New Bidirectional EVSE

[dtbaker61]

Slick, what equipment are you using? I can make out the inverter but not the batteries in your photos.

The inverter is just a 3000w pure-sine, around $300. Charge controller is a renogy 40a, and there is a 365watt module on the roof.

The batteries are some ten yr old 12v-200ah deep cycle AGMs I pulled from a client's that was upgrading to Lithium. If you are considering something similar, I would suggest any 12v-100ah AGMs for the garage as a good balance between no maintenance, ok with temp swings down to freezing, etc. The 100ah are about the size of a regular car battery and much easier to move around.

If you put 4x 12v-100ah batteries in parallel you'd have enough energy for short outages.... and then you can back up with the MME, so you really don't need to oversize the stationary pack.

I keep them charged up with one (365watt) module on the roof for daily charge and light use in the garage to charge cordless tools, a little compressor, a little composter, garage radio, etc.

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[HuntingPudel]

It is probably impossible in MME, I don't recall any AC inverter capability for VTL built into MME.

Ioniq 5 limited trim comes with a J1772 plug device (not a combo, no DC connections) that allows the car to provide a modest 120V load (230V abroad), something like 2 kW. They call it VTL (to load). There must be some power switching behind the connecter, not sure where the internal inverter is. The Ioniq 5 internal inverter is powered by the traction battery (not sure if direct which is preferable or after the DC/DC converter). There is very little in the VTL plug, just resistors, diode, and temperature sensor. You could power some home stuff like a gas furnace, but this VTL is far short of VTH, said to be coming later for Hyundai too.

V2L inner secrets (Not Many) from the Ioniq 5 forum.

See the video at about 0:46 for the external connector:

Right, but V2L is completely different from 2-way charging. V2L is uses a relatively small inverter and is intended to function with a single load, like a coffee pot. It is usually accomplished in conjunction with a NEMA 5-15R socket. 2-way charging as I have read about it is intended to keep vital appliances up and running for relatively long periods. Totally different use cases. ?‍??

 

[louibluey]

Right, but V2L is completely different from 2-way charging. V2L is uses a relatively small inverter and is intended to function with a single load, like a coffee pot. It is usually accomplished in conjunction with a NEMA 5-15R socket. 2-way charging as I have read about it is intended to keep vital appliances up and running for relatively long periods. Totally different use cases. ?‍??

Agree. My comment was bit off topic in hindsight, but I was just noting that there could be at least faux bidirectional power with the AC Contacts, with some cars.

V2H for sure should be direct DC to the bidirectional EVSE. It's been coming for years now, I think with test units in JP or KR, was it Nissan? Someday.

It's the whole transferring power through straw analogy that @dtbaker61 coined some months back.

So I guess there eventually has to be a 240V inverter somewhere, probably with DC transfer to a 240V inverter in the bi directional EVSE. I suppose again as @dtbaker61 says, you eventually need all that enphase type phase matching and safety cutoff too.

But, do note that if the Ioniq 5, 2 kW is real (no idea), especially if it is true sinewave (no idea) you could power a small transfer switch to power critical loads in a home (esp. the gas furnace controls and motor). No different than doing the same with a small Honda generator as my home backup is setup to do now (if, and that is a big if) the 2 kW rating is real or something close to that continuous. ? (I have no idea what that means, but woof right back at you )

Here's an example. I am usually skeptical of this kind of video, but I think he actually got it right (for relatively small loads). I prefer a small transfer panel, but his main lock out is probably legal too.

@HuntingPudel quote: "2-way charging as I have read about it is intended to keep vital appliances up and running for relatively long periods. Totally different use cases. ?‍??" Nope, and you really should read more, instead of wasting your time with teenager icons to insult forum members.

How to Power Your Home with a Hyundai Ioniq 5 or Kia EV6!

 

[HuntingPudel]

<SNIP>
? (I have no idea what that means, but woof right back at you )

<SNIP>

ROFL, Louey. ? is me. ??

 

[AmbiguousPresentation]

What DOES work with the MME is to extract 12v from existing connection points and wire to a stand alone (off-grid) Inverter. Caveats to make sure the onboard dc-dc converter can keep up are:
1. make sure MME is ON, and auto-timeout is set OFF
2. make sure TOTAL 12v loads are no more than 2000 watts, and probably safest to stay below 1500

this means if you want to run a 1500watt teapot while camping, do NOT turn on eHeat or a/c as well.

If you want to run occasional bigger loads for brief periods in a whole house situation, I'd recommend putting a pretty good size 12v battery bank in the middle, and use the MME basically just as a battery charger jumpered direct to the external pack. Since the MME is holding the 12v at 14.4, the current will never go much higher than 40 amps if the 'big' battery bank doesn't discharge below 12.0

I have a 'little' battery backup system in my garage with about 8 kWhr of battery, hooked up to a 3000watt inverter. if grid goes out, I can:
1. isolate house w MAIN=off
2. turn off all big 240v circuits, including my grid-tied solar backfeed
3. backfeed inverter output thru my 14-50 EV charger outlet
4. jumper from MME to battery bank if its a long outage.... giving me access to whatever is in the MME HV battery (enough to run critical loads for DAYS)

Does the AC draw from the 12V battery? I’d have thought it was tied in with the cooling for the HVB, but I admit that was a blind assumption. I’m trying to figure out if I can add a little connection to the LVB in the frunk and hook it up to a little crockpot so I can cook lunch while trekking through the mountains. ?

 

[dtbaker61]

Does the AC draw from the 12V battery? I’d have thought it was tied in with the cooling for the HVB, but I admit that was a blind assumption. I’m trying to figure out if I can add a little connection to the LVB in the frunk and hook it up to a little crockpot so I can cook lunch while trekking through the mountains. ?

I have found it best to connect to the designated 'connection points' under the drivers side cover rather than directly to the 12v battery terminals. the battery itself is awkwardly under a cross brace. Much easier to use a 1-7/8" hole saw to gain direct access to suggested connection points.

You should probably only use a 1500watt inverter.... which will safely limit the power to more more than 2000watts so that the MME dc-dc can 'keep up' with your power extraction. Make sure the MME is 'on' so that you are not draining the 12v battery.

whats happening is that the inverter pulls the power directly from the dc-dc via the connection points rather than pulling all the current thru the little LVB which is not really big enough for that kind of current.

 

[AmbiguousPresentation]

I have found it best to connect to the designated 'connection points' under the drivers side cover rather than directly to the 12v battery terminals. the battery itself is awkwardly under a cross brace. Much easier to use a 1-7/8" hole saw to gain direct access to suggested connection points.

You should probably only use a 1500watt inverter.... which will safely limit the power to more more than 2000watts so that the MME dc-dc can 'keep up' with your power extraction. Make sure the MME is 'on' so that you are not draining the 12v battery.

whats happening is that the inverter pulls the power directly from the dc-dc via the connection points rather than pulling all the current thru the little LVB which is not really big enough for that kind of current.

That makes sense, and as you point out, those connectors are more accessible anyway. Do we know how much of the 3kW 12V power budget gets used by the car while driving? I think I can get away with a fairly low draw from my crockpot once it heats up, but I need it to stay warm while I’m driving if I want my pulled pork to be ready in the evening. ?

 

[HuntingPudel]

Should probably start a V2L thread, since this thread is for a V2H EVSE. ??

 

[AmbiguousPresentation]

Should probably start a V2L thread, since this thread is for a V2H EVSE. ??

It’s still V2H, isn’t it? I need an inverter for my crockpot.

 

[HuntingPudel]

It’s still V2H, isn’t it? I need an inverter for my crockpot.

V2H supplies the house via a bidirectional EVSE and automated cutoffs that prevent mains back feed. V2L supplies a single, much smaller load through an inverter connected to the 12V battery. So, no. It is not V2H. ??‍?

 

[bshaw]

That makes sense, and as you point out, those connectors are more accessible anyway. Do we know how much of the 3kW 12V power budget gets used by the car while driving? I think I can get away with a fairly low draw from my crockpot once it heats up, but I need it to stay warm while I’m driving if I want my pulled pork to be ready in the evening. ?

Just so you know --- the frunk was spec'd to serve shrimp on a bed of ice.
This whole "crockpot for pulled pork in the frunk" idea is completely new and untested.

But, seriously, I would go the other way on your calculation and figure how much power the crockpot is drawing on a continuous basis, and then figure out if driving concurrently is going to be do-able. Less than 100W by the crockpot -- maybe that's going to be ok while driving?

 

[AmbiguousPresentation]

V2H supplies the house via a bidirectional EVSE and automated cutoffs that prevent mains back feed. V2L supplies a single, much smaller load through an inverter connected to the 12V battery. So, no. It is not V2H. ??‍?

Doh, I sit corrected. ?. Although if we merge this thread with the towing thread, and use an inverter to feed power to appliances in the trailer while we drive down the highway…

 

[dtbaker61]

That makes sense, and as you point out, those connectors are more accessible anyway. Do we know how much of the 3kW 12V power budget gets used by the car while driving? I think I can get away with a fairly low draw from my crockpot once it heats up, but I need it to stay warm while I’m driving if I want my pulled pork to be ready in the evening. ?

I would not use a significant load while driving.... either the eHeat, or A/C, would likely spike the total load higher than 2000watts if everything came on at once. The DC-DC circuit breaker is 160amps(12v), so I would NOT go over 2000watts if you can help it.

If you are parked, just leave the car 'on', turn the 'auto-off' setting off, fire up the crockpot in the frunk lock the car and go for your hike.

 

[Rpgonzalez]

If you want to run occasional bigger loads for brief periods in a whole house situation, I'd recommend putting a pretty good size 12v battery bank in the middle, and use the MME basically just as a battery charger jumpered direct to the external pack. Since the MME is holding the 12v at 14.4, the current will never go much higher than 40 amps if the 'big' battery bank doesn't discharge below 12.0

where are you getting the 40A figure from? Is that because you are hooking the mach-e up to your 40A charge controller and then to the battery?

 

[dtbaker61]

where are you getting the 40A figure from? Is that because you are hooking the mach-e up to your 40A charge controller and then to the battery?

when the 'buffer battery' is depleted (or sagging from heavy load) to around 12.0v, and the MME dcdc is trying to maintain 14.4v, the current I measured in jumpers peaked at 40amps breifly, but settled to about 30a and dropped as the voltage came up in the buffer battery.

I didn't need to put it thru a charge controller... the current is self limiting given the voltage difference between MME system and buffer battery.

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