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Charge Current Limit Sticky

Solstice

New Member
Oct 30, 2019
4
0
Syracuse, NY
When I first got my Model 3 (Dual Motor Long Range) in September, I was charging off a 120-volt outlet in my garage using the Gen 2 Mobile Connector. I had manually lowered the charge current to 11 amps to reduce the chances of tripping a breaker.

The Model 3 will remember current limit based on location and, I thought, is supposed to remember the last limit set at a given location. I took this to mean that it would remember a higher limit I set later on.

I have since installed a JuiceBox Pro 40 (240 volts and 40 amps off a NEMA 14-50 outlet) and my car still always defaults to 11 amps. If I want it to charge faster, I have to sit in the car after plugging in and manually increase the charge current limit. The car will detect that it can draw more current but I have to manually increase the limit.

Manually increasing the limit can take a while because it will determine that it can pull 16 amps when the limit is set at 11 amps. I then increase the limit to 16 and it takes a few seconds to determine that it can pull more (say 21 amps) and then I have to manually increase again. I have to repeat this process until I get up to 40 amps.

This also means that I cannot start charging from my phone and get more than 11 amps.

Does anyone have any suggestions? Is there a way to force the car to forget the old charge current limit?
 

justsomeguy

Member
Jul 4, 2019
295
288
Vancouver, Bc
When I first got my Model 3 (Dual Motor Long Range) in September, I was charging off a 120-volt outlet in my garage using the Gen 2 Mobile Connector. I had manually lowered the charge current to 11 amps to reduce the chances of tripping a breaker.

The Model 3 will remember current limit based on location and, I thought, is supposed to remember the last limit set at a given location. I took this to mean that it would remember a higher limit I set later on.

I have since installed a JuiceBox Pro 40 (240 volts and 40 amps off a NEMA 14-50 outlet) and my car still always defaults to 11 amps. If I want it to charge faster, I have to sit in the car after plugging in and manually increase the charge current limit. The car will detect that it can draw more current but I have to manually increase the limit.

Manually increasing the limit can take a while because it will determine that it can pull 16 amps when the limit is set at 11 amps. I then increase the limit to 16 and it takes a few seconds to determine that it can pull more (say 21 amps) and then I have to manually increase again. I have to repeat this process until I get up to 40 amps.

This also means that I cannot start charging from my phone and get more than 11 amps.

Does anyone have any suggestions? Is there a way to force the car to forget the old charge current limit?
The part about stepping up the current suggests the issue might not be with the car, but the EVSE itself. The car doesn't guess or determine the available amperage by any means other than asking the EVSE what it is able to provide. That is the purpose of the EVSE, as it is impossible for the car to tell.

If the EVSE is fine, you can try slightly adjusting the charge limit after manually setting the maximum amperage and applying the setting. I think I read on here someone had to do that for their setting to stick.
 

Solstice

New Member
Oct 30, 2019
4
0
Syracuse, NY
The part about stepping up the current suggests the issue might not be with the car, but the EVSE itself. The car doesn't guess or determine the available amperage by any means other than asking the EVSE what it is able to provide. That is the purpose of the EVSE, as it is impossible for the car to tell.

If the EVSE is fine, you can try slightly adjusting the charge limit after manually setting the maximum amperage and applying the setting. I think I read on here someone had to do that for their setting to stick.

I'll try doing that. Thanks.

One additional detail is that I have two JuiceBoxes load sharing the same circuit. It actually starts at 8 amps and then steps up to offer more current on it's own (the limit I had previously set) after checking with the server to see what the load is from the other JuiceBox. So the car has does have the sense to automatically start drawing more than the 8 amps it was initially offered by the EVSE. Also, my other vehicle (a Pacifica PHEV) seems to be handling this setup fine on the other JuiceBox.

I'll try charging using my mobile connector on the NEMA 14-50 tomorrow to see if I still have the same issue.
 

Solstice

New Member
Oct 30, 2019
4
0
Syracuse, NY
justsomeguy, your suggestion appears to have worked. I waited until I was able to get all the way up to 40 amps and then reset the charge limit several times for good measure. The next time I got home, it ramped up all the way to 40 amps on its own. Many thanks for the help.

(I never even bothered trying using my mobile connector.)
 

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