Truck batteries for boats

[thinwater]

Bit misleading/meaningless quoting Wh/Kg ? AH per £1 makes more sense to me....

Yes, and no. Ah/cost is an important metric, I agree. But so are Ah/volume, as we add more electrics with a fixed battery space, and Ah/mass. (Technically Wh makes sense, but since we are nearly always comparing 12 volts, Ah works. If talking 24V, make the correction.)

For to the multihull sailor, what would you pay for a boat that was the same, but 1000 pounds lighter? In fact, this is exactly the math people go through when buying a performance multihull, even a cruising boat. $5000? $20,000? That means saving weight is worth $5-$20/pound, depending on where you stand. Weight at the masthead is worth more than this, in the bilge, the lower end of the range. For me, lets say $8/pound.

If I save 35 pounds per usable 100 Ah, that's $280. The batteries don't even cost that much, so it's a hell of a deal. It's also worth something not to muscle mass around at installation time.

Everyone has a cost/pound savings value, even if they don't realize it. This will vary a lot.

 

[Refueler]

C'mon guys ... enough ??

 

[Refueler]

"In many cases, Lithium convertees are like ex smokers, just because they stopped it's the worst habit ever and everyone else should stop. "

I am an ex heavy smoker ... 60 cigs a day for over 20yrs .... and I stopped. I promised myself that I would never be one of those 'born-again non-smokers' who go from smoking to "pain in the butt" non smokers !

 

[thinwater]

... Lithium convertees are like ex smokers, just because they stopped it's the worst habit ever and everyone else should stop.

Are the ex-smokers wrong? No. In fact, they know first hand.

I am surprised no one mentioned that cars still use LA, and discussed the reasons why. Obviously, they are valid.

 

[Bouba]

Yes, and no. Ah/cost is an important metric, I agree. But so are Ah/volume, as we add more electrics with a fixed battery space, and Ah/mass. (Technically Wh makes sense, but since we are nearly always comparing 12 volts, Ah works. If talking 24V, make the correction.)

For to the multihull sailor, what would you pay for a boat that was the same, but 1000 pounds lighter? In fact, this is exactly the math people go through when buying a performance multihull, even a cruising boat. $5000? $20,000? That means saving weight is worth $5-$20/pound, depending on where you stand. Weight at the masthead is worth more than this, in the bilge, the lower end of the range. For me, lets say $8/pound.

If I save 35 pounds per usable 100 Ah, that's $280. The batteries don't even cost that much, so it's a hell of a deal. It's also worth something not to muscle mass around at installation time.

Everyone has a cost/pound savings value, even if they don't realize it. This will vary a lot.

The costs mount…after (let’s be generous) 8 years the batteries fail…now, your back is eight years older…so we are either adding the cost of hiring someone to remove them…or paying for an osteopath (assuming that you have fully paid off the osteopath from the time you installed them)

 

[Refueler]

This 'weight' argument is relative ... but IMHO not really valid ...

One of the biggest arguments used to justify Li - is lighter weight for similar AH.
So you decide to fill the battery box with a greater capacity Li battery of similar physical box size - you get more AH ... Wh .. whichever term you wish to use. So instead of gaining advantage of less weight for similar AH ... you up the AH because the Li can for same physical size be greater capacity ... which in turn means heavier ..

 

[dunedin]

"In many cases, Lithium convertees are like ex smokers, just because they stopped it's the worst habit ever and everyone else should stop. "

I am an ex heavy smoker ... 60 cigs a day for over 20yrs .... and I stopped. I promised myself that I would never be one of those 'born-again non-smokers' who go from smoking to "pain in the butt" non smokers !

How did 60 cigs s day fit with working in the petroleum business

 

[Refueler]

How did 60 cigs s day fit with working in the petroleum business

I actually gave up when I was a Senior Officer on the ships ....

In fact I was working on RoRo ship out of Miami - carrying cargo to Honduras and Guatemala when I gave up .... not a type of ship I liked and I went back to Tankers ...

Strange thing being that when not in smoking approved areas - I went without ... didn't seem to bother me.

By time I came ashore - I had given up smoking.

 

[Dockhead]

Not Eve, not JK.

They don't "drop in" without making the same changes as using your own cell pack.

If you think Lithium is great, that's fine. There are cases where it is great, but there are more cases where lead acid makes sense.

I get enquiries about power systems on a very regular basis, a lot of which ask about Lithium. Maybe the guy weekend sails from his local marina, after being on shore power all week, if his batteries don't quite last a weekend at anchor an addition LA battery or a solar panel fixes that with a minimal cost. There are plenty of other case examples that would make a Lithium installation absurd.

In many cases, Lithium convertees are like ex smokers, just because they stopped it's the worst habit ever and everyone else should stop.

To each his own, of course, and far be it from me to tell anyone what kind of power system he needs.

And for someone who doesn't cycle his batteries a lot -- and I think that might be a significant proportion of sailors, maybe even a majority -- it probably doesn't matter much, so why incur the expense and go to the trouble.

But if you actually USE your power system, the advantages of lithium are now so overwhelming as to be almost silly. It's one thing to compare the cost per kWh of power is one thing. And already favorable. But if you divide that by the cycle life, then lithium is already like 10x cheaper than lead.

When people were building these systems with CALB and Winston and so forth, they were much more expensive per kWh of capacity, but if you factored in cycle life, it looked better. But now with the cheap EVE and so forth cells, they're not even more expensive per kWh of usable power, and when you factor in 10x or whatever more cycle life, then the case becomes pretty overwhelming.

 

[PaulRainbow]

To each his own, of course, and far be it from me to tell anyone what kind of power system he needs.

And for someone who doesn't cycle his batteries a lot -- and I think that might be a significant proportion of sailors, maybe even a majority -- it probably doesn't matter much, so why incur the expense and go to the trouble.

Indeed that's one of the things i've been saying all along.

But if you actually USE your power system, the advantages of lithium are now so overwhelming as to be almost silly. It's one thing to compare the cost per kWh of power is one thing. And already favorable. But if you divide that by the cycle life, then lithium is already like 10x cheaper than lead.

I agree. It's also a big benefit when it comes to charging, my solar puts everything it can yield into the Lithium bank, whereas with LA it would be restricted by the resistance of the batteries. On sunny days in the UK i'm up to 100% by 13:00-14:00

When people were building these systems with CALB and Winston and so forth, they were much more expensive per kWh of capacity, but if you factored in cycle life, it looked better. But now with the cheap EVE and so forth cells, they're not even more expensive per kWh of usable power, and when you factor in 10x or whatever more cycle life, then the case becomes pretty overwhelming.

I remember fitting 3x100Ah Victron Lithium batteries a few years ago, when they cost £1100 each, not many people wanted to go Lithium then.

 

[Dockhead]

This 'weight' argument is relative ... but IMHO not really valid ...

One of the biggest arguments used to justify Li - is lighter weight for similar AH.
So you decide to fill the battery box with a greater capacity Li battery of similar physical box size - you get more AH ... Wh .. whichever term you wish to use. So instead of gaining advantage of less weight for similar AH ... you up the AH because the Li can for same physical size be greater capacity ... which in turn means heavier ..

Not necessarily. I replaced 8x Trojan T105's weighing 224kg with 16 EVE 280K's weighing 88kg and fitting into half the space. And at the same time got a usable power increase from 5.4kWh to 11.5kWh. So that's more than double the power and 2.5x less weight. At the same time. You'd had to increase your power by like 5x to equal the weight of lead.

But weight is more or less important depending on the boat. I'm in 54' mono, fairly light displacement and used sometimes for racing, so plus or minus 150kg is somewhat good but will not noticeably affect performance. A smaller mono will care more. A performance catamaran will care A LOT.

Saving weight was not one of the main purposes of my switch to lithium; just a nice side effect. For others it could be quite important.

 

[Refueler]

Not necessarily. I replaced 8x Trojan T105's weighing 224kg with 16 EVE 280K's weighing 88kg and fitting into half the space. And at the same time got a usable power increase from 5.4kWh to 11.5kWh. So that's more than double the power and 2.5x less weight. At the same time. You'd had to increase your power by like 5x to equal the weight of lead.

But weight is more or less important depending on the boat. I'm in 54' mono, fairly light displacement and used sometimes for racing, so plus or minus 150kg is somewhat good but will not noticeably affect performance. A smaller mono will care more. A performance catamaran will care A LOT.

Saving weight was not one of the main purposes of my switch to lithium; just a nice side effect. For others it could be quite important.

Home goal !!

You just confirmed what I said ...

The extrapolation is that if you have a battery box of x by y by z size - you will fill that box and gain the extra AH capacity with Li ... but you will lose a lot of the weight advantage by virtue of putting in more Li ...

Blimey - why is it such hard work ??

 

[PaulRainbow]

Home goal !!

You just confirmed what I said ...

The extrapolation is that if you have a battery box of x by y by z size - you will fill that box and gain the extra AH capacity with Li ... but you will lose a lot of the weight advantage by virtue of putting in more Li ...

Blimey - why is it such hard work ??

But that isn't what he has done. He's taken out 8 x T105s, each of which takes up a similar space to a 4 cell Lithium pack. So he's saved half the space, reduced weight by 136Kg and increased available power considerably.

Most of my Lithium installations have been to mid sized yachts, around the size of yours. Typically fitted with a pair of LA batteries, which i replace with a single Lithium pack, so half the space. A pair of LA batteries, circa 110AH weighs about 60Kg, the Lithium pack weighs just over 20Kg, the one i did last week had a pair of deep cycle batteries that weighed 90KG and were only 120Ah each ! 70Kg saving there. So ball park power increase is from 110Ah with LA (when it was new) against 224Ah with a 280Ah Lithium pack.

If you are considering Lithium i would very strongly urge you to look at buying the cells and a BMS, much cheaper and a neater footprint. Buy good cells and a JK BMS. You already have a suitable mains charger, so you just need a DC-DC charger, a new fuse and a few odds and ends.

 

[geem]

But that isn't what he has done. He's taken out 8 x T105s, each of which takes up a similar space to a 4 cell Lithium pack. So he's saved half the space, reduced weight by 136Kg and increased available power considerably.

Most of my Lithium installations have been to mid sized yachts, around the size of yours. Typically fitted with a pair of LA batteries, which i replace with a single Lithium pack, so half the space. A pair of LA batteries, circa 110AH weighs about 60Kg, the Lithium pack weighs just over 20Kg, the one i did last week had a pair of deep cycle batteries that weighed 90KG and were only 120Ah each ! 70Kg saving there. So ball park power increase is from 110Ah with LA (when it was new) against 224Ah with a 280Ah Lithium pack.

If you are considering Lithium i would very strongly urge you to look at buying the cells and a BMS, much cheaper and a neater footprint. Buy good cells and a JK BMS. You already have a suitable mains charger, so you just need a DC-DC charger, a new fuse and a few odds and ends.

Yep, I built a 280Ah 12v battery for a friend this week. An afternoons work.

 

[Refueler]

I didn't say HE had filled the battery box ... my point is that many people will fill the box and get the extra AH ... so the weight advantage is lost - but you get the extra AH ...

 

[Dockhead]

Home goal !!

You just confirmed what I said ...

The extrapolation is that if you have a battery box of x by y by z size - you will fill that box and gain the extra AH capacity with Li ... but you will lose a lot of the weight advantage by virtue of putting in more Li ...

Blimey - why is it such hard work ??

I don't understand what you're saying.

Yes -- I filled the box (or the space for the box) and gained a lot of extra power. More than double. And that was only one box -- I had two.

And I saved 150kg. Although I got double the power. To be clear -- double the power, less than half the weight and volume.

So what exactly are you on about?

Comparing EVE 280K's to Trojan T105's, the power density of the former is 130Wh/kg. The lead batteries? 24Wh/kg. It's a difference of about 5x. So you can double or triple your power, and still save weight. A box stuffed with lithium is still lighter than the same box stuffed with lead.

 

[geem]

I don't understand what you're saying.

Yes -- I filled the box (or the space for the box) and gained a lot of extra power. More than double. And that was only one box -- I had two.

And I saved 150kg. Although I got double the power. To be clear -- double the power, less than half the weight and volume.

So what exactly are you on about?

Comparing EVE 280K's to Trojan T105's, the power density of the former is 130Wh/kg. The lead batteries? 24Wh/kg. It's a difference of about 5x. So you can double or triple your power, and still save weight. A box stuffed with lithium is still lighter than the same box stuffed with lead.

My boat was originally built as all electric in 1980. No gas onboard. It had 4x250Ah 8D batteries for the domestic load. These weigh 70kg each. Total domestic battery weight was 280kg. We now have 16x280Ah lithium cells using half the battery box space. I converted part of the battery box to a separate locker to store our sewing machines. The lithium cells give us 1100Ah of capacity which due to the far higher DOD available is closer to 2000Ah so almost double the original battery capacity for far less space. The weight of the lithium cells and components to make the two batteries is 90kg. A massive weight saving of 190kg over the original design.
If you use your boat for liveboard or extended summer cruising, lithium is a game changer. If you are a weekend sailor, marina based, there is little benefit, unless your electric system needs a complete overhaul anyway.

 

[fredrussell]

Blimey - why is it such hard work ??

Because you’re not properly reading what he’s saying! See Paul’s post 73.

I accept sailing is a ‘grey haired’ pastime (certainly for me at least) - and we’re all a bit stuck in our ways but just how long is it going to take for everyone to accept that for a house bank LiFePo is better than lead in pretty much every respect? I’m always amazed to hear of people replacing dead lead with new lead. As various people have said on this thread and others, even with the initial ‘changeover’ cost of B2B, fuses and so on, the huge amount of cycles LiFePo gives compared to lead means that in the long run you’ll be getting that money back.
The last new lead acids I bought for boat lasted two years. TWO YEARS! Admittedly they were cheap no-brand jobbies from the chandlery, but this is on a marina boat with shore power and a decent charger. Those batteries were pampered.

 

[Refueler]

Because you’re not properly reading what he’s saying! See Paul’s post 73.

I accept sailing is a ‘grey haired’ pastime (certainly for me at least) - and we’re all a bit stuck in our ways but just how long is it going to take for everyone to accept that for a house bank LiFePo is better than lead in pretty much every respect? I’m always amazed to hear of people replacing dead lead with new lead. As various people have said on this thread and others, even with the initial ‘changeover’ cost of B2B, fuses and so on, the huge amount of cycles LiFePo gives compared to lead means that in the long run you’ll be getting that money back.
The last new lead acids I bought for boat lasted two years. TWO YEARS! Admittedly they were cheap no-brand jobbies from the chandlery, but this is on a marina boat with shore power and a decent charger. Those batteries were pampered.

Maybe read correctly what I posted ?

My comment as I answered to Pauls - who also did not read my post correctly .. was that many people will add batterys till the battery boxes are full getting the increased AH but losing much of the weight advantage ...

Yes it is hard work when people don't read properly !

 

[PaulRainbow]

Maybe read correctly what I posted ?

My comment as I answered to Pauls - who also did not read my post correctly .. was that many people will add batterys till the battery boxes are full getting the increased AH but losing much of the weight advantage ...

Yes it is hard work when people don't read properly !

What you actually said, in a response to Dockhead, who only replaced half of his batteries with Lithium was (in poat #75) "my point is that many people will fill the box and get the extra AH ... so the weight advantage is lost - but you get the extra AH ..."

My highlighting. That isn't correct, as i and others have explained to you. Even if you filled all of the original battery space there would still be a significant weight saving, in some cases 50% or more. Generally, people only fill half of the original battery space with Lithium, making the saving even greater. No one in this thread has said they filled all of the available battery space.

Blimey - why is it such hard work ??