Level 1 vs Level 2 Charging

[gregb31]

Just purchased an i3 and was curious about the efficiency of Level 1 vs Level 2 charging - when I just needed to top off the charge and I knew either level would do the job overnight.

I discovered this link:

http://www.veic.org/documents/default-source/resources/reports/an-assessment-of-level-1-and-level-2-electric-vehicle-charging-efficiency.pdf

I appears Level 2 is a bit more efficient

 

[mindmachine]

Just purchased an i3 and was curious about the efficiency of Level 1 vs Level 2 charging - when I just needed to top off the charge and I knew either level would do the job overnight.

I discovered this link:

http://www.veic.org/documents/default-source/resources/reports/an-assessment-of-level-1-and-level-2-electric-vehicle-charging-efficiency.pdf

I appears Level 2 is a bit more efficient

Did you read the article? It states specifically the less the total draw of the charging session, the less efficient Level 1 charging is and the bigger the loss over Level 2 charging. So if you only need to top off your charge as you say the Level 2 will be substantially more efficient in those cases. Additionally the Level 1 is more efficient if used for a large KWH draw like if you wanted to fully charge from empty, but Level 2 would still be more efficient in that case as well. For small draw charging sessions of less than 2kwh the level 1 charger suffers almost 30% efficiency loss, compared to approximately 15% loss with level 2.

 

[DAZ]

Best to forget Level 1 charging, other than in an emergency. My Prius Plug In has a 4.4kWh battery and charges Level 1 in three hours versus Level 2 in 1.5 hours. Every newer EVs have larger batteries that take forever charging on Level 1. Whether you purchase or lease, make the commitment to purchase a Level 2 EVSE and get with the times and shorter length charging. It's money well spent.

 

[WoodlandHills]

Let me be the contrarian here and say that depending upon your usage profile a Level 1 may be all you need. If you just use your car for local errands, drive 20 miles or less a day, then a Level 2 is unnecessary. We used our car for over a month with just a Level 1 while awaiting permits and inspections for our Level 2 with no difficulty at all. We were always able to plug in at the end of our last trip of the day and have a full charge in the morning.

 

[mindmachine]

Let me be the contrarian here and say that depending upon your usage profile a Level 1 may be all you need. If you just use your car for local errands, drive 20 miles or less a day, then a Level 2 is unnecessary. We used our car for over a month with just a Level 1 while awaiting permits and inspections for our Level 2 with no difficulty at all. We were always able to plug in at the end of our last trip of the day and have a full charge in the morning.

+1 I agree.
However the OP ask only about efficiency!

 

[jadnashuanh]

The break-even point between the increased cost to charge with a Level 1 device verses a Level 2 will depend on if you need to buy and install a Level 2 device and your current electricity costs. Most people find a level 2 unit will cost them about $1k or so installed (assuming you don't have an incentive from your local government), and that will buy a lot of electricity. So, then, it comes down to a convenience factor, and for me, that convenience factor outweighed any thought of using the Level 1 device except in an emergency. If there are any times when you might come home 'empty', and then decide you want to go somewhere again, you'll be happy you have a Level 2 unit available (or one nearby, or better yet, a DC fast charge station).

 

[mindmachine]

The break-even point between the increased cost to charge with a Level 1 device verses a Level 2 will depend on if you need to buy and install a Level 2 device and your current electricity costs. Most people find a level 2 unit will cost them about $1k or so installed (assuming you don't have an incentive from your local government), and that will buy a lot of electricity. So, then, it comes down to a convenience factor, and for me, that convenience factor outweighed any thought of using the Level 1 device except in an emergency. If there are any times when you might come home 'empty', and then decide you want to go somewhere again, you'll be happy you have a Level 2 unit available (or one nearby, or better yet, a DC fast charge station).

Your discussion has zero to do with the OP's question. The question is about the efficiency of level 1 vs level 2
charging if you only want to top off a partially charged battery!

Any thoughts on the real question as originally asked? Every one seems to prefer to prognosticate rather than comment on the actual question asked!

 

[jadnashuanh]

Level 2 is more efficient - you get more watts stored verses input than with Level 1. Efficiency can also imply total money output, and you may never recoup the cost of buying a Level 2 EVSE, depending on your use and local electrical rates. It IS certainly more convenient for most people since you're ready to go again much sooner. SO, in that vein, yes, it does address the OP.

 

[gregb31]

I Just purchased my Rex and I became interested in the choice between Level 1 and Level 2 charge efficiency after reading that charging lithium Ion batteries to the maximum level will ultimately decrease the longevity of the battery. But apparently BMW does limit the max charge (I think I read 96%). And the article makes it clear that in all cases and especially low charge events that Level 2 is more efficient.

My remote app is not working yet but apparently I can also set limits on how much I want to charge the battery using the settings in the car. Either way I installed my own Bosch charger in about 2 hours for about $650 total so I will be using Level 2 at home.

 

[jadnashuanh]

The car allows setting the maximum charge RATE, but it does not allow you to set a max limit on when it will stop. IOW, it will always try to achieve the user 100% value (not the battery's ultimate 100% value). I think, but am not certain, they leave that buffer at the top so you have some place to put any regenerative energy when you actually drive off with a full battery, plus, not constantly bumping off max helps with longevity, too.

 

[AviatorMan]

Just purchased an i3 and was curious about the efficiency of Level 1 vs Level 2 charging - when I just needed to top off the charge and I knew either level would do the job overnight.

I discovered this link:

http://www.veic.org/documents/default-source/resources/reports/an-assessment-of-level-1-and-level-2-electric-vehicle-charging-efficiency.pdf

I appears Level 2 is a bit more efficient

Yes, perhaps 2% to 3%, which will cost me ~ $10/year.

There is this link as well:
TinyURL.com/mdwhjns


And, check out this thread:
http://www.mybmwi3.com/forum/viewtopic.php?f=11&t=1712

I drive 35 to 55 miles/day and have no need for Level 2 and will not be installing it. It only makes sense if you have a driving profile where you arrive at home and then want to go out again a few hours later. For many, not the case..