120v Mobile Charger reducing amps

[mongo]

115v to 116v to 112v is all it seems?

You shouldn't get 3 or 4 volts of drop with a 4 amp load step. That resistance would be equivilent to 300 feet of 12 gauge wire.
What voltage does the car read with really low charge current (or not charging at all, if it still displays)?

 

[20221229 3RWD]

You intend to try to use 16a charging on an outlet that has been struggling to supply 12a? Doesn't sound like a good idea to me. If it were me, I'd instead be trying to discover if any of the wiring was bad, and exactly what other appliances might be on the same circuit. This is happening for a reason, and you should either stop using this outlet, or find out what the problem really is and fix it (or bite the bullet and put in a proper dedicated charging circuit).

All good points … level 2 was supposed to be installed today (delayed a couple of days).

The NEMA 5-20 held for a few minutes at 16amp but derated to 12amp a few min ago?

Not sure if it is the outlet, wire or other appliances on the circuit? Again, I am surprised by the variability here. I expected a consistent 12amp from the NEMA 5-15?

Is it the car? Is it other appliances on the same Circuit? Is it the outlet? Is it the wire? Is it voltage variability from the electricity provider?

Likely a combination of them all at this point?

Maybe the higher voltage and amperage of the level 2 will be less variable and a much more consistent charge?

Just sharing process/thoughts for others on the forum.

 

[20221229 3RWD]

You intend to try to use 16a charging on an outlet that has been struggling to supply 12a? Doesn't sound like a good idea to me. If it were me, I'd instead be trying to discover if any of the wiring was bad, and exactly what other appliances might be on the same circuit. This is happening for a reason, and you should either stop using this outlet, or find out what the problem really is and fix it (or bite the bullet and put in a proper dedicated charging circuit).

Holding solid at 12amp for 1hr 52min so far.

Not my intention of buying the NEMA 5-20, but if I can get a consistent 12amp then the 5-20 it was probably worth it. No doubt better than 8amp. The 25% amp drop is interesting though.

davewill … Do you have a level 2 charger, does it work well for you?

All interesting stuff …

 

[davewill]

Holding solid at 12amp for 1hr 52min so far.

Not my intention of buying the NEMA 5-20, but if I can get a consistent 12amp then the 5-20 it was probably worth it. No doubt better than 8amp. The 25% amp drop is interesting though.

davewill … Do you have a level 2 charger, does it work well for you?

All interesting stuff …

I'm not surprised by your results. The car is detecting something wrong with the circuit, such as a poor wire connection or a worn outlet, that is adding a lot of resistance (which causes voltage sags the car can see). By using a 5-20 adapter, you have succeeded in fooling the car into backing down only to 12a instead of backing down to 8a, but that's not a good thing. If there is a poor connection, it will be generating more heat with the higher current. Of such things are house fires born. The most common cause of poor connections are worn outlets, as I mentioned, and the common practice of using the spring secured back stab method of wiring outlets rather than securing the wires under a screw.

Yes, I've got two EVs and two J1772 EVSEs, one on a 240v 40a circuit (6-50) and one on a 240v 50a circuit (14-50). I have J1772 because they were installed originally for a Nissan LEAF and a RAV4EV. The first one was done 11 years ago and I followed the install instructions for the EVSE when I went 40a. Done today, I'd have done it as 50a, but it hasn't really made a difference as both EVSEs supply a max of 30a, which has been entirely adequate.

 

[20221229 3RWD]

A solid 10hr 1 min run here to full charge from 83% to 100% using the NEMA 5-20 plug with a consistent 12amp load (after and initial 24 minutes at 16amp).

Charging at a consistent 12amp (50% faster than 8amp de-rate using NEMA 5-15) feels like a win.

Level 2 charging is still being installed, good to see though that this level 1 setup appears to be consistent now and capable of adding 4.72 miles/hr of range.

 

[mongo]

A solid 10hr 1 min run here to full charge from 83% to 100% using the NEMA 5-20 plug with a consistent 12amp load (after and initial 24 minutes at 16amp).

Charging at a consistent 12amp (50% faster than 8amp de-rate using NEMA 5-15) feels like a win.

Level 2 charging is still being installed, good to see though that this level 1 setup appears to be consistent now and capable of adding 4.72 miles/hr of range.

What's the voltage at the car at 16, 12, and 4 amps?

 

[20221229 3RWD]

A solid 10hr 1 min run here to full charge from 83% to 100% using the NEMA 5-20 plug with a consistent 12amp load (after and initial 24 minutes at 16amp).

Charging at a consistent 12amp (50% faster than 8amp de-rate using NEMA 5-15) feels like a win.

Level 2 charging is still being installed, good to see though that this level 1 setup appears to be consistent now and capable of adding 4.72 miles/hr of range.

I had a Bryant brand NEMA 15-40R installed this past weekend within a 4’ run of the breaker box on a 50 amp breaker.

I charged the car today for the first time via this level 2 installation. Charged in 245 min at ~ 33mph pulling 32 amps consistently.

Seems to be working great!

However, see the attached chart … I am surprised by the volatillity in the voltage?

Have any of you experienced similar?

 

[davewill]

I had a Bryant brand NEMA 15-40R installed this past weekend within a 4’ run of the breaker box on a 50 amp breaker.

I charged the car today for the first time via this level 2 installation. Charged in 245 min at ~ 33mph pulling 32 amps consistently.

Seems to be working great!

However, see the attached chart … I am surprised by the volatillity in the voltage?

Have any of you experienced similar?

It's only swinging 2 volts, except when your car finishes and starts drawing much less where it rises 5 volts. Not any kind of problem.