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Level 1 or Level2 for the PHEV?

33K views 79 replies 23 participants last post by  atc98092 
#1 ·
This topic is PHEV-specific. HEV owners don't have an external charging option, and EV owners are likely to have solid reasons for wanting Level 2 charging in their homes. But PHEV owners have to make a decision and the choices are hardly self-evident.

PHEV owners receive a level 1 charger when they purchase their Niro. We can plug it in to standard household electrical outlets, it takes longer to charge our PHEV than level 2 would take, but given that our maximum EV range is 26 miles and we can get a full charge overnight on Level 1, most of us are content with the level 1 charger's performance. Not having to hire an electrician and pay significant sums of money to install level 2 charging equipment reinforces that perspective.

But the owner's manual recommends level 2 and describes the level 1 charger as an "emergency charger". Many of us are concerned about maximizing the lifetime of our PHEV battery, and we're left questioning the owner's manual guidance because conventional wisdom suggests that slow (level 1) charging is likely to be better for battery longevity, but the owner's manual seems to contradict that conventional wisdom.

There are a lot of other threads on this forum that discuss these sane questions. My hope is that this thread will give this specific topic a home for future discussion.

In this post, lafe005 points out some level 2 advantages, in terms of both time and temperature. It's worth considering if you live in a cold climate, are concerned about charging efficiency/economics, or if your situation would allow you to avoid depleting the charge in your PHEV battery if you can use a level 2 charger, when you would be more likely to (almost) fully deplete it with a level 1 charger. That's because depleting the battery is not great for longevity either, although I think most of us PHEV owners are inclined to do that when exceeding our 26 mile range, because that's kind of the point of owning a PHEV. It would be interesting to see a scientific study on which is worse: depleting or avoiding depletion by fast charging.

Several threads speculate that Kia recommends level 2 not because it's necessarily better for your battery, but because of corporate liability concerns. The thinking seems to be that if you install a level 2 charger, it's going to land on a brand new dedicated circuit in your garage, because not many people have 240 V outlets in their garage and so level 2 likely requires an electrician to install new wiring that conforms to modern electrical codes, but if you use the level 1 "emergency charger", you might plug that in to old, substandard, house wiring and because the level 1 charger pulls a lot of current, if you have crappy or overloaded wiring in your garage, it could lead to a house fire which could lead to a lawsuit against Kia. I don't completely buy that theory, because it's not like the level 1 charger is necessarily pulling more current than is "legal" or "standard". The draw is comparable to a high powered hair dryer, although it's different from a hair dryer in that it runs for hours, rather than minutes. So yeah, if you have crappy garage wiring, that long high current draw could heat up your house wiring and start a fire when a hair dryer would not, but I don't really think that this is the reason why Kia recommends level 2 in the PHEV owner's manual. Which is not to suggest that I know what their real motivation actually is.

Looking forward to reading what others might be thinking on this topic.
 
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#3 ·
Because the charger is only using 3.3 KWh, the load on a circuit of a 30 amp/240v is less than the 15 amp/120v.

You have to understand how a 240V circuit is wired for this to make sense. A 240V circuit is literally 2 120V circuits. A 120V circuit has Live and Neutral wires, a 240V circuit has 2-120V live wires. A 240 V circuit at the circuit breaker is literally 2-15 amp circuits next to each other.

A level 1 charger maxes out the live wire on 1-15 amp circuit. (15 amps)
A level 2 charger uses at most 90% of the capacity of the circuits. (13.5 amps each wire)

These are maximum possible current draws, with ideal wiring and minimal resistance (Ohms about 8 ohms for these numbers).


Watts = Volts x Amps
Volts = Watts ÷ Amps
Amps = Volts ÷ Watts
Ohms = Volts ÷ Amps

Cold weather makes Ohms rise, this is more resistance. More Ohms causes a much higher current flow to keep the same watts. Amps squares as ohms increases. Watts also equals the sqaure of Amps x Ohms. W=A² x O
 
#5 ·
I read an article about 120 vs 240 charging in regard to which is best for battery life. It stated that while 120 volt charging does not heat the traction battery as much as 240 charging does, it charges and heats the battery for a longer period of time makeing 240 volt charging slightly better for battery life in the long run. I am currently charging with 120 volts and it is working well for me but I will most likely install a 240 circuit in the near future to maximize battery life. I tried to find the articale to post a link but couldn’t find it second time around.
 
#6 ·
Charging the last 10 or 15 percent is what shortens battery longevity (capacity). No issue there as the Niro has a substantial buffer in that charging to "100%" is actually around 80%. Excessive heat from fast charging can also shorten life, but it is hard to imagine that the small increase in heat from Level 1 charging over a longer time is worse that the higher increase for a shorter period. I'd have to see the research that supports it. It would have to be a long term lab test on individual cells controlling carefully the charging and noting the temperature, and the reduction in capacity a few thousand charging cycles later to be valid.

No special knowledge of the field, but of note in a college coop job, I programmed satellite battery testing routines (major issue was designing programs that would fit in the limited RAM of the minicomputers of the day). These were NiCad batteries and we tested the entire battery, not individual cells. What we were looking for cell voltage reversals and how to prevent them happening in space. Satellites were very expensive back then and a battery failure means you have to replace the entire satellite.
 
#16 ·
There is energy in the home mains supply. The issue is that this AC energy has to be converted within the car to DC for charging. This in car AC to DC converter is rated at 3.3kw. Now in the US and Canada we have single phase supply 120v. Elsewhere it is often only240V. The in car converter is more suited to a 240v supply since it is designed to run at that rate given that the 240v is more universal.. It does allow charging at half the voltage but that also in North America means half the amperage given that 120v circuits come with thinner wiring.This about quadruples the charging time and impacts the service lifetime of the charging process. Probably this is the source of KIA preferring 240v level2 charging.
 
#19 ·
Level1/level 2

Haven’t been able to find that artical on level 1 vs level 2 charging. I wish Kia would give an explanation as to why they recommend level 2 over level 1. Theories range from legal to longevity. I asked my local Kia service manager but he had no clue and said the level one charger was fine. Heat is the enemy. Less heat over a longer period of time (level 1) or more heat over a shorter time (level 2), which is better? Based on what I’ve read in this forum and elsewhere and given the fact that Kia recommends level 2 I will be installing a 240 circuit and switch to level 2 before summer hits. Right now I have my charging programmed to be done at 5:30 Am. It’s been in the 20-30 degree range at night so not as worried about the battery heat issue at the moment.

Another factor in battery longevity is number of charging cycles. Right now I plug my car in after every days use whether I have 5 or 20 miles of range left. Should I be topping off the 20 mile range if I don’t think I’m going to need it the next day? Any thoughts?
 
#20 · (Edited)
Haven’t been able to find that artical on level 1 vs level 2 charging. I wish Kia would give an explanation as to why they recommend level 2 over level 1. Theories range from legal to longevity. I asked my local Kia service manager but he had no clue and said the level one charger was fine. Heat is the enemy. Less heat over a longer period of time (level 1) or more heat over a shorter time (level 2), which is better? Based on what I’ve read in this forum and elsewhere and given the fact that Kia recommends level 2 I will be installing a 240 circuit and switch to level 2 before summer hits. Right now I have my charging programmed to be done at 5:30 Am. It’s been in the 20-30 degree range at night so not as worried about the battery heat issue at the moment.

Another factor in battery longevity is number of charging cycles. Right now I plug my car in after every days use whether I have 5 or 20 miles of range left. Should I be topping off the 20 mile range if I don’t think I’m going to need it the next day? Any thoughts?
batteries always prefer to be charged at slower charge rates

I would stay with L1 until Kia engineering explains their L2 preference

L2 is better (for the battery) than L3 and L1 is better than L2.
 
#23 ·
On the PHEV, you are in the middle of the battery capacity when you have used all the EV miles.

Still, more charging cycles is directly related to loss of capacity so you are doing the right thing although with a very minor effect.
 
#26 ·
On the PHEV, you are in the middle of the battery capacity when you have used all the EV miles.
So if i really do understand what you are saying,, If i drive my 42km (26 miles) on my PHEV, the battery is at half capacity/charged ?.. So, the battery of a PHEV is what? 50% HEV and 50% EV.. Is that it ??


What is the total capacity ? 24.7 Ah ?
 
#24 ·
I have to add that I suspect that there is precious little difference in battery life between level 1 or 2 charging nor levels used or charged to. From a study of pure EV's, I think enemy #1 is heat. Leafs driven in hot climates loose battery life considerably faster than those driven in cooler areas. Charging in the coolest part of the night or at least with a cool interior in the shade likely trumps other precautions.

I don't care here in winter but in the heat of summer, I'll level 1 charge to be full a little after dawn and avoid charging with a hot interior.
 
#28 ·
That i know, i drive one!...


It's the: ...are in the middle of the battery capacity... that i have pointed out.! How can you tell that when i am out of EV miles, that i am in the "middle of" !?
 
#29 ·
Many houses (including mine) were built pre-3 prong outlet. i.e. old crap. Lots of times (such as in my house and in my garage) 3 prong outlets got installed at some point but are not actually wired with that ground wire. This old wiring heats up easily, tends to be shoddy, and is straight up a fire hazard on anything drawing even 12 amps regardless of what amperage the circuit is. Just because someone replaced the fuse box at some point and put a breaker panel in and there's a 30 amp breaker, doesn't mean the wiring supports that. Our garage had a two prong outlet wiring with a 3 prong outlet (obviously 3rd prong/ground not hooked up) with a 6 outlet plugin stuck into that outlet. i.e. up to 6 different devices plugged into one incorrectly wired outlet. Which reminds me....yeah...people are way more likely to hook a power strip up to the level 1 outlet and run half a dozen things off the same outlet where one of those things is the level 1 charger. I can imagine a scenario where someone runs a 50 foot cheapo indoor extension cord out of the garage and uses the level 1 charger plugged into the car sitting in the driveway. That's not going to happen with a level 2 outlet.

So yes there is exactly ZERO logic that says the level 1 charger is not as good for your battery. Complete nonsense. It is, however almost certainly less of a fire hazard to use level 2 because yes there are fewer possible ways to be a complete idiot.
 
#36 · (Edited)
Interesting thing about the PHEV.

If you run EV miles to 0 and the ICE starts as the car goes into hev mode, when you get home and plug it in to recharge the battery, SOC is typically shown to be 10-12%. 11% of 8.9 = ~ 1

Also, EPA sticker Spec says 3.3 miles/kwhr so 26/3.3=7.9 kwhr ev mode usable, leaving 8.9-7.9=1kwhr hev engage point.

I assume the car likes to target 1Kwhr remaining as the point to transition from ev to hev mode.

Of course, I think, as you do, that the car keeps a low and high reserve beyond these points to maximize battery life.
 
#42 ·
From a technical standpoint, there are zero EV miles on a hybrid. All there is is recaptured energy developed from burning gasoline. That includes direct engine to battery charging, and momentum derived battery charging. This simply makes the total system more efficient than an ICE only vehicle.

You can make the same statement about the PHEV once the EV miles from plugging in are exhausted.
 
#44 ·
So what you're saying is that there is 120 or 240 AC at the plug and the car transforms and rectifies it as required for charging. The control box? Does it do any more than cut the power when told by the car? If that's all it does, why so expensive?
 
#48 · (Edited)
You are correct the Niro PHEV onboard charger electric circuitry will only accept around 16 amps maximum. It is very dangerous to use a 50 amp breaker on this circuit if that is what your are thinking of doing . You should replace the breaker with one for 20 amps. Your circuit breaker is the main safely device in your circuit that will limit power surges, react to an over amperage situation or protect from a complete short of the system. You can get a double pole 20 amp breaker for less than $10 and keep yourself and your loved ones safe.
Also when you buy a Level 2 charger make sure it is UL listed. A good licensed electrician will not install it or work on the system if it is not UL listed for liability reasons. If someone got hurt or there was a structure damage due to fire he would be liable for working on it.
If the structure was damaged and it was determined a non UL listed device was installed there could be some contention if the insurance company is actually liable. These devices transfer amperage that can cause death and structure damage if they are not installed correctly or an unexpected event happens - car runs over plug and smashes it, plug dropped in water etc.
 
#49 ·
You are correct the Niro PHEV onboard charger electric circuitry will only accept around 16 amps maximum. It is very dangerous to use a 50 amp breaker on this circuit if that is what your are thinking of doing . You should replace the breaker with one for 20 amps. Your circuit breaker is the main safely device in your circuit that will limit power surges, react to an over amperage situation or protect from a complete short of the system. You can get a double pole 20 amp breaker for less than $10 and keep yourself and your loved ones safe.
Also when you buy a Level 2 charger make sure it is UL listed. A good licensed electrician will not install it or work on the system if it is not UL listed for liability reasons. If someone got hurt or there was a structure damage due to fire he would be liable for working on it.
If the structure was damaged and it was determined a non UL listed device was installed there could be some contention if the insurance company is actually liable. These devices transfer amperage that can cause death and structure damage if they are not installed correctly or an unexpected event happens - car runs over plug and smashes it, plug dropped in water etc.
I believe the CB is there to protect the wire not the appliances plugged into the outlet.

If my AV system only uses 200 watts (<2amps) do I need to replace the 15amp CB protecting the line?
 
#50 ·
On equipment that draws substantial current or a dedicated circuit you are always encouraged to limit the amperage to the rated device. For example a dryer is on a 30 amp circuit to limit its current draw to 30 amps. Sure you could wire it for 60 amps with a 60 amp circuit breaker and 60 amp wiring. If the Dryer heating element touches the case or if the motor binds and draws excessive amperage the circuit wired for 60 amps will supply 60 amps to the dryer until that threshold is exceeded. The appliance wiring is not rated for 60 amps and by code it must be put on a 30 amp breaker to limit the amount of current it sees.

A Level 2 car charging device is for example rated for 20 amps (or more in some cases). If a circuit is capable of supplying 50 amps and there was a catastrophic failure of the device you could have 50 amps going to a device that is rated for 20 amps. Even if the device has some safety protection and regulating circuitry this is still considered a very unsafe situation. A Level 2 car charger should have its own dedicated circuit that is installed for that device with its circuit protection designed around that device. That is the difference between a normal house branch circuit that can have many items plugged into it and a dedicated circuit.

A Level 1 charger on the other hand can be plugged into any grounded circuit. That is why KIA and others supply the Level 1 chargers. The are convenient, don't require a dedicated circuit and can be immediately used by the consumer to charge their new vehicle. Imagine a consumers dismay if they found they were supplied with a Level 2 charger that required a special dedicated circuit and then the average consumer would be tasked with paying an electrician to install a new circuit for a substantial cost before the consumer could charge their car.

Here is a short video on Charging Station Safety - they have other videos on how to size circuit protection and many other topics
https://www.youtube.com/watch?time_continue=86&v=_TFgeRBLyls
 
#51 ·
I understand and appreciate your points but I see many more examples of over designing circuits for the intended load (e.g. dedicated 15/20a circuits for refrigerator, garbage disposal, ...).

I'm more comfortable running my 240v 16a L2 cord on a 240v 30a dryer wire/CB than down sizing the CB.

FWIW, It's not hard to trip a 30a CB vs a 20a CB. In fact, it's easy to trip the whole house 200a CB. I know, I've done it.
 
#52 ·
I'm not the least bit worried running a 16A charger on a 50 amp circuit. As others have mentioned, the breaker rating is to protect the wiring, not the end device. How many devices in any home are plugged into a 120V/15A circuit that draw less than an amp?

In the future when/if I or a future owner want to charge at a higher rate for something that can use it, then all they have to do is replace the outlet with a NEMA 14-50R receptacle for less than $10 and it's ready to go. Since the box already has the 50A breaker, and I have plenty of AWG 8 wire pulled from the hot tub install, why not?
 
#53 ·
I've been reading this thread with great interest because I was very close to buying the PHEV, but the salesman said it should not be charged on a 120V circuit and the service dept confirmed it.
I didn't believe them so came to this forum for information, but it doesn't look like there is a concrete answer from KIA.
I tried calling KIA but got nowhere, so still not sure about why the manual says to use the 120V charger as a backup charger only.
 
#54 ·
Arrgh I hate ignorant dealers and service people. :rolleyes:

The owner's manual and features guide for the PHEV both clearly state that the 120V charger is perfectly fine for home use.

Although, there is a random "Use only as a backup charger" thrown in there just to confuse things. I think this is more of a "We're not responsible if the jacked up wiring in your garage burns your house down because you used the 120V charger" thing than a you'll hurt your car using it thing based on the rest of the paragraph. The same page says that the Trickle Charger is for charging at home. I'm starting to wonder if Kia has any actual editors for the Owner's Manual. That's some massively contradictory information on one page. Lovely.

In any event, I've had my PHEV for a year and a half and have used the 120V charger hundreds of times without issue. I decided installing a Level 2 charger wasn't worth it to me as I'm perfectly fine charging overnight.

I wonder how many people have been scared away from buying a plug-in Niro because of crap like this? :mad:
 

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#57 ·
Wow, just finished reading this post. It's too bad Kia hasn't explained why L1 is for emergency use. We also don't have a definitive study on what's best for battery longevity. Speaking for myself, I installed a L2 charger so that I could complete overnight charge during my utilities off peak rate between 10pm and 3am. That saves me almost 30% on electricity cost. Another issue is the degree of smartness built into the Niro charger. Smart mult-stage chargers decrease the charging current as charge nears completion to avoid over charging. This is important to longevity and I haven't seen much, if any, discussion on this
 
#58 ·
That ramp down on charging current is really only applicable to DC Fast Charging. When I've used a Level 2 charger that shows a current graph, it's pretty much flat across the charging session.
 
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