BMW i3 Long Term Battery Capacity Report: Better Than Expected | Hacker News Reader

BMW i3 Long Term Battery Capacity Report: Better Than Expected

bmwblog.com

99 pointsjseliger77 comments

There is the LeafSpy app for Nissan Leaf owners that lets you monitor and log (to DropBox) several battery parameters.

Unfortunately Nissan removed the 80% charge timer in newer models, so you have to estimate charge time if you don't want to hit 100%.

That being said, you do want to charge to 100% periodically so the cells can be equalized. You can see this happening if your EVSE can log current.

The BMW i3 is a really nice car to drive around London for short trips. There's a pretty good charging infrastructure through ChargeNow and the car is nippy. It takes a short while to get used to the regenerative braking system and I particularly like the rear mounted camera for parking.

Is there anything special about the camera or did you previously have a vehicle without one? Rear view cameras will be mandatory on US cars starting with the 2018 MY.

> Rear view cameras will be mandatory on US cars starting with the 2018 MY.

Woah, never expected that. I remember thinking they'd be a gimmick when I first got one. Life changer.

Apparently this has been in the works since 2014 (and would actually only add ~$140 to the cost of a vehicle) [0]. We'll see if our current administration wants to eliminate this as well...

[0] https://www.usatoday.com/story/money/cars/2014/03/31/nhtsa-r...

That's assuming the vehicle already has a screen to show the video on.

You can put a screen in the rear view mirror for cars without cartainment systems; that's what I did with our 2012 Accord

I am 100% against those cameras on everyday cars(not trucks). In a few minutes im heading to the local pool to swim laps. That parking lot is a nightmare. Older people in the nicer/largest cars heads-down watching the screen while backing up. Ive seen far to many close calls. Cars should be limited to 0.01 mph while using such cameras.

Remember what happens next. They will want to remove mirrors. Then rear windows will go. Backing and changing lanes will become like instrument flying. Pedestrians and two-wheelers beware.

I agree to a certain extent. I believe backup cameras are this generation's equivalent of the automatic car. Where I grew up, you had pretty much no choice but to learn to drive using a manual/stick which in my (biased) opinion teaches you greater respect and understanding of a vehicle and a better appreciation of how to use the gears to your advantage in various conditions. I now have an automatic car and I've noticed it's so easy to just drop into a zen state on the highways which I didn't find so much with a manual car.

Perhaps it's a stretch, but I feel the same way about reverse cameras. We were taught to not rely solely on mirrors but to physically check over our shoulders before reversing, but so often these days (usually in SUV-dominated supermarket lots) I see people fire up their car, look down at the screen and start reversing without physically checking out the surrounding environment. The cameras are a great aid for sure, but I think over reliance on them is dangerous and I hope the basics will continue to be taught to learner drivers as cameras become more prevalent. Of course, soon none of us will be driving anyway so maybe it doesn't matter.

I wouldn't call cameras "this generation" anything. My experience is not that young people are relying upon these cameras. It's old people, people who cannot so easily look over their shoulders. Cameras are also, today, on newer and more expensive/larger cars generally bought by older people. It's like the pickup trucks with those little steps that fold out. They aren't marketing those to actual cowboys.

Could you explain a bit more? If you are going backwards, and looking at the view behind you, then what is the issue? I have one on my car, and it shows ~140 degree field of view - I can see more from the camera than I can through any of the mirrors.

You only get 140, not the 360 if you actually bother to turn your head. If i remember correctly, i think you need a 150 field test to enlist in the military. 140 isnt enough, especially when the camera is at the bumper rather that at the driver position 10 feet back. You dont see the pedestrian approaching from the side or, in the case of this parking lot, the huge "dont back in" sign hung over the spots near ventilation equipment. Few of these parking cameras can look up. The resolution and size of a screen also means you dont percieve movement in your peripheral field as you would viewing a situation directly.

I agree with your point about people using backup cameras exclusively—they are bad drivers. Still, for many cars that view would've formerly included a blind spot large enough for child-size things.

> They will want to remove mirrors. Then rear windows will go.

Great. Our vehicle has a camera mirror that enables an unobstructed view of what's next to us as we change lanes, and it's a revelation. I'll take any sensor- and camera-assisted situational awareness and accident prevention I can get.

I'd prefer if they required video plus proximity audio feedback. Video only systems don't give you the same urgency gauge as audio feedback does.

The most useful feature on new cars that I've seen are the Mercedes (I believe) proximity indicators on side mirrors.

There's a tiny red light that illuminates to the bottom left of the mirror when a vehicle is alongside the driver's car. Solves the blindspot problem in one swoop.

>Solves the blindspot problem in one swoop.

Except if the indicator can fail silently in any case. Then the problem is worse than it ever was.

Only if it happens more often than people fail to properly execute the over-the-shoulder look. I doubt that.

That's why it's called assistance. Blindspots can still be checked by physically moving, and they should be.

That kind of problem is now well handled. See ISO 26262.

tl;dr of ISO 26262 would be interesting. Could not find anything short and meaningful quickly.

I prefer solving it through the low-tech expedient of turning my head.

I think rear cameras are wonderful. They make reversing maneuvers so much easier, and cover a blind spot that is impossible to cover in any other way short of getting out of the car.

But I don't get the worry over side blind spots. They're only blind spots if you keep your head pointed resolutely forward.

If you can see through an overly wide and poorly placed B pillar, more power to you.

It's been my experience that the majority of drivers can't. And not all cars are well designed with regards to visibility.

Lean forward so you can see around it. If you can't position your head so that you can view your blind spot (possibly with the aid of mirrors) then you can't drive safely and need to adjust your seat or get a new car.

The problem isn't sample size 1 (e.g. you, me, or any individual HN reader). It's "drivers" in aggregate.

My doing anything isn't going to prevent the 800k+ blind spot accidents or ~300 blind spot fatalities in the US annually.

My point is mandating an awareness aid that it's now economical to produce might.

I didn't realize you were talking about the aggregate. With statements like "If you can see through an overly wide and poorly placed B pillar, more power to you" and "not all cars are well designed with regards to visibility" I thought you were trying to say that my strategy cannot work in general, not merely that people won't bother.

All my cars (and motorcycle) have 3.5" adhesive convex mirrors stuck to the OEM side mirrors (both sides). Cost 3USD each to remove each side's blind spot.

Mazda has had those (as well as audio alerts) standard for years as well. Fairly certain several other manufacturers have also integrated the tech.

You could also solve it (more reliably) by using aspherical mirrors, but those are illegal in the US.

My rear mounted camera (Subaru Forester) is fouled by dust all the time. Pretty much useless. I live on a gravel road, and it takes just one trip home after the car wash to completely obscure the lens.

For city driving it could probably work ok.

I have one on my Merc and it's actually behind a flap that opens when I put the car in reverse - so the view is always clear, it can't get dirty. Of course, that's at a cost of one extra thing thay can brake(the flap motor).

I have made it a point to walk behind the car every so often and wipe the lens with a finger or cloth. I realize the long-term implications of the build up of micro-scratches, but so far, so good.

GM seems to have the best battery health system. Doesn't let you charge past 85%, 90%, always keeps 10% or 15% in reserve. Only reports the chunk between. Dedicated robust temperature control system.

Volt has been out since 2011 with as-far-as-I-know no battery degradation issues. Some people have driven well over 300,000 miles with no problems.

Why do we even call "90%" if the battery is disallowed to charge higher for (presumably) longevity reasons? Why not call that "100%"? Assuming I disabled the automatic cutoff at the filling station, I could squeeze a bit more gasoline in my tank by filling the pipe up to the gas cap, but I wouldn't say I'm at 95% for not doing this.

(In contrast, it makes sense to say that the car reports "empty" even when it's at 10%, because you can keep driving it .)

For discussions of longevity actual capacity is relevant because where the full/empty lines are drawn has a big effect on how much wear and tear gets put on the pack in a cycle. A literal 100% charge is very different than a nominal 100% charge.

The degree to which each percentage point effects longevity surely varies depending on battery design. It would be a lot more useful it describe it in terms of recharge-discharge cycles than to say "it is limited to charge only up to 90%" and let the listener try to infer what that means about lifetime.

That's how the i3 works as well. There are 22kwh of batteries in board, but it only uses about 18kwh for the sake of efficiency and longer life.

The issue I have with the i3 is that it was hinted they could upgrade the batteries but they won't do so, at least in the US.

I am very happy with my second generation Volt, averaging 66 miles per charge since I got it in March (Georgia weather) and it should squeak out a few more as summer progresses. I am really curious what my range will be in Winter seeing as a friend with an i3 loses twenty miles per charge in our coldest and the Tesla 80 at work goes under 200 range max by a good number.

still not sold all battery is the way to go, range is always there, but recharge times and sheer weight of so much battery is contrary to where manufacturers want to take cars (lighter weight is better regardless of propulsion method)

> (lighter weight is better regardless of propulsion method)

This is true for efficiency reasons, but lighter cars also save lives. Here's a recent discussion:

The Effect of Fuel Economy Standards on Vehicle Weight Dispersion and Accident Fatalities

Antonio Bento, Kenneth Gillingham, Kevin Roth

http://papers.nber.org/tmp/22190-w23340.pdf http://www.nber.org/papers/w23340

> we find that CAFE has been providing safety cobenefits because it encourages down-weighting. Using the Department of Transportation’s value of a statistical life, at $9.4 million, the welfare benefits of reduced fatalities, found in our simulations to range between 393 and 439 lives nationally, are more than $3.5 billion annually. ... our findings suggest that CAFE would pass a cost-benefit test based on benefits from reduced fatalities alone. This is particularly notable because the current EPA analysis does not include benefits or costs from fatalities, but relies heavily on myopic consumers realizing large future fuel savings to pass a cost-benefit test, which recent economic evidence brings into question (Busse, Knittel, and Zettelmeyer, 2013; Allcott and Wozny, 2014; Sallee, West, and Fan, 2016). Our results suggest CAFE standards may have positive net benefits even without any undervaluation of fuel economy.

GM have apparently been putting a serious amount of work into their battery engineering: https://www.wired.com/2016/01/gm-electric-car-chevy-bolt-mar... It's just that no-one seemed to notice until recently.

>Volt has been out since 2011 with as-far-as-I-know no battery degradation issues. Some people have driven well over 300,000 miles with no problems

This is nice but anectdotal evidence is useless when looking at failure rates. Does GM put out any actual data on the Volt/Bolt? Im really curious how they stack up against Toyota for reliability.

http://insideevs.com/zero-first-generation-chevrolet-volt-ba...

I have a 2013 Volt with 67K (50K ev) miles and there is, so far, no change in ev range.

There's also https://www.voltstats.net/

Best out of who? Tesla's seems very robust as well.

Best of affordable cars. I get your point, but none of the Tesla's available on the market are really outside high end luxury segment.

> Some people have driven well over 300,000 miles with no problems.

I assume at least 2/3 of those miles were on gas?

The Volt with most miles (in real life) is 379201.03 and its has 132643.18 ev miles, so you are about right for that one.

edit: https://www.voltstats.net/Stats/Details/1579

There may be longevity tale unfolding with PHEVs, but we can only guess.

I've heard complaints about how during the winter months the Volt will keep the gas engine on to keep things heated up and it will cut the range almost in half (60ish to mid 30s) during the winter. I'm not sure if that's the overall range or the electric range.

That's probably enough for a lot of us commuters, especially if you've got charging options at work but that'd make it a non viable winter getaway car (which you'd probably already know if you're researching hybrids).

The range drop applies only to electric mode, and it doesn't drop by half unless you're driving very slowly (in other words, you spend a lot of time with the heater on and don't go very far). Pre-conditioning the cabin while the car is plugged in helps tremendously in moderately-low temperatures.

There's a setting on the center console screen to adjust how aggressively the Volt uses the engine for heating.

Yeah that makes sense. The pre-conditioning is a really cool thing.

How would that make it nonviable? The whole point of the gas motor in a Volt is to let you drive beyond battery range. Once you deplete the traction battery, you're essentially driving a standard hybrid that still gets excellent gas mileage and has similar range to standard gasoline cars. It's not like the i3 range extender where you lose substantial power once it kicks in, it has a microscopic fuel tank, and it's really just a last resort if the batteries can't get you where you're going.

I said that I wasn't sure if that was the TOTAL or the electric range. My point was that if that's the total range it's a problem.

I know nothing about these cars beyond the Winter complaint I heard.

OK, I was unprepared for that level of cluelessness. Maybe take a few seconds to look it up before spreading misinformation? I mean, not to be harsh, but I don't see how it's in any way believable that the total electric plus gas range of a Volt could be as low as 30 miles.

For the record, total range for the Volt is officially 420 miles. Chop the electric range in half and it would be about 400 miles. Chop both in half (range on gas won't be nearly as badly affected in the cold) and it's still 210 miles.

This is an interesting article, but the cross-validation is perhaps suspect? It seems likely the 'percentage used' indicator is based on the same underlying measurements as the 'estimated capacity' service indicator. So it's quite likely illusory validation of the 4% loss figure.

The i3s that I see in London don't appear to be plugged in, they seem owned by people who don't have that at home. I presume they plug in at work but without knowing that there is no way for knowing for sure.

Are people buying these things, doing a small amount of miles with them and powering them from the petrol engine on-board rather than plugging in? In that way getting preferential parking spaces at airports and in the city centre, no congestion charge needed? I am fine with people using them in 'Prius mode' if it does mean people that did rule out electric due to not having home infrastructure can actually go 'electric lite', running off petrol and opportunistic charging.

More likely that they plug it just around the corner.

If they don't have it near the entrance to their building it means that there is one very near by, the council will not put a new one if there is one within walking distance from your residence.

The street level charge spots usually have a hour limit for this reason even for resident parking.

Source: I live in central London(W2) and when inquiring with Westminster council about a charge spot they've directed me to 3, one at the end of my street and 2 in streets parallel to mine all within 5min walking distance.

TL;DR: if manufacturer gives a guarantee for a component, the component will last for honoring the guarantee.

There is a catch. A coworker had the battery on his wife's Honda Insight go bad. No worries - it was only 18 months old, so get it replaced under warranty. Afterwards, they were informed that the new battery would be covered under Honda's replacement part warranty - 12 months. And not the remainder of the 8 year/80,000 mile original equipment warranty.

I suspect that they were wrong. Unless this is a state by state thing or something, a warranty replacement cannot shorten the length of the existing warranty. The replacement part warranty should only apply to any time after the expiration of the original warranty.

Sucks, but it depends where you live. In Poland the law specifically says that if a replacement is provided under warranty then the replacement has to be covered for the same amount of time as a brand new component would be covered for(so in this case if the battery is replaced at any point under warranty the replacement has to have 8 years of warranty by law)

That can't be legal.

It likely is legal. The BestBuy extended warranties work the same way. If BestBuy ultimately needs to replace your product, then your extended warranty is finished.

Extended warranties are totally different from original warranties.

Warranties on cars are much more highly regulated than service plans on consumer electronics.

http://www.insightcentral.net/KB/faq-purchasing.html

Seems like this source disagrees. They may wish to get their money back.

They don't mention the warranty on the replacement battery, which is what my friend discovered isn't so great.

Thanks for this information. I didn't think about checking replacement parts warrenty rules, silently assuming they were the same. That they are not smells fishy.

If you're shopping for a hybrid or EV, talk to the service manager and ask what the policy is. It's possible Honda may have changed it since then.

Was it a manufacturer warranty or one of the after-market ones that some dealerships sell?

One of the original Tesla founders pointed out that the 2-3 year life everyone is used to from laptops and phones was mostly due to lack of any business need for longer lasting batteries.

Now that EVs demand it, people are doing the engineering to make it happen.

I wonder why would someone buy an I3 instead of a Model 3? Model 3 seems to win on all fronts: looks, performance and value for money/price. Is i3 really just a POC for BMW?

The i3 is available _right now_ and the Model 3 isn't. Actually getting getting the car might be a consideration for a lot of people. My housemate has an i3 and it's a fantastic vehicle - the best utilization of plan area of any vehicle I've ever been in.

This is hacker news, where allowing the theoretical, unavailable best to be the enemy of the available good is all part of the game :/

All the batteries in the world won't make the i3 pretty.

It's ugly on purpose to minimize sales.

This is unfortunately so true. I am waiting for the model 3 even though it might mean losing the sizeable German government subsidy, because the i3 is such an eyesore. BMW, if you're listening, stop being afraid of cannibalizing your petrol car sales and make a decent looking EV in the i3 price segment, because this just made you lose a sale to Tesla, and I'm far from alone here. Unless the reason is that the i3 is just a compliance car and you lose money making one, in which case, get your act together because it's 2017 and you risk doing a RIM vs Apple.

Why

This is full of suspect data and shilling on a car that has gotten a lot of bad press. This feels like pure PR. Please respond if you disagree.

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