Extended charging time at home charger

[bi3mw]

(To preface: I did a few searches and couldn't find anything so am creating a post. Additionally, I'm in the US and my area is in the 5 degrees F temperature range right now, so I know this is effecting battery life when driving.)

The car was purchased a few days ago with 1500 miles on it, so it has had some time to "learn" driving styles, though I'm certain not consistent driving styles. However- I plugged the car in yesterday after work and it was on the charger for 12+ hours. Got up this morning and it was only 92% charged after almost 13 hours of charging.

Is this because it hasn't had a full charge since I got the car three days ago, or is this an actual representation of standard charging time for 110v home charging? Also, I ran a quick errand this morning in Eco Pro (not Pro Plus) mode. I drove 6.2 miles and it went from 92% to 38%. I know cold temps affected it, but I'm surprised it went down that low.

 

[PhilH]

You've not said the type of charger you're using, so it's difficult to give a definitive answer. However, if you're using a 10 amp charger at 110v, this is only just over a kilowatt, so a complete charge would take around 18 hours minimum.

 

[bi3mw]

You've not said the type of charger you're using, so it's difficult to give a definitive answer. However, if you're using a 10 amp charger at 110v, this is only just over a kilowatt, so a complete charge would take around 18 hours minimum.

Ah. It's a 12 amp charger and I have other appliances pulling on the breaker as well. That would likely explain it.

 

[WoodlandHills]

Other appliances on the same circuit do not affect the cars charge time. As long as the total load does not trip the breaker the charging cord will pull its maximum.

You do realize that the charge cord/device found in the frunk is called the Occasional Use charger for a reason? We used the OU cord for a month or so until we got our Level 2 permitted and connected and it is possible with a little planning. Just don't drive much and keep the car plugged in whenever it isn't actually moving! Unless you have access to a Level 2 at work where you can get a full charge in a few hours, you really need one at home.

 

[cove3]

<<< keep the car plugged in whenever it isn't actually moving!>>

I've read optimal is 50% charge and that ev batteries don't like being fully charged for extended periods. I've not seen a definition of extended period.

Net: when you plug in, you will get a full charge unless you watch it. How long can the car sit at full charge not being used without degrading the battery?

Ron

 

[PhilH]

There's no problem keeping the battery fully charged, except for a prolonged period of non-use: i.e. weeks rather than hours or days.

 

[WoodlandHills]

You cannot fully charge an i3: the software keeps a little headroom at the top to extend battery life, the same at the bottom: you can't fully discharge the pack either. I thought that horse had been beaten throughly in many previous posts here.......

 

[bi3mw]

Other appliances on the same circuit do not affect the cars charge time. As long as the total load does not trip the breaker the charging cord will pull its maximum.

You do realize that the charge cord/device found in the frunk is called the Occasional Use charger for a reason? We used the OU cord for a month or so until we got our Level 2 permitted and connected and it is possible with a little planning. Just don't drive much and keep the car plugged in whenever it isn't actually moving! Unless you have access to a Level 2 at work where you can get a full charge in a few hours, you really need one at home.

I did not realize that it wasn't actually intended to be the primary charging source. Definitely am getting a quick charge for the garage. I've been perusing the forums here for information on that as well.

Thanks for the help!

 

[cove3]

<<<You cannot fully charge an i3: the software keeps a little headroom at the top to extend battery life, the same at the bottom: you can't fully discharge the pack either.>>

I know usable is 18.8 of the 21.6 nominal. You're saying this factory set cushion therefore allows one to keep the battery fully charged for many months if not longer, assuming you don't use the car, with no impact on battery life/capacity?

The reason I ask is the e-golf users manual recommends keeping it at 40-50% if not using the vehicle for an extended period of time, although they don't define what extended is. Since both the i3 and e-golf use the same battery technology, the recommendations should be the same for both cars

There are times when I won't use the car for 3 or 4 weeks, hence my interest

Ron

 

[WoodlandHills]

BMW is saying that not me...... IIRC the last time this issue was discussed it was posted that BMW suggest storing the car with a full charge if parked for an extended time. Of course that means with something less than the maximum that can be pumped into the pack since you cannot fully charge an i3 battery when using an EVSE.

Is there "no" impact on the pack by storing it that or any other way? Of course not, literally everything that happens to the pack has some impact upon its life, but you already know that. From your posts we can tell that you have been doing this a lot longer than most of us......

Besides, you can't be seriously suggesting that we keep our cars at 50% charge all the time..... Is that what you do with your EV? How do you deal with having only 1/2 the range?
You must have developed some range extending strategies over the years for dealing with a 1/2 charged car, could you share some tips?

How long a life are you getting from your current battery pack using the 1/2 charged method?

 

[I33t]

<<<You cannot fully charge an i3: the software keeps a little headroom at the top to extend battery life, the same at the bottom: you can't fully discharge the pack either.>>

I know usable is 18.8 of the 21.6 nominal. You're saying this factory set cushion therefore allows one to keep the battery fully charged for many months if not longer with no impact on battery life/capacity?

Ron

Who here is suggesting we might keep the battery fully charged for many months if not longer ?

You could not possibly do that if you use the car.

 

[mindmachine]

<<<You cannot fully charge an i3: the software keeps a little headroom at the top to extend battery life, the same at the bottom: you can't fully discharge the pack either.>>

I know usable is 18.8 of the 21.6 nominal. You're saying this factory set cushion therefore allows one to keep the battery fully charged for many months if not longer assuming you don't use the car with no impact on battery life/capacity?

The reason I ask is the e-golf users manual recommends keeping it at 40-50% if not using the vehicle for an extended period of time, although they don't define what extended is. Since both the i3 and e-golf use the same battery technology, the recommendations should be the same for both cars

There are times when I won't use the car for 3 or 4 weeks, hence my interest

Ron

I am not an electrical engineer but mechanical so take what I say accordingly; but, at least for me I am only charging to around 50 to 80% SOC most of the time. Especially if i intended to let the car sit for 3 weeks I would charge it to 50% SOC and not more. I am retired and frequently I don't drive the i3 for a full week at a time and watching the SOC for 7 days I have never seen a drop in the SOC. And for sure it can't help but be better for your battery to leave it at 50% then it would be to charge it to 100% SOC even considering the headroom left by BMW.

 

[jadnashuanh]

FWIW, the EVSE is totally disconnected by the car once the battery reaches the allowed full capacity (you'll see the charging indicator on the EVSE go off and hear the contactor open). It won't reactivate it until it has dropped somewhere in the 5-6% range from that full charge (which will take awhile) or if you tell it to pre-condition. The battery logic in the i3 is fairly sophisticated, and with the warranty provided, I'm not worrying about it. Any later battery replacement will likely have higher density, and the existing pack will still have value. BMW has started a program to use them as storage batteries for things like solar collectors and buffers as they will still operate fine in that mode for a number of additional years. There was a press release recently in the last few weeks describing that usage. Being able to use the full capacity at the spur of the moment is worth it to me rather than sitting at half capacity.

 

[Boatguy]

You do realize that the charge cord/device found in the frunk is called the Occasional Use charger for a reason? We used the OU cord for a month or so until we got our Level 2 permitted and connected and it is possible with a little planning. Just don't drive much and keep the car plugged in whenever it isn't actually moving! Unless you have access to a Level 2 at work where you can get a full charge in a few hours, you really need one at home.

I did not realize that it wasn't actually intended to be the primary charging source. Definitely am getting a quick charge for the garage. I've been perusing the forums here for information on that as well.

I've been using the "occasional use charger" in a 110v/15a outlet for the last four months/3,600 miles (only option at my current rented residence). Yes, it's very slow; it's only charging at about 1.1Kwh / hr. I'm usually home by 6pm and don't leave until 8am so 14hrs a night usually does the trick.

You have determine if that works for your driving requirements and lifestyle. If so, there is no reason the "occasional use charger" couldn't be used indefinitely, it's a very simple piece of electrical equipment.

That said, when I move back into my home I'll be getting a Level 2 charger.

 

[jadnashuanh]

If your normal usage gets the battery almost empty before a recharging opportunity, it could take over 20-hours to get back up to full again. So, it really depends on how far you go, and how often you can recharge. The equipment itself doesn't really care, it will work. Most people will find that inadequate, but I'm sure it works for some. Those with 220-240vac available, get a different EVSE with their car, and it's at least 2x as fast as those whose normal power available is 120vac and counting in that 220vac is more efficient in the car when charging, it's even (slightly) faster than the power output alone would seem to indicate.

 

[WoodlandHills]

What does stuff in the VW manual have to do with an i3? Unless you are just here to troll.....

 

[cove3]

As the owner of two 5 series and former owner of 3.0cs, 2800cs, and 2002, member of BMWCCA, and author of a restoration project article in Roundel, I hardly consider myself a troll.

Since the nickel/cobalt/manganese module cell battery technology in the i3 and e-golf is similar, I would think you would be alert enough to reason that the optimal level of charge of 40-50% recommended by VW for an e-Golf not in use for an extended period of time would have something to do with the post that said because the i3, like the e-golf, has a reserve (usable kwh vs rated kwh) it can be charged 100% for an extended period of non-use with no effect.

Both statements can't be right. In the interests of both i3 and e-golf owners, I was just trying to determine which one was right, as we're talking about maximizing the life and output of a $10,000 battery. There are times for various reasons, not always predictable, when I won't use the car at all for 3-4 weeks. Should I keep it charged 100% or 40-50%?

Correct me if I'm wrong for asking.

Ron

 

[Sparky]

You will be on to the i4 before the battery warrantee is up.....who cares.

 

[cove3]

I generally keep cars more than 8 years, I'd rather not get down to 70% while I own it as it reduces range, plus battery condition would affect resale value.

Ron

 

[Sparky]

It doesn't look like you even own one!