With lithium do we actually need a dedicated starter battery?

[Iron E]

Originally Posted by Fore and Aft

SVJedi no one I know talks about kWh it's all Ah.
Captain Rivet 300-400 AH Lithium at 12 volts, along with 400-600w of solar is what I normally see on most boats I survey. Generators are not that common either.
AGM battery storage is another story, and you will often see 600AH plus at 12 volts. Some of my customers switch from AGM to Lithium batteries then remove the generator. In a funny way Lithium helps them simplify their yacht.
Cheers

I'm not going to speak for Jedi, but for me, when if I'm only considering smaller 12 volt DC systems that have basic windlass, lights, radar, radio, etc... then Ah math is fine.
But when considering larger complex lifepo4 battery systems with solar panels, inverters, appliances such as air fryers, a/c, multiple induction hobs, etc... kWh is the most straightforward way for me to math them out.

[s/v Jedi]

Originally Posted by Iron E

I'm not going to speak for Jedi, but for me, when if I'm only considering smaller 12 volt DC systems that have basic windlass, lights, radar, radio, etc... then Ah math is fine.
But when considering larger complex lifepo4 battery systems with solar panels, inverters, appliances such as air fryers, a/c, multiple induction hobs, etc... kWh is the most straightforward way for me to math them out.

Indeed, it’s also a worldwide industry standard. As 12V house batteries are quickly becoming a thing of the past, we have switched to kWh because Ah doesn’t make sense until you add how many Volts and is awkward.

[newhaul]

Originally Posted by s/v Jedi

Indeed, it’s also a worldwide industry standard. As 12V house batteries are quickly becoming a thing of the past, we have switched to kWh because Ah doesn’t make sense until you add how many Volts and is awkward.

Ok I have yet to work on a boat that was under 75 ft that wasn't 12 volt.
Heck one of the tugs I worked on was even 12 volt. The main engine was air start. The compressor was 12 v start

[Bowdrie]

Originally Posted by newhaul

Ok I have yet to work on a boat that was under 75 ft that wasn't 12 volt.
Heck one of the tugs I worked on was even 12 volt. The main engine was air start. The compressor was 12 v start

A 1930s 130' motor yacht I was aboard in the late '70s was all 120VDC.
Two banks, each consisting of 10 8D batteries.
Need 120VAC? No problem, the motor-generators provided it without scores of circuit boards or gizmos.
The original direct-reversing Atlas-Imperial 6cyl. 10x13 engines used air, their smoothness would make a modern engine blush with envy.
A Sperry gyro ran the pilot.
A simple boat by modern standards, the engine lathe and drill press would generally keep you going if something needed repairing.

[s/v Jedi]

Originally Posted by newhaul

Ok I have yet to work on a boat that was under 75 ft that wasn't 12 volt.
Heck one of the tugs I worked on was even 12 volt. The main engine was air start. The compressor was 12 v start

Sounds like you are on a different world. All the modern 50’+ boats are 24V or 48V.

[ranger58sb]

Originally Posted by newhaul

Ok I have yet to work on a boat that was under 75 ft that wasn't 12 volt.
Heck one of the tugs I worked on was even 12 volt. The main engine was air start. The compressor was 12 v start

It's been quite common, at least for 45'-plus U.S. built powerboats over the last 20 years or so, to have morphed to 24VDC... with some 12V stuff too. Our current ride (nominally 58') is very typical: 24V starters, freshwater pump, toilets, lighting...

Ditto, 240VAC appliances (especially ACs, water heater, electric cooktops) plus some 120VAC stuff (fridges, microwave/oven, entertainment systems, navigation electronics, etc.).

-Chris

[CaptainRivet]

That why I state AH and voltage, kWh I have to calculate/not intuitive and think eg AH to C rate is direct, same with resulting currents.
What I see more and more that the lithium banks getting bigger and bigger as the batteries get cheaper. First they install 50-75% of former lead capacity mostly with old lead as backup (don’t trust lithium, they know lead), then the lead lets them down and on other side they learned how reliable, quickly and effective lithium charges plus bank don’t need to be full every day.
They learned bank must not be full every day, actually better it’s at 85%. the bank can be used as buffer compared to lead and on good or motorsailing days they have now spare energy which more capacity can store and you can live off the bank on bad days.
Space is available as less batteries installed, so you can double available capacity in same space as to lead before and it’s often cheaper and simpler to add more capacity then modify your solar arch to fit bigger panels.
I am facing the same and just add 2 more 1p4 cells with BMS for below 1000Euro adding 608AH capacity or another 2 days of buffer.

Weekend sailors just put more capacity in and live of it, recharge by shorepower instead adding solar.

[newhaul]

Originally Posted by s/v Jedi

Sounds like you are on a different world. All the modern 50’+ boats are 24V or 48V.

For modern aka new boats that's my youngest son . He is lead mechanical engineer for one of the build teams at Delta Marine.
99% of the boats I tinker with are at least 20 years old with a couple as much as 100 years old. The newer ones arec12v but also under 30 ft.

I'm retired so I don't work on boats anymore . Tinkering sounds better.

[CaptainRivet]

So back to topic.
Who wants a starter or needs one as its a cat for 2nd engine, here are a pack of 4x 100AH cells that can do 3C constant and 500A peak (equals to approx 1000CCA if you wanna replace lead) for 150Euro already incl. Tax for US and europe, chose the 105AH cells. Installed them lately:

Just found this amazing item on AliExpress. Check it out!
109,23€ 48%OFF | 4pcs VariCore 3.2V 320Ah 280Ah 105Ah LiFePO4 battery 3C Lithium iron phosphate battery for 4S 12V 24V Golf Cart Yacht solar RV
https://a.aliexpress.com/_EQlhZFd

Cheaper then an equal size AGM...lasts longer and works. As BMS use a BMV 700 or 712 and an jk active balancer that also monitors cell voltages.

[more]

Originally Posted by CaptainRivet

S

Just found this amazing item on AliExpress. Check it out!

Cheaper then an equal size AGM...lasts longer and works. As BMS use a BMV 700 or 712 and an jk active balancer that also monitors cell voltages.

i find this and buy 8 pcs https://eur.vevor.com/off-grid-solar...p_010485988472

[newhaul]

Originally Posted by more

i find this and buy 8 pcs https://eur.vevor.com/off-grid-solar...p_010485988472

I wish and the site says only 18€ . Heck of a good price if I could get it here in the USA.

[more]

Originally Posted by newhaul

I wish and the site says only 18€ . Heck of a good price if I could get it here in the USA.

check now price 583.99 €

https://eur.vevor.com/off-grid-solar...p_010485988472

but my is on way. company want i return inverter. this is not my mistake. i order and pay

[CaptainRivet]

Originally Posted by more

i find this and buy 8 pcs https://eur.vevor.com/off-grid-solar...p_010485988472

Hope for you they are what described and not a scam...

[CaptainRivet]

Originally Posted by more

check now price 583.99 €

https://eur.vevor.com/off-grid-solar...p_010485988472

but my is on way. company want i return inverter. this is not my mistake. i order and pay

Good deal if they are legit and work.

And thats by the way a good and cheap low frequency inverter in 12V and 3000W with 9000W peak for the steal of 270Euro, you won't get anything better for that money.
https://m-eur.vevor.com/low-frequenc...p_010340279905
Who cannot or want to afford a victron and has eg induction stoves or AC which has a lot surge and will kill the cheap HF inverters very quick. Installed 3 of them already and they are my goto choice if you wanna cheap and reliable 3kw one in 12V. Its not complaining if you pull 4000W for 5min...heavy duty with a lot reserves. Yes standby is a bit higher so you don't want that to run 24/7, its low-frequency budget so thats where they saved money. but then just install a small 300-500W hf you run your permanant 230V loads and get the big boy for your galley. Or a great boost inverter for the Victron Multi/Quattro in 12V to run your electric galley.

[newhaul]

Originally Posted by more

check now price 583.99 €

https://eur.vevor.com/off-grid-solar...p_010485988472

but my is on way. company want i return inverter. this is not my mistake. i order and pay

Now that price sounds more like it really should be . Hope you get them for the 18€ they were listed for if not time to talk to a barrister.