Electric vehicles

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2078 posts

Uber Geek

#1327272 18-Jun-2015 13:37

RUKI: Just from the news line - love it:

"BMW's MINI Plant in Oxford UK is showcasing a high-efficiency street lighting system that doubles as a charging station for electric vehicles (EVs).

The EV charging cable connects to a standard connector on the Light & Charge street light and the integrated control panel allows drivers to start charging with the swipe of a card regardless of vehicle model."

Why don't they just put solar cells on the roof of the Mini and it can recharge overnight if you park it under a street light?

RUKI

1402 posts

Uber Geek

#1327355 18-Jun-2015 14:30

kemosabe: ....Most Prius battery seem to last more than 7 years (based on the first two generations, would expect newer ones to be better?. Even then, its typical now that you get a few cells replaced and have it professionally balanced and your good for another few years. The cost of that is probably not much different to a large expense on a typical car, i.e something like a clutch replacement.

Actually they last more than 7 years - 10-12 if you don't drive much. But with extensive driving - 5 years tops. Refer to my test results of 256000Km 2009Prius - Dead! (4 modules dead, the rest - very low capacity) That Prius was driving Auckland - Wellington regularly and still does after battery was changed to the brand new.

- Prius 1997-2000 - out of the game - I buy those packs for parts (connectors, relays, some other bits) - batteries are almost always dead with few rare exemptions (if low ODO).
- 2001-2003 - leaky (NP1) - I buy those packs for parts (connectors, relays, some other bits) - batteries are always dead with only one excemption - it was 2013 replacement from Toyota - tested and it showed good results.
- >2004 (NP2) - in Prius, Camry, Lexus, Estima - good quality, reliable and what is more important - interchangable. Wreckers however think that untested packs worth weigh in gold which is not true. One of the packs from 2008 Prius with 120000 km showed not so good results with two modules out of 28 significantly reduced capacity. Still operational but not for long.

Balancing is important for Li chemistry to avoid overcharge and explosion.

"professionally balanced" .... That is not applicable to Prius NiMH Pack. You can only fully charge all modules in the pack, but pack's performance would be impacted by the weakest module and the Usable Remaining Capacity of the pack will be even less than capacity of the weakest module.

Individual modules replacement (without all the modules being load tested) - does not provide long-lasting results. It is a quick fix in many cases for the car to be sold, I suppose.

If one module failed - there is another few just about to. That would be an indication of either
- someone's dodgy fix in second hand Prius or
- the whole pack is condemned - because the rest of modules are at the end of their life (could be few weeks or even months before they fail after individual module replacement, but you can't "be good for another few years" as kemosabe suggests).

NiMH Batteries in Toyota Hybrid have to be in conformance with each other - i.e. similar capacity, and performance under load to provide maximum output. There are certain things to be observed during the test. Proper test can only be conducted when all modules are load tested simultaneously under the same load.
Plenty of info and data is available on my site - just go and look up test results of those aged batteries.
Here is first generation Prius batteries tested (owner experienced "turtle"):
First Generation Prius Battery Test Results

lchiu7

6476 posts

Uber Geek

Trusted

#1327410 18-Jun-2015 15:41

I scanned this thread only but didn't find any mention of the BMW i3 EV.

I was in the US recently (CA) and friend had bought one (lives in the SF Bay Area). With discounts, federal and CA grants he paid about $40K(US) he said.

There are charging stations around his area so he doesn't have battery angst much of the time. I saw them at the supermarkets, malls, even the local library.

But he did have to upgrade his internal household power to provide a 240V line so he could install a fast charger (2-3 hours) rather than the overnight charger the 110V provides.

I took a drive in this car (I had driven one briefly before) and it's quite peppy and very driveable. You do have to get used to the compression like braking that occurs when you take your foot off the accelerator. In fact when you do that apparently the brake lights come on. I quite liked it, even the quirky clam shell doors.

Apparently in NZ they are only initially going to sell the model with the onboard petrol engine also since there are not enough charging stations around to make a pure EV worry free. That takes it out of the price range for most people.

Staying in Wellington. Check out my AirBnB in the Wellington CBD. https://www.airbnb.co.nz/h/wellycbd PM me and mention GZ to get a 15% discount and no AirBnB charges.

frankv

5680 posts

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Lifetime subscriber

#1327431 18-Jun-2015 16:29

heylinb4nz:
frankv: Does your cost of ownership include an allowance for battery replacement? What is the life of a battery in terms of number of recharges or in years?

Depends on many factors

number of slow vs fast recharges, type of charger used, discharge rate, quality of the battery, temperature operated in.

Most Li running on overnight (not fast charges) are rated to 1000 charges.

So based on a range of say 180 km you are looking at battery replacement every 180,000 kms (or 18 years at 10,000 kms per year), but taking into 80% rule its going to be more like 144,000 kms \ 14 years.

So factoring in a cost of around $6000 for a battery replacement (equivalent to an engine rebuild in a petrol car) add 4.1 cents per Km ($4.10 per 100km) to allow for the battery replacement. Which is around 2L of 91.

Savings dont sound so great now do they :(

Even if you got the maximum (180,000 kms) then you are still around $3 per 100 kms before you even add the electricity cost for a charge.

I drive about 80km weekdays to/from work, and probably about 80-100km in a weekend, say 500km/week. Even if I work on the basis of only recharge every other day (i.e. 3 times a week = 150 times a year), I get a bit less than 8 years, nowhere near your 14-18 years. OTOH, assuming a smart charger, I would be able to charge to only 80% every day, never run the battery below 20%, and therefore (hopefully) extend the battery life by quite a lot. Maybe to 10 years (3000 charges), which is what Nissan apparently expect. So 10 * 25,000kms/yr = 250,000km/battery. 250,000/$6000 = 41c/km for the battery. (I think you're out by a factor 10 in your calculations? Or am I?)

Fred99

13684 posts

Uber Geek

#1327450 18-Jun-2015 17:27

frankv:
heylinb4nz:
frankv: Does your cost of ownership include an allowance for battery replacement? What is the life of a battery in terms of number of recharges or in years?

Depends on many factors

number of slow vs fast recharges, type of charger used, discharge rate, quality of the battery, temperature operated in.

Most Li running on overnight (not fast charges) are rated to 1000 charges.

So based on a range of say 180 km you are looking at battery replacement every 180,000 kms (or 18 years at 10,000 kms per year), but taking into 80% rule its going to be more like 144,000 kms \ 14 years.

So factoring in a cost of around $6000 for a battery replacement (equivalent to an engine rebuild in a petrol car) add 4.1 cents per Km ($4.10 per 100km) to allow for the battery replacement. Which is around 2L of 91.

Savings dont sound so great now do they :(

Even if you got the maximum (180,000 kms) then you are still around $3 per 100 kms before you even add the electricity cost for a charge.

I drive about 80km weekdays to/from work, and probably about 80-100km in a weekend, say 500km/week. Even if I work on the basis of only recharge every other day (i.e. 3 times a week = 150 times a year), I get a bit less than 8 years, nowhere near your 14-18 years. OTOH, assuming a smart charger, I would be able to charge to only 80% every day, never run the battery below 20%, and therefore (hopefully) extend the battery life by quite a lot. Maybe to 10 years (3000 charges), which is what Nissan apparently expect. So 10 * 25,000kms/yr = 250,000km/battery. 250,000/$6000 = 41c/km for the battery. (I think you're out by a factor 10 in your calculations? Or am I?)

It's not 250,000km / $6000, but $6000 / 250,000km = 2.4 cents per km.

DS248

1697 posts

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Lifetime subscriber

#1327451 18-Jun-2015 17:27

frankv:
...

... 250,000/$6000 = 41c/km for the battery. (I think you're out by a factor 10 in your calculations? Or am I?)

Your calculations incorrect (dividing km/$ does not yield c/km).

Try $6000 / 250,000 km = 600,000 c / 250,000 km = 2.4 c/km for your case.

dwl

371 posts

Ultimate Geek

#1327461 18-Jun-2015 17:54

heylinb4nz: Most Li running on overnight (not fast charges) are rated to 1000 charges.

This did apply for the generation of batteries being produced a few years ago (and some were even worse) but I think the chemistry has been improving.

If I use the possibly slightly unrealistic example of Winston LiFePO4 (was Thunder Sky) they are claiming 5000 cycles for 80% DOD and 7000 cycles for 70% DOD. This may be starting from only 80% charge (just a guess) so might only be 60% of nominal capacity but that is huge difference.

While this might be advertising hype, I understand that some manufacturers are getting much better results than the old 500-1000 cycles. Unfortunately probably won't know for sure until a few more years have passed and it will depend on a good BMS.

[Edit] Added data from A123 prismatic cell which claims 3000 cycles with 90% capacity remaining:

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

kemosabe

66 posts

Master Geek

#1327469 18-Jun-2015 18:27

DS248:
frankv:
...

... 250,000/$6000 = 41c/km for the battery. (I think you're out by a factor 10 in your calculations? Or am I?)

Your calculations incorrect (dividing km/$ does not yield c/km).

Try $6000 / 250,000 km = 600,000 c / 250,000 km = 2.4 c/km for your case.

If that is correct, does that mean a leaf costs to run:

> 30 kWh @ $0.21 = $6.30 per charge good for mixed driving 100 km?
> Add 3c per km for battery life replacement cost for a total of $9.3 per 100 km

vs

An economical petrol can do 6 litres per 100km, @ $2.1 = $12.60 per 100 km ?

Something doesnt seem right in that?

dwl

371 posts

Ultimate Geek

#1327487 18-Jun-2015 19:31

kemosabe: If that is correct, does that mean a leaf costs to run:

> 30 kWh @ $0.21 = $6.30 per charge good for mixed driving 100 km?
> Add 3c per km for battery life replacement cost for a total of $9.3 per 100 km vs

An economical petrol can do 6 litres per 100km, @ $2.1 = $12.60 per 100 km ? Something doesnt seem right in that?

Right ball park but quite a lot of other plus or minus.

- if a lot of city driving, where the EV more likely comparison, probably worse than 6 litres per 100km - might push up to $14 per 100km

- we have night rate power 11pm to 7am so charge cost could drop to $3-$3.50, dropping cost to say $6.50 per 100km

- capital cost for Leaf currently higher - if $10k premium over say 200,000 km that is another $5 per 100km - now up to $11.50 per 100km

- maintenance costs for Leaf probably lower - maybe save $1 per 100km - back down to $10.50 per 100km

- now the killer, after 2020, RUC at $5.80 per 100km (which is needed to be fair to petrol) - even if had to pay, totals similar

Have I got this right?

DS248

1697 posts

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Lifetime subscriber

#1327501 18-Jun-2015 19:55

Not certain why is does not seem correct based on your figures,

Some data suggest electricity use can be lower than 30kWh / 100 km (more like 20 for a Prius running on electricity?). Would bring the consumables cost for EV down even further below ICE. Presumably improvements in battery technology will also reduce battery costs in the future.

But there are of course a lot of other costs to consider. Perhaps the most important being that petrol has a high road use tax applied. Removing that (or applying a road user charge on the EVs) would close the gap somewhat.

linw

2849 posts

Uber Geek

#1327574 18-Jun-2015 22:58

What would scare me is having a huge Li battery charging in my internal garage every night. Have you seen the fires from MUCH smaller radio control Lipo batteries?

While petrol would also make a helluva bomb, at least you haven't got someone playing with a cigarette lighter around it all night!

RUKI

1402 posts

Uber Geek

#1327626 19-Jun-2015 08:51

dwl:
While this might be advertising hype, I understand that some manufacturers are getting much better results than the old 500-1000 cycles. Unfortunately probably won't know for sure until a few more years have passed and it will depend on a good BMS.
[Edit] Added data from A123 prismatic cell which claims 3000 cycles with 90% capacity remaining:

Of course they are improving. But improvement comes with compromise - e.g. Capacity vs number of cycles.
I've heard from guys specialising in Li rebuild of portable devices that they are observing more capacity in newer Li modules but longevity is reduced.

I would be keen to test Li from 3 -5 year old EVs with known ODO (e.g. Japanese import) for remaining capacity.
Leafs and Plug-in Prius would be good to try.
I looked up online recently how they are build - packs from both cars could be dismantled to get access to individual modules.
Audi seems to use module approach and could be dismantled as well.
No way you can do it with Tesla as those are spot-welded.

Would be also interesting to get quote from Nissan and Toyota for the battery pack replacement. Unfortunately they would not do it without rego.

If anyone has NZ rego of Leaf or Prius Plug-In - could we kindly ask you to get quote for traction battery replacement - battery & labour separately?

MikeAqua

7785 posts

Uber Geek

#1327889 19-Jun-2015 15:36

I'm seriously interested in the idea of an electric boat project. Most of the electric boats in the US are flat water boats that operate at low speeds. There are water bodies in the US that don't allow hydrocarbon powered boats. There are excellent oil cooled stainless housing motors available and marinised battery packs. You can get electric outboards up to about 80HP.

There are a few substantial issues to be resolved for the fast planing hulls we typically use in NZ though: -
Battery weight - petrol/diesel (or an empty fuel tank) is lighter than the water it displaces. A battery is not. This reduces the ability of a boat to float when swamped - an important safety feature, which must be overcome with more buoyancy foam. this adds weight along with buoyancy.
Battery durability - will a battery withstand the pounding motion of a planing boat on a choppy day? A suspension system will add weight.
Recharging - a car will recharge when braking, no such option in a boat with current technology. A bigger battery per engine kW is therefore needed.
Electric field - will there be an inductive field from the motor/battery? If yes will this accelerate corrosion of metals especially aluminum?
Run flat risk - How predictable/measurable is battery drain?

There are some pros for an electric boat: -
- Quiet (good for fishing)
- Clean
- Simple/reliable/low maintenance
- Could recharge with solar and maybe even deploy a wind-gen when at rest.
- Stable weight distribution. The battery will have a constant weight -unlike a fuel tank which lightens as fuel is burnt requiring trim adjustment.
- Low centre of gravity

Components for EVs and Boats
I've done research on EVs suppliers last year again - a lot of options with motors and control boards are made in US. Those same components are used in EVs and Electrical Boats.
For New Zealand Electrical Boats for recreation could be even more appealing than EVs.
Local search brings couple of companies in Auckland who seems to be onto it already - offering re-selling of components from overseas.

Mike

qyiet

454 posts

Ultimate Geek

Trusted

#1327892 19-Jun-2015 15:44

MikeAqua: I'm seriously interested in the idea of an electric boat project.

I've always wondered about the viability of an electric Jet sprint boat.

Jet sprints only last for 2-3 min but in that time need to dump a huge amount of energy. I guess it transforms the battery problem somewhat, but I suspect an electric jetboat would do quite well.

Warning: reality may differ from above post

MikeAqua

7785 posts

Uber Geek

#1327895 19-Jun-2015 15:48

I was thinking about a fishing trailer boat - whip out sit and fish or idle around a reef and go home.

Jet sprint is probably similar to a drag car - great power to weight ration for a short run time. Weight is very important because it's skinny water so you want to float high.

qyiet:
MikeAqua: I'm seriously interested in the idea of an electric boat project.

I've always wondered about the viability of an electric Jet sprint boat.

Jet sprints only last for 2-3 min but in that time need to dump a huge amount of energy. I guess it transforms the battery problem somewhat, but I suspect an electric jetboat would do quite well.

Mike

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