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Where is the charge limit coming from (Bolt/Charger/AC ckt) ?

Posted: Sun Feb 14, 2021 9:17 pm
by syedbhuq
Hi
I have a 2020 Bolt LT have a Chargepoint 240V Level 2 home charger capable of charging 40A with a 50A Circuit Breaker (which I have).

But when I charge, it always clips at 16A (Chargepoint can go 16A/24/32/40A based on Circuit Breaker capability).

So, if my Chargepoint and my Circuit Breaker are capable of going to 40A, is the Bolt limiting that down to 16A ? Can the Bolt be programmed to accept 24A or 32A or 40A ?

I am trying to understand where the limitations of 16A is coming from ? (Is it the Bolt or a settings on the Chargepoint home charge).

Tks
Syed

Re: Where is the charge limit coming from (Bolt/Charger/AC ckt) ?

Posted: Sun Feb 14, 2021 11:22 pm
by theothertom
The Bolt will accept up to 32 amps if the charger will supply it. There is no setting on the car where you (or anyone) can change that.
The limit is coming from the charger. I don't see how the charger knows what the "circuit breaker capability" is. There's most likely a setting somewhere in or on the charger so you can set the amps. If you don't have an owner's manual, you can probably find one online or call customer support.

Re: Where is the charge limit coming from (Bolt/Charger/AC ckt) ?

Posted: Mon Feb 15, 2021 12:23 am
by AyeJay
OK .. Charging station and the car are capable of 32A - 7.2kW @ 240V .. Circuit breaker is 50 Amp, 240V ..

Have you confirmed that the wires used in that circuit are #6 gauge copper conductors? (as they should be)
If they are not .. say #10 or #12 gauge copper conductors the charging station would probably sense that and limit the max amps drawn.

This would be an unusual (potentially hazardous) situation where the circuit breaker is oversized for the actual capability of the wires in the circuit. It's not likely this is the case but on the other hand I've seen worse so I'm mentioning it here.

I would recommend having a licensed electrician with EV charging experience take a look at this and for other possible wiring errors in your system.

AJ

Re: Where is the charge limit coming from (Bolt/Charger/AC ckt) ?

Posted: Mon Feb 15, 2021 1:17 am
by theothertom
AyeJay wrote:OK .. Charging station and the car are capable of 32A - 7.2kW @ 240V .. Circuit breaker is 50 Amp, 240V ..

Have you confirmed that the wires used in that circuit are #6 gauge copper conductors? (as they should be)
If they are not .. say #10 or #12 gauge copper conductors the charging station would probably sense that and limit the max amps drawn.
AJ

How would the charger do that?

Re: Where is the charge limit coming from (Bolt/Charger/AC ckt) ?

Posted: Mon Feb 15, 2021 3:12 am
by cwerdna
theothertom wrote:The Bolt will accept up to 32 amps if the charger will supply it. There is no setting on the car where you (or anyone) can change that.
The limit is coming from the charger. I don't see how the charger knows what the "circuit breaker capability" is. There's most likely a setting somewhere in or on the charger so you can set the amps. If you don't have an owner's manual, you can probably find one online or call customer support.

To be clear, please see https://clippercreek.com/three-things-d ... arge-time/ about the max station (EVSE) delivery rate vs. max vehicle acceptance rate (of the vehicle's on-board charger).

In this case, the car's on-board charger has the max of 32 amps at 240 volts.

For L1 and L2 AC charging over J1772, the external unit (the EVSE, it's NOT a charger) has a pilot signal (https://openev.freshdesk.com/support/so ... -sae-j1772) that tells the attached vehicle how much it can draw at max and the vehicle is supposed to comply.

Re: Where is the charge limit coming from (Bolt/Charger/AC ckt) ?

Posted: Tue Feb 16, 2021 2:00 am
by syedbhuq
Thanks to all of you who replied.

I found out that I had to do a factory reset on the Chargepoint Charger, do the setup again and this time around I am getting 32A for the Bolt.
I read on this thread that Bolt can accept up to 32A so even though my Chargepoint Charger can go 40A, in this case the car is the limiting factor.

All my install, breaker rating, wiring guage etc are all correct and at code per install.

Tks