[Darsh]

For the camping trip this summer we're planning to bring our bolt. The campsites have a 30amp outlet (RV outlet) available for charging.

I called the park to find out what is the voltage available at the outlet. They said it 110volt.

I have the tesla Mobile Connector and the teslatap, however it won't be any faster than the stock bolt charger at 110v.

I could the change the amp setting in the car from 8amp to 12amp. I'm thinking that is the max I can use in this situation.

So if I charge the bolt at this outlet, ofcourse I'll need an adapter but, what will be the charge rate I'll get? Would it still be level 1 charging.

Is that correct?

Darsh

 

[bro1999]

For the camping trip this summer we're planning to bring our bolt. The campsites have a 30amp outlet (RV outlet) available for charging.

I called the park to find out what is the voltage available at the outlet. They said it 110volt.

I have the tesla Mobile Connector and the teslatap, however it won't be any faster than the stock bolt charger at 110v.

I could the change the amp setting in the car from 8amp to 12amp. I'm thinking that is the max I can use in this situation.

So if I charge the bolt at this outlet, ofcourse I'll need an adapter but, what will be the charge rate I'll get? Would it still be level 1 charging.

Is that correct?

Darsh

Yes, you'll be limited to 12 amps charging.

 

[XJ12]

some people have reported finding a nearby outlet that's on another leg to get 240V.

 

[GlenandhisBolt1!]

XJ12: This could be problematic. The two outlets would have to be on opposite poles of the circuit to get 240V AC, which means one of them is miswired. 110 V AC and 240 V AC have a lot in common. 110V AC uses neutral (usually white) and +110 VAC black ('load') wires, while 240 VAC uses the same +110 VAC line, but a -110 V AC (usually red) line on the other pole. For 240V AC, the two lines are in phase, producing a net 240 V AC. If the two outlets are wired correctly, the result is still 110V AC, although each circuit should be capable of it's full current rating. But it's still a bad idea to mess with so much power.

 

[raitchison]

Maybe you know this and are just trying to simplify but AC doesn't really have + and -. AC "alternates".

With 220v in North America at least you have two 110v circuits that are out of phase with each other, the difference in potential caused by the difference in phases gives you "220v" They don't have to be (and usually aren't) 180° (opposite) phases either they just have to be significantly out of phase for it to work.

When I was in the Navy we had 440v 3 phase ungrounded system, each line was 120° out of phase with the other two. For our 120v outlets we used transformers to reduce 440v to 60v (still 3 phase 120° out of phase) and put any two of them to the different poles of the outlets giving us a nominal 120v.

For what @XJ12 is talking about you'd just need to find different outlets that have their 110v line out of phase with each other, put them on opposite poles and you have 220v, no "common" line is required. I'd imagine for a 30A 110v outlet it's going to be one outlet per circuit so there's a decent chance that the outlet in the neighboring site is on a different phase.

Still seems dicey because you'd have to MacGyver something together with multiple extension cords into a connector/adapter that took the power wire for each and fed them to the same female connector but you could double your output to ~2.6kW (with the included charger) or go all the way up to ~6.6kW if you have a portable EVSE that supports it AND all of your extension cords, adapters, and connectors are capable of safely handling a full 30A.

 

[XJ12]

I read somewhere (okay, it was on a Tesla website), that modern RV parks now use ground fault protection and trying to combine two 110VAC that are on different buses will trip the GFCI. But, I would think modern RV parks would also have the 240V 14-50 outlets available.

 

[daveo4Bolt]

we really need Chevy to offer:

1. support for more than 12 amps with 120volts
2. in car charging control for AMP control when one encounters uncommon charging scenarios

 

[XJ12]

we really need Chevy to offer:

1. support for more than 12 amps with 120volts
2. in car charging control for AMP control when one encounters uncommon charging scenarios

Could haul around a step up transformer I guess. $80

https://www.ebay.com/itm/3000-Watt-...448689?hash=item54208e4971:g:E1IAAMXQEgpTDoXe

Don't see the specs for this unit at this cost. Not sure if the 3000 watts is for continuous duty or not.

24 amp (80% of 30 amp service) by 120VAC is 2,880 watts. Interesting that it would split to 12 amps per leg where you could use the Bolt's OEM EVSE.

Edit: Okay, missed the specs at the bottom the first time. They recommend the transformer to be 1.5 X the load. So need 5000 watt. Found this one on Amazon for $130: [ame]https://www.amazon.com/ELC-T-5000-5000-Watt-Converter-Transformer/dp/B00EBC5HSS[/ame]

Edit again. Oops this transformer now says 2 times the load. rated 2500 watt continuous. well, getting very close.

 

[raitchison]

Could haul around a step up transformer I guess. $80

https://www.ebay.com/itm/3000-Watt-...448689?hash=item54208e4971:g:E1IAAMXQEgpTDoXe

Don't see the specs for this unit at this cost. Not sure if the 3000 watts is for continuous duty or not.

24 amp (80% of 30 amp service) by 120VAC is 2,880 watts. Interesting that it would split to 12 amps per leg where you could use the Bolt's OEM EVSE.

That does not look like it could handle 3000W continuous.

 

[XJ12]

That does not look like it could handle 3000W continuous.

Here's one for $130: [ame]https://www.amazon.com/Simran-AC-3000-Transformer-Converter-Conversion/dp/B004MPR43A[/ame]

just had to google 3000 watt continuous rated.

edit: still might be under sized if there's a surge current when starting the EVSE. Don't know if that's a concern or not.

 

[Nook]

Here's one for $130: https://www.amazon.com/Simran-AC-3000-Transformer-Converter-Conversion/dp/B004MPR43A

just had to google 3000 watt continuous rated.

edit: still might be under sized if there's a surge current when starting the EVSE. Don't know if that's a concern or not.

I realize this is an old thread, BUT although a transformer is able to create 220V, you are still wattage limited at the cord. I wanted to make that clear for future readers.

So, if you plug a regular cord into a 20A socket, you have 120V*20A to work with. If you convert to 220V, you now have 10A max. Real max would be less than that. Bottom line is you can't involve only one regular outlet and end up being able to charge on 220V, unless you can turn your charger down to 8A (which is not common). That's not worth the expense and hassle compared to using the stock charger on 120V 12A for zero extra dollars and zero extra time.

 

[XJ12]

I realize this is an old thread, BUT although a transformer is able to create 220V, you are still wattage limited at the cord. I wanted to make that clear for future readers.

So, if you plug a regular cord into a 20A socket, you have 120V*20A to work with. If you convert to 220V, you now have 10A max. Real max would be less than that. Bottom line is you can't involve only one regular outlet and end up being able to charge on 220V, unless you can turn your charger down to 8A (which is not common). That's not worth the expense and hassle compared to using the stock charger on 120V 12A for zero extra dollars and zero extra time.

Has been a while. Believe the original premise was having 110V 30 amp available at a trailer park.

But good to caution that this shouldn't be tried at home.

 

[hatchy]

Is there even a way to DIY an 8 amp limit @ 240v? Say if you were at a 120v 30 or 20amp outlet. How does the evse tell the car to limit the charge rate, and is it easy to limit it to less than 12 amps?


That would be interesting to build one if it is possible. Kind of a very specific problem scenario to build a solution for, but still would be neat.

 

[Nook]

Is there even a way to DIY an 8 amp limit @ 240v? Say if you were at a 120v 30 or 20amp outlet. How does the evse tell the car to limit the charge rate, and is it easy to limit it to less than 12 amps?

That would be interesting to build one if it is possible. Kind of a very specific problem scenario to build a solution for, but still would be neat.

Questionable as to why, but you would need to spoof the car communications and inject an 8A max into the request. I would start with the guts of a TeslaTap (assuming it has electronics in it) and go from there.
The more expensive chargers can adjust their rates, some to as low as 8A, but again 240A @ 8A is only 50% faster (at most) than stock charger at 12A.

Theoretically, an on the ball charger could monitor the temperature of the wire (indirectly most likely), deduce it was being overdriven, and lower the allowed current until the temperature came down.

 

[GregBrew]

I realize this is an old thread, BUT although a transformer is able to create 220V, you are still wattage limited at the cord. I wanted to make that clear for future readers.

So, if you plug a regular cord into a 20A socket, you have 120V*20A to work with. If you convert to 220V, you now have 10A max. Real max would be less than that. Bottom line is you can't involve only one regular outlet and end up being able to charge on 220V, unless you can turn your charger down to 8A (which is not common). That's not worth the expense and hassle compared to using the stock charger on 120V 12A for zero extra dollars and zero extra time.

Wiring is rated by Voltage and Amperage, not by the Watt. Most household wiring isn't going to be Voltage limited (which is a function of insulation), but by Ampacity. A residential main electrical panel is rated by voltage (usually 240V AC in the States) and Current, not Power.

Typical residential wiring (#12AWG and #14AWG ) NM-B (Romex) and THHN is rated for 600V AC. Thus, 240V AC is no problem.

The cross-sectional area of a conductor limits current. A house circuit made of #12AWG Cu NM-B should be perfectly capable of carrying 240V AC at 20A intermittently, or 16A (80%) constantly. #14AWG Cu numbers would be 15A intermittently, or 12A constantly.

For safety, all up and down-stream outlets should be changed from 5-15R or 5-20R to a receptacle reflecting a 240V AC 20A circuit (without Neutral). Blank plates work well, too. It may not meet the local building codes, though.

A capable EVSE should be able to pull 3840W (16A x 240V AC) from such a #12AWG Cu circuit all day long. I've been using just such a setup for years. The stock Bolt EVSE at 240V would only pull 2880W (12A x 240V AC). No problemo.

Just because you double the voltage (on capable wire), current need not be reduced by half within a household. Transformers (which few homeowners ever deal with) *are* power limited. Check with the utility.

https://www.houwire.com/pdf/Article_310-Conductors_for_General_Wiring.pdf


Edit 11:12PDT to add last paragraph.

 

[Nook]

For safety, all up and down-stream outlets should be changed from 5-15R or 5-20R to a receptacle reflecting a 240V AC 20A circuit (without Neutral). Blank plates work well, too. It may not meet the local building codes, though.

A capable EVSE should be able to pull 3840W (16A x 240V AC) from such a #12AWG Cu circuit all day long. I've been using just such a setup for years. The stock Bolt EVSE at 240V would only pull 2880W (12A x 240V AC). No problemo.

Just because you double the voltage (on capable wire), current need not be reduced by half.

https://www.houwire.com/pdf/Article_310-Conductors_for_General_Wiring.pdf

You are correct, Greg, for your scenario. The suggestion was "buy this xfmr, generate 220V, and then charge faster". The issue is the xfmr suggested plugs in with the common computer cord, the vast majority of which are 16gauge, thus making the xfmr cord the fuse. This scenario also was a campground with 120V 30A only, so no screwing with outlets allowed..

 

[GregBrew]

You are correct, Greg, for your scenario. The suggestion was "buy this xfmr, generate 220V, and then charge faster". The issue is the xfmr suggested plugs in with the common computer cord, the vast majority of which are 16gauge, thus making the xfmr cord the fuse. This scenario also was a campground with 120V 30A only, so no screwing with outlets allowed..

Yikes! Yeah, sorry. Been a while since I read the whole thread.

 

[ga2500ev]

Is there even a way to DIY an 8 amp limit @ 240v? Say if you were at a 120v 30 or 20amp outlet. How does the evse tell the car to limit the charge rate, and is it easy to limit it to less than 12 amps?

The EVSE sends a signal down one of the connectors called the Control Pilot (CP). That signal is a 1000 Hz square wave used both to signal to the car that an EVSE is connected and to signal the maximum amount of current that the vehicle can draw. This is done using the ratio between the time the signal is high and the signal is low. It's called the duty cycle (DC). The image below shows the mapping of the DC to the allowed current.

More descriptions on J1772 can be found along with the above image here.

That would be interesting to build one if it is possible. Kind of a very specific problem scenario to build a solution for, but still would be neat.

OpenEVSE is all about building your own EVSE. It includes specs for controlling the max current. Once one has a clear understanding of the fact that an EVSE is little more than a smart extension cord with a special plug, the idea of building one's own to spec isn't a daunting as someone may think.

ga2500ev

 

[hatchy]

240A @ 8A is only 50% faster (at most) than stock charger at 12A.

50% faster could be a game changer for some people. Given, 30a 120v is probably not common, but if you are one who has it..

 

[banksdad]

we really need Chevy to offer:

1. support for more than 12 amps with 120volts
2. in car charging control for AMP control when one encounters uncommon charging scenarios

I would have agreed in the beginning of my ownership, but I just don't see it being a practical decision for GM. The nightmare of how many people would have problems make it not worth it. The only way this could work would be to have a dedicated 120V outlet on a 30 amp circuit. Most homes don't need that, and thus don't have it. And if you were going to add it, you might as well add the 240v 50 AMP circuit and just spend the $500 on a charger.