New battery technology. If or When?

I keep reading about fancyful developments in the pipeline that promise cheaper, lighter and more powerful batteries for everything from phones to cars and it makes me ask..is it likely, or just a pipedream?

From our point of view just think about all the unsold expensive lithium bike batteries that could be made obsolete overnight.. Well, not exactly overnight... but would they have to be made more expensive to ensure the sale of the older ones?

I wish cheaper, lighter, more powerful batteries were available. I've been cycle-camping over the last week and pedaling a large, spare +4kg battery around isn't a lot of fun!

im sending mine to jimmy at bga reworking when the time comes to get recelled with the cells i want to pay for and silver interconnections if i want to pay the extra for 7% over copper or nickle.

 

40 cells cost £220 so there is no way in hell id but a new one from magura again for 700 bloody quid when i can have what i got renewed

im sending mine to jimmy at bga reworking when the time comes to get recelled with the cells i want to pay for and silver interconnections if i want to pay the extra for 7% over copper or nickle.

 

40 cells cost £220 so there is no way in hell id but a new one from magura again for 700 bloody quid when i can have what i got renewed

Hey SW. You often make comments about the cost of new or replacement cells and as I have never had a problem with any of mine in 5 years of riding ebikes I wonder if your ultra heavy usage is causing problems and wearing them out faster..

the 400w batt that came with my bike has lost about 25-30% since 2014 end so not that bad tbh as not going to last forever but as i now have 2 batts with the new 500w one i just swap them round each ride then charge them up until the next ride.

 

so the 400w batt will be sent for recell around 2019 220 give or take

Batteries are improving all the time. You don't need to look back far to see how much they've improved.

Funnily I was reading about 21700 cells today, 20 Amps constant from a 4P10S 37 V 16 Ah doesn't sound too bad!

Batteries are being developed, but relatively slowly.

 

When I first started looking at ebikes in 2011 most companies were using lithium batteries of around 400wh.

 

Fast forward six years and capacity has increased to, commonly, 500wh, although those packs are slightly heavier/bigger than the 400wh ones.

 

That's a useful improvement in capacity, but hardly ground breaking.

 

Inevitably, capacity will increase, but next year's Bosch batteries are 500wh, so we won't see a bigger Bosch pack until at least 2019 - seven/eight years since the last increase.

 

I dunno about you lot, but I don't have so many years left as to be able to waste a few waiting for improvements.

 

For me it's make the best of what's available - Bosch twin battery - and get riding.

The 18650 is going to be around for a while. When 21700 production kicks in seriously they (18650s) will have to go down in price, way down. For the moment $6.90 is the cheapest price on (not very interesting for us) 21700 cells, the bad boys are still at $10.

Bosch packs have reached their limit with 18650, 3450mah 10a rated cells (500wh). Their limit is the battery pack size at 10s4p whilst other shark type large packs vary from 621 - 745 wh. Currently with 18650 there is a trade off between amp rating and capacity with cells, the cells can have both but can't deliver both at the same time without impacting on range.

My first e-bike battery in 2010 weighed 3.5kg and gave 300 wh at 18 amps max. My latest one weighs 1kg gives 210wh and gives 30 amps max.

 

Bosch started in 2011 with 40 cell 300wh battery that weighed just under 3kg Their latest batteries are 500wh and the same weight.

The rumour is around 21 Wh from Tesla's new 2170 cells. That would mean only 24 for a 500 Wh pack.

 

The potential is there to package that up into a 2*2*6 downtube pack. The cells would measure something like 4.5 * 4.5 cm 'square' but with rounded edges, and 42 cm long, plus whatever space needed for connectors and BMS. That could be downtube integrated very nicely with no loss of capacity from current batteries.

 

I'd imagine that is no more than a year or two away from reality.

 

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Funnily I was reading about 21700 cells today, 20 Amps constant from a 4P10S 37 V 16 Ah doesn't sound too bad!

Bigger cross sectional area, bigger current flow, it's not rocket science.

The rumour is around 21 Wh from Tesla's new 2170 cells. That would mean only 24 for a 500 Wh pack.

 

The potential is there to package that up into a 2*2*6 downtube pack. The cells would measure something like 4.5 * 4.5 cm 'square' but with rounded edges, and 42 cm long, plus whatever space needed for connectors and BMS. That could be downtube integrated very nicely with no loss of capacity from current batteries.

 

I'd imagine that is no more than a year or two away from reality.

 

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Batteries integrated into a downtube, very neat and suitable for people who have the charger and mains point adjacent to their bike storage location, a bummer otherwise.

Tesla 2170s are supposed to be 322wh/kg. That compares with about 252 wh/kg for Samsung GA cells, so a fair step up and should give a 2.5kg 600wh battery That would be big enough capacity and light enough for most people, but I guess we can still look forward to 500wh 1kg batteries.

Has anyone opened up the Bosch power packs? I'm still confused why they're so big if they really are only 40 cells as reported.

 

In a 4*4*4 layout, the cells would only be around 72*72*260 mm so there must be quite a lot of spare space in there already.

 

Was a more slimline look just never a design criteria before?

 

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I have a load of recycled Panasonic 2.9ah cells from defective Bosch batteries. They come in blocks of 4. A 400wh battery would be 40 cells, so everything adds up.

Doesn't seem fair that credit for Panasonic's batteries keeps being attributed to Tesla.

Doesn't seem fair that credit for Panasonic's batteries keeps being attributed to Tesla.

 

True. I suppose an upside is that if a new cell type fails prematurely or doesn't deliver as promised, Tesla can get the blame.

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All this is interesting but the original question was about a new battery technology not how much more existing tech can be optimised .. if or when?

All this is interesting but the original question was about a new battery technology not how much more existing tech can be optimised .. if or when?

 

Not very promising. Several chemistries have been mooted and some are being experimented on, but they most often fail on at least one key factor. Very short life is the most common, but inadequate capacity to bulk and/or weight is also common.

 

At present lithium-ion is still the best option for most circumstances. Sodium "salt" batteries are out there and in use in cars and trucks, but they are only suitable for every day or nearly every day continuous use. That's because when not being used they have to be maintained at high temperatures, typically between 220 and 350 degrees C, and even when well insulated that wastes current. Ford's "Think" car and the Smart For-Two electric car have used sodium batteries, but I don't know if Smart still do.

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All this is interesting but the original question was about a new battery technology not how much more existing tech can be optimised .. if or when?

It depends on what you want optimised. Is it capacity, is it speed of recharge or is it number of recharge cycles , is it size or is it energy density.(watthr per kg). And or is it safety and price and availability of materials.

In terms of chemistry you need to have two elements or compounds with very different electrochemical properties, preferably light , like lithium or aluminium and capable of reacting reversibly..

The thing is lithium ion isn't one technology. There's at least four chemistries, along with a variety of cell packaging techniques.

 

They've all got in common the use of lithium, which as it is reasonably plentiful and light weight seems likely to continue as the choice for weight sensitive applications for some time. But that doesn't mean there's no technological breakthroughs going on, or even that no new chemistries are being developed. A lot of it just gets lumped under the li ion banner and thought of, a little unfairly IMO, as just optimisation.

 

There's fundamentally good reasons lithium fulfills a central role, and with the exception of zinc air, I've not seen other totally different chemistries that get close.

 

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The thing is lithium ion isn't one technology. There's at least four chemistries, along with a variety of cell packaging techniques.

 

They've all got in common the use of lithium, which as it is reasonably plentiful and light weight seems likely to continue as the choice for weight sensitive applications for some time. But that doesn't mean there's no technological breakthroughs going on, or even that no new chemistries are being developed. A lot of it just gets lumped under the li ion banner and thought of, a little unfairly IMO, as just optimisation.

 

There's fundamentally good reasons lithium fulfills a central role, and with the exception of zinc air, I've not seen other totally different chemistries that get close.

 

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I am fairly sure I read somewhere that the shortage if lithium would impede electric car production.. but could be wrong..