New Solid state batteries on the horizon.

[ditchcrawler]

On 20/02/2021 at 22:31, alistair1537 said:

I haven't started my cruising phase yet - I only got the boat in 2020 and lock-down and the build and, and...also, I am a bit worried about reports that LiFePO4 don't get along with Alternators? Or is it the other way round? In any case, very few alternators are built with LiFePO4 in mind.

What have you got between your batteries and the alternator for when the batteries are fully charged?

[Dr Bob]

2 hours ago, dmr said:

I have no first hand experience of lithiums, so have a basic question......

Lots of batteries look to be made up of lots of little cylindrical cells spot welded together, this looks a bit naff to me.

Prismatic cells is I believe a posh name for square cells ? So when you have 160Ah cells is this one big square cell?, or is it still several smaller square cells interconnected?

 

Obviously some cells in series, but is each individual cell a full 160Ah?

 

.............Dave

 

Lithium batteries are basically a thin film of anode separated from a thin film of cathode separated by the electolyte....often a solid. This is quite thin ...say a few mm thick. For the 18650 round type batteries, the active part is a long strip of the 3 layers rolled into the cylinder with one tab to the positive and one to the negative.  In the U.K. It's called Swiss roll, in the US ...jelly roll. For the big prismatic rectangular cells, it is still these 'thin' 3 layers but either it is a jelly roll but flattened into a rectangular shape or layers are cut and stacked together but in this case there have to be connections between the multiple positive and negative plates. It does vary for different manufacturers. Most of the work our company has done has been on the 18650 type cylindrical cells. 

 

[Dr Bob]

13 hours ago, IanD said:

I was simply quoting from a site which most people acknowledge as being one of the best sources of reliable information about lithium batteries on yachts

Simply quoting from internet sites in a way to encourage others to do things that could be dangerous is very irresponsible. You cherry picked the info you quoted so didnt included all the important stuff....and part was just sales speil from a battery manufacturer.

Too many people on the internet cut and paste what they read without a thought to what their actions may result in. You have no experience of the subject yet you put yourself over as the expert. Very poor show.

[Tony Brooks]

1 minute ago, Dr Bob said:

Simply quoting from internet sites in a way to encourage others to do things that could be dangerous is very irresponsible. You cherry picked the info you quoted so didnt included all the important stuff....and part was just sales speil from a battery manufacturer.

Too many people on the internet cut and paste what they read without a thought to what their actions may result in. You have no experience of the subject yet you put yourself over as the expert. Very poor show.

 

Oh how true. I recently had an email exchange about keeping "deep discharge" LA domestic batteries in good order over winter. I explained why they should  ideally be kept fully charged. He responded with a website that advised the such batteries should be left to fully discharge themselves and then fully  recharged and so on. They said leaving the battery on "trickle charge" would damage it (note the words trickle charge, not float charge). Careful reading of then site found a statement that the authors were not professionals in the fields covered in the site. I think they misunderstood  warning they read somewhere that old-fashioned non-smart chargers should not be left permanently charging and interpreted that as saying such batteries  should not be left on charge.

 

Websites (including mine) need treating with extreme scepticism until proven they are accurate and not pushing product.

[IanD]

4 hours ago, Dr Bob said:

Simply quoting from internet sites in a way to encourage others to do things that could be dangerous is very irresponsible. You cherry picked the info you quoted so didnt included all the important stuff....and part was just sales speil from a battery manufacturer.

Too many people on the internet cut and paste what they read without a thought to what their actions may result in. You have no experience of the subject yet you put yourself over as the expert. Very poor show.

You really are determined to be unpleasant, aren't you?

 

I quoted from a very well-regarded non-selling-stuff site (which I've read the entire content of, as well as many others about LiFePO4) including the link to the full article (so the OP could go and read this), and that was all -- you're the one making yourself out to be the expert, not me, I was just trying to be helpful.

 

There's a lot of information on the page I cited -- have you read it all, and is there anything there you disagree with? If not, why start throwing insults?

 

If you also go elsewhere and read about the experiences of the thousands of lumpy water sailors who've used lithium cells, you'll find that what I quoted from Nordkyn is accepted as correct -- 100Ah cells (or smaller) are the recommended solution, anything bigger is more fragile, definitely don't go above 200Ah.

 

Isn't that pretty much what you said?

 

This happens to also be what the battery supplier said in the quote, but that doesn't make it any less true -- they probably have experience of all the people who didn't follow the advice and came to them complaining of cell failure...

Edited February 22, 2021 by IanD

[alistair1537]

23 hours ago, dmr said:

I have no first hand experience of lithiums, so have a basic question......

Lots of batteries look to be made up of lots of little cylindrical cells spot welded together, this looks a bit naff to me.

Prismatic cells is I believe a posh name for square cells ? So when you have 160Ah cells is this one big square cell?, or is it still several smaller square cells interconnected?

 

Obviously some cells in series, but is each individual cell a full 160Ah?

 

.............Dave

This is a primer for the question you asked - https://www.lithiumion-batteries.com/cylindrical-vs-prismatic-cells.php

[alistair1537]

21 hours ago, ditchcrawler said:

What have you got between your batteries and the alternator for when the batteries are fully charged?

I don't use any connection between alternator and the LiFePO4 - they're solar and generator charged. My engine is fitted with a 175A auxiliary alternator, but that's 12V - My LiFePO4 are 24 V. Anyway, in Summer I have no issues - I was fully charged today by 11.30 even - in winter I need the generator for an hour or two depending on the day's sunlight. 

[peterboat]

4 minutes ago, alistair1537 said:

This is a primer for the question you asked - https://www.lithiumion-batteries.com/cylindrical-vs-prismatic-cells.php

I have both prismatic cells and cylindrical cells as yet both have worked well, I have to say Tesla went with cylindrical cells and seem to be doing very well with them 

[dmr]

3 minutes ago, alistair1537 said:

This is a primer for the question you asked - https://www.lithiumion-batteries.com/cylindrical-vs-prismatic-cells.php

 

Thanks, I also found a Very similar site from another company that also concluded that prismatic cells have a lot of disadvantages, though both sites are from companies that make cylindrical cells ?.

 

Ive done a bit of Googling and answered my question that Dr Bob did not really answer ? Prismatic cells are one big cell rather than many smaller cells in parallel.

It would be interesting (for me anyway) to know more about the two prismatic constructions    squashed cylinder or end connected.

Sounds like lithium cells have very similar construction to capacitors. Also looks like Tesla is very much using cylindrical cells.

 

Lots of cylindrical cells spot welded together does look a bit daft and a waste of space but I had not really thought through the advantages:...lots of gaps for cooling and redundancy IF you can make the cells failsafe.

 

.................Dave

[alistair1537]

1 minute ago, dmr said:

 

Thanks, I also found a Very similar site from another company that also concluded that prismatic cells have a lot of disadvantages, though both sites are from companies that make cylindrical cells ?.

 

Ive done a bit of Googling and answered my question that Dr Bob did not really answer ? Prismatic cells are one big cell rather than many smaller cells in parallel.

It would be interesting (for me anyway) to know more about the two prismatic constructions    squashed cylinder or end connected.

Sounds like lithium cells have very similar construction to capacitors. Also looks like Tesla is very much using cylindrical cells.

 

Lots of cylindrical cells spot welded together does look a bit daft and a waste of space but I had not really thought through the advantages:...lots of gaps for cooling and redundancy IF you can make the cells failsafe.

 

.................Dave

The other advantage I read is that the cost to produce cylindrical cells is less.

[dmr]

3 minutes ago, alistair1537 said:

The other advantage I read is that the cost to produce cylindrical cells is less.

 

And strength, round things are always stronger than square things, nobody ever made a steal loco with a square boiler. ?

 

So why not make really BIG cylindrical cells?

[alistair1537]

1 minute ago, dmr said:

 

And strength, round things are always stronger than square things, nobody ever made a steal loco with a square boiler. ?

 

So why not make really BIG cylindrical cells?

LTO technology does...

[magnetman]

LTO looks incredibly good for boat systems but it's quite expensive. 

 

Very tempting to have a play with it for the stealth mode electric drive. 

A very nicely presented video by a most pleasant woman about LTO on the GWL website. 

 

 

[Dr Bob]

11 hours ago, dmr said:

Ive done a bit of Googling and answered my question that Dr Bob did not really answer ? Prismatic cells are one big cell rather than many smaller cells in parallel.

 

I do apologise. I thought my answer pretty clear and obvious but in my defence it was late at night and I had been watching some entertaining VAR decisions from the evenings footy.

[peterboat]

11 hours ago, magnetman said:

LTO looks incredibly good for boat systems but it's quite expensive. 

 

Very tempting to have a play with it for the stealth mode electric drive. 

A very nicely presented video by a most pleasant woman about LTO on the GWL website. 

 

 

I watched a video of a guy building a bank of these for him motorhome a while ago

[doratheexplorer]

This thread is like CWDF bingo, it's hilarious!

 

LA v LiFePo - check!

Pump out v cassette v compost - check!

Genny v engine - check!

Newbies v oldies - check!

 

Just waiting for two fat ladies to turn up now and start arguing about narrowboats v widebeams!  ?

[Slim]

On 20/02/2021 at 22:38, alistair1537 said:

They're selling them to old gits? 

Which you will become one day (if you're fortunate). In the meanwhile you come over as an inexperienced newcomer who thinks he knows it all. 

Just some of my thoughts. 

[Slim]

8 minutes ago, doratheexplorer said:

This thread is like CWDF bingo, it's hilarious!

 

LA v LiFePo - check!

Pump out v cassette v compost - check!

Genny v engine - check!

Newbies v oldies - check!

 

Just waiting for two fat ladies to turn up now and start arguing about narrowboats v widebeams!  ?

May have something to do with the fact that some of us are stir crazy. "Those who can do, Those who can't, teach" (No reflection on teachers, my late wife was one) 

[IanD]

12 hours ago, magnetman said:

LTO looks incredibly good for boat systems but it's quite expensive. 

 

Very tempting to have a play with it for the stealth mode electric drive. 

A very nicely presented video by a most pleasant woman about LTO on the GWL website. 

 

 

 

"quite expensive" here means about $1000/kWh retail, roughly 3x the cost of LiFePO4 -- which is already pretty damn expensive for battery banks big enough for electric narrowboat drive. No problem with low-temperature or high-current charging, cycle lifetime is enormous (30000 claimed) but difficult to see how this would ever be useful in a boat application.

 

Great technology for ultra-high-cycle applications, but probably not for boats (except in the Arctic...) until/unless the cost drops dramatically.

[IanD]

2 hours ago, Dr Bob said:

 

I do apologise. I thought my answer pretty clear and obvious but in my defence it was late at night and I had been watching some entertaining VAR decisions from the evenings footy.

 

Still waiting for an apology for slagging me off for daring to refer the OP to probably the best source of unbiased information about marine LiFePO4 (Nordkyn) after your post about LiFePO4 safety -- won't hold my breath though... ?

 

[and I notice you've avoided answering my resulting question about which parts of the advice given there you think are wrong -- could that be because it's correct?]

[magnetman]

20 minutes ago, IanD said:

 

"quite expensive" here means about $1000/kWh retail, roughly 3x the cost of LiFePO4 -- which is already pretty damn expensive for battery banks big enough for electric narrowboat drive. No problem with low-temperature or high-current charging, cycle lifetime is enormous (30000 claimed) but difficult to see how this would ever be useful in a boat application.

 

Great technology for ultra-high-cycle applications, but probably not for boats (except in the Arctic...) until/unless the cost drops dramatically.

Ok I should have said useful for series hybrid. 

 

Small bank of LTO cells, diesel driven charging set. 

 

Electric drive canal boat. Diesel generator automatically kicks in to rapidly recharge the -small- battery bank. 

 

This is where high cycle life could become interesting because you could be talking about several cycles per day.

 

You could even arrange it so that you cruise on electric then when the boat is stationary for locks the generator is operating to put some power back into the batteries. 

 

And solar of course but that won't be enough. You would need a diesel engine as well.  

 

Probably a bit pointless but the benefit of silent cruising is significant. 

 

Mind you soundproofing a diesel will get it pretty quiet to be fair. 

 

[The Gravy Boater]

1 hour ago, Slim said:

May have something to do with the fact that some of us are stir crazy. "Those who can do, Those who can't, teach" (No reflection on teachers, my late wife was one) 

Those who can, teach... those who can't, teach teachers... and those who can't teach teachers manage them. 

[IanD]

9 minutes ago, magnetman said:

Ok I should have said useful for series hybrid. 

 

Small bank of LTO cells, diesel driven charging set. 

 

Electric drive canal boat. Diesel generator automatically kicks in to rapidly recharge the -small- battery bank. 

 

This is where high cycle life could become interesting because you could be talking about several cycles per day.

 

You could even arrange it so that you cruise on electric then when the boat is stationary for locks the generator is operating to put some power back into the batteries. 

 

And solar of course but that won't be enough. You would need a diesel engine as well.  

 

Probably a bit pointless but the benefit of silent cruising is significant. 

 

Mind you soundproofing a diesel will get it pretty quiet to be fair. 

 

But if you have a small battery bank so the generator kicks in all the time you haven't got a potentially-green series hybrid, you've just got a diesel-electric boat with some temporary energy storage, with little or no fuel or CO2 saving.

 

The whole point of a series hybrid boat is that the battery bank can be charged up by solar (or renewable energy when plugged-in someday) and have enough charge for a day's travel, which means something like 20kWh -- the exact value can be argued about, but it needs to be pretty big.

 

Until charging points appear then most boats in the UK will also need an onboard diesel generator for when the sun doesn't shine or when you want to travel more than solar can support, but this is a backup not the main means of providing power.

 

Also running the generator in locks is the last thing you want to do, this is one time when you really *don't* want noise and exhaust fumes... ?

Edited February 23, 2021 by IanD

[magnetman]

Yes most boats will remain diesel powered for a long time which is what I said. 

 

I still think that short term storage of power then using that power is a valid approach. This also allows very simple upgrade if the charging points turn up and the batteries get cheaper. 

 

It's sort of like future proofing while still recognising that diesel is king and will be for some time to come. 

 

Maybe LTO is a red herring here but I think the cycle life is interesting, if it is true. 

 

 

ETA and it would be more efficient because the diesel engine could be geared to run at its ideal operating rpm with the highest possible efficiency. I'm talking about diesel IC-modern high efficiency alternator-battery. 

 

Minimise the links maximise the efficiency. 

Edited February 23, 2021 by magnetman

[IanD]

17 minutes ago, magnetman said:

Yes most boats will remain diesel powered for a long time which is what I said. 

 

I still think that short term storage of power then using that power is a valid approach. This also allows very simple upgrade if the charging points turn up and the batteries get cheaper. 

 

It's sort of like future proofing while still recognising that diesel is king and will be for some time to come. 

 

Maybe LTO is a red herring here but I think the cycle life is interesting, if it is true. 

 

 

ETA and it would be more efficient because the diesel engine could be geared to run at its ideal operating rpm with the highest possible efficiency. I'm talking about diesel IC-modern high efficiency alternator-battery. 

 

Minimise the links maximise the efficiency. 

 

Suggest you read the threads on hybrid boats about efficiency -- there is a fuel/CO2 saving compared to a diesel (about 40%) but less than you might expect because losses in power transmission/generation/use partly offset the higher engine efficiency, in fact a lot of the saving is due to using much less fuel when going slow past moored boats and none in locks rather than higher efficiency when cruising.

 

Of course the more energy that comes from solar/renewables the bigger this saving becomes, which is why a big battery bank is needed because on a narrowboat it takes at least a couple of days of sun to replace the energy of a day of cruising.

 

A series hybrid with a big battery bank and onboard generator does offer all the advantages you've mentioned including fuel/CO2 saving, silent cruising, and future zero-emission (yes I know...) compatibility.

 

Which is why more and more people are going this route, including me (thanks again to peterboat for the Finesse recommendation, who do a "proper job" of it) -- but it's not cheap, the higher installation cost currently far exceeds the fuel savings over the lifetime of the boat. But if you want the advantages and can afford it, IMHO it's the way to go ?

Edited February 23, 2021 by IanD