Lithium Battery Revolution Phase II

[ttmott]

It's looking like Lithium battery technology is about to take another leap in both energy density and safety within the next five or so years.
The technology and production capability has been validated for Lithium Sulfur chemistry using a non-flammable boron nitride based electrolyte.
The change in energy density is the big news however. The typical Lithium Iron Phosphate battery we use for boats now have an energy density of 160 Wh/Kg. It appears the LiS technology will deliver 400 Wh/Kg.
This means that a typical LFP battery the size of a Group 31 lead acid battery that has a useable energy of 100 Amp Hours will now have useable energy of 250 Amp Hours.
Amazing.

 

[Strecker25]

Wow, that’s incredible. The recreational off-road industry seems to be starting to head in this direction (dirt bikes, quads, etc) and in my opinion density/weight/range will be the biggest barrier to adoption. This will be a huge jump

 

[copb8tx]

It's looking like Lithium battery technology is about to take another leap in both energy density and safety within the next five or so years.
The technology and production capability has been validated for Lithium Sulfur chemistry using a non-flammable boron nitride based electrolyte.
The change in energy density is the big news however. The typical Lithium Iron Phosphate battery we use for boats now have an energy density of 160 Wh/Kg. It appears the LiS technology will deliver 400 Wh/Kg.
This means that a typical LFP battery the size of a Group 31 lead acid battery that has a useable energy of 100 Amp Hours will now have useable energy of 250 Amp Hours.
Amazing.

Would love to read more about this and the company(s) that are leading the way. That's a huge step up in enabling the adoption of battery tech.

 

[b_arrington]

It's looking like Lithium battery technology is about to take another leap in both energy density and safety within the next five or so years.
The technology and production capability has been validated for Lithium Sulfur chemistry using a non-flammable boron nitride based electrolyte.
The change in energy density is the big news however. The typical Lithium Iron Phosphate battery we use for boats now have an energy density of 160 Wh/Kg. It appears the LiS technology will deliver 400 Wh/Kg.
This means that a typical LFP battery the size of a Group 31 lead acid battery that has a useable energy of 100 Amp Hours will now have useable energy of 250 Amp Hours.
Amazing.

What's the charge acceptance rate looking like with this chemistry? Seems like this would be an important point. With the dock power being typically 30amp or 50amp (more rare), even with fast charge acceptance it's going to take quite a while to charge these higher capacity batteries.

 

[ttmott]

What's the charge acceptance rate looking like with this chemistry? Seems like this would be an important point. With the dock power being typically 30amp or 50amp (more rare), even with fast charge acceptance it's going to take quite a while to charge these higher capacity batteries.

Good point, they didn't discuss those capabilities. Charging in cold environments also.
An amp hour is an amp hour regardless of where it is stored. The bottleneck in charging is still lead acid - the slowest by far. The discerning difference is lead acid requires full charge every time where Lithium is perfectly happy with partial charge. So a charge rate of 100 amps at 12 volts DC (let's say) is 5 amps at 240VAC (shorepower). A lithium battery of 50 AH takes around two minutes to charge whereas a 100AH lead acid battery (50AH useable) will take two hours.
So I think no matter any lithium solution is best.
Consider also you want to fully operate your boat (including air conditioning) for 8 hours on batteries. Let's say you will need 1500 Ah useable storage. Current lead acid would be 30 Group 31 batteries and require literally days of charging after that 8 hours. Current LFP would be 15 Group 31 size batteries and require about three hours of charging. The next generation batteries would be 6 batteries of the same size; charge rate TBD....

 

[ttmott]

My big pause on the technology is where insurance liability is going with the lithium batteries..

 

[Flyer5]

My big pause on the technology is where insurance liability is going with the lithium batteries..

I would think they will have to recognize the difference between the LI Ion and the Li Po batteries. Li Po are very safe. This really is great news about the technology. Pricing will be the next hurdle. If it is not affordable, it won't matter how well it works.

 

[ttmott]

Good point, they didn't discuss those capabilities. Charging in cold environments also.
An amp hour is an amp hour regardless of where it is stored. The bottleneck in charging is still lead acid - the slowest by far. The discerning difference is lead acid requires full charge every time where Lithium is perfectly happy with partial charge. So a charge rate of 100 amps at 12 volts DC (let's say) is 5 amps at 240VAC (shorepower). A lithium battery of 50 AH takes around two minutes to charge whereas a 100AH lead acid battery (50AH useable) will take two hours.
So I think no matter any lithium solution is best.
Consider also you want to fully operate your boat (including air conditioning) for 8 hours on batteries. Let's say you will need 1500 Ah useable storage. Current lead acid would be 30 Group 31 batteries and require literally days of charging after that 8 hours. Current LFP would be 15 Group 31 size batteries and require about three hours of charging. The next generation batteries would be 6 batteries of the same size; charge rate TBD....

A bit of a correction need to convert Wh to Ah. Ah=Wh/V... Sorry for the mis-calculation.

 

[dtfeld]

My big pause on the technology is where insurance liability is going with the lithium batteries..

Interesting developments. Of course running the ancillary systems for 8 hours vs running the boat on plane for 8 hours is still likely out if the question. Energy density between LFP and diesel is still off by a factor or 40-50.

I don’t get the insurance issue. From a safety standpoint the latest LiFePO4 chemistry is about as stable/safe as LA from what I’ve read. Maybe the rub is replacement cost?

 

[dtfeld]

And regardless of density, capacity, etc, etc, the main impediment to EV adoption isn’t the batteries, but the infrastructure to generate/transmitt electrical power to charge all of these batteries.

It’s the one thing that the media never discusses (I guess they are too stupid to ask) when they do a puff piece on the latest electric car/ gadget. Designing something to consume electricity is pretty easy, figuring out how to generate the power in the first place is the real challenge.

 

[ranger58sb]

Battery bank architecture is a typical issue we've looked at in relation to lithium batteries. Our typical set-up (many, many boats designed like this) is banks of dual-purpose main batteries -- start an engine, service house loads. Our set-up has a third large bank, for the bow thruster (and we've re-purposed that to also service inverter loads).

High current requirements -- like engine cranking and bow thrusters -- so far doesn't fall into "mainstream" LFP batteries. There are a few that can handle high current, I think, but they're not really common... and I didn't see any that could deal with the theoretical limits our specific thruster might require.

House banks separate from start/thruster banks -- many boats are set up that way too -- seem to be an easier LFP application. Or we could split our existing architecture that way, but it'd take a boatload of work.

A few months ago I saw an araticle about a potential new battery chemistry mostly made up of salt (sodium) or silicone or some such. I forget details, but it sounded promising. The people working on it also said it'd be at least 5-10 years (something like that) down the road sometime...

-Chris

 

[b_arrington]

And regardless of density, capacity, etc, etc, the main impediment to EV adoption isn’t the batteries, but the infrastructure to generate/transmitt electrical power to charge all of these batteries.

It’s the one thing that the media never discusses (I guess they are too stupid to ask) when they do a puff piece on the latest electric car/ gadget. Designing something to consume electricity is pretty easy, figuring out how to generate the power in the first place is the real challenge.

That's kind of where I was going with the charge rates. Electrical infrastructure in slips can be kinda dodgy. And lots of boats are on moorings without regular access to power between uses.

 

[ranger58sb]

What's the charge acceptance rate looking like with this chemistry? Seems like this would be an important point. With the dock power being typically 30amp or 50amp (more rare), even with fast charge acceptance it's going to take quite a while to charge these higher capacity batteries.

50A shore power service not uncommon around here. 50A of AC is a boatload of DC amps.

-Chris

 

[Maybe A Dancer]

Wonder what the actual weight of these will be?

The weight issue would apply differently to our current technology boats, for instance with my thrusters and gen set I'm carrying 7 batteries on board, however if we're going to apply this new battery tech to an all-electric Tesla thyp boat, how much weight does that equate to vs engines and fuel?

BEST !

RWS

 

[ttmott]

Wonder what the actual weight of these will be?

The weight issue would apply differently to our current technology boats, for instance with my thrusters and gen set I'm carrying 7 batteries on board, however if we're going to apply this new battery tech to an all-electric Tesla thyp boat, how much weight does that equate to vs engines and fuel?

BEST !

RWS

Weight is watts/Kg (see first post). A typical 100ah lithium battery weighs about 30 pounds. This new technology would then weigh about 12 pounds for the same energy.

 

[ttmott]

Battery bank architecture is a typical issue we've looked at in relation to lithium batteries. Our typical set-up (many, many boats designed like this) is banks of dual-purpose main batteries -- start an engine, service house loads. Our set-up has a third large bank, for the bow thruster (and we've re-purposed that to also service inverter loads).

High current requirements -- like engine cranking and bow thrusters -- so far doesn't fall into "mainstream" LFP batteries. There are a few that can handle high current, I think, but they're not really common... and I didn't see any that could deal with the theoretical limits our specific thruster might require.

House banks separate from start/thruster banks -- many boats are set up that way too -- seem to be an easier LFP application. Or we could split our existing architecture that way, but it'd take a boatload of work.

A few months ago I saw an araticle about a potential new battery chemistry mostly made up of salt (sodium) or silicone or some such. I forget details, but it sounded promising. The people working on it also said it'd be at least 5-10 years (something like that) down the road sometime...

-Chris

That is the real question. However, Lithium battery cells themselves can deliver massive current, more than SLA batteries; the limiting factor is the Battery Management System (BMS). The BMS is the electronics that protect the battery. The higher end LFP batteries have capabilities to deliver high current and that is specifically due to the BMS. I had/have a design to completely change the boat over to LFP batteries including engine cranking. The only SLA battery is for the generator starting. I had an engineering firm work the design but they didn't want the engines started on the lithium bank due to a remote possibly of cascading BMS trips; that's another story that I discussed in another thread. The batteries in the design were five Battleborn GC3's which were 270Ah each. Each can provide 300A continuous with a peak of 500A for 30 seconds before the BMS tripped the battery off line. Five of these properly arranged in parallel could support 1500 amps continuous. More than enough energy for reliable cranking and enough to supply the entire boat's electrical needs for 8 hours then the generator automatically comes on line to recharge the bank.

These batteries are 80 pounds each which is 400 pounds total. The new tech if it performs similarly would weigh 160 pounds total. Amazing.
As an edit - That is over 13 SLA 8D batteries which would weigh 2106 pounds - now there is an eye-opener.

 

[ranger58sb]

However, Lithium battery cells themselves can deliver massive current, more than SLA batteries; the limiting factor is the Battery Management System (BMS). The BMS is the electronics that protect the battery. The higher end LFP batteries have capabilities to deliver high current and that is specifically due to the BMS. I had/have a design to completely change the boat over to LFP batteries including engine cranking. The only SLA battery is for the generator starting. I had an engineering firm work the design but they didn't want the engines started on the lithium bank due to a remote possibly of cascading BMS trips; that's another story that I discussed in another thread. The batteries in the design were five Battleborn GC3's which were 270Ah each. Each can provide 300A continuous with a peak of 500A for 30 seconds before the BMS tripped the battery off line. Five of these properly arranged in parallel could support 1500 amps continuous.

Thanks for that. Something I don't know about continuous and peak amp output ratings: Is that additive when batteries are paralleled, for a given voltage (as your note suggests)? Remains the same, for batteries in series to higher voltage?

So if continuous and peak ratings for single 12VDC batteries are 300/500 respectively, two batteries in parallel would be rated at 600/1000? Or if in series at 24VDC, it would remain at 300/500?

I see Battleborn offers an 8D shape, cranking amps not stated, 270-Ah capacity, BMS set at 300A continuous and 500A surge. Our thruster wants 560A. (I think that's peak, but then again, I think a thruster is maybe always surge by definition?)

270Ah 12V LiFePO4 Deep Cycle 8D Battery | Battle Born Batteries

Our thruster is powered by a pair of 8Ds in series at 24VDC. The PO had some crap batteries in there, and since I repurposed the thruster bank to also service inverter loads, I also replaced the crap with a pair of Lifeline GPL-8DLs. 255-Ah bank capacity at 24VDC. I don't see a peak/surge rating for those but they do list CCA/MCA/HCA as 1350/1675/1975A respectively -- and maybe that speaks to peak/surge?)

If I act right now, I could consider moving those two new 8Ds to replace our crap port bank (minimum 1400 CCA cited in the Sea Ray manual)... and then replacing the thruster/inverter bank with a pair of the Battleborn 8Ds...

But... if I've got those ratings calcs right, it looks like a pair of Battleborn 8Ds at 24VDC would only reach 500A peak, not technically enough to satisfy our thruster.

Have I got that right?

FWIW, the Battleborn 8Ds only offer a 15-Ah increase in capacity (ignoring for a minute the capability to draw these down much deeper per cycle)... and they cost $2,399 each, compared to the Lifelines at approx $750 each (ignoring for a minute the greatly increased number of cycles).

-Chris

 

[ttmott]

Chris, I'm sure you know this but Lead Acid batteries are fully discharged at 50% or their rated capacity. You cannot discharge more than that. Lithium batteries on the other hand can be fully discharged without damaging them but to get the full life out of them it is best to limit their discharge to between 80 and 90 percent. Some lithium batteries have CCA/MCA but they are pretty much dedicated to the high end bass fishing boats. They wouldn't be applicable to our applications.
You are correct that Lithium batteries in series are limited to the current of one battery but in parallel it is accumulative. One important thing however - To prevent more current from one battery than another and the chance of cascading BMS trips in a parallel configuration the conductors from the batteries must be equal length and gauge to a common robust buss-bar both on the positive side and negative side. The battery bank needs to think it is one battery.
Before any decision I would measure the current that the bow thruster consumes in conjunction to the inverter system and size the battery configuration appropriately.

 

[ranger58sb]

Chris, I'm sure you know this but Lead Acid batteries are fully discharged at 50% or their rated capacity. You cannot discharge more than that.

Before any decision I would measure the current that the bow thruster consumes in conjunction to the inverter system and size the battery configuration appropriately.

Uh... no. Not fully discharged at 50% of rated capacity. Per manufacturer (Lifeline, in this case), longest lifespan is to not routinely discharge lower than 50%. Different thing. Fully discharged (100% DoD) 12V battery is 10.5V, whereas 50% DoD is 12.15V. Different chart, open circuit voltage at 0% SOC is <11.58V and OCV at 50% SOC is 12.18V.

Yep, understand all that about lithium capabilities... greatly increased depth without damage, etc.

And thanks for confirming math.

All I've got is thruster specs, which I assume would be "worst case" or some such? (Max draw?) How measure? Multi-meter during operation? At the thruster?

All (or at least most) of this relevant to my earlier comment about battery architecture. I perceive it as a boatload of work to split engine starting from house service, and from thruster service to house service. And real-estate for a whole 'nother battery bank, with manageable wire pulls, isn't all that easy to come up with.

So that influenced my earlier decision to just re-purpose (multi-purpose) our thruster bank to service the inverter too... and call it good. It took replacing the earlier charger with an inverter charger (plus remote control panel and monitor), some short wiring pulls and some additional connections inside the AC/DC panel, done. Not even all that expensive, in the grand scheme of things.

-Chris

 

[dtfeld]

I would think a combination thruster/inverter battery makes a lot of sense to go with a LiFePO4 battery, and sized appropriately, would be a really nice upgrade to your boat. I say sized appropriately because, if you do a rough audit of your daily 12/24V DC requirements, you might be just as well off with a set of 4 smaller batteries, set up in a 2S/2P. That would give you 200Ah @ 24V. The smaller batteries are a lot more manageable (LiFePO4 is lighter, but not necessarily "light"), and if there is a problem with one battery, correcting/repairing is also a lot less expensive. Battle Born are about the same $/Ah, so you could scale to your needs.

There are other brands that might be worth a look as well.