Page 1 of 1

new household plug for level 1 charging - how many amps?

Posted: Tue Jan 07, 2020 10:28 am
by jmk2015rex
I have a 2015 i3 Rex and live in Washington state. I get by with level 1 charging overnight with no problems. I am having a new dedicated outlet installed - still for level 1 charging. The new outlet will be in a more convenient location. Simple question I hope - should the outlet be for 20 amps or 15? Finally, once the new outlet is installed, can I change my charge setting to maximum? Sorry if this has been answered before, but I have read the BMW manual and searched this forum and we are still not clear on the amps and setting. We are not going the level 2 route.

Re: new household plug for level 1 charging - how many amps?

Posted: Tue Jan 07, 2020 10:47 am
by keepgoing
get the level 1 (120 v AC) plug in 20 amps, especially it is a new install which the cost different between 15 amps and 20 amps is almost nothing. You can set the charging to maximum without any issue.

Re: new household plug for level 1 charging - how many amps?

Posted: Tue Jan 07, 2020 12:57 pm
by jmk2015rex
Perfect - thank you!

Re: new household plug for level 1 charging - how many amps?

Posted: Wed Jan 08, 2020 12:01 am
by jadnashuanh
The electrical code calls for items plugged in for extended time frames to not exceed 80% of the listed circuit size, so on a 15A circuit, the max you could use would be 12A. Depending on the model year and the OEM EVSE, it is no bigger than that 12A (later ones, I've heard, are 10A), so on a dedicated 15A or 20A circuit, you could set the car's charging rate to maximum without issues. That all assumes that there is nothing else on the circuit (the reason the restrictions are there in the first place), but also, as a receptacle ages, the spring tension reduces, and that acts like a resistor (think heating coil), and things can overheat, making things worse, potentially melting the plug and receptacle.

Check to see if the plug gets hot. It could easily get warm, but should not get hot. If the plug slides in easily, you should replace the receptacle before things burn.

Re: new household plug for level 1 charging - how many amps?

Posted: Mon Jan 13, 2020 7:27 am
by Obioban
As long as you're getting a plug added, why not make it 240V instead of 120? Even if it's only 20 amps (and use a 240V 16A charger).

The car uses less power to charge the same amount on 240V than 120V (aka 240V charging is more efficient than 120V charging). A 240V 16A charger can be had for $200 used, easily. That way you can also keep the stock 120V charger in the frunk, for emergencies.

Re: new household plug for level 1 charging - how many amps?

Posted: Mon Jan 13, 2020 10:35 am
by MKH
As long as you're getting a plug added, why not make it 240V instead of 120
Ditto that. If your electrical panel will support adding a 220 v circuit, it's not much harder than adding a 110. All a 220 is ( in the US) is two 110 circuits tied together - takes up two breaker spots with a double breaker in your electrical panel. Just depends on if your panel will support the added circuits. My older house has a 100 amp panel, and I put in the 220v circuit for mine myself. Great youtube video on how to do it.

https://www.youtube.com/watch?v=X9ro7Tc2nFI