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Discussion Starter #1
Hi,

I've just joined the forum.
I'm a long standing electric car enthusiast and used to race early 'ev's' in the 80s with the BVS as it was then. I've often wanted to convert a car in the past then recently had a Leaf on lease for a couple of years and finally I'm currently in the process of converting my Smart Roadster to Electric, although it's taking a long time as I don't have much time to spare. Mechanically it's mostly together but after looking into batteries I've realised there isn't a good answer or at least not one that doesn't involve lots of risk and expense.

I'm a product designer by trade although not in this field but I've been considering the problem and think there may be a requirement some innovation here.

So my question comes in 2 parts;
As I suffered terrible range anxiety with the Leaf on long trips (and had to borrow someones mains socket one night) having a 'fuelcan' of power seems like a useful thing. I've seen people carrying generators around to combat this issues but a LiFePo4/Li-ion powerpack of say 2KW/h that you can carry around in the boot and plug in when your out of juice seems like it may be useful?.

I also think standardising on a high power battery format would help the future of EVs, all the car companies are developing their own battery format, controls, voltages etc but at some point there must be some/a standard. By that I mean rather like AA batteries we settle on a NN format where you can plug in a number of packs to either replace or upgrade your capacity. I'm thinking along the lines of the 18650/ laptop sized cells in arrays of say 200 (~2kw/h at the moment), this NN battery 'cartridge' then attaches to a controller that manages the batteries (which configures the output perhaps) and the whole lot is a carry-able size which you can plug into the car. So depending on the car there might be 10-20 of these?!.
I'm considering doing this for my conversion.. although as it might take a while I might have to survive on Lead for this years launch.

I'd like to hear any views on this, I know its better for the batteries to be on the floor, the control is important and how would you monitor them, but conceptually it would be a great thing for many reasons.

The 'fuelcan' is perhaps easier although could use the same concept, but as EV range increases is there a need for this?. Will range anxiety disappear?, certainly not unless charging is totally universal (i.e. no stupid cards) and as common as petrol stations are now.

I'm thinking of starting something soon so comments and thought's would be appreciated.

Paul
 

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All EVs take the motor out of circuit whilst connected to an external power source, to prevent you driving off whilst still connected. So your 'fuelcan' would only be a means of transferring a charge to the battery, which takes time. You couldn't connect it and immediately drive off.
 

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If your going to drive around with "spare" batteries in the boot, surely you'd be better off just adding more batteries permenantly...

I suspect standardising the batteries wont happen. They're integral to the design of the car (both mechanically and electronically), and are a major upselling point for manufacturers. They have no desire to design a system which allows you to buy the "cheap" model with say a 40kwh battery, then get some aftermarket 80kwh pack and bolt it in... They'd much rather sell up to the 80kwh model.

For your Smart project, i'd be looking at getting a pack from an salvage leaf/zoe. Dont waste your time with lead. Heck, find a salvage leaf and transplant the lot, drivetrain, electronics, battery. You might need to dismantle and reconfigure the battery to make it fit where you need it to go, but retaining all the factory BMS and electronics means it will all just work.
 

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I think there is little point in standardising EV battery packs as they are maintenance free, and made for specific applications (e.g. the Nissan Leaf and Nissan e-NV200 are different).

The fuel can idea is nice on paper, but I'm not sure how it would work in practice. You could have a LiPo battery and an inverter, but this would then need to be connected to the charge point and charge pretty slowly. The alternative would be an ultra capacitor capable of DC charging but this capacitor technology doesn't really exist and it would need complex circuitry to work.

I think a better solution is better infrastructure, and for those who need it, cars with longer range and/or faster charging.
 

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Discussion Starter #5
I don’t disagree with the points you make as it’s still early days with electric cars and there is still a long way to go with power storage.
However, you can buy a 2 year old Leaf for £6k, so that’s a £20k drop in 2 years, why?, the only reason is that the later ones have better range, in fact the newer Leafs aren’t as good as the original ones with all the goodies on, the rest of the car is perfectly good. A Tesla loses proportionally less because it’s range is currently acceptable (and they are so cool) but you have to be rich to by the cheapest one… I also see a Roadster battery upgrade is $29k.

Depreciation of EVs is going to be terrible for quite a long time and the only reason is batteries. I have seen a number of posts on here where people are wondering how to improve the batteries in their cars and the current methods mean you have to do a lot of research and string together a load of bits and you’ll probably still end up with a potentially dangerous setup. There are very few products where you can’t easily replace/upgrade the batteries?!... a mobile perhaps but then you throw it away after 2-3 years.. probably because the battery doesn’t last as long as it used to. The chances of me making anything remotely good is slim but I don’t think the principle is completely wrong.

The fuelcan is purely a ‘I’m stuck on the motorway and now way to get off’ fix, I avoided motorways on long trips as it sucks more power and what do I do if I run out on a motorway?!. (there was no way I was going to drive slowly with Lorries stuck behind me). You say just add more batteries, (but of course you can’t) and most people have run their tanks low, bigger batteries only mean it takes long to run low.. but you’ll still do it. Surly it’s just something you charge slowly at home and carry around?

I'll investigate a salvage leaf (or by any leaf and strip the parts out from a good one, they're almost cheap enough to do that :D). It might be my quickest way to get the Smart finished.
 

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Depreciation of EVs is going to be terrible for quite a long time and the only reason is batteries.
On what basis do you claim that? I believe the depreciation is due to lack of appetite, fear and misunderstanding. Even a 2011 MieV (or clone) has sufficient capacity to be an excellent local, 2nd car for many families but they refuse to consider. I recently drove a new Polo FSi on holiday in Spain and would far prefer a MiEv for local or city driving!
 
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However, you can buy a 2 year old Leaf for £6k, so that’s a £20k drop in 2 years, why?
Paul - the reason for poor residuals on the Leaf is because of all the issues around 'take up' of new technology combined with range anxiety and concern in particular about the great unknown - what happens when the battery packs up. Having watched the market closely for 2 years I think that residual values are now picking up as confidence in the product improves. That's my take on it.

You asked

"Will range anxiety disappear?, certainly not unless charging is totally universal and as common as petrol stations are now".

I used to agree until another Andrew (one of the mods) pointed out that 'petrol thinking' should NOT be applied to EVs. It took a while for me to understand the point - that stopping now and then to re-fuel/re-charge is not as good a solution as re-charging at home and overnight (I know - not everybody can). For that to happen - for those of us with off street parking - battery range has to improve significantly. When it does range anxiety will disappear - for some.
(I used to think - what a pain, having to plug in every night and unplug every morning until I thought about how long it takes queuing for diesel once a week.)

Finally - carry on with your 'fuel can' thinking. I can never understand forum folk who reply to an inquiring mind with 'You're doing it wrong/there's no need/ just spend £XXXX'
Some of them must still be on horses.
 

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Some basic calculations on current battery performance will show you that the 'jerry can battery' idea really isn't feasible. Not unless you want to tow the thing around in a trailer.

Also, there's no such thing as range anxiety. Most cars are very clear about how much range they have left, bordering on the pessimistic. There is however 'charger anxiety'...which is an infrastructure problem, not a vehicle problem.
 

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I like your thinking Paul. I don't understand much of it because I gave up physics at the age of 14. But I like your 'Thinking'.

I too thought wondered 'rescue packs' - could the AA man drop a black box on your passenger seat that would give you 10 miles of juice to get to the nearest charger etc etc. but now I have a leaf I realise range anxiety a)fades with use (and access to an ICE) and b) will be gone essentially completely when your standard car is 200 miles. Whatever the weather. And that's only hopefully only 5 ish years away.

Will faster charging make as big an impact as bigger batteries? If you could get 50-60 miles in 5-6 minutes then again I think RA would become much less of an issue as the stop time would be much more akin to a ice car. Overall though overnight home charging is where most EV's are going to get charged.
Do any new houses get built these days without at least one car space outside?

Rambling a bit now...
 

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Sadly lots of new houses are being built with a car space not exactly outside! Near the house but not on the property. So where will they run their cables to their chargers?
Yet another failure of modern housing planning. Ok maybe not yet considered a failure but in years to come folks will say "why didn't the builders make the property a single piece of land so we could install chargers?"
 

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Discussion Starter #11
Some basic calculations on current battery performance will show you that the 'jerry can battery' idea really isn't feasible. Not unless you want to tow the thing around in a trailer.

Also, there's no such thing as range anxiety. Most cars are very clear about how much range they have left, bordering on the pessimistic. There is however 'charger anxiety'...which is an infrastructure problem, not a vehicle problem.
I'm not particularly excited about the jerrycan idea but I'm not sure your calculations add up, as a reference point, the Tesla powerwall is ~15kwh and weights 120Kg, so that's ~8Kg/1kwh, so a 2kwh charge pack would weight 16kg.. not too bad. However, the more interesting product that I'm interested in is the 2kwh standard battery size (which would increase as tech becomes better).
 

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Discussion Starter #12
what happens when the battery packs up
You plug in some 'new' batteries!... oh yes you can't do that at the moment.
I used to think - what a pain, having to plug in every night and unplug every morning until I thought about how long it takes queuing for diesel once a week
I was fortunate enough to be able to plug in every night and we have chargers at work which are free to use. I also liked the auto-heating that you could set to come on in the winter.
Finally - carry on with your 'fuel can' thinking. I can never understand forum folk who reply to an inquiring mind with 'You're doing it wrong/there's no need/ just spend £XXXX'
Some of them must still be on horses
Thanks for the support, I must confess that I am a bit surprised that a group who are forward thinking enough to be interested in electric cars are so dismissive of anything that isn't currently available. Elon wouldn't have got anywhere if he had listened to people who said it couldn't be done. I don't suppose I'll ever have the time or money to do this, but I'll look forward to buying a car where I can remove the batteries from so that I can plug in the latest technology.
 

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I'm not particularly excited about the jerrycan idea but I'm not sure your calculations add up, as a reference point, the Tesla powerwall is ~15kwh and weights 120Kg, so that's ~8Kg/1kwh, so a 2kwh charge pack would weight 16kg.. not too bad. However, the more interesting product that I'm interested in is the 2kwh standard battery size (which would increase as tech becomes better).
So the Powerwall 2 has a 13.2 kWh capacity. However it's maximum continuous discharge is 5 kW. It weighs 122 kg.

So all else being equal (which in real life it won't), this theoretical jerry can that has a fifth of the capacity of the Powerwall would weigh 24 kg but would have a total capacity of 2.64 kWh and be able to charge at a maximum rate of 1 kW. It's going to take a long time to get 2 kWh of energy into the car's battery...especially as the thing will taper off massively as it discharges.

This is a really rough calculation, so I'm sure you can pick holes in it. However the real question is, why wouldn't you just get a car with a larger battery in the first place?

Also, if you can emergency charge at any three pin plug at around 2 kW (10 amps), why would you ever need the jerry can?
 

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There's various possible interpretations of the 'jerry can' idea:
  • One you permanently carry in the boot in case you run out. There really is no point to this one - the equivalent amount of capacity would take less space/weight added to the main pack rather than having it separate. If the point is simply so you can run out without noticing and then "aha!" get the one out of the boot, then you can get that as a software feature with the larger main pack - the car can prevent you using the last 10% of the main battery until you pull the "reserve tank" lever. (like a 1970's Rover P6!).
  • One you don't normally have in the car, but put it in ahead of a long trip to extend the range (perhaps even rental). Potentially some merit in this.
  • One you lift out of the car daily to solve the on-street parking problem. A grand idea, though probably infeasible with current technology. You can't readily hand-carry more than about 20kg, which doesn't give much capacity (using your numbers above, about 10 miles for a 20kg pack).
  • One that the AA (or a friend) bring around and plug in when you've run out of juice at the side of the road. These already exist, though for the AA it's normally quicker to just tow you to a nearby chargepoint than to sit there while charge decants from their battery (or diesel generator) into your car. The other option (also already existing) of a box allowing you to transfer charge from one EV to another is perhaps more interesting - the modern day equivalent of a set of jump leads.
 

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................ a software feature with the larger main pack - the car can prevent you using the last 10% of the main battery until you pull the "reserve tank" lever.
I have my own built in 'software'. It's called a working brain. And it's able to advise me when the car's battery is getting down to the last ten miles range, by input from a Mark 1 eyeball. I have found that I can now avoid driving until the car is completely out of charge. And that means that I don't need to design and build a spare battery pack to keep in the boot. I know it's a bit of an 'off the wall' solution but it works for me.
 

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"The other option (also already existing) of a box allowing you to transfer charge from one EV to another is perhaps more interesting - the modern day equivalent of a set of jump leads."

Do they? Sounds a great idea. Got a name/link?
 

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... - could the AA man drop a black box on your passenger seat that would give you 10 miles of juice to get to the nearest charger etc
I think this is critical to the whole 'e-jerrycan' idea.
How far is this thing supposed to get you?
Yes it will vary for all the usual reasons, but: 2 miles? 10 miles? 20 miles? '2-mile' packs daisy-chained for extra range?
One size isn't going to fit all.
 

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"The other option (also already existing) of a box allowing you to transfer charge from one EV to another is perhaps more interesting - the modern day equivalent of a set of jump leads."

Do they? Sounds a great idea. Got a name/link?
Here you go, complete with cheesy video:
ORCA Inceptive | Andromeda Power, LLC

Sadly, these units are insanely expensive - but they show the possibility.

A more realistic approach would be if the car manufacturers made the on-board AC chargers also accept DC. That would just require a cable and some minor electronics for the communications, rather than the hefty power electronics in the Andromeda unit (you'd be using the on-board charger to do that job).

400V DC (typical battery voltage) is equivalent to the peak voltage of 283V AC, so not far off what 230V chargers need to be rated for. I'm not so familiar with the chargers on other cars, but the Tesla one at least already accepts 277V AC and has a software-controlled regulator, so converting it to DC input might be as simple as a software upgrade.

Quite a lot of work to make it safe of course, but if the demand is there the end product need not be expensive.
 

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For recovery, surely the obvious solution is for AA/RAC to have van with large battery pack with CHAdeMO and CCS connectors - 15 mins charge should get enough emergency range. Van battery could be charged by generator or rapid charger.

In terms of putting temporary battery in boot, it seems counterintuitive to fill the boot when going on a long journey as more likely to need space. However perhaps a more modular approach to the battery could allow a rental scheme. Buy the car with say 40kwH but pop in for an additional 20kwH before going on holiday and pay for time. In theory it could be automated - but battery swap has a bit of a bad history...
 

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For recovery, surely the obvious solution is for AA/RAC to have van with large battery pack with CHAdeMO and CCS connectors - 15 mins charge should get enough emergency range. Van battery could be charged by generator or rapid charger.

In terms of putting temporary battery in boot, it seems counterintuitive to fill the boot when going on a long journey as more likely to need space. However perhaps a more modular approach to the battery could allow a rental scheme. Buy the car with say 40kwH but pop in for an additional 20kwH before going on holiday and pay for time. In theory it could be automated - but battery swap has a bit of a bad history...
Considering most AA/RAC vans have a towing dolly, wouldn't it be quicker and cheaper to tow the car to the nearest charging station?

How big a battery pack are you going to need to supply 40 kW through a Chademo adaptor?
 
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