You will need a lower current EVSE, the factory dual voltage one cannot be set to only draw 16 Amps. If you try to use it on a 20 Amp circuit, it will trip the breaker. I use a Clipper Creek LCS-20 for 16 Amps at 240 VAC. It is simple, reliable, and it just gets the job done. You can find cheaper options, but the Clipper Creek units are solid. I got mine used on Craigslist so it was even cheaper.

 

I agree with the clipper creek LCS-20. I purchased that in 2014 when I bought my Gen 1 Volt, then used it on m Gen 2 Volt, and currently using it on my Bolt EUV. For me, 16 amps is PLENTY good enough for home charging. It does appear Clipper Creek is no more, bought or merged with Enphase, but I imagine you can still find the LCS-20 somewhere.

 

The GM dual level charger is a failure on multiple levels… one of which is the lack of complete control over charging current.

You are better off getting yourself a good adjustable EVSE or a dedicated 16 amp EVSE. For adjustable models, I’m a big fan of the Autel lineup. If you want a dedicated 16 amp model, Clipper Creek makes a nice one, and my favorite is the AeroVironment/Webasto TurboCord (or TurboCord Dual if you also want 120V mode).

 

Or maybe a suitable after-market cable which can be configured to serve a max of 16amps or so to the vehicle?

Welcome to the forum. The dual voltage comes with two adapters, one for 120V and another for 240V/32 amps. Turns out, one can buy additional adapters that tells the EVSE to limit the amps.
edit: looks like the lowest amps is 24 for the adapter. Still too high. Some of the older dual voltage units could be hacked to adapt the 120V adapter to 240V to limit it to 12 amps. Not sure it works with the latest EVSEs supplied by GM.

 

Where can you buy different adapters for the GM supplied EVSE?

 

Hello!

New 2023 Bolt EUV owner here. We're setting up in the garage for charging. The wiring for the whole garage is max 30amp, with 20amps available for a charger.

This currently goes to an outlet which was set up for a table saw, but we can adapt cheaply from NEMA L6-20-R to NEMA 14-50 for use with the built-in charging cable.

The trick is that there seems to be no software setting to limit amperage except for at 120 volts. If we do this are we just going to over-current and fail? Or will it smartly test or remember limits? Is there a way to force the software to draw less? Or maybe a suitable after-market cable which can be configured to serve a max of 16amps or so to the vehicle?

Thanks in advance

Aftermarket would maximize the circuit power. If you can live with 12 amps you can use the 120V cord for the dual-voltage and connect it to a 5-15 to 6-20 adapter. It will deliver 240V, and the cord will limit the EVSE to 12A. A $15 solution to the problem that leaves 4A on the table.

ga2500ev

 

ga2500ev's solution of using the Chevrolet dual level charge cord's 5-15 plug for 12 A is good, but I would build the L6-20 to 5-15 adapter from parts instead of using an off-the-shelf adapter. I don't think you can find an L6-20 to 5-15 adapter that's UL-listed, if you can find one at all.

Plenty of wall-mountable EVSEs can be configured for 16 A, but none of them come with L6-20 plugs. But for most of them it's not too difficult to remove the plug cord and replace it with an L6-20 plug cord, as the cords are meant to be removed when hard-wiring. That's the solution I'd favor. It avoids the use of adapters, which are a point of failure and a fire risk. Or you could skip the plug and receptacle altogether and hard-wire the EVSE right where your existing receptacle is.

Here's a Dewalt 16 A dual level charge cord with a 6-20 plug. I am unsure of the quality, but it looks like it's possibly better than the Amazon cheapos, which I do not trust for safety. The Dewalt is on sale now. It would need to be adapted to your L6-20.

 

This DeWalt has a 3 year warranty. That's good! Pretty unusual for a 16 amp 240v EVSE.

 

Thanks everyone! Very helpful - I was a bit unsure as to weather a rate-limited EVSE would break the Bolt's brain. Sounds like that will be fine.

Love the idea of rewiring the ending, but for now will go with the adapter. It's an indoor garage, so not too worried about water/etc in the adapter. I can probably fashion something to make sure it can't work loose over time as well.

 

Just to fill in a little information here...

The Bolt can charge up to 48A on 240V (earlier models were limited to 30A, I believe). When you plug the EVSE into the vehicle, they talk to each other and settle on the slowest of the two limits. So, you can plug an EVSE that's limited to 16A into a Bolt which takes 48A and they agree on 16A. You can plug an EVSE that's set to 80A (on a 100A circuit) into a Bolt and they'll settle on 48A. Safe either way.

 

An adjustable like Grizzl-e and many others could select 16A and maybe move to some new location if needed with any of the amp choices.

 

Optional plugs for the Chevrolet dual level charge cord:
14-30 plug, 24 A, GM part # 84900628
TT-30 plug, 24 A, GM part # 84900629 (max 12 A on the Bolt)

 

Thanks everyone! Very helpful - I was a bit unsure as to weather a rate-limited EVSE would break the Bolt's brain. Sounds like that will be fine.

You‘ll be fine. The Bolt can handle anything down to 6 amps. I do it all the time.

Love the idea of rewiring the ending, but for now will go with the adapter. It's an indoor garage, so not too worried about water/etc in the adapter. I can probably fashion something to make sure it can't work loose over time as well.

Don’t re-wire it. There are plenty of adapters out there. I have an almost embarrassing number of them. And for the most part, voltage doesn’t matter… it’s amperage that matters. If an adapter can handle 20 amps at 120V, it should be able to handle 20 amps At 240V. The limiting factor is the insulation… but that usually doesn’t become a weak point until the voltage gets ridiculous.

 

2017-2021 Bolts Level 2 AC charge at a maximum 32 A. And the EVSE and the car don't really talk to each other and agree on a charging rate. The EVSE tells the car the maximum available current, and the car take what it wants. It's not a negotiation. There is no agreement. The communication is one-way. It's up to the car to abide by the restriction put forth by the EVSE.

 

Here is how I pictured the conversation going:

Cable plugs in.
Bolt: Oh, yeah, I like that. Give me the full 48!
EVSE: I've only got 32. Will that be OK?
Bolt: Sure, whatever.

And somewhere, the wires are wondering why nobody asked them how much they could handle.

 

The other thing about getting an adjustable like the Grizzl-e is that if you decide you need more amps you can upgrade the circuit and still use the same charger. They are super bomber and very reasonably priced. Grizzl-E Classic | UNITED CHARGERS INC. I got this one. To adjust amps out you need to open the unit and change dip switches, but its easy.

 

Im in a similar situation, but needed a faster charger than the 120v asap, so I bought an evse that was $180 on amazon (non ul rated) that plugged into my 6-20 outlet and it works great, but that money could have been used towards my emporia unit I just bought instead, but I knew nothing of these and needed one right away to get the range to make the car usable. But, on the plus side, if my emporia unit ever fails I still have the other that can fully charge in 10 hours (overnight for me).

 

I originally purchased an adjustable evse because I knew my load center was minimal. I've been charging at 24A for many years on three cars. I have time of use and could go up to fill my normal use in the best two hours but it's fine.
All cars can adjust to charger. The Tesla lets me adjust via app and shows the voltage. Bolt needs to step it up and show voltage. Remember 10% is NEC.

 

Hello!

New 2023 Bolt EUV owner here. We're setting up in the garage for charging. The wiring for the whole garage is max 30amp, with 20amps available for a charger.

This currently goes to an outlet which was set up for a table saw, but we can adapt cheaply from NEMA L6-20-R to NEMA 14-50 for use with the built-in charging cable.

The trick is that there seems to be no software setting to limit amperage except for at 120 volts. If we do this are we just going to over-current and fail? Or will it smartly test or remember limits? Is there a way to force the software to draw less? Or maybe a suitable after-market cable which can be configured to serve a max of 16amps or so to the vehicle?

Thanks in advance

This link will show a 16 amp unit, also the vendor will install just about any plug you want, I started with one if these on my Spark EV (less than $200) Or you can make / get and short cord adapter.

Dostar Duosida 16A 3.84kW Portable Charging Station - EVSE D25-16A

No Coupon Needed Sale! I'm adding the best coupon value directly to the prices shown here! Shown with optional travel case, these are a new item and great way to protect your new Duosida EVSE!, add to cart here: https://tinyurl.com/bsacarrycase 16A 3.84kW Portable Electric Vehicle Charging...

www.bsaelectronics.com

 

Hello!

New 2023 Bolt EUV owner here. We're setting up in the garage for charging. The wiring for the whole garage is max 30amp, with 20amps available for a charger.

This currently goes to an outlet which was set up for a table saw, but we can adapt cheaply from NEMA L6-20-R to NEMA 14-50 for use with the built-in charging cable.

The trick is that there seems to be no software setting to limit amperage except for at 120 volts. If we do this are we just going to over-current and fail? Or will it smartly test or remember limits? Is there a way to force the software to draw less? Or maybe a suitable after-market cable which can be configured to serve a max of 16amps or so to the vehicle?

Thanks in advance

To flow inline with these great suggestions, my input follows the adjustable amp EVSE path. In short, if you can tolerate the 120 volt, 12 amp setting (Level 1) on the GM EVSE, this could be your best approach (i.e., least expensive) for the short term, until you can "score" a good deal on an adjustable Level 2 charger, such as the Autel MaxiCharger. I used the the Level 1 @ 12 amps on a business trip to a "charging desert," so I know it will work, although it does take time to charge at ~1.4kW per hour. My strategy was to plug in every chance I got. This is just a thought, as some of the other suggestions may be a but quicker, although a higher end EVSE may be more long-term

 

Hello!

New 2023 Bolt EUV owner here. We're setting up in the garage for charging. The wiring for the whole garage is max 30amp, with 20amps available for a charger.

This currently goes to an outlet which was set up for a table saw, but we can adapt cheaply from NEMA L6-20-R to NEMA 14-50 for use with the built-in charging cable.

The trick is that there seems to be no software setting to limit amperage except for at 120 volts. If we do this are we just going to over-current and fail? Or will it smartly test or remember limits? Is there a way to force the software to draw less? Or maybe a suitable after-market cable which can be configured to serve a max of 16amps or so to the vehicle?

Thanks in advance

I have a similar situation. I installed a NEMA 14-50 outlet tied to a 30 amp breaker and use a ShockFlo 40 amp variable current charger with push-button settings of 16, 20, 24, and 32 amps. I usually use the 20 amp setting, sometimes 16 amps. The only other constant connections to that circuit are a Freezer and an electric fence charger. The ShockFlo charger is simple (no WiFi), well made and can be used outdoors. although I do sometimes have to plug it in twice before it will start. I notified the manufacturer and they sent a replacement, but it had the same problem. They offered a refund but I declined and kept the charger. I can live with the small problem.

 

I have a similar situation. I installed a NEMA 14-50 outlet tied to a 30 amp breaker and use a ShockFlo 40 amp variable current charger with push-button settings of 16, 20, 24, and 32 amps. I usually use the 20 amp setting, sometimes 16 amps.

That ShockFlo 40 amp EVSE is not safe to use on a 30 amp circuit. All it takes to start a fire is for some curious kid or adult to walk by and push the current adjustment button. The National Electric Code requires current adjustment means to be behind a cover, door, or password. (NEC 625.42(B) and 750.30(C)). And the reviews indicate the EVSE's cable is insufficient for 40 A. The EVSE is not UL or ETL certified, and would never be certified by any safety organization.

If the manufacturer has screwed up such basic things, how can you trust that they didn't also screw up other safety features, like checking for a ground, having a working GFCI, or disconnecting the power at the correct times? You can't trust any of the cheap junk sold on Amazon. The manufacturer and seller is overseas and couldn't be held liable for any problems. Amazon escapes liability by calling themselves merely a marketplace, and not the seller.

If it plugs into the wall, it should be certified by a safety organization and sold by a reputable, liable seller. That means a brick-and-mortar store in this country, or its online store. Otherwise you risk shock or fire. You can get a UL-certified adjustable current EVSE like the Grizzl-E Classic for less than that ShockFlo's price.

 

I bought a Vevor charger with Bluetooth and app directly from Vevor for $150 including shipping. You can easily set the charge rate from 10 - 32 amps.

 

Thanks for your responses. I will rethink my setup. I had looked at the Grizzle-E but didn't want to open up a box to change the current setting.

 

It's really easy to reset. Or you can order it at a specific setting and Grizzle-E will set it up for you at the factory.

 

2017-2021 Bolts Level 2 AC charge at a maximum 32 A. And the EVSE and the car don't really talk to each other and agree on a charging rate. The EVSE tells the car the maximum available current, and the car take what it wants. It's not a negotiation. There is no agreement. The communication is one-way. It's up to the car to abide by the restriction put forth by the EVSE.

Yes, this. However, it's not entirely up to the car to abide by the restriction. If the car exceeds the current that the EVSE told it it was allowed to take, the EVSE can and will terminate the charge by shutting power off.

A 50 A receptacle isn't allowed on a 30 A circuit that has more than one receptacle: NEC Table 210.21(B)(3).

625.40 is more important in this case. Every outlet installed for the purpose of supplying EVSEs greater than 16 amps or 120 volts has to be on its own branch circuit. Supplying a fridge or electric fence or any other receptacles on the same circuit as a 240 V EVSE outlet? Not allowed. The only exceptions for this are for supplying more than one EVSE, and only in specific cases.

 

Yes, this. However, it's not entirely up to the car to abide by the restriction. If the car exceeds the current that the EVSE told it it was allowed to take, the EVSE can and will terminate the charge by shutting power off.

Nothing in the J1772 standard requires the EVSE to monitor the current being drawn by the car or break the circuit when too much current is drawn. EVSEs generally don't incorporate overcurrent circuit breakers, and if it's not a smart EVSE, it's probably not able to measure the current.

 

@hndyman, minimally you could try to cover the current adjustment button on your existing ShockFlo so it can't be pressed accidentally. It's understandable if you're reluctant to spend more money on a different EVSE.

 

@schwinn, the car continues requesting power even after charging of the main battery is complete. It uses power for things like 12-volt battery maintenance and main battery conditioning.

The car will stop requesting power when it detects that the charge connector latch release button has been pressed. That's when the EVSE cuts the power.

 

@schwinn, the car continues requesting power even after charging of the main battery is complete. It uses power for things like 12-volt battery maintenance and main battery conditioning.

The car will stop requesting power when it detects that the charge connector latch release button has been pressed. That's when the EVSE cuts the power.

Fair enough. Though that still means the car doesn't tell the EVSE "open contactor"... correct?

EDIT: I will also note that the charger actually says 0.00kW is being delivered. That should mean it's basically OFF. I also haven't ever seen any conditioning happening yet (car is in the garage, which hasn't gotten too cold yet, even though I'm in CT. Ir's 47F out right now, for example.

 

Semantics. There is no "open the contactors" message exactly. What there is is a "give me power" signal from the car, which while maintained, means the EVSE should keep the contactors closed. When the car stops sending that signal, the EVSE opens the contactors.

 

The "conversation" goes more like this:

Cable plugs in...
EVSE - "I'm capable of 32A".
Bolt - "Close the contactor".

Some time later...
Bolt - "Open the contactor".

I'm not sure the latter happens. My Juicebox, for example, I can hear the contactor close to supply power. But after that, it stays "green flashing" on the indicator, as it's trying to supply power to the car the entire time. The car is done charging, but the JB still keeps flashing green. It has no idea that charging stopped. In fact, the app keeps saying it's "charging" even though it also says it's delivering 0kW. Again, this is on L2 only...

Fair enough. Though that still means the car doesn't tell the EVSE "open contactor"... correct?

EDIT: I will also note that the charger actually says 0.00kW is being delivered. That should mean it's basically OFF. I also haven't ever seen any conditioning happening yet (car is in the garage, which hasn't gotten too cold yet, even though I'm in CT. Ir's 47F out right now, for example.

The car does tell the EVSE to "open contactor". The car controls the process using voltages on the control pilot line. There are various "states" that the CP line can be in, and they are controlled by the EV by changing the voltage on the line. The EVSE monitors the voltage and responds based on the state. There is a state for "charging" which turns the contactor on and "charge complete" which is the same as disconnected, which turns the "contactor off".

The state that you are seeing is "charging", but the EV is drawing no power. But rest assured that the EV is in control of that process.

ga2500ev

 

Not to get pedantic, but I do want to learn.

From what I'm seeing in the link provided before (ie, to summarize), the resistor on the PP line tells the EVSE that the car what the max capability of the CABLE is. Easy.

Next, the CP line has 12V. When connected, this tells the EVSE and car that the car is connected.

Next, the EVSE controls a PWM signal on the CP line to tell it what is capable of delivering. The car then tells the station to being charging (ie, the "open contactor" signal). Once the car is satisfied with the voltage being delivered, it opens up its own contactors to charge the battery.

As noted by the article, "While CCS also transmits the car's state of charge, type 2 dosen't. So the charging station doesn't know if or when your car is fully charged. But the station also doesn't need to know that, the car is keeping an eye on that." For this reason, I don't believe there is ever a "open contactor" signal from the car (until you disconnect the cable, of course... or if there is an error).

That's the point I was trying to make... that the charger never stops while it's connected. The CAR tells it to stop delivering power. This is why my JB doesn't know the car is "done" charging (probably because the car could also stop charging for peak management reasons, which my car is setup to do as well).

I do agree, maybe the station is still drawing power from the house. I would expect his should show up in the reading (after all 0.5A @ 240V as noted by jmcbrew = 120W which is within the double digits of the reading on the app - yes, I know this could still be lying to us). However, I challenge this is going to the car, because the charging spec doesn't allow this low of a delivery (note the graph on the link, which limits you to 6A minimum... which I have seen others report as the minimum charging level of the Bolt?). For this reason, maybe the 0.5A is actually just being used by the station? That does seem like a large load for "nothing" but I would want to see what the draw is into the car, to be sure it's actually getting there.

 

The proximity pilot line does not run back to the main body of the EVSE. The EVSE is not monitoring the proximity pilot. Proximity pilot is in the plug handle, and exists only for the car to detect that a connector is plugged into the car's charging port, and whether the latch release button is pressed.

6 A is not the minimum power that can be delivered. 6 A is the minimum current limit that the EVSE can signal to the car. The car is free to use any current between 0 and the limit. Remember, this whole thing is a glorified extension cord. The EVSE connects power to the car, then it's up to the car to use the power however it wants to.

The EVSE itself uses a few watts to power its electronics. Any power draw beyond that is going to the car. (or is lost in the cabling)

Best to go to the source. You can read SAE J1772-2010.

 

The specs linked by @balazer go into far more detail than consumers need to know, they are spelled out primarily for equipment manufacturers to ensure consistent product functionality.

One item worth noting, this spec is dated 2010, which is prior to adoption of CCS (which was in draft form at the time and ratified in 2012). Initially, DC charging was described using the J1772 plug and socket, but was relatively low powered (80A maybe?). Thus CCS eventually specified separate terminals for DC power transfer. However, this item (5.5 in the document) is interesting:

5.5 Digital Data Transfer​

A duty cycle of 5% indicates that digital communication is required and must be established between the EVSE and vehicle before charging. This is required for DC charging. Digital communication is optional at any valid control pilot duty cycle for AC Level 1 & 2 charging. When optionally used with AC Level 1 & 2 charging, more functions may be accommodated than by Control Pilot duty cycle functionality alone. Digital data transfer is currently under development (read this to mean ISO15118/CCS protocol development).​

What this indicates is, J1772 specs were ratified with CCS DCFC in mind, though not yet completed. The same control pilot circuit defines the duty cycle requirements to trigger the EV to invoke digital communications needed for DCFC.

As has been discussed elsewhere, the ISO15118 Specs outline communications for CCS charging, but the ISO15118 specs also apply (optionally) for AC charging using J1772 couplers. In subsequent ISO15118 specification standards, Vehicle to X, and Plug & Charge (secure method with digital certificates) were defined. Therefore, mechanisms are in place for enabling both V2X and P&C functionality on both AC and DC charging. The keyword is the optional clause in both J1772 and ISO15118 specs, and few, if any AC charging equipment makers, nor OEMs, have pursued this option, but they could! Similarly, none have pursued DC charging on the J1772 coupler.

BTW, Tesla has followed J1772 communications specs for AC charging since their first mass produced EV (Model S in 2012), thus enabling their cars and AC chargers to work on any EV that is equipped with J1772 or Tesla sockets. This allowed for adapters because of the common communications protocols. However, in V3 Tesla AC chargers, they added optional capabilities for digital communications for Tesla vehicles only, and for billing purposes. While this is an optional provisioning step, it is primarily only used when billing is intended, and Tesla will only provision billing for sites with 6+ AC destination chargers, and only if the site host requests it. Therefore, Tesla V3 AC chargers remain compatible with J1772 EVs by default. A final word on this, the provisioning can also be performed to limit AC charging to Tesla vehicles only, or for specific Tesla vehicles without adding billing capabilities. This is accomplished similar to a MAC address filter, the unique vehicle ID has to conform to a pattern to authorize charging. Tesla Tap claims to have built a bridging capability into their adapters allowing J1772 EVs to appear as a generic Tesla EV, but not comply with the requirements for the specific Tesla, or billing schemes.

Because Tesla has adopted the ISO15118 stack in newer models, and offers a retrofit for older models to use CCS, it is conceivable AC billing could be modified in future firmware releases allowing all EVs to use Tesla AC chargers and be automatically billed by Tesla. Or, this could be done side by side with native Tesla protocols for legacy Tesla EVs that don't support CCS like they are doing on the DCFC Supercharger network.

Digging a bit deeper into the billing aspects. Tesla "Plug&Charge" is effectively the same as CCS AutoCharge. I know Plug&Charge is a confusing topic, because it is used to describe both the certificate based ISO15118 P&C, as well as AutoCharge. In the original CCS specs from 2012, provisions were made to allow vehicles to share their unique ID with the charger. This could be MAC address for the charging port, or VIN, but in either case, this identifier is unique and thus can be used to link the car to a billing account on the charging network's systems. While this identifier is nearly universally implemented on both native CCS equipped EVs (VW group may not comply???), it is also implemented in the ISO15118 stack on Tesla cars. Evidence of Tesla complying is that CCS compatible Teslas can enroll in EVGo's Autocharge+ the same as most CCS equipped EVs. While Autocharge lacks the security of a certificate and TLS encrypted session, it is simple to implement and could be easily done on both AC and DC Tesla chargers if Tesla is willing to do so.

Because AutoCharge lacks security, it is unlikely to be the long term Plug&Charge method. But, since J1772 is included in the ISO15118 stack, it is conceivable ISO15118 P&C with certificates could be implemented universally, on AC and DC chargers, over J1772, CCS, or NACS plugs and sockets. AutoCharge is a more universal implementation of plug & charge in that it requires minimal computing due to the lack of certificates and not using the optional asymmetrical encryption that is required for ISO15118 P&C. But most new EVs are being designed with ISO15118 P&C capabilities in mind, so over time it should become the dominant billing method.

My take on the proximity overlap, the Control Pilot pin detects the presence of an EV being connected to start the duty cycle signaling. The Proximity Pilot serves a different function, detecting when the plug is fully engaged and safe to send energy over the power pins to the car. Thus, when the lever on a J1772 or CCS plug is pressed, the circuit is opened to stop the flow of energy before the plug can be removed. Failing to do so could result in arcing with relatively high voltages and currents being passed to the car, resulting in personal or equipment damage. In other words, the PP functions as a safety measure while the CP is only concerned with signaling. No doubt there is a linkage between the proximity detection as the Control Pilot will signal to the EVSE to stop sending energy (end the session) when the PP is opened.