With lithium do we actually need a dedicated starter battery?

[Pete7]

Originally Posted by CaptainRivet

no not mixing as buffer you connect/charge them via isolated DC2DC converter or charger from the LFP but you can directly connect the alternator to the buffer and charge the buffer. but you don't connect the starter to the AGM.

Well actually you can mix LFP and LA, some of us are actually doing it

Originally Posted by CaptainRivet

or if you have a 115A Mitsubshi or 125A Valeo alternator that have an AGM regulator but internal temp protection you simply connect the alternator to an Argofet on one output LFP hybrid starter/house and on other the AGM buffer.

Belt width will likely need to be changed. Mine is 10mm which is why I went down the DC>DC route rather than faffing around with having pulleys machined with keyways.

Originally Posted by CaptainRivet

By the way you can bring your dumb 80A alternator with V-Belt just to the next alternator shop and let it modify for external regulation, normally in the 100Euro range. then you get a Balmar 614 or ars 5 mastervolt which is 350Euro and you get 50A save and regulated charge. So for 500Euro thats done.

Yes but its expensive, Sterling show you how to do it in there alternator regulator instructions available for free on their website, or just use a £180 Victron DC>DC charger.

Originally Posted by CaptainRivet

A 30A DC>DC is 300 and not really protecting the alternator...just limiting the current

Is the "300" $$ or Wh? Either way the lead acid protects the alternator. Yes you might need to buy A new SLA every decade, but they are readily available, even on Sundays.

Originally Posted by CaptainRivet

but is that enough if motor sailing with low rpm on an exceptionally hot day??? plus you still need a lead.

Probably, but if not Renogy and Sterling do a 60A version and Victron now have a 50A. If you want redundancy, stack two 30A victron Orions.

Pete

[Wandering1]

Not really. Seperate diesel generator with its own battery. 115A of charging at 24v. Hydro generator, wind turbine, 920w of solar. Why would the battery be flat?

[seaexplorer]

All lithium batteries can be used without a BMS in an emergency (like if lightning fries the BMS).

BMS's should not shut off the whole system if the voltage gets too high - that is bad design. Any decent charging source will have its own high voltage cutoff.

LFP batteries are far more reliable than LA and a system with solar MPPTs can run DC devices directly off the sun without batteries in an emergency (during the daytime).

[seaexplorer]

I have to wholeheartedly agree with CaptainRivet's original post.

Its time to for lead free future. They are unreliable, heavy, space guzzling, short life and massively more expensive than LFP over the long term (10x cycle life).

[CaptainRivet]

Originally Posted by Wandering1

Or stick with the 2x100Ah lead starter batteries that cost me €105 each and should last 5 years in the tropics and 7 or 8 in more temperate climate.
Your system looks bpvery expensive for little gain.
Our starter motor is 4kw so 16kw surge is possible.

2x100AH lead won't start 560A@24V...and then this is his housebank to...20AH is not even enough for a costal cruiser :-)

[Fuss]

Originally Posted by CaptainRivet

Again you have no glue what Toshiba LTO Scrib cells are, just as headline the are the holy grale of lithium and the state of the art cells beside Winston.


let me educate you:
they where originally developed by Toshiba to work as boast cells for Lifepo4 in EVs as in EV during acceleration you need high C-rates which Lifepo4 cannot deliver. you cannot use supercapcitors as the duration of accerlation is much longer them they can contain in AH. That was necessary as due to fire risks they needed to move away from Li-ion which have capacity and high c-rates but are unstable and can get runaway.
So the capacity and steady driving are covered by Lifepo4 while when you accelerate the current comes from the Toshiba with up to 25C !!! for the motor to spin up. finished accelerating the lifepo4 take over and also recharge the LTO. compared to Li-ion and Lifepo4 the LTO cannot get termal runaway, can be kept at any SOC as long as you want to (also floated) and can be balanced at any SOC. They are ultrastable, you can use 100% of capacity, deviation between cells is minimal and don't need a BMS and just a balancer to keep the pack running.
Voltage range is 1.6V till 2,8V but 85% of capacity is between 2,0 and 2,4V means 6x2.0V is 12V and 14,4V, so you can simply charge them in parallel with your Lifepo4 with the same settings (or with any lead settings) but compared to lifepo4 you can completly discharge them and also float at 2,8V...only way to destroy them is charging with >3,5V for longer duration but even then they don't catch fire or get a runaway...they just bloat and then stop working. they produce 3 types but only 2 are really avaliable...the combined type in 20AH which have 25C pulse for 10 sec straight (thats what you want) or 20 and 23AH high energy density type that only have 10C.

Why they are not widely used or exclusvly in EVs is very simple, they are very expensive (average 1,08$ per AH while lifepo4 at 0.2-0.4$ per AH) and heavy as energy density is close to lead. Additional limited production capacity, only Thosiba produce the LTO SCIB and has longtermed contracts with manufacturers. so they are not sold via reseller normally and only spec fitting cells are sold like winston. Due to EV crisis some manufacturer sold the overstock to resellers and you can get them for a huge bargain (far below production cost!)

they are the prefect starter battery as every start needs less then 1AH, so you don't need huge capacity but can deliver the surge a starter need easily.
you can keep/balance/float them at any SOC/voltage. 20AH 1p6S can handle a 2000W starter found on most leisure boats engine up to 75hp.
original they are white with toshiba logo and sold in ready assembled packs, the overstock sold to reseller take this pack appart, heatshrink and weld studs on, thats why is blue without branding.


batteryhookup bought a huge lot and selling them for 18$ per piece, trustworthy reseller.

The question was, Do you know anyone using these LTO Toshiba cells for starter batteries on a yacht?
I don’t know what the drivel above has got to do with that question. But I guess it shows that no, you don’t know anybody.

[s/v Jedi]

Originally Posted by Fuss

The question was, Do you know anyone using these LTO Toshiba cells for starter batteries on a yacht?
I don’t know what the drivel above has got to do with that question. But I guess it shows that no, you don’t know anybody.

I would do that. I mean it’s just a buffer to aid the dc-dc chargers. Where can I buy them in the US?

[CaptainRivet]

Originally Posted by seaexplorer

All lithium batteries can be used without a BMS in an emergency (like if lightning fries the BMS).

BMS's should not shut off the whole system if the voltage gets too high - that is bad design. Any decent charging source will have its own high voltage cutoff.

LFP batteries are far more reliable than LA and a system with solar MPPTs can run DC devices directly off the sun without batteries in an emergency (during the daytime).

Depends on cell quality, deviation and C-rate used.
Without BMS 4S in general yes, 8s for several month yes, 16S weeks. In 8 and 16S the closer you go to its approach C-rate the less time without BMS.
Sure in emergency case always.

[CaptainRivet]

Originally Posted by Fuss

The question was, Do you know anyone using these LTO Toshiba cells for starter batteries on a yacht?
I don’t know what the drivel above has got to do with that question. But I guess it shows that no, you don’t know anybody.

Yes i do, i installed them in 2 boats, one d2-50 and the other beta 30hp....as well as in cars/RVs.
More the yinglong as Toshibas were hardly avaliable before and very expensive....now you get them for a steal....thanks to EV crises and not because they are bad.
108$ you spend on a nice dinner easily, not a big risk....and in boat bucks peanuts

[Fuss]

But they are not forum members right…very convenient for you rivet…you just have say and prove nothing.
No one on cruisersforum took your LTO advice and no one will step up and show that I am wrong.. it’s just parroted advice. No actual personal experience.

[ranger58sb]

Originally Posted by CaptainRivet

To clarify:
What boat do you have?
Motorboat or sailboat, both engine close or far like cat in different hulls?
You have two engines each need 560A surge capability to start in 24V, so both banks are in the rear, so on them is the whole house loads too, except inverter.
Inverter/bowtruster is in front I assume?
Your bowtruster can run on Lithium? Have a look in the manual or ask manufacturer as they are models that need the high resistance and voltage drop of a lead otherwise the motor burns out/shorts as current goes too high.

As you are at 24V you cannot just use winston cells and battery monitor as 8 cells in series are not that stable anymore and you need a BMS. As all banks have motors with high surge loads you cannot use mosfet BMS as you will kill them over time with the surge...so you need contacter based BMS means which switches the loads and charge with relays and not with mosfets...would highly recommend REC BMS. Calculate with 1000Euro for first REC BMS and 500Euro per BMS additional ones

Power boat. Twin 900-hp diesels, each with the nominal 1400 CCA requirement. Both banks aft, and each bank also runs approx half of the house/electronics DC load.

Thruster bank is also aft, and that where the 560A/4.5 mins requirement comes from. I repurposed the bank to also service a 3000W inverter, which in turn powers are AC-only fridge and freezer (when the genset isn't running)... and so far I can get through about one night at anchor before recharging. (And we would normally recharge -- and heat water -- during breakfast and dinner anyway...)

Mostly I'm thinking ahead, 'cause I updated batteries over the last two years. Currently three banks of 2x Lifeline 8D AGMs in series to 24VDC, 255-Ah nominal capacity per bank (when new), and 1350 CCA (which works OK).

I shopped on the idea of LFP for the inverter (thruster) project, but never found anything that looked like it would work...

-Chris

[newhaul]

On my boat it's a FLA start battery a dc-dc to my 250h LFP . Also I carry a small lithium jump pack that I have verified will start me if needed .
No specific reason it's just how I designed my system .

[CaptainRivet]

Originally Posted by Fuss

But they are not forum members right…very convenient for you rivet…you just have say and prove nothing.
No one on cruisersforum took your LTO advice and no one will step up and show that I am wrong.. it’s just parroted advice. No actual personal experience.

Yes one is here...
Do what you want. I don't care....
Non dealt with LTO as its an exot, a lot still fighting proven Lifepo4 and construct outliner uses case to justify still using lead....so no surprise.
I give my experience for free, take it or leave it.
Who rather wann get the next cheap lead for the next 3-5 years for the same money instead spent now 108$ and be done with it for next 15years...your personal choice...
If it 500Euro i can understand but for that bargain why not trying...what do you have to loose and what to gain..

[Donahue]

Originally Posted by CaptainRivet

In short you have no backup, just a 50$ starter that will fail on you as lead are unreliable, murphy is waiting...you fixed nothing, just put a bandage on a wound....

Means you need to add another drop in to the get the BMS current capability to start or exchange the BMS.

An isolated lead acid starter battery has been the standard for a very long time--maybe 80 years? Not sure how that suddenly becomes unseamlike or obsolete because lithium batteries can also (sometimes) start an engine. Lithium is a game changer when it comes to house loads, even really big ones. But it's hard to beat lead on pure cranking amps. Even a cheap starter battery is probably rates to 800-1000 cranking amps. To get that equivalent in lithium (at least LFP) you need a massive and very expensive bank. The draw of a cold starter motor or a loaded up winch can be massive. Why put those loads on an expensive lithium system when a dependable lead acid battery gets the job done. When lead acid batteries fail, moreover, they almost always give a fair warning.

[krid2000]

Originally Posted by s/v Jedi

I would do that. I mean it’s just a buffer to aid the dc-dc chargers. Where can I buy them in the US?

Looks like Battery Hook Up can ship them via FedEx in 2 days.

Dirk