With lithium do we actually need a dedicated starter battery?

[rslifkin]

Originally Posted by CaptainRivet

What does a lead starter 99% of time in a vessel…nothing just sitting around float charged and as dead weight, if not floated they make 3 years max.

Mine sit on a float charge most of the time, but my 2 start batteries certainly don't sit around as dead weight. They get used every single time I start the engines or the generator.

[newhaul]

Originally Posted by CaptainRivet

True, you are the exception that always exists…
Ctek is a battery maintainer and without my batteries lasted less then 3 years…5 cars in parallel and was racing too, so they just stand unused for some time, 6 month in winter…

What does a lead starter 99% of time in a vessel…nothing just sitting around float charged and as dead weight, if not floated they make 3 years max.

That’s why I say we don‘t need them anymore, a lithium house can do much more reliable also the job of the starter and the house at the same time. Want backup use a buffer battery for your nav electronics that additionally protect them, create more stable and clean power and can in emergency start your engine too. You won‘t need if house is installed correctly but you always can.
Both batteries are always in use, so you know they work when needed.

Ok question how is the FLA start battery float charged?

JMO but floating batteries is a surefire way to kill them prematurely just same as PSOC will kill all lead based deep cycle batteries.

Now if you are doing proper maintance the iron wind is being run for a bit every month or so .

[rslifkin]

Originally Posted by newhaul

Ok question how is the FLA start battery float charged?

JMO but floating batteries is a surefire way to kill them prematurely just same as PSOC will kill all lead based deep cycle batteries.

Now if you are doing proper maintance the iron wind is being run for a bit every month or so .

Indefinite float at an appropriate voltage won't hurt any kind of lead acid battery. Their preferred state is 100% changed and floating all of the time and pretty much any use beyond that will shorten their lifespan. Too high a float voltage will do damage though.

[SOLAR SUPPORT]

Large AH 4s LFP connected parallel with small AH 6s LTO without BMS. Hybrid single group. Service, Engine, Windlass, Bow Thruster all in one. Use a parallel connection switch to start the engine. Charge together. Disconnect the LTO battery if you want on anchor.

[Bowdrie]

Originally Posted by rslifkin

Indefinite float at an appropriate voltage won't hurt any kind of lead acid battery. Their preferred state is 100% changed and floating all of the time and pretty much any use beyond that will shorten their lifespan. Too high a float voltage will do damage though.

Agree.
The first house bank I had was 4 J-305s, 2 Trojans, 2 Rolls.
The Trojans went somewhat over 9 years, the Rolls lasted ~10.
The Rolls required you to keep an eye on them at closer intervals, (the price of a bit of increased capacity, (plate area,) being less "top water").
Too high of float causes corrosion of the positive plates.

[CaptainRivet]

Originally Posted by rslifkin

Mine sit on a float charge most of the time, but my 2 start batteries certainly don't sit around as dead weight. They get used every single time I start the engines or the generator.

Your lithium can easly and more reliably do both too. Dead weight and wasted energy and money for float charger...

[rslifkin]

Originally Posted by CaptainRivet

Your lithium can easly and more reliably do both too. Dead weight and wasted energy and money for float charger...

The weight doesn't matter. We're talking about ~120 lbs of batteries on a boat that weighs over 27k lbs and isn't overly weight sensitive. Plus, the start batteries are 6 years old and counting, so there's not exactly a big cost to having them, and the charger that feeds them was pre-existing when I started upgrading the house power systems. I don't keep the start batteries floating on solar power, but when we're on shore power or if the generator is running they get floated. And we're a powerboat, so engine runtime is longer relative to the number of start cycles (so keeping them well topped off is easy).

However, being a powerboat, I consider a separated source of starting power to be absolutely critical to safety. No manual switching or other places where mistakes can be made. Any kind of failure or mistake with house power won't leave me without starting power, as nothing can draw from the start batteries once the ignition keys are turned off. So even if I manage to do something dumb and leave the boat electrically dead, the engines and generator will still start.

[CaptainRivet]

Originally Posted by rslifkin

The weight doesn't matter. We're talking about ~120 lbs of batteries on a boat that weighs over 27k lbs and isn't overly weight sensitive. Plus, the start batteries are 6 years old and counting, so there's not exactly a big cost to having them, and the charger that feeds them was pre-existing when I started upgrading the house power systems. I don't keep the start batteries floating on solar power, but when we're on shore power or if the generator is running they get floated. And we're a powerboat, so engine runtime is longer relative to the number of start cycles (so keeping them well topped off is easy).

However, being a powerboat, I consider a separated source of starting power to be absolutely critical to safety. No manual switching or other places where mistakes can be made. Any kind of failure or mistake with house power won't leave me without starting power, as nothing can draw from the start batteries once the ignition keys are turned off. So even if I manage to do something dumb and leave the boat electrically dead, the engines and generator will still start.

Ok again exception, especially bigger motorboats...

on my 8t cat its the opposite 4x110AH= around 120kg dead weight at the end in the sugarscoups where already upgraded 95kg bigger engine+ saildrives sit...eleminating them is a big plus as this is significant wheight out the end balancing weight of the bigger engines by throwing the 120kg starters out and use a 6kg LTO in BB hull as starter.
The 60kg 1088AH LFP hybrid starter/house moved more midships.
cats have a starter battery in the other hull anhow, so hull where the housebank sits the house can do the job of the starter too, no need for extra starter here. Thats how its setup even with lead by factory in a lot mass production cats incl. My Lavezzi where when alternator runs a VSR connect the BB starter to hybrid house in STB. Can do the same with LIFEPO4 house and a LTO starter. Or both alternator charge house and BB starter with a DC2DC charger. Saves cost, weight and complexity.

[newhaul]

Originally Posted by CaptainRivet

Ok again exception, especially bigger motorboats...

on my 8t cat its the opposite 4x110AH= around 120kg dead weight at the end in the sugarscoups where already upgraded 95kg bigger engine+ saildrives sit...eleminating them is a big plus as this is significant wheight out the end balancing weight of the bigger engines by throwing the 120kg starters out and use a 6kg LTO in BB hull as starter.
The 60kg 1088AH LFP hybrid starter/house moved more midships.
cats have a starter battery in the other hull anhow, so hull where the housebank sits the house can do the job of the starter too, no need for extra starter here. Thats how its setup even with lead by factory in a lot mass production cats incl. My Lavezzi where when alternator runs a VSR connect the BB starter to hybrid house in STB. Can do the same with LIFEPO4 house and a LTO starter. Or both alternator charge house and BB starter with a DC2DC charger. Saves cost, weight and complexity.

So if I read correctly your setup is LTO start to a dc/DC to charge LIFEPO4 house?

If so what's the difference LTO or lead of some chemestry?
Aside from the difference in weight and the differing complexity of the installation

[newhaul]

Originally Posted by CaptainRivet

Ok again exception, especially bigger motorboats...

on my 8t cat its the opposite 4x110AH= around 120kg dead weight at the end in the sugarscoups where already upgraded 95kg bigger engine+ saildrives sit...eleminating them is a big plus as this is significant wheight out the end balancing weight of the bigger engines by throwing the 120kg starters out and use a 6kg LTO in BB hull as starter.
The 60kg 1088AH LFP hybrid starter/house moved more midships.
cats have a starter battery in the other hull anhow, so hull where the housebank sits the house can do the job of the starter too, no need for extra starter here. Thats how its setup even with lead by factory in a lot mass production cats incl. My Lavezzi where when alternator runs a VSR connect the BB starter to hybrid house in STB. Can do the same with LIFEPO4 house and a LTO starter. Or both alternator charge house and BB starter with a DC2DC charger. Saves cost, weight and complexity.

Now as I have said to you several times over the years as you have learned the tech. Your boat your choice my boat my choice.

[CaptainRivet]

Originally Posted by newhaul

So if I read correctly your setup is LTO start to a dc/DC to charge LIFEPO4 house?

If so what's the difference LTO or lead of some chemestry?
Aside from the difference in weight and the differing complexity of the installation

Both alternator charge lifepo4 house+starter bank in STB and LTO in BB via an 200A argofet.
The LTO in BB is the dump load for both alternator thats always connected like a lead if the BMS of the Lifepo4 shuts off the alternator charge via a BP220smart. but LTO doesn't need to be float charged as no measurable self discharge, so need for another charge source then alternator but i can always bypass the argofet with a switch and parallel directly if needed, its both Lithium.
As i have 2 volvo engines with D+ and my 2x 115A Mitsubishi alternators are original with internal temp protection and not extrernally regulated, so they need a dump load when lifepo4 shuts off which the LTO starter via the argofet of the other hull is.

Very simple, economical and effective lithium capable setup for 2 engines with 2 alternators and without lead thats giving me 170A charge from alternator. cost me 150Euro for the argofet, 120 for the BP220 and 100Euro for a 2nd cable i needed to root STB to the BB plus 50 euro for rooting the starter of each engine (connected to alternator originally) directly to the lifepo4 in STB and BB to LTO.
The additional cables i would need for externally regulated alternator too, so its just 150+120=270Euro for 2 alternators running at max they can reliably do plus always working surge protection without lead and a battery lifetime of min 15 years...

[Fuss]

Originally Posted by CaptainRivet

Both alternator charge lifepo4 house+starter bank in STB and LTO in BB via an 200A argofet.
The LTO in BB is the dump load for both alternator thats always connected like a lead if the BMS of the Lifepo4 shuts off the alternator charge via a BP220smart. but LTO doesn't need to be float charged as no measurable self discharge, so need for another charge source then alternator but i can always bypass the argofet with a switch and parallel directly if needed, its both Lithium.
As i have 2 volvo engines with D+ and my 2x 115A Mitsubishi alternators are original with internal temp protection and not extrernally regulated, so they need a dump load when lifepo4 shuts off which the LTO starter via the argofet of the other hull is.

Very simple, economical and effective lithium capable setup for 2 engines with 2 alternators and without lead thats giving me 170A charge from alternator. cost me 150Euro for the argofet, 120 for the BP220 and 100Euro for a 2nd cable i needed to root STB to the BB plus 50 euro for rooting the starter of each engine (connected to alternator originally) directly to the lifepo4 in STB and BB to LTO.
The additional cables i would need for externally regulated alternator too, so its just 150+120=270Euro for 2 alternators running at max they can reliably do plus always working surge protection without lead and a battery lifetime of min 15 years...

This system design does not work. It has fundamental design faults that if not apparent to you now, will be further down the track. I have previously commented on these problems and others too I seem to remember but somehow you’re not listening. It’s certainly not simple and the LTO introduces another complexity that will later need solutions.

[newhaul]

Originally Posted by CaptainRivet

Both alternator charge lifepo4 house+starter bank in STB and LTO in BB via an 200A argofet.
The LTO in BB is the dump load for both alternator thats always connected like a lead if the BMS of the Lifepo4 shuts off the alternator charge via a BP220smart. but LTO doesn't need to be float charged as no measurable self discharge, so need for another charge source then alternator but i can always bypass the argofet with a switch and parallel directly if needed, its both Lithium.
As i have 2 volvo engines with D+ and my 2x 115A Mitsubishi alternators are original with internal temp protection and not extrernally regulated, so they need a dump load when lifepo4 shuts off which the LTO starter via the argofet of the other hull is.

Very simple, economical and effective lithium capable setup for 2 engines with 2 alternators and without lead thats giving me 170A charge from alternator. cost me 150Euro for the argofet, 120 for the BP220 and 100Euro for a 2nd cable i needed to root STB to the BB plus 50 euro for rooting the starter of each engine (connected to alternator originally) directly to the lifepo4 in STB and BB to LTO.
The additional cables i would need for externally regulated alternator too, so its just 150+120=270Euro for 2 alternators running at max they can reliably do plus always working surge protection without lead and a battery lifetime of min 15 years...

Dang complex if you ask me . All I have to do is run a cable from my alternator + output to the power in on the DC DC A cable to the negative bus and a dense wire to the ignition run lug . All done

[SOLAR SUPPORT]

LTO batteries are more expensive than LA batteries. This is the only obstacle to replacing worn-out LA engine batteries with LTO batteries on boats. All lithium battery chemistries were first produced in cylindrical form and later all evolved into prismatic form. The same conversion applies to LTO cells. We will also see prices drop.

[rslifkin]

Originally Posted by SOLAR SUPPORT

LTO batteries are more expensive than LA batteries. This is the only obstacle to replacing worn-out LA engine batteries with LTO batteries on boats. All lithium battery chemistries were first produced in cylindrical form and later all evolved into prismatic form. The same conversion applies to LTO cells. We will also see prices drop.

That's a common issue with newer tech. Something may be better, but depending on the application, it's not necessarily better enough to justify a significant price premium. Once the price comes down enough, then the situation changes. The same thing has happened with LFP house batteries. Now that the prices have come down enough and there are some good drop-in options available, adoption is picking up noticeably.