I can only charge 11 pm to 7 am then I'll be very grateful for my 32A charger. It's annoying if you have to park at a 50A DCFC for an hour during the day, especially if it's not nearby. My other car is a year-old Mirai (actually the Bolt is my wife's, just now replacing her 200,000 mile 1987 MBZ 300TD wagon, but I get to use it sometimes) which doesn't have that restriction: the Mirai refills at 3600 mph in 70 °F weather, half that at 100 °F, and there are two hydrogen stations each 5 minutes off my commute between Palo Alto and Monterey.

The suggestion to simply cut the J1772 cable short would work provided the ends are crimped or screwed down. Soldering of course is insane at 32A. I'd go with crimped spade terminals if I went that route, they can't work loose the way screws can. But most of the cost of a J1772 cable is in the length of the cable and it offends my sense of economy to pay for something I'm just going to cut off. (Earlier today I ordered a 30' 50A RV extension cable with NEMA 14-50 at both ends that should meet all my needs length-wise, and those sell at such high volumes to RV owners as to only cost $50! Hopefully the GFCI protections won't complain about it, why should they at a very generous 6/3 + 8/1?)

Talking about economy, I can see why a 32A EVSE costs $500 when you add up the components and pay for assembly. What I don't see is how Chinese companies on Alibaba like Duosida and Zencar can make any money selling them in unit quantity for $200. Are they cutting corners: any houses burned down by a Chinese EVSE for example? Are they benefitting from higher EV volume than possible in countries that worship fossil fuel and therefore buy fewer EVs? Is it their lower labor costs? And should we buy American because the president says we should, or should we follow his example and buy at the lowest possible price?

 

[devbolt]

The portable 120V EVSE that comes with the Bolt can run either at 120V, or with the right set of adapters, run at 240V. See this post on the GM-Volt website for more information:

http://gm-volt.com/forum/showthread.php?218442-2016-Volt-120v-EVSE-is-L1-L2-Conversion-Capable

The same unit used in the 2016 Volt is used for the Bolt. Lots of people on the GM-Volt website have ordered the adapters and not burned up their EVSEs or burned down their houses.

 

[user 1034]

Let me say I have been charging with a 240V adapter for about 2 months now. That OEM charger on 240V is quite nice. It has allowed me to put off buying the Clipper Creek until I have handled some of my finances.

I have run the battery to about 25% remaining and it took a full day to charge. Not bad on a weekend where I am not going anywhere.

 

[redpoint5]

Should be a simple matter to simply cut the cable to any length you desire and solder on new connectors. I wouldn't make cable length be my driving factor when selecting an EVSE.

You do not want to be cutting the cable and soldering new connections on. That's just asking for trouble..

I've already done it with a Leaf EVSE and use it daily on my Prius plug-in. Soldering a connection is not asking for trouble. Neither was wiring in my own 50 amp breaker and outlet. This stuff is dead simple to work on, and between breakers, grounds, and fuses, you aren't going to hurt anything.

 

[devbolt]

Should be a simple matter to simply cut the cable to any length you desire and solder on new connectors. I wouldn't make cable length be my driving factor when selecting an EVSE.

You do not want to be cutting the cable and soldering new connections on. That's just asking for trouble..

I've already done it with a Leaf EVSE and use it daily on my Prius plug-in. Soldering a connection is not asking for trouble. Neither was wiring in my own 50 amp breaker and outlet. This stuff is dead simple to work on, and between breakers, grounds, and fuses, you aren't going to hurt anything.

Your Prius Plug-In only draws a max of 2.2 kW for 1.5 hours. Have you tested it at 7.7 kw for 9 hours?

 

[sparkyps]

But then why recommend 8A? If the contactor is rated at 12A and switches at 0A then how much better would 8A at 240V be than 12A? The point of the 8A option is to protect the house wiring, not the EVSE.

8A is all you need for the range you specified in your original post and the time you said you had for charging. 8A will result in lower temperatures in your EVSE, likely prolonging its life.

If you have the budget, a 32A wall mounted EVSE in each location would be even better. That eliminates the worry about length of the J1772 cord as it can be neatly coiled on a wall bracket.

If you want custom, there are people who manufacture units based on the OpenEVSE board and they are happy to make the cords whatever length you desire on both ends.

 

[SeanNelson]

You do not want to be cutting the cable and soldering new connections on. That's just asking for trouble..

Soldering a connection is not asking for trouble.

Whether trouble has been requested or not depends on who's doing the soldering and how much they know about what they're soldering.

 

[vrpratt]

Thanks to everyone for the help. For $33 in parts from Barron Park Supply I made up the recommended "L1.5" adapter between an NEMA 14-50 socket and the Bolt's EVSE. Since the neutral pin was unused I removed it from the plug, allowing it to be plugged into either an NEMA 14-50 socket (for RV or range, at the Palo Alto end) or 14-30 socket (for 240V dryer, at the Pacific Grove end), and with slightly less friction. It worked like a charm.

Just to be sure about the current drawn by the car I measured the voltage drop across a series-connected 5.4 mΩ resistor with one leg of the plug in the neutral position (for 120V) and then in the standard position (240V) and got 65 mV each time, hence I = 65/5.4 = 12A at each voltage.

Thinking I'd have to run heavy-duty wiring from my outdoor service panel to the Bolt, for $50 I had earlier bought a new 30' RV extension cable (14-50 with 6/3+8/1 wires) weighing 21 lbs, damned heavy. That came to $50/21 = $2.38 a pound, a tad less than today's spot market price of $2.60 for high grade copper! I figured it might also come in handy if camping out in an RV park a fair distance from the nearest available socket.

But then it dawned on me that there was an indoor panel in the garage a mere 6' in front of the car. Well duh. The panel had a 30A double pole breaker for a dryer in the laundry that we'd since replaced with a 120V dryer and was therefore unused. It was a straightforward (albeit tedious) matter to install an NEMA 14-50 socket on the wall between the panel and the car, connected by 3' of awfully stiff Romex at $3.30 a foot through a hole I drilled sideways in the intervening stud. The socket even comes with a conveniently adjacent on-off switch in the form of the breaker itself! I'll upgrade the breaker to 40A when I get an L2 EVSE but for now 30A is overkill for this 12A "L1.5" EVSE. Anyway it's great, the Bolt now charges twice as fast as before.

The adaptor itself would be a building inspector's nightmare: some day some idiot is bound to plug a 120V-only device into its innocent-looking distal end and set the house on fire. I guess I'll keep the breaker off when not in use and also leave something plugged into the 120V end at all times, or hide the adapter when not in use. What would have obviated this would have been an EVSE with a 240V plug plus an adaptor for 120V use. To use it at 240V, instead of adding an adaptor you'd remove it.

My original question here was about where to get an L2 EVSE with a short J1772 cable. For $332 including $50 for shipping, Chinese vendor Zencar was happy to make up an EVSE for me with a 2.5 m (8.2') J1772 cable. They had 4.5 m standard but wanted a few dollars more for it because the cable was longer and I didn't need the extra two meters at either end of my 90-mile commute, or anywhere else for that matter given that I was happy to lug around the 30' extension cable on non-commute trips. Supposedly it also works at 120V as an L1 charger, for which I'll need yet another adaptor, of the kind I referred to at the end of the previous paragraph. Anyone else tried the Zencar EVSE?

 

[devbolt]

Label the adapter with big lettering in red that says "240V only". Keep it with the EVSE and don't leave it plugged into the 14-50 socket.

AeroVironment makes the TurboCord dual-voltage EVSE that allows you to plug it into a 120V/20A outlet, or a 240V/20A socket. Max draw is is 16A on either socket. Bolt will automatically restrict itself to 12A max when using 120V.

http://store.evsolutions.com/turbocord-dual-240v120v-ul-listed-p28.aspx

 

[LeftieBiker]

Anyone else tried the Zencar EVSE?

There is a topic on it in the Leaf forum. I think it's well liked, but you'd want to verify that, as I haven't really followed the topic.

 

[vrpratt]

8A will result in lower temperatures in your EVSE, likely prolonging its life.

I can think of two reasons not to run at 8A when the voltage is 240.

1. You'll only get 2/3 as many years of use out of the EVSE before something fails. This is because running it at 8A will add 50% to the total number of hours per year the whole unit is in operation. The contactor is the only part that has to carry the higher current at 12A and it was designed to do so, making "higher temperature" in the contactor an unlikely cause of premature failure, and an impossibility in the controller which is entirely unaffected by the higher 12A current.

2. And anyway the Bolt won't let you. As soon as it senses 240V the Bolt removes the 8A option (you can sometimes see it disappear when starting the car). The point of the 8A default at 120V is that some 120V circuits may have 10A breakers or fuses, so you should check that you're charging on at least a 15A breaker before switching to 12A. (An easy way to check this is to turn off all 10A breakers and fuses, if any, and see if you're still getting power to the EVSE.) Presumably GM reasoned that no one puts 10A breakers on 240V circuits, typically it's 30A and above, so why hassle the owner by defaulting to 8A?

What I don't understand is why GM didn't provide a full-blown 240VAC 32A EVSE with a simple 120V adaptor already plugged in and awaiting removal when a 240V outlet becomes available. The plug should be an NEMA 14-30/50, with a neutral blade that it will fit both NEMA 14-30 and 14-50, and perhaps detect the 14-30 L-shaped neutral socket for automatic switching from 32A to 24A. At 120V the Bolt should default to an overridable 8A as at present. How much more does a 32A contactor cost than a 12A one? Nothing else inside that Clipper Creek unit should need to change, the controller's power supply is already a universal 120/240V one. The Bolt's 120V EVSE seems like pointless penny-pinching.

 

[devbolt]

What I don't understand is why GM didn't provide a full-blown 240VAC 32A charger with a simple 120V adaptor already plugged in and awaiting removal when a 240V outlet becomes available. The plug should be an NEMA 14-30/50, with a neutral blade that it will fit both NEMA 14-30 and 14-50, and perhaps detect the 14-30 L-shaped neutral socket for automatic switching to 24A. At 120V the Bolt should default to an overridable 8A as at present. How much more does a 32A contactor cost than a 12A one? Nothing else inside that Clipper Creek unit should need to change, the controller's power supply is already a universal 120/240V one. The Bolt's 120V EVSE seems like pointless penny-pinching.

Because the EVSE will report 32A down the pilot signal, regardless of the voltage or circuit. While the Bolt will restrict itself to 8A or 12A on 120V, if used with another BEV, that BEV may choose to try to pull more amperage than the circuit can safely handle. Best scenario is the circuit breaker trips before the wires start a fire. It might be possible to engineer in a solution that restricts amperage depending upon the adapter that is in use, but that adds complexity, which adds cost.

Tesla supplies such an EVSE with their cars, but those cars also cost twice as much as the Bolt, so Tesla can afford to subsidize the cost of the EVSE included with the car.

 

[vrpratt]

What I don't understand is why GM didn't provide a full-blown 240VAC 32A charger with a simple 120V adaptor already plugged in and awaiting removal when a 240V outlet becomes available.

Because the EVSE will report 32A down the pilot signal, regardless of the voltage or circuit. While the Bolt will restrict itself to 8A or 12A on 120V, if used with another BEV, that BEV may choose to try to pull more amperage than the circuit can safely handle. Best scenario is the circuit breaker trips before the wires start a fire. It might be possible to engineer in a solution that restricts amperage depending upon the adapter that is in use, but that adds complexity, which adds cost.

Regarding fire, the National Electrical Code specifies the minimum wire gauge for each breaker in the house. If the homeowner has installed a higher-amperage breaker than the original, or rats have chewed up the wiring, or the breaker has corroded somehow, there will be a risk of wiring causing a fire whether or not you have an EVSE. Provided the house wiring and breakers are intact and within code the risk of wiring causing a fire due to circuit overload from any cause including your EVSE is negligible compared with the other common ways electrical fires can start. That's what breakers are for.

Regarding overload, there is nothing to stop people from plugging two 1000-watt appliances into the same 120V circuit protected by one 15A breaker, or two 1500-watt space heaters on one 20A breaker, other than their common sense and the tripped breaker. And there is no reason an EVSE needs to draw more than 8A at 120V or 24A at 240V until the user permits it to do so, relying on the same common sense plus a large clear warning notice at the beginning, middle, and end of the instructions for how to speed up charging. The Jencar EVSE can be factory configured with a buyer-specified menu of user-selectable amperages. The one I've ordered, with a 2.5 meter cable and arriving next week, will have a 16A-20A-24A-32A menu, selectable with an RFID card that avoids any moisture ingress. If I use it with a breaker less than 40A I'll select the appropriate amperage so as not to trip the breaker, e.g. 24A if on a dryer outlet with a 30A breaker. If I forget to do so, worst case is the breaker will trip.

One thing I don't understand is the concern about using the Bolt's EVSE with another car. If it works like any other L2 EVSE at 240V how could there be a problem?

If the EVSE provided with the Bolt had the user-selectable amperage feature at both 120V and 240V it wouldn't have been necessary for the Bolt to duplicate that feature as the EVSE wouldn't supply any more current than instructed by the user. This is no different than the current EVSE limiting itself to 12A at 240V even though the Bolt would happily draw 32A if the EVSE would let it. But one assumes GM must have at least considered that option and had a reason for giving the Bolt that feature at 120V, maybe because Clipper Creek weren't willing or able to let the user control the current at their EVSE. Like I said in the beginning, if GM had more control over the EVSE design they could have provided a 240V one.

 

[devbolt]

One thing I don't understand is the concern about using the Bolt's EVSE with another car. If it works like any other L2 EVSE at 240V how could there be a problem?

This was in reference to GM supplying a dual-voltage 32A EVSE with the car. The Bolt would in theory automatically restrict itself to 12A or 8A on 120V despite 32A capabilities being advertised by the EVSE. But a non-Bolt might see 32A and try to pull that much, regardless of voltage. If someone had access to a dual-voltage 16A unit, it would be easy enough to determine if the Bolt self restricts itself to 12A on 120V

If the EVSE provided with the Bolt had the user-selectable amperage feature at both 120V and 240V it wouldn't have been necessary for the Bolt to duplicate that feature as the EVSE wouldn't supply any more current than instructed by the user. This is no different than the current EVSE limiting itself to 12A at 240V even though the Bolt would happily draw 32A if the EVSE would let it. But one assumes GM must have at least considered that option and had a reason for giving the Bolt that feature at 120V, maybe because Clipper Creek weren't willing or able to let the user control the current at their EVSE. Like I said in the beginning, if GM had more control over the EVSE design they could have provided a 240V one.

Complexity of the EVSE is one factor. The less complex it is, the cheaper it is to build. Ignorance or forgetfulness of the Bolt owner is another. If you are going for the mass market, you have to go for the lowest common denominator, which means going for less technically savvy buyers who don't want be bothered with having to constantly be adjusting the EVSE depending upon the circuit they're plugged into.