Lithium fears

[stranded]

At the time I built my system, there was a substantial price difference and Victron was out of budget. They appear to have come down quite a lot now, I might make the switch and leave my Epevers as spares.

I think that at £56 the 75/15 bluesmart mppt I bought this winter was half the price I paid for a 75/15 not smart at all mppt 10 years ago.

 

[lustyd]

@Neeves you pose an interesting question about data.

As I have said in other threads I am not convinced that Lithium is for most UK sailors. I am running a spreadsheet for my 200 watts of solar and 390 Ah of AGM house batteries this summer. While the boat will only be used hard for six weeks this year, for some reason work keeps piling in, it will be interesting to compare results.

We have 200W too but 300Ah lithium. This means we have more capacity than you and our capacity fills faster than yours from the same solar. I can't see a downside, given that my lithium bank is cheaper overall than your AGM will be and won't degrade as fast or as often.

While it is slightly more complex, I can't see much of an argument the other way in 2024 aside from "it's what was on the boat when I got it"

 

[oldbloke]

In Australia one of the fears underlining Lithium uptake, or lack of uptake, in cars is the fear of there not being sufficient re-charging facilities. Its a big country, 1,000km between capital cities is 'normal'.

I see the advantage of Lithium in yachts, more amps for your kg (and Lithium prices, historically high have been falling). Lithium seems the ideal development, especially in Australia with its well know sunshine. Lithium is portrayed as much more efficient than Lead, negating the need for a gen set, no need for dangerous gas nor running the inboard diesel (and no longer upsetting the neighbours - and being environmentally unfriendly)

This thread is focussed at those who use Lithium as liveaboards for their practices of the amps they harvest from their solar.

Yesterday and the previous few days we enjoyed almost maximum sunshine, minimal clouds and (watching the forecasts, see below) all opportunity to fill the Lithium battery bank.

Today its effectively rained all day, rain fall on Pittwater has hovered around 20mm and the weather (defined by rainfall) and forecast for the next week is, and I average:

Tomorrow 10mm. worst case is 15mm
Day 2 10mm..............................15mm
Day 3 20mm..............................30mm
Day 4 30mm...............................50mm
Day 5 30mm...............................50mm
Day 6 20mm................................30mm

Now these are forecasts - not certainty.

Basically no sunshine.

What size of battery do you need to survive as a liveboard, relying on Lithium? No gas, no gen set - you do have a B2B of 40 amps. Pittwater is relatively civilised - Avalon (of Home and Away fame is a 20 minute walk)

My crude and uneducated guess is a 600 amp battery bank - or an inconvenient time under engine (shades of charging Lead batteries)

What is the reality?

Jonathan

Water power started the industrial revolution, you just need to add a water wheel

 

[Sandy]

We have 200W too but 300Ah lithium. This means we have more capacity than you and our capacity fills faster than yours from the same solar. I can't see a downside, given that my lithium bank is cheaper overall than your AGM will be and won't degrade as fast or as often.

While it is slightly more complex, I can't see much of an argument the other way in 2024 aside from "it's what was on the boat when I got it"

I understand you can fill the batteries faster and will have an extra 30% of usable power, but how often do need to fill the batteries faster or run it down to 20% - I understand that's good working limit.

Looking at the numbers – 240 Ah against my 195 Ah usable amp hours.

I sized the bank before I added solar so that I can run with everything at 'full chat' for 24 hours before any need to recharge. To date the longest passage has been six weeks with a mix of engine and occasional marina charging. The next time I head off on a long adventure I won't need to plug into into a marina.

On your last point, the boat had 'bog standard lead acid' when I got it. The AGMs are only three years old and should have another seven to ten in them. Upgrading to lithium would be a complete waste of beer tokens at the moment.

The power management system is Victron allowing me to keep a close eye on what is going on.

 

[Sandy]

Water power started the industrial revolution, you just need to add a water wheel

Have you seen the price of a Watt and Sea unit?

 

[geem]

Have you seen the price of a Watt and Sea unit?

My 20 year old Duogen is still going but I certainly won't be buying a new one. Crazy price when you compare to the cost of solar. I think for the price of a new Duogen I could install new lithium and solar!

 

[Sandy]

My 20 year old Duogen is still going but I certainly won't be buying a new one. Crazy price when you compare to the cost of solar. I think for the price of a new Duogen I could install new lithium and solar!

I looked in detail at them. Ideal for sailing at high latitudes in winter.

 

[Tranona]

I understand you can fill the batteries faster and will have an extra 30% of usable power, but how often do need to fill the batteries faster or run it down to 20% - I understand that's good working limit.

Looking at the numbers – 240 Ah against my 195 Ah usable amp hours.

I sized the bank before I added solar so that I can run with everything at 'full chat' for 24 hours before any need to recharge. To date the longest passage has been six weeks with a mix of engine and occasional marina charging. The next time I head off on a long adventure I won't need to plug into into a marina.

On your last point, the boat had 'bog standard lead acid' when I got it. The AGMs are only three years old and should have another seven to ten in them. Upgrading to lithium would be a complete waste of beer tokens at the moment.

The power management system is Victron allowing me to keep a close eye on what is going on.

Agree with your thinking. The zealots often emphasise properties of their favoured products rather than whether they add value in specific circumstances. In this case they forget that people have been cruising successfully with LA based systems for years and there is really no need to change unless you want to something different that is not viable with LA or your LA needs replacing and you can use the properties of lithium to reduce the size and possibly cost of your energy storage. While the first reason has been worth pursuing for some for 4 or 5 years, it is only in the last 1-2 years that availability of product and reduction in cost has made lithium worth considering as replacement. No doubt in 7 years time when your bank needs replacing the choice will be obvious.

 

[lustyd]

I’m not a zealot I may just have different requirements. We were on board for two months with AGMs and our 200W didn’t keep up with house loads so we had to run the engine to top them up. The Lithium has changed that and the same 200W now keeps up with house loads. I’m not imagining it, I measured it and lived with it.

 

[PaulRainbow]

I lived aboard my last boat full time with 200w of solar and a bank of T105s. In the Summer, they kept up with my consumption, but used gas for cooking.

 

[geem]

..........

I looked in detail at them. Ideal for sailing at high latitudes in winter.

I don't think the Duogen air mode is robust enough. Certainly not on my mk1 version. The blades are not balanced. It can't take strong gusty conditions without wearing parts rapidly.
The alternator rotor is not balanced. They go through alternator bearings for fun. Eclectic are in denial about having a problem. I asked them if they had uprated the alternator bearings in the later versions and they said not. If I get time whilst I am home over the winter, I will see about getting the rotor balanced.
I haven't decided if I will refit it for the East to West trip back across the pond next year. For the power it develops, I am coming to the opinion that its more trouble than its worth, now its so old that it requires even more regular maintenance. I found out I could add my crappy Renogy panels to the upturned dinghy on the foredeck so we will see how we get on with solar only on the trip up to Bermuda.
I have to say, I much prefer the water mode for charging but it's ability to collect discarded fishing nets and destroy itself in the process is not so good.
I doubt we will be able to run it in water mode here because of the sargassum weed in the water stopping it every 5 mins

 

[Tranona]

I’m not a zealot I may just have different requirements. We were on board for two months with AGMs and our 200W didn’t keep up with house loads so we had to run the engine to top them up. The Lithium has changed that and the same 200W now keeps up with house loads. I’m not imagining it, I measured it and lived with it.

That is your experience and in contrast Sandy was saying his current setup is perfectly adequate for his use and sees no benefit FOR HIM in changing. The different properties are not in question. Look back at the last sentence in your post#22. You say can't see any alternative but there clearly is because the vast majority of boats do not have lithium and seem to get along quite nicely.

If I recall rightly your batteries were knackered so you decisions on replacement will be different from somebody in 2024 who sees 7 years life in their current batteries.

 

[Neeves]

Water power started the industrial revolution, you just need to add a water wheel

WattnSea are magic - but costly (as said) and are only useful if the water or the yacht move ie anchor where there is strong tidal flow or make reasonable passages.

WnS are not much use if you are sitting in an ideal tropical anchorage (which is the location of many liveaboards).

The best investment for renewable energy is solar - limited by ones ability to instal a decent display.

Jonathan

 

[Sea Change]

I understand you can fill the batteries faster and will have an extra 30% of usable power, but how often do need to fill the batteries faster or run it down to 20% - I understand that's good working limit.

20% is a very conservative limit. In practise you can use 100% of the capacity and the lithium batteries will still outlive any lead acid chemistry, by a long way.

Looking at the numbers – 240 Ah against my 195 Ah usable amp hours.

I sized the bank before I added solar so that I can run with everything at 'full chat' for 24 hours before any need to recharge. To date the longest passage has been six weeks with a mix of engine and occasional marina charging. The next time I head off on a long adventure I won't need to plug into into a marina.

On your last point, the boat had 'bog standard lead acid' when I got it. The AGMs are only three years old and should have another seven to ten in them. Upgrading to lithium would be a complete waste of beer tokens at the moment.

The power management system is Victron allowing me to keep a close eye on what is going on.

How much are AGMs? I'm paying about £120/kwh for lithium. For lead acid to be cheaper (assuming 50% usable capacity) you'd need to be paying less than £80 for a 110Ah battery.

 

[Neeves]

Have you seen the price of a Watt and Sea unit?

I am reminded of a recurring thought

- the Duogen offers two mechanisms to produce electricity. Its a clever idea, though as Geem mentions, not too well engineered. WattnSea recognising the impressive electricity product of a hydro generator and are a power source of choice for ocean racers. When we used a LVM wind gen in hydro mode, a sort of trailing log, it produced impressive levels of electrical power (from memory 8 amps at 8 knots) - but was a faff to convert from wind mode to hydro mode (and we did not have Sargasso issues).

Are there opportunity to make a combined electric outboard/hydro generator?

Jonathan

 

[lustyd]

That is your experience and in contrast Sandy was saying his current setup is perfectly adequate for his use and sees no benefit FOR HIM in changing. The different properties are not in question. Look back at the last sentence in your post#22. You say can't see any alternative but there clearly is because the vast majority of boats do not have lithium and seem to get along quite nicely.

If I recall rightly your batteries were knackered so you decisions on replacement will be different from somebody in 2024 who sees 7 years life in their current batteries.

If you’re going to misinterpret what I said then I can understand your confusion.

 

[vas]

Are there opportunity to make a combined electric outboard/hydro generator?

Jonathan

last time I checked, Sailing Uma was doing just that, check them out on youtube.
Lovely couple, during covid (iirc) removed diesel engine and leg on their small yacht and replaced with el. motor/leg combo that produces current when sailing. Mated with some lifepo4 banks and a massive solar panel they've travelled up to Norway iirc.

V.

 

[Sea Change]

Are there opportunity to make a combined electric outboard/hydro generator?

Jonathan

Some of the Torqueedo (or it may possibly the ePropulsion) outboards have a regen facility. It's been discussed on here; one concern raised was that you'd have to mount it pretty low down on the back of a yacht to actually work, which would then risk swamping the whole thing in following seas, or even just with your own stern wave.

With solar panels down to £65 for 400w+ it's pretty hard to justify any other form of generating electricity these days, unless you just don't have the space for them.

 

[Sandy]

20% is a very conservative limit. In practise you can use 100% of the capacity and the lithium batteries will still outlive any lead acid chemistry, by a long way.

How frequently do you run the batteries down to zero?

Where is the 'real world data' that backs up the technology claim that it will outlive any other form of battery, has anybody run lithium for 15 years?

I've seen a lot of claims about lithium, but have seen little real world data. By 'real world' I mean large numbers of data points over many years and environments.

At least with this forum we can start exploring the real world data.

 

[Sea Change]

How often do you run the batteries down to zero and how frequently? Where is the 'real world data' that backs up the technology claim that it will outlive any other form of battery, has anybody run lithium for 15 years?

I've seen a lot of claims about lithium, but have seen little real world data. By 'real world' I mean large numbers of data points over many years and environments.

At least with this forum we can start exploring the real world data.

I've never actually gone down to 0%, it's not necessary and would reduce the lifespan of the batteries. From memory I think 12% might be the lowest I've personally gone, and a friend dropped to 6%.

Rod Collins is the guru for lithium, he's been running a battery for about 14yrs with almost no noticeable degradation.