Low priced LiFePO4 Batteries vs High priced

[s/v Jedi]

Originally Posted by wholybee

Max current of a battery is only one factor of "performance." You can get about 3x the usable capacity in the same space/weight as an AGM, an expected life of upto 15-20 years, and almost no peukert effect. I would never say an AGM outperforms a Lithium, even a cheap Lithium.

I would never install a cheap drop-in in my boat, but for many boats I think a cheap drop-in is fine. Most boats are only used for day sailing or on weekends. A cheaper drop-in would (IMHO) be fine for that.

Technical writers who have no technical understanding of Lithium batteries are giving Lithium a bad name, along with mainstream media reporting on how dangerous Lithium is. I don't think cheap drop-ins will contribute to this. Truth is, I know people that installed cheap drop-ins against my advice. They are all happy and have had no problems, are now telling me "told you so." I still don't recommend them, but they certainly aren't making a bad name for Lithium.

Of course you are correct, but consider the context in which you write this: for house battery applications. If one instead considers start batteries, which need to give maximum power for very short periods and are always fully charged and in float charge… this is all terrible for a LFP battery while an AGM battery shines for that application.

LFP is a huge game changer for boats, but it can’t replace everything. LTO is a good candidate for replacing AGM start batteries as the best option for that application, but not many picked that up yet, incl. myself. I hooe to find the time to dive into those

[goboatingnow]

Originally Posted by s/v Jedi

Of course you are correct, but consider the context in which you write this: for house battery applications. If one instead considers start batteries, which need to give maximum power for very short periods and are always fully charged and in float charge… this is all terrible for a LFP battery while an AGM battery shines for that application.



LFP is a huge game changer for boats, but it can’t replace everything. LTO is a good candidate for replacing AGM start batteries as the best option for that application, but not many picked that up yet, incl. myself. I hooe to find the time to dive into those

An LFP battery properly specs will outperform an AGM in starter applications as it delivers more consistent voltage over its SOC range

There’s no need to charge it to 100% or float it

Hence an LFP starter properly charged to LFP parameters will always outperform AGM.

[wholybee]

Originally Posted by goboatingnow

An LFP battery properly specs will outperform an AGM in starter applications as it delivers more consistent voltage over its SOC range

There’s no need to charge it to 100% or float it

Hence an LFP starter properly charged to LFP parameters will always outperform AGM.

While it is true that LFP deliver a more consistent voltage, starters are wound to operate at the lower voltage a Lead-Acid will sag down to under load. So, you will be operating a starter that is designed to run at 9-10 volts, at 13. Does this matter to the starter? idk. But, I don't think there is as much as an advantage as you state because starters are designed to work under the conditions LA give.

I expect that I will eventually go to a single LFP bank that is both house and starter. Not because I think LFP is better, but because my battery space is small, and by doing so I can add 50-100% more house bank capacity.

[goboatingnow]

Sure

The point is AGMs are a poor fit for a boat

In theory given the higher availability and reliability of LFP I’m actually considering removing the starter battery completely as I can easily start the engine from the domestic LFP bank. My BMS can be programmed to adjust the current limit during starting

I’d then just carry a backup standard small. lithium jump ( Li/NMC) start for emergency ( I carry one any way. )

The reality is my SLA starter is not a suitable emergency source for my LFP anyway as it’s small

My new LFP system is based on essentially 3x12v nominal LFP batteries each around 100Ah

The system is designed to degrade battery by battery so all three LFP batteries would have to simultaneously fail to knock out the whole bank.

Hence the LA starter serves no useful advantage and I’m of the opinion it’s wasted

[newhaul]

Originally Posted by goboatingnow

Sure

The point is AGMs are a poor fit for a boat

In theory given the higher availability and reliability of LFP I’m actually considering removing the starter battery completely as I can easily start the engine from the domestic LFP bank. My BMS can be programmed to adjust the current limit during starting

I’d then just carry a backup standard small. lithium jump ( Li/NMC) start for emergency ( I carry one any way. )

The reality is my SLA starter is not a suitable emergency source for my LFP anyway as it’s small

My new LFP system is based on essentially 3x12v nominal LFP batteries each around 100Ah

The system is designed to degrade battery by battery so all three LFP batteries would have to simultaneously fail to knock out the whole bank.

Hence the LA starter serves no useful advantage and I’m of the opinion it’s wasted

All opinions aside What works for you doesn't necessarily work for others .
On my vessel I'm looking at a u1 gell cell battery for starting my iron wind and alternator protection considering the similar charging voltage profiles .
Works for me on my vessel

[goboatingnow]

Originally Posted by newhaul

All opinions aside What works for you doesn't necessarily work for others .

On my vessel I'm looking at a u1 gell cell battery for starting my iron wind and alternator protection considering the similar charging voltage profiles .

Works for me on my vessel

Of course your entitled to your opinions.

My point was that LFP is inherently very reliable. My experience is they are more robust and tolerant of bad treatment then cheap SLA

Hence the “ conventional “ thinking of retaining the LA in the face of having 2or 3 LFP batteries doesn’t makes lot of sense.

Alternator protection is easy to solve if you apply some simple electronics. I suspect the industry will oblige over the next years.

Hence designing a whole system around projecting an alternator seems nonsensical to me. Especially as it’s a rare occurrence anyway , and in fact the standard alternator may well survive anyways.

So it’s not what works for me I’m a EE with years of domain expertise. Whatever I do will “ work “

The issue is looking at boats LFP solutions from a completely new systemic approach discarding old LA approaches and leveraging new technology and LFP advantages.

What I’m seeing is a poorly thought out” transition “ Thinking strategy which to me makes little technical sense.

So what works for you is fine but it may not be the optimum use of the technology , involve additional unnecessary complication and also expense. Sure it works…. But. ???

[s/v Jedi]

I have no doubt that LFP can start the engine, but other considerations aren’t brought forward or they are ignored:

- the guy with 100A max load enforced by BMS may not be able to start the engine due to BMS limitations

- the start LFP being at 100% SOC all the time will greatly reduce lifespan

But yes, eliminating the start battery completely can fix that… or it leaves you with an empty house battery, unable to start the engine! I mean that is the reason to have a start bank.

[newhaul]

Originally Posted by goboatingnow

Of course your entitled to your opinions.

My point was that LFP is inherently very reliable. My experience is they are more robust and tolerant of bad treatment then cheap SLA

Hence the “ conventional “ thinking of retaining the LA in the face of having 2or 3 LFP batteries doesn’t makes lot of sense.

Alternator protection is easy to solve if you apply some simple electronics. I suspect the industry will oblige over the next years.

Hence designing a whole system around projecting an alternator seems nonsensical to me. Especially as it’s a rare occurrence anyway , and in fact the standard alternator may well survive anyways.

So it’s not what works for me I’m a EE with years of domain expertise. Whatever I do will “ work “

The issue is looking at boats LFP solutions from a completely new systemic approach discarding old LA approaches and leveraging new technology and LFP advantages.

What I’m seeing is a poorly thought out” transition “ Thinking strategy which to me makes little technical sense.

So what works for you is fine but it may not be the optimum use of the technology , involve additional unnecessary complication and also expense. Sure it works…. But. ???

Outside of the lfp and charging gear the 1994 2512 inverter charger is the most modern I want my boat .
Gel cell 50 dollar battery and I'm off cruising no I'm not a fan of " fancy electronics" minimum for operation is what I'm all about .
As I said many times across the forum my boat my choice your boat your wallet.

[newhaul]

Originally Posted by s/v Jedi

I have no doubt that LFP can start the engine, but other considerations aren’t brought forward or they are ignored:

- the guy with 100A max load enforced by BMS may not be able to start the engine due to BMS limitations

- the start LFP being at 100% SOC all the time will greatly reduce lifespan

But yes, eliminating the start battery completely can fix that… or it leaves you with an empty house battery, unable to start the engine! I mean that is the reason to have a start bank.

but but the pocket jump pack

[goboatingnow]

Originally Posted by s/v Jedi

I have no doubt that LFP can start the engine, but other considerations aren’t brought forward or they are ignored:

- the guy with 100A max load enforced by BMS may not be able to start the engine due to BMS limitations

- the start LFP being at 100% SOC all the time will greatly reduce lifespan

But yes, eliminating the start battery completely can fix that… or it leaves you with an empty house battery, unable to start the engine! I mean that is the reason to have a start bank.

Yes but I intend to have 3x100Ah lfp batteries. Any one can start the engine

I can have my LFp at 90% if I want degradation of LFp to 100 % has little effect on life cycles.

I can program the bms to allow engine start. My load tests so far so no reason to be concerned per se.

One less lead acid is good for me.

[mitiempo]

Originally Posted by wholybee

Max current of a battery is only one factor of "performance." You can get about 3x the usable capacity in the same space/weight as an AGM, an expected life of upto 15-20 years, and almost no peukert effect. I would never say an AGM outperforms a Lithium, even a cheap Lithium.

I would never install a cheap drop-in in my boat, but for many boats I think a cheap drop-in is fine. Most boats are only used for day sailing or on weekends. A cheaper drop-in would (IMHO) be fine for that.

Technical writers who have no technical understanding of Lithium batteries are giving Lithium a bad name, along with mainstream media reporting on how dangerous Lithium is. I don't think cheap drop-ins will contribute to this. Truth is, I know people that installed cheap drop-ins against my advice. They are all happy and have had no problems, are now telling me "told you so." I still don't recommend them, but they certainly aren't making a bad name for Lithium.

Longevity is also a factor of performance. A well treated AGM or FLA battery should last 6-8 years. While the cells in a lithium battery are long lasting a $10 internal BMS isn't quite as robust. I have already seen a few failures. With a sealed battery the average consumer is SOL when the BMS fails.

The majority of low end drop-in batteries are new to the market. We'll see what their long term durability is.

[goboatingnow]

Originally Posted by mitiempo

Longevity is also a factor of performance. A well treated AGM or FLA battery should last 6-8 years. While the cells in a lithium battery are long lasting a $10 internal BMS isn't quite as robust. I have already seen a few failures. With a sealed battery the average consumer is SOL when the BMS fails.



The majority of low end drop-in batteries are new to the market. We'll see what their long term durability is.

Agreed the quality of the associated systems is undoubtably questionable , it’s why I’m doing my own bms.

Agreed the durability is out on drop in , I know people like Victron and Mastervolt are working on high end solutions (at a cost of course )

I’m at METSTRADE in two weeks and I appointments with tech people in several major LFP players. I’ll be interested in collating their perspectives on the light of ABYC and ISO standards.

[UFO]

I have 1120Ah of EVE @ 12V (16 x 280Ah x 3.2V) at a cost of approx USD$1800 delivered to Perth Australia. More was spent on upgrading to Victron Smart hardware, but the over all cost worked out around $1500 more than swapping out for 880Ah of good quality AGM's.


I do have a very good BMS, which as Jedi has previously stated, balances them when coming up to 100% SOC, although as the BMS is set to 13.6V as fully charged, it leaves a bit of headroom between that and the actual fully charged state - In reality they never get above around 90%(ish)


Anyway, I have been a live aboard now with them for over 18 Months and they have not missed a beat, even when dropping down to around 20% SOC due to lack of Sunshine (and they say Queensland is the Sunshine state - Should be called the rainy state).


I am, so far, very happy with them and even if they only live as long as AGMS I would consider myself still ahead, as the next lot will not require all new hardware and not having to charge them to 100% SOC on any sort of basis is great whilst living aboard.

[T1 Terry]

Originally Posted by UFO

I have 1120Ah of EVE @ 12V (16 x 280Ah x 3.2V) at a cost of approx USD$1800 delivered to Perth Australia. More was spent on upgrading to Victron Smart hardware, but the over all cost worked out around $1500 more than swapping out for 880Ah of good quality AGM's.


I do have a very good BMS, which as Jedi has previously stated, balances them when coming up to 100% SOC, although as the BMS is set to 13.6V as fully charged, it leaves a bit of headroom between that and the actual fully charged state - In reality they never get above around 90%(ish)


Anyway, I have been a live aboard now with them for over 18 Months and they have not missed a beat, even when dropping down to around 20% SOC due to lack of Sunshine (and they say Queensland is the Sunshine state - Should be called the rainy state).


I am, so far, very happy with them and even if they only live as long as AGMS I would consider myself still ahead, as the next lot will not require all new hardware and not having to charge them to 100% SOC on any sort of basis is great whilst living aboard.

With 11 yrsexperience in a lot more than a single system, let me assure you that setting the end of charge at 13.6v will result in a progressive loss of capacity and the BMV wandering further and further out of range compared to reality. If you doubt this, charge the battery to the 13.6v 100% SOC, then adjust the BMS to 3.6v per cell and measure just how many Ah go into the battery and see if that matches 10% of the over all capacity .....

T1 Terry

[Pete7]

Originally Posted by blazing928

Don’t forget insurance.

This year Pantanius added very specific insurance requirements for installation of lithium batteries, certificates for instal and the accreditation certificates from the installer, so no self installs will get insurance, unless its checked by a accredited installer perhaps.

I personally wouldn’t buy cheap batteries for a boat, as you cant get off and buy a new set in the ocean….

Interesting. Having just renewed my insurance with Pantaenius, there is absolutely no mention in any of the policy documents of lithium, LiFeP04 or even batteries.

What does your policy say, and were about in the policy?

Pete