Lithium ion house battery bank disappointment

[Pete7]

Originally Posted by arsenelupiga

i dont see how you dont see the benefits of LFP.

Here is calc for australia

480 AH gel replacemet cost = 2600.

400 AH four LFP cost 2,860.

Add BMS to have full insight for $500.

In my case no charger replacement. Reprogram Victrons and add extra switch to disabel alternator charging.

what is there not to like ?

So I use a pair of FLA Varta Hobby 110 AH 12v batteries. The current ones were fitted in 2011 and doing well meeting our needs. They have never been down below about 12.3v or 70%. They cost $150 each so to compare to your example above a bank of 440 AH would cost me $600 rather than $3300. I won't live long enough to see 5 lots of battery changes if each batch lasts over 7 years.

Now what happens in an emergency? well I disconnect the duff battery and run off the good one until I am safely in harbour. Then walk up the road to the nearest auto factors or chandlers and buy a 12v battery. doesn't even have to be a deep cycle FLA, anything will do for a temporary solution on a Sunday morning.

Were do you buy an LFP on a Sunday?

Okay, I do see that some people who like buying into technology early on would be attracted to LFP and I for one are extremely grateful they are willing to be beta trial users for the benefit of the rest of us. Me? I think the $2500 difference would buy a nice folding propeller which will make the boat go a darn sight faster than saving a few kgs in battery weight.

Pete

[Journeyman]

Originally Posted by senormechanico

Before: 4 six volt Trojan flooded in series/parallel. 440 aH @ 12.6 volts.
After: 4 200 aH HiPower 3.2 volt LiFePo4 in series. 200 aH @ 13.2volts.

The difference is amazing in many ways.
Lighter weight (important in a multihull).
No corrosive off gassing or holes in clothing.
More output from the watermaker due to slightly higher voltage and almost no sag as they discharge.
Much faster charging, almost no taper in current. (well, a little when going only to 13.8v).

I would NEVER go back to lead.
I even bought a LiFePo4 start battery for my home's emergency generator.
It holds a charge for a year with no float !
Starts right up when I check it every six months to make sure it's gonna start if I ever need it. No float charger attached.

Senor,

Thanks for coming back.
You are comparing flooded lead acid with Li Ion. All of the benefits you mention above, including the space savings, are achieved by going from flooded lead to TTPL lead. With the exception of weight.

My dilemma is comparing my TTPL AGM bank to Li Ion.

Thanks again,
Juan

[DotDun]

Originally Posted by StuM

Right you are, seems he's actually talking about 20 cells. Took a while to work out what he meant

And, that justifies the $6000 he is paying. Typical street pricing @ $300 per 200AH cell.

[DotDun]

Originally Posted by Pete7

So I use a pair of FLA Varta Hobby 110 AH 12v batteries. The current ones were fitted in 2011 and doing well meeting our needs. They have never been down below about 12.3v or 70%. They cost $150 each so to compare to your example above a bank of 440 AH would cost me $600 rather than $3300. I won't live long enough to see 5 lots of battery changes if each batch lasts over 7 years.

Now what happens in an emergency? well I disconnect the duff battery and run off the good one until I am safely in harbour. Then walk up the road to the nearest auto factors or chandlers and buy a 12v battery. doesn't even have to be a deep cycle FLA, anything will do for a temporary solution on a Sunday morning.

Were do you buy an LFP on a Sunday?

Okay, I do see that some people who like buying into technology early on would be attracted to LFP and I for one are extremely grateful they are willing to be beta trial users for the benefit of the rest of us. Me? I think the $2500 difference would buy a nice folding propeller which will make the boat go a darn sight faster than saving a few kgs in battery weight.

Pete

Agree! I can't cost justify LFP when I can buy T-105s for $94/ea. My last set of (4) T-105s lasted 8 years. At 3 years old, ELCI breaker tripped at the dock, 5 days later the AH counter said -493AH. Oh crap! Minus 493AH on a set of 450AH batteries, probably toasted them! Nope! Check water, charged to 100%, lasted another 5 years. FLA is simply just brain dead easy to maintain and cost ~20% of the equivalent LFP bank, which are finicky and require extra electronics/monitoring.

[Journeyman]

Originally Posted by daletournier

I was researching Lithium two nights ago as I planned to do a battery upgrade in South Africa at the end of the year and was considering them.

Woke up yesterday morning and my bank was 10.8v!!!!! Developed a short during the night grrrrrrrr. Thus im installing new batteries today. Just purchased 8 trojans.

I'm completely sold on the advantages of lithium, not sure how anyone can argue against these advantages. But deep cycle trojans and equivalents still have a place. Cheap, very robust and you can have a simple system to built around them. I think the simplicity is important if you are in far and away places. They also take a kicking, I've had solar regs and a balmar reg fail in the past without damage to deep cycle 6v on my previous boat.

Like all batteries owner management is everything, my batteries have died prematurely due to PO not understanding charging regimes, I really should have replaced them earlier.

I expect to get 5-6 years (comfortably) out of this set for a cost of approx $1300usd (900a/hr).

Next time it will be lithium or the equivalent at the time.

Dale,

If you read my original post you have my argument against Li Ion vs TPPL AGM for my application.

I am beginning to see that most advocates of Li Ion are comparing it with flooded lead acid batteries. That comparison has been encouraged and exploited by Li Ion marketers. They fooled me on the space savings issue.

Kind of like concluding an electric car is superior to an internal combustion engine car based on comparing a Tesla Model S with a Ford Model T.

Gotta love the marketing departments.

Jman

[Journeyman]

Originally Posted by Thalas

This has been a surreal thread for OP to ask about differences and when people point them out, he just flat out says it’s not true. Yes LiPo4 is more expensive up front. No, it’s not “needed” or for everyone. That said regardless of OPs “facts”...

LiPo4 IS half the weight.
LiPo4 IS double the density.
LiPo4 CAN be discharged 80% vs 50%
LiPo4 DOES have many more cycles making it more reliable and cost effective in the long run.
LiPo4 DOES maximize charging from limited solar as it isn’t more difficult to charge that last 10%.

As a mic drop, here’s a 5.5kwh DIY powerwall running residential AC in about the space of 8 AGM batteries at a lot less weight.

Thalas,

It will seem less surreal if you can give a reasoned counter argument to the individual points raised from my measured data, and Real world cruising experience in my original post as concerns solving my application issues.

Money is not an issue in my willingness to invest in Li Ion. The issue is Li Ion doesn’t improve on my TPPL AGM lead battery installation other than weight savings in my application.

Jman

[Journeyman]

Originally Posted by arsenelupiga

i dont see how you dont see the benefits of LFP.

Here is calc for australia

480 AH gel replacemet cost = 2600.

400 AH four LFP cost 2,860.

Add BMS to have full insight for $500.

In my case no charger replacement. Reprogram Victrons and add extra switch to disabel alternator charging.

And diy.

Say 3500, which is 900 more
saves you 130kg,
adds 320 AH usable, vs 96AH (as per lagoon manual not to go below 80% charged)
adds extrsa energy as there is no absorbtion.

what is there not to like ?

Arsenal,

I have no problem with Li Ion cost. Would gladly pay more if I could get my required space savings with them or they solved any other issues in my application.

If your existing batteries were not to be discharged below 80% I can easily see why you are I mpressed with Li Ion. That is not a limitation with my TPPL AGM bank.

As I said earlier, no argument about the weight savings. Just not an application issue in my kind of monohull.

Cheers,
Jman

[Journeyman]

Originally Posted by valhalla360

I'm still hung up on 250amp-hr at 12V is claimed to be a lot of power consumption.

Seriously 3hr of air/con at 20% duty cycle? Are you cooling only the bathroom cubical for those 3hr?

On a hot day bringing a 37' boat down from say 95F to 80F is likely going to take at least an hour of continuous run time and unless it's a super insulated boat and after 10am, you just give up on cooling, I would expect a higher ongoing duty cycle once cooled down. It could easily be 3-4 time the amp-hr for very limited air/con usage. If you actually bring the boat down into the 70'sF and run it for 8-10hr per day, that's a whole different ballgame and much more typical.

I would consider 250amp-hr moderate usage at best and arguably light usage. For minimal demand, standard lead-acid batteries do quite well and are cost effective. It's not until you get into high demand situations that you can start to justify the expense and complications of lithium. Also if you motor a lot, the tapering off of charge rates for lead-acid is less of an issue as you have long charge times available.

So, yeah, with low demand, lead-acid are very much still competitive and there isn't a lot of weight and space saving to be gained.

Valhalla,

Not sure what your point here is. Since my Li Ion option and my existing TPPL AGM installation both have the same energy density (see my original MasterVolt LFP comparison), how does Li Ion support higher demand any better?

Cheers,
Jman

[alctel]

Originally Posted by Journeyman

Valhalla,

Not sure what your point here is. Since my Li Ion option and my existing TPPL AGM installation both have the same energy density (see my original MasterVolt LFP comparison), how does Li Ion support higher demand any better?

Cheers,
Jman

Look up peukert's law

Also no-one is saying ditch your expensive AGMs and go to lifepo4, if you are happy with them just keep on using them - it's not worth it to switch if your current set does what you want it to.

[Colin A]

Originally Posted by Journeyman

Arsenal,

I have no problem with Li Ion cost. Would gladly pay more if I could get my required space savings with them or they solved any other issues in my application.

If your existing batteries were not to be discharged below 80% I can easily see why you are I mpressed with Li Ion. That is not a limitation with my TPPL AGM bank.

As I said earlier, no argument about the weight savings. Just not an application issue in my kind of monohull.

Cheers,
Jman

Looking at the documentation for both Odyssey and Northstar AGM TPPL they both seem to indicate a cycle life below 500 cycles with repeated DOD below 50%. Odyssey for instance lists 300 cycles going to 20%

In theory at least a lithium pack would go well over 1000 cycles discharged to between 10-20% remaining.

[Pizzazz]

This is a popular topic and we still can't agree on some facts:

Lead acid batteries are significantly less expensive than lithiums, around 5x or more when you factor in the charging system.

You can use (abuse) lead acid batteries with a similar usage profile to lithiums (i.e. discharge to 20%, only rarely charge to 100%). This is how golf carts use them and most industrial equipment. It is not good for the battery but if you factor in a more frequent replacement, lead acid still comes ahead by a factor of two or more.

Flooded batteries take abuse better than AGMs, and golf cart batteries especially can charge up to c/3 in bulk mode which is sufficient for most users.

So, what is the use case for lithiums? If you race and care about weight. Not a big issue for cruisers but I guess some people with cats may differ.

If you have an objection to battery abuse and prefer to baby the battery instead of making it serve you, then probably lithiums will give you a piece of mind.

If you need high discharge rates frequently (e.g. running an air conditioner off the batteries for hours on end, then recharging) or electric propulsion. Lithiums take this much better. But most people do not use batteries in this way. An occasional high current discharge (microwave, a couple of hours of AC, etc.) is possible with lead acid.

Lastly, if lithiums were so much better in total cost of ownership, boaters would have already switched. They haven't and this tells you something.

SV Pizzazz

[Paul L]

Originally Posted by Colin A

Looking at the documentation for both Odyssey and Northstar AGM TPPL they both seem to indicate a cycle life below 500 cycles with repeated DOD below 50%. Odyssey for instance lists 300 cycles going to 20%

In theory at least a lithium pack would go well over 1000 cycles discharged to between 10-20% remaining.

The Rolls AGM spec shows much higher cycle life
http://rollsbattery.com/wp-content/uploads/batteries/S12-230AGM.pdf

[CatNewBee]

just lost a gel 120Ah, boiled and smelled like rotten eggs.

Lithium is the way to go, and it is affordeble if you DIY.

[Anders]

Originally Posted by arsenelupiga

i dont see how you dont see the benefits of LFP.

Here is calc for australia

480 AH gel replacemet cost = 2600.

400 AH four LFP cost 2,860.

Add BMS to have full insight for $500.

In my case no charger replacement. Reprogram Victrons and add extra switch to disabel alternator charging.

And diy.

Say 3500, which is 900 more
saves you 130kg,
adds 320 AH usable, vs 96AH (as per lagoon manual not to go below 80% charged)
adds extrsa energy as there is no absorbtion.

what is there not to like ?

That's very expensive batteries. I would expect to pay around 120 pounds for my 135 Ah batteries, 4 of them would make 540Ah at a cost of 480 pounds, xe.com says that's USD686 OR AUD883.

[nebster]

Here are some density numbers from the worksheet I concocted when I was sourcing cells. Apologies for the imperial units; they were more practical for me back when I was putting these data together.

Lifeline AGM group 8DL rated 50% DOD since this is lead acid: 10 Wh/lb, 1.35 kWh/ft^3.

Lithionics "group 9DR", rated 80% DOD since this is LFP: 37 Wh/lb, 1.76 kWh/ft^3. This is a well-respected manufacturer that embeds traditional prismatic LFP cells inside a casing, complete with management hardware, interconnects, and likely some degree of additional shock and thermal protection. The volumetric density advantage is 30% over the AGM above. This was the "least efficient" lithium pack in my dataset.

Victron/MG Energy 200AH/12V LFP, rated 80% DOD: 33 Wh/lb, 2.39 kWh/ft^3. This is another engineered pack, in a different form factor that is probably more space-efficient given typical prismatic cells.

Victron/MG Energy 200AH/24V NMC Li-ion, rated 80% DOD: 63 Wh/lb, 4.57 kWh/ft^3. This chemistry is too thermally aggressive for a boat, in many peoples' opinion. These packs also require some room for active cooling (fans) on the ends, so their real volumetric density would probably be*lower, depending on your space. I put them in here just for comparison.

Raw cell options:

CALB CA 180AH LFP, 80%: 37 Wh/lb, 3.79 kWh/ft^3. Doesn't include space for any extra protection, interconnects, etc. Still, this is good baseline for LFP if you roll your own pack.

CALB CAM 72AH LFP, 80%, further derated for required spacing: 39 Wh/lb, 4.82 kWh/ft^3. This is the newer generation of aluminum-shell (instead of plastic-shell) LFP cells. These cells require spacers to electrically isolate each cell from the adjacent ones, so the real volume here is approximated by me and includes the penalty for that extra space (which improves cooling and makes thermal monitoring easier, as a small side benefit). We should see engineered packs coming to market that use these cells soon, if they are not out there already, because this is still LFP*with its safety advantages but with much better volumetric density.

Tesla S modules, Li-ion NCA chemistry, 80% derated: 82 Wh/lb, 8.08 kWh/ft^3. Also too aggressive for boats, IMHO, but I put these in here because they are the most dense (in both metrics) of the cells, salvage modules, and packs that I captured. They set an approximate upper bound on what could be done today, thermal runaway notwithstanding.

I didn't look at MasterVolt since they seemed expensive and not well oriented towards the hobbyist/DIY market, but I think you should see at least a 30% higher volume efficiency versus AGM and maybe more -- lots more, if you go with newer cell designs. You should see considerably more than 2x weight improvement as well with most lithium packs.

Some of the other points on cost, risk, replacement, management, and simplicity are all fair points to consider. But the part about equivalent volume definitely doesn't ring true in my experience.