D Cells

[halfmedley]

Not much activity on the forum today so far so I thought I'd post this statement for debate:

"The 'vehicle specific' battery is the achilles heel of all electric bikes".

A little clarification: I am not talking about are the relative merits of NiMh vs Li-Ion and other chemistries. Nor the amount of volts or amp hours.

The "achilles heel" is that all ebikes persist in using proprietary batteries made up of cells in customised cases. When said battery is used up, I assume for most people it will be next to useless and expensive to replace. Assuming that there will actually be a replacement available.

A fifty year old car can still run because its energy source (petrol) is still available, but more importantly, is 'vehicle agnostic'. Can any of us guarantee that our 'vehicle specific' batteries will still be available to buy in even ten years time? I predict there will be a lot of unusable ebikes around simply because, for the non-technical, it is no longer possible to get any 'fuel', i.e. a compatible battery. (Compatible in all senses, one that will actually 'fit' the bike and the charger)

What's to be done? One of the great advantages of petrol is its ubiquity, it can power all kinds vehicles from all kinds of manufacturers. So, therefore why don't ebike makers standardise in a similar fashion, i.e. stop using proprietary batteries and simply provide a lightweight shell into which rechargeable D Cells are inserted?

Why D Cells? The D Cell has been around for ages, can be bought almost everywhere, and is constantly being improved. D cells of 12,000mAH (12AH) are now available and 10AH varieties have been available for some time.

The 'bike' bit of ebikes can be kept going for years by simple maintenance; a well made electric motor would probably outlive its owner; yet ebike longevity is severely limited by the 'vehicle specific' battery.

So, what are your thoughts?
Is the 'vehicle specific' battery the achilles heel of all ebikes?

 

[flecc]

The problem with D cells is the inference that they are NiMh, and batteries constructed of these in series are problematic. Cells have to be from one production batch and run and really need to be individually carefully matched to ensure reliability, and the failure rate at manufacturing stage can be high. This is why e-bike and battery manufacturers were so keen to get into lithium.

Standardised lithium cells could arrive one day once development reaches some stability, but that's a long way off yet, many years indeed. They have to be controlled by complex internal electronics, and recelling could bring many problems.

The most likely solution could be cellpacks complete with electronics in a set of standard shapes and sizes, three probably sufficient, which could be slipped into any manufacturer's case.
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[halfmedley]

That sounds a gloomy prognosis Flecc (NiMH = problematic and Lithium = years away), yet seems to confirm my contention that the proprietary battery really is the achilles heel of all contemporary ebikes. Furthermore, we're going to end up with a not insignificant amount of unusable ebikes in the not-too-distant future when manufacturers stop providing specific batteries. Somewhat detrimental to the reputation of ebikes and maybe will make think people twice about buying one?

For the layman without a technical background and presented with battery unavailability, the ebike will have a very short life. Does this mean that ebikes will become even more niche than they are now? A mere technical exercise rather than a truly viable form of transport?

 

[flecc]

I agree that the battery is the real problem, on all self contained e-vehicles.

I've been trying to buy an adequate electric town car for some years, but year after year they are delayed through battery problems. At the moment there's a growing consensus among e-bike dealers, importers and manufacturers that Li-polymer is the way to go, doubts about lithium iron meaning that's some way off for the mass market. Even when in the mass market, it will take some time for it's development to reach maturity in the way NiMh did, hence the years I mentioned.

You may remember a devils-advocate thread of mine proposing that e-bikes would never make it, since the batteries that are needed to make them really successful and cheaper would also make the electric scooter successful and cheaper. Since history shows that consumers in the mass market always opt for the "superior" transport mode as I demonstrated in that thread, the e-bike could indeed be just a niche product in the UK.

Even without better batteries, we see signs of this possibility now in the under £900 E-Go scooter, an attractive proposition at two thirds of cost of the better e-bikes and with better weather protection, 30 mph, and with range just as good or better then many e-bikes. Also no road tax, very low insurance cost, and free charging points here in London and likely to spread elsewhere.

E-bikes are currently going through a sales boom in the low countries and Germany, 250,000 a year, but that's where bikes are hugely popular anyway and almost everyone owns at least one bike. Only a revolution in our cycling infrastructure and really tough motor vehicle restrictions could change things here, but I still see the e-moped as being more popular in the UK in the future.
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[halfmedley]

since the batteries that are needed to make them really successful and cheaper would also make the electric scooter successful and cheaper.

And following on from that, I guess when such batteries are available, they would also make the electric car cheaper, and congestion aside, I reckon most people would opt for the comfort/safety/flexibility of four-wheeled eCar over a two-wheeled eBike/eScooter.

Returning to my original argument, do you think that manufacturers will ever agree on a standardised battery form factor? Standardisation being a mark of a mature industry?

 

[John Fleet]

..in the under £900 E-Go scooter, an attractive proposition at two thirds of cost of the better e-bikes

It's actually £1,055 registered i.e. on the road, plus insurance and (for some the costs of CBT). Add a helmet and other safety gear and it's realistically about the same price as the better e-bikes. The initial batch sold out within days and next deliveries are claimed to be in September - and if that date's anything like as reliable as those quoted by e-bike suppliers I guess it could mean sometime next year before more stocks are available!

Still seems a VERY good buy to me compared with an electric bike for the same money - certainly so as a serious commuting tool, but misses out on all the many miles of cyclepaths with which this country is blessed......

 

[flecc]

..in the under £900 E-Go scooter, an attractive proposition at two thirds of cost of the better e-bikes

It's actually £1,055 registered i.e. on the road,

Thanks John, I'd meant to type under £1000.

No chance of a discount with that quick sell out, doesn't surprise me though and tends to make my point.
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[The Maestro]

I think the limiting factor with batteries is down to the shape and fittings since I am sure that you will be able to buy a battery of the required output forever. I can't see this problem being solved on electric bikes unless batteries become much smaller. With a bicycle frame being very small and batteries being large and bulky, manufactures and buyers are always going to prefer one kind of placement over another, one kind of placement may suit one certain style of bike well but not suit another at all. You can't really compare it to petrol because thats a liquid and manufacturers can choose to make their fuel tank where-ever they want and make it what size they like.

As for electric cars I don't see what was wrong with Lead Cobalt batteries as used in the Mars II from the 1960s (140+ mile range). They probably wouldn't be bad on an ebike either but I think industry has jumped on this Nimh, Lithium bandwagon when in many ways it inferior particularly cost.

 

[Footie]

Still seems a VERY good buy to me compared with an electric bike for the same money - certainly so as a serious commuting tool, but misses out on all the many miles of cyclepaths with which this country is blessed......

Depends on your terrain. I looked at the E-Go scooter and liked it; it would have been perfect for the wife to use for work (4 mile, 8 miles round trip).
I emailed them (technical@egoscooters.co.uk) and asked them how it would cope on our local hills here in North Cornwall. Unfortunately, the response was not good.

Hi thanks for the enquiry The eco-scooter only copes with very small hills, It does struggle with the larger hills.
Many Thanks
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[flecc]

Depends on your terrain. I looked at the E-Go scooter and liked it; it would have been perfect for the wife to use for work (4 mile, 8 miles round trip).
I emailed them (technical@egoscooters.co.uk) and asked them how it would cope on our local hills here in North Cornwall. Unfortunately, the response was not good.

Hi thanks for the enquiry The eco-scooter only copes with very small hills, It does struggle with the larger hills.
Many Thanks
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This is the problem at present with all self contained electric vehicles, especially using lead acid batteries, usually a combination of rather poor range and poor hill climbing. One can be boosted at the expense of the other to some extent, but not enough.

The G-Wizz car is the same, not bad on the flat but imitates a loaded milk float on hills.

Once we have really light high capacity batteries this could change, but that's what's been holding up any real progress.

It's good to see the honesty of the e-go reply. Most e-vehicle importers and distributors position themselves in flat areas and keep quiet about hill climb ability. Getting test rides and drives on real hills is nigh on impossible.
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[Tiberius]

Most e-vehicle people position themselves in flat areas and keep quiet...
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So buying a house on top of a hill in the West Country was only my first mistake.

Nick

 

[flecc]

Of course I meant importers and distributors Nick.

I'll amend that.

Mind you, as someone who also lives up a steep hill, I know it's a bad place to be with an e-vehicle.
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[Tiberius]

Of course I meant importers and distributors Nick.

I'll amend that.

No need, Tony. I understood what you meant.
(Just couldn't keep quiet.)

 

[flecc]

No need, Tony. I understood what you meant.
(Just couldn't keep quiet.)

We're too quick for each other, I've already done the amendment.
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[prState]

I suppose someone has looked into motorized wheelchair batteries.

Surely, some are being powered by Nimh or other by now and not just SLA.

And by this my point being, it would help of course, if we could always cannibalize some other common use for these battery types we need. I'm not sure what else is out there (golf carts, lawn mowers?).

I mean, there is no problem if you need SLA batteries. And there seems to be an obvious reason for that!

 

[flecc]

All the wheelchairs and suchlike that I've seen still use lead acid. I'd guess the reason is the same as that for their continued use in cars, the most reliable technology we have despite all the efforts at advance with other chemistries.

Add to that their cheapness and there's no reason to change on a slow moving vehicle unless weight is an overriding issue as it is with e-bikes.

Faster vehicles also needing good hill climbing just have to have a much lighter battery to perform adequately.
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[halfmedley]

You can't really compare it to petrol because thats a liquid and manufacturers can choose to make their fuel tank where-ever they want and make it what size they like.

On the contrary, that's exactly what I was comparing batteries to, and what they should be judged against, if e-vehicles are going to replace petrol driven ones.

Let me put it another way. At the moment I can go to a wide variety of vendors (Shell, Esso, BP etc) and buy their 'energy'. This 'energy' will 'fit' into a wide variety of vehicles, from the very new to the very old, with few compatibility issues. In other words the fuel is 'vehicle agnostic'.

Now take all contemporary ebikes (in fact all e-vehicles). When the 'energy' runs out (beyond recharging) you have to replace the battery. Can one be bought from a variety of energy companies? No. You have to go the dealer, who in turn has to go to the bike manufacturer, who in turn has to go to the battery supplier (probably in China). So, when the battery has run out, will you be able to guarantee there will be easily available replacement, that will fit your specific bike? Hence my argument that for ebikes to have any longevity, the batteries need to be standardised.

 

[Footie]

.... At the moment I can go to a wide variety of vendors (Shell, Esso, BP etc) and buy their 'energy'. This 'energy' will 'fit' into a wide variety of vehicles, from the very new to the very old, with few compatibility issues. In other words the fuel is 'vehicle agnostic'.

Now take all contemporary ebikes (in fact all e-vehicles). When the 'energy' runs out (beyond recharging) you have to replace the battery. Can one be bought from a variety of energy companies? No. You have to go the dealer, who in turn has to go to the bike manufacturer, who in turn has to go to the battery supplier (probably in China). So, when the battery has run out, will you be able to guarantee there will be easily available replacement, that will fit your specific bike? Hence my argument that for ebikes to have any longevity, the batteries need to be standardised.

In this present climate of ever-rising fuel cost I'm not sure that fuel based energy has a future at all. I recently read one report that estimated by 2010 a litre of fuel will be £7 plus. If something is so expensive few can afford it, it can hardly be called a standardised energy source. It will be more of standard fuel energy for the wealthy only.

Unfortunately, I think we are a very long way off from any form of standardisation of ebike batteries. SLA has been the backbone of the earliest ebikes and many still use them. Modern advances have now given us newer technologies NiMH, Lithium Ion, etc, these may be becoming the new standard but again they are expensive. LiFePo4 is the next step forward, still cheap (untested) - all very new.

When my ebike was 8 months old I decided I had to replace the batteries because the SLA were only giving me 8 miles (hilly terrain). Even at only 8 month old I could not find a supplier in the UK who stocked the odd sized SLA batteries to fit into my ebikes case. This was simply because no UK company was prepared to import them from China - not interested in following others standardisation. After much head scratching I took a gamble and had a slim-line LiFePo4 battery made, that fitted in my case, by Ping (China).

This is far from any standardised battery replacement but it has saved my ebike. I say yes please lets have standardisation but not at the expense of fledgling technology.
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[halfmedley]

I say yes please lets have standardisation but not at the expense of fledgling technology

I agree with all of what say Footie, though I'm not sure any Goverment which wants to hold on to power (sorry, I mean "which has the best interests of its people at heart") would tolerate all the civil unrest that might accompany such fuel prices as you mention. Though of course, Government's are as subject to the whims of oil prices as much as anyone.

Your experience finding a replacement battery suggests that it wasn't particularly straightforward. What made me suggest the D Cell, wasn't its internal chemistry particularly but its shape, which is established and has been around for donkeys years. Yet that wouldn't stand in the way of technological development - indeed over time we've had zinc/carbon; alkaline; NiCd and NiMh in the D Cell form factor, and no doubt Li-Ion ones will become available too. By the simple expedient of adopting a standard size (which can fit into any shape of case) the whole 'user experience' becomes greatly improved (the user can change to better batteries when they come to market) and simplified (the user buy them at the supermarket). Not too much to ask is it?

As a footnote it seems the car industry is wrestling with the battery=achilles heel problem and is coming up with different 'business models' to reassure potential customers. The Norwegian "Th!nk" e-car company is proposing a system of leasing:

Batteries / Technology & Innovation / Home - Think

 

[flecc]

The problem with the D cell where lithium is concerned is that it wastes space. Unlike many other types, lithium cells can be any shape and therefore utilise all of the internal space of a case for capacity as in the eZee battery with it's ten rectangular cells.

They can also be soft pack cells like those in the latest Panasonic battery on the Kalkhoffs:



Some years ago Peugeot's 207 electric car was also leased as a way of coping with it's £4000 NiMh battery replacement cost. It seemed to die out eventually though, before it's time probably.
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