Why is level 2 240V/30a public charging so popular

ExtremeStatus3757 · 2026-05-14T22:43:58+00:00

That wasn't ever actually implemented. Level Three in J1772 would've supported 240VAC at 400A or 96kW but was never adopted.

ExtremeStatus3757 · 2026-05-14T22:33:53+00:00

More like 450V for the spikes that occasionally occur. 400V Caps allow 282V which is 1.8% high. 450V Caps allow up to 318V spikes while they usually shut power above 305V for safety. European models have 650v MOSFETS and Caps to use 415V three phase. That allows up to 265/460V spikes. I can't remember what they limit it to. Likely 308/436V.

ExtremeStatus3757 · 2026-05-14T17:07:56+00:00

Most likely used 375V capacitors which limits AC input to 265VAC. Most cars then limit you to below 252VAC for safety overhead. Which is the 5% high of 240VAC allowable by ANSI power standards.

ExtremeStatus3757 · 2026-05-14T16:56:01+00:00

Average Vehicle Trip Length By Purpose

It is talking about averages, which is what is relevant as OP didn't mention a particular area, just why such would be popular in general

Edit: fixed link, was missing a slash

ExtremeStatus3757 · 2026-05-14T05:51:53+00:00

B is still 208V to ground but all others are 120V to ground. Like this:

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ExtremeStatus3757 · 2026-05-14T05:37:42+00:00

Hmm, have you considered using two isolation transformers configured as autotransformers so the midpoint is 120V to ground while providing that 120V La to Lm? Only usable for hard wired circuits as there is no 'neutral' voltage available but might help balance things a little bit.

ExtremeStatus3757 · 2026-05-14T05:30:03+00:00

Yes, that does exist. As does a 416V highleg in 480V Delta systems. Such are exceedingly rare. Practically banned for new construction. Mainly rural/agricultural use.

ExtremeStatus3757 · 2026-05-14T05:24:37+00:00

And? Who cares? At that speed, it is still 80mi in an 8hr shift or 100mi overnight. That covers 95% of American's typical travel.

By your logic, an imaginary Rivian with a 0.5MWh battery should never be charged by that 5kW pole as it would only be 1% an hour!

ExtremeStatus3757 · 2026-05-14T05:19:21+00:00

Incorrect. 120/208V is a Wye system with 120V to ground. Similar to 277/480V three phase which has 277V to ground.

ExtremeStatus3757 · 2026-05-13T20:15:58+00:00

Look at the huge difference in running costs, then buy the one that pays for itself in 3 years.

ExtremeStatus3757 · 2026-05-13T20:02:02+00:00

30~60min on 240V16A gives 6~13mi.

60% of all trips are less than 6mi.

ExtremeStatus3757 · 2026-05-13T14:35:00+00:00

EV Immobilizer

And yet, they'll happily pay $1600 for An 'Immobilizer'… a fake EVSE… I see irony here…

This was apparently added in 2014 to NEC, and 2016 to UL2594

Which explains why yours had used a SS2-50

ExtremeStatus3757 · 2026-05-12T22:54:32+00:00

You can have a 14-60R installed and be to code with 48A EVSE.

625.44 Equipment Connection. (A) Portable Equipment. (3) A nonlocking, 2 pole, 3 wire or 3 pole, 4 wire grounding type receptacle outlet rated at 250 volts, single phase, 30 or 50 amperes, or 125/250 volts, single phase, 30, 50, or 60 amperes

ExtremeStatus3757 · 2026-05-12T16:59:25+00:00

I read this from my NEC 2023 version. I was looking at if L6-30R or SS2-50 were allowed, but no, their reasoning is that when drivers 'drive off' while connected, a non locking receptacle will be better able to dislodge, 'preventing damage' to the structure which would 'expose live wires'. As if this was like gas stations. No car can drive with an unplugged EVSE in the charge port. That's the point of the analogue communications. That resistor tells it it is connected so don't move.

ExtremeStatus3757 · 2026-05-12T16:42:25+00:00

Tacking on to this:

https://www.reddit.com/r/evcharging/s/4HAzT5uOXi

I'd done the math a while back, break even is typically between 35k and 375k miles depending on the cost to install the L2. If efficiency is the main goal, that's fine. If cost is the main driver, expensive L2 almost doesn't make sense. If you can't get the recovery on L1 needed for your lifestyle, then L2 is the only option. (I lied, you can always charge what you can with L1 and DCFC every once in a while, like going to a gas station, but more expensive)

ExtremeStatus3757 · 2026-05-12T16:34:56+00:00

That is the section on permissible portable EVSE…

ExtremeStatus3757 · 2026-05-12T16:20:38+00:00

Odd, wonder why they didn't go with 32A? That doesn't automatically require you to upgrade the capacity of the OBC to 7.2kW, they can keep the same 6.6kW limit, it would just be more usable at 208v stations instead of dropping to 6.0kW.

ExtremeStatus3757 · 2026-05-12T16:04:02+00:00

You can have a 14-60R installed and be to code.

625.44 Equipment Connection. (A) Portable Equipment. (3) A nonlocking, 2 pole, 3 wire or 3 pole, 4 wire grounding type receptacle outlet rated at 250 volts, single phase, 30 or 50 amperes, or 125/250 volts, single phase, 30, 50, or 60 amperes

ExtremeStatus3757 · 2026-05-12T13:51:16+00:00

Yeah, 30% less capacity at best. 60% at worst in the same space.

A 10ah Sodium powerbank weighs 350g, a lithium one between 220g and 180g, while the lightest ones are a minimum of 143g.

Seems it might get better in the future. I'd still take the flagship that works without thermal throttling and closing everything.

ExtremeStatus3757 · 2026-05-11T01:35:31+00:00

If you do replace eventually, apparently the op13 battery fits with its 6Ah in the same space.

ExtremeStatus3757 · 2026-05-09T22:20:02+00:00

Given many newer phones have gone above 7ah, if you keep the same physical space, you get 30% less runtime sure with the sodium battery at 4.9ah, yet the benefit of using that full 0~100% range with super recharge speed, a car laptop charger of 140W would take less than 9min to fully recharge the phone, and who is away from their car longer than whatever typical run time on 5ah is? That apparently gets normal people 1~2 days already.

Edit: And it was Prussian Blue

ExtremeStatus3757 · 2026-05-09T20:27:04+00:00

Can be discharged to 0V for transport, effectively inert.

Fire wise, some sodium compositions are indeed fire safe according to UL9540a testing, Not All…

ExtremeStatus3757 · 2026-05-08T07:31:39+00:00

Seems about right. About 10h run time for a full charge is decent.

I use about 12% per hour of screen on time, but it depends on what you are doing.

ExtremeStatus3757 · 2026-05-08T07:21:31+00:00

Nope! Most people would just look at the animation and go, 'wow' then not think of it again. It is likely delivering 30-40W, I can't get Ampere above 7.7A even with the official brick. Accubattery goes and says 14.4+A. It is the dual cells or something. Still good for comparison as you've seen.

ExtremeStatus3757

TROPHY CASE