Lithium batteries worth buying?

[Poey50]

The outstanding advantage of lead acid is that it will take a bit of abuse and neglect. LFP has a lot going for it and I love my DIY installation but you have to keep it strictly within charging, discharging and temperature parameters to get a return on your big investment.

 

[Refueler]

The outstanding advantage of lead acid is that it will take a bit of abuse and neglect. LFP has a lot going for it and I love my DIY installation but you have to keep it strictly within charging, discharging and temperature parameters to get a return on your big investment.

Thats one of my beefs with online sites ......... about level of discharge as one ....

I was reading a site that wrote clearly - you can discharge LiFePo4 to ZERO and not have any residual effects - that battery will charge back up fine ...

Well Howdy Doo !!

Let me actually correct that :

ALL lithiums have a tabled ZERO figure ... but that is not 100% discharged. The site neglects to mention that a Lithium cell at ZERO still shows voltage. Depending on the 'chemistry' this can be anywhere from 2.0V to 3.1V ... and others of course.

Here's a site that actually gets nearer to the TRUTH than many :

Technical Information LiFePO4 Care Guide: Looking after your lithium batteries

But Howdy-Doo ... look at this :

I have cut and pasted to avoid naming the idiots who wrote this - yes they are in business to advise and sell us LiFePo4 batterys ...

And last but not least, LiFePO4 batteries can not only reach 3,000-5,000 cycles or more… They can reach 100% depth of discharge (DOD). Why does that matter? Because that means, with LiFePO4 (unlike other batteries) you don’t have to worry about over discharging your battery. Also, you can use it for a longer period of time as a result.

Whats that phrase ? Caveat emptor

No Lithium battery - no matter what chemistry should be installed without BMS ...... unless you have money and boats to burn !!

 

[Zing]

No Lithium battery - no matter what chemistry should be installed without BMS ...... unless you have money and boats to burn !!

I don’t think you should be so insistent on that. I had a successful installation for 9 years with no BMS. The BMS broke at the start and I reckoned I didn’t really need it, so didn’t replace it. I was correct and I didn’t need it. Charge sources had their own cut offs and I never discharged below zero and temp was never going to be an issue for me. Easy peasy. I have a BMS in my new installation. It‘s a belt to my braces, but I don’t need it.

 

[Buck Turgidson]

Here youtube.com/watch?v=2bNBYJZde6M is a good example of first the "snake oil salesman" pushing only the benefits without going through the process of needs assessment and second demonstrating that if you do it properly it is neither cheap nor a trivial activity. It is clear that in their situation lithium is one of the choices that could be appropriate, but there are many ways of improving an existing system that is normally fitted to that sort of boat for far less cost and work.

Without clicking the link I guess that's Ryan and Sophie. The reason I'm probably correct is that he is a Lithium battery salesman by trade and I stopped watching their channel after watching the relevant episode/sales pitch.

 

[Kelpie]

This thread makes for rather glum reading.
I'll just add that lithium works for us. One of the best upgrades I have ever made to the boat. My system is very basic and about as low cost as you can get. No alternator charging, no temperature protection for cold weather charging, no automatic switchover to FLA etc etc.

Our system is a single 271Ah bank with everything running through a 120A BMS. Charging is solely from solar, with about 800w currently hooked up. This powers all of our cooking, our 50l fridge, our 40l freezer, and some of our cabin lights and charging sockets. It does not currently power nav instruments or autopilot, although I am working on a manual changeover to allow that.

Total cost was about £1000, of which £407 was the cells and BMS, and a hefty £375 was the inverter. I know there has been inflation since last year and the cells are probably another £100-£150 just now. My solar panels were secondhand although they are pretty cheap these days anyway, as I used standard domestic sized (1600x992) rigids.
The vast majority of the costs would have been the same regardless of what type of battery I was using. We left the old systems, both FLA battery and gas cooker, in place as a backup.

Longevity and low weight are often cited as advantages of lithium, but for me it's all about the charge acceptance. Watching the amps go in without slowing down is very satisfying. Knowing you can use the entire capacity is great too (with the BMS to prevent you totally discharging the battery, of course). Whereas with lead acid you are always damaging the battery as you use it, even with the best care in the world.

I think one of the headaches for weekend sailors wanting to switch to lithium is that they will end up sitting full too much of the time, if you leave them charging. It would get tedious having to partially discharge them and then disconnect when leaving the boat for a while, and then of course when you arrive to start a cruise you'd need to stay in your berth for a few hours charging them up to full again. Not ideal at all. But for off-grid and full time use, they are fantastic.

 

[geem]

This thread makes for rather glum reading.
I'll just add that lithium works for us. One of the best upgrades I have ever made to the boat. My system is very basic and about as low cost as you can get. No alternator charging, no temperature protection for cold weather charging, no automatic switchover to FLA etc etc.

Our system is a single 271Ah bank with everything running through a 120A BMS. Charging is solely from solar, with about 800w currently hooked up. This powers all of our cooking, our 50l fridge, our 40l freezer, and some of our cabin lights and charging sockets. It does not currently power nav instruments or autopilot, although I am working on a manual changeover to allow that.

Total cost was about £1000, of which £407 was the cells and BMS, and a hefty £375 was the inverter. I know there has been inflation since last year and the cells are probably another £100-£150 just now. My solar panels were secondhand although they are pretty cheap these days anyway, as I used standard domestic sized (1600x992) rigids.
The vast majority of the costs would have been the same regardless of what type of battery I was using. We left the old systems, both FLA battery and gas cooker, in place as a backup.

Longevity and low weight are often cited as advantages of lithium, but for me it's all about the charge acceptance. Watching the amps go in without slowing down is very satisfying. Knowing you can use the entire capacity is great too (with the BMS to prevent you totally discharging the battery, of course). Whereas with lead acid you are always damaging the battery as you use it, even with the best care in the world.

I think one of the headaches for weekend sailors wanting to switch to lithium is that they will end up sitting full too much of the time, if you leave them charging. It would get tedious having to partially discharge them and then disconnect when leaving the boat for a while, and then of course when you arrive to start a cruise you'd need to stay in your berth for a few hours charging them up to full again. Not ideal at all. But for off-grid and full time use, they are fantastic.

I guess it depends where you start from. Changing to lithium would not even be an upgrade for us. We have been cruising for 8 years on lead batteries. We are totally set up for lead. Converting over would change nothing for us except create a large hole in our bank balance. Our batteries don't drop below 85% charged over night even with a fridge and fridge freezer running in the Tropics. We already have all the advantages you have but without lithium. If I was starting from a blank bit of paper I can see some merit but most people aren't.

 

[Kelpie]

I guess it depends where you start from. Changing to lithium would not even be an upgrade for us. We have been cruising for 8 years on lead batteries. We are totally set up for lead. Converting over would change nothing for us except create a large hole in our bank balance. Our batteries don't drop below 85% charged over night even with a fridge and fridge freezer running in the Tropics. We already have all the advantages you have but without lithium. If I was starting from a blank bit of paper I can see some merit but most people aren't.

I agree with that but will just say that the 'large hole in the bank balance' is not a given. We have had this conversation on other threads and it depends on your circumstances.
'Drop in' lithium, even at the budget end of the scale, is going to cost more than lead acid. But DIY lithium may not. The difference in price for the actual battery is of course just one part of the puzzle. Most people will not accept my solar-only charging situation, so will spend money on alternator upgrades. But that is a choice, and not a necessity.

 

[geem]

I agree with that but will just say that the 'large hole in the bank balance' is not a given. We have had this conversation on other threads and it depends on your circumstances.
'Drop in' lithium, even at the budget end of the scale, is going to cost more than lead acid. But DIY lithium may not. The difference in price for the actual battery is of course just one part of the puzzle. Most people will not accept my solar-only charging situation, so will spend money on alternator upgrades. But that is a choice, and not a necessity.

We mainly charge from solar. One issue is being 24v we need twice as many cells as you. We have wind/water turbine that can't easily be regulated for lithium. Our insurance company Pantaneus insist on professional installation. It all get way more complicated when you dig deeper in to it. What do you do about low voltage disconnect in the middle of the night mid Atlantic? All the nav lights, autopilot, chartpotter, cabin lights, etc go off. It's not as simple as it seems

 

[Tranona]

Without clicking the link I guess that's Ryan and Sophie. The reason I'm probably correct is that he is a Lithium battery salesman by trade and I stopped watching their channel after watching the relevant episode/sales pitch.

You are right. This sort of simplistic thinking, or rather expression irritates. "This is what I did and so should you" gives lithium a bad name.

 

[geem]

I agree with that but will just say that the 'large hole in the bank balance' is not a given. We have had this conversation on other threads and it depends on your circumstances.
'Drop in' lithium, even at the budget end of the scale, is going to cost more than lead acid. But DIY lithium may not. The difference in price for the actual battery is of course just one part of the puzzle. Most people will not accept my solar-only charging situation, so will spend money on alternator upgrades. But that is a choice, and not a necessity.

Another thing to consider. I know you have plans to cross the pond. Just be aware that it's not always sunny and a lot of time the sails will shade the solar. Even running on wind self steering you may have an issue with keeping batteries charged mid Atlantic. Most people would start the engine or a generator. If you can't do this how will you keep the lithium battery charger?

 

[Zing]

I agree with that but will just say that the 'large hole in the bank balance' is not a given. We have had this conversation on other threads and it depends on your circumstances.
'Drop in' lithium, even at the budget end of the scale, is going to cost more than lead acid. But DIY lithium may not. The difference in price for the actual battery is of course just one part of the puzzle. Most people will not accept my solar-only charging situation, so will spend money on alternator upgrades. But that is a choice, and not a necessity.

I’ve done the sums for my installation. My lithium pack is far cheaper than the previous lead pack to replace considering its life cycle. It is better in every other way as widely discussed. When compared to lead:

1. Cheaper
2. Longer life, so more reliable.
3. On balance as safe or safer.
4. Much more compact.
5. Half the weight.
6. Almost no charge/discharge losses.
7. No peukert losses.
8. No significant voltage drop under load, so full electrical power at all times.
9. Far faster charging (a big deal when reliant on a genset).
10. Full capacity is always available and with negligible harm to life.
11. With a BMS, simpler to manage. Without, a little worse than lead.
12. Maintenance free.
13. Negligible capacity losses in storage.

The only real downsides are they are a pain to acquire affordably as you have to buy from China and wiring up the BMS is a hassle.

 

[Kelpie]

Another thing to consider. I know you have plans to cross the pond. Just be aware that it's not always sunny and a lot of time the sails will shade the solar. Even running on wind self steering you may have an issue with keeping batteries charged mid Atlantic. Most people would start the engine or a generator. If you can't do this how will you keep the lithium battery charger?

The lithium doesn't power the nav instruments and autopilot. That's all still on the 2x110Ah lead acid leisure batteries which we inherited with the boat.
If we can't charge the lithium the fallback is to switch to gas cooking. That means that even on the cloudiest of days there is enough energy to keep the fridge and freezer running, which would become the only large loads on the lithium system.

 

[geem]

I’ve done the sums for my installation. My lithium pack is far cheaper than the previous lead pack to replace considering its life cycle. It is better in every other way as widely discussed. When compared to lead:

1. Cheaper
2. Longer life, so more reliable.
3. On balance as safe or safer.
4. Much more compact.
5. Half the weight.
6. Almost no charge/discharge losses.
7. No peukert losses.
8. No significant voltage drop under load, so full electrical power at all times.
9. Far faster charging (a big deal when reliant on a genset).
10. Full capacity is always available and with negligible harm to life.
11. With a BMS, simpler to manage. Without, a little worse than lead.
12. Maintenance free.

The only real downsides are they are a pain to acquire affordably as you have to buy from China and wiring up the BMS is a hassle.

It's funny what you see as advantages.
Can you install lithium for less than £500 all in. If not it's not cheaper.
Longer life for a cheap system? Jury is out on that. Let's see what happens in 5 years time.

Safer or as safe? I don't think so. My lead batteries won't burn.

Half the weight. Give you that one

Discharge losses. Who cares. It doesn't matter

No Peukerts loss. Ditto above.

No voltage drop. Ditto above. Never had a problem.

Faster charging. Ditto above. We charge on solar. Never on a gen.

no 10. Not sure what that means.

No 11. Nothing to manage on lead. Charging automatic on Victron reg.

Maintenance. Give you that one. Top up Trojans once per month.

So bottom line. I have to top up with water and my lead batteries are heavy. Not convinced lithium offers much for the average sailior.

 

[geem]

The lithium doesn't power the nav instruments and autopilot. That's all still on the 2x110Ah lead acid leisure batteries which we inherited with the boat.
If we can't charge the lithium the fallback is to switch to gas cooking. That means that even on the cloudiest of days there is enough energy to keep the fridge and freezer running, which would become the only large loads on the lithium system.

Do you plan to use wind self steering across the pond?

 

[Tranona]

This thread makes for rather glum reading.
I'll just add that lithium works for us.

That is the whole point - your circumstances are atypical and far away from the OP who has a "weekend" 40' or so Hanse in the Solent. Lithium, whether professionally fitted or DIY is simply not appropriate. His power needs and that of the vast majority of UK boaters can be met by Lead Acid.

Providing electrical power for cruising yachts is like a game of snakes and ladders, with the ladders being the increasing needs as you add more electrically powered items, or want to be independent of the shore for longer periods and the snakes at the point where your generating and storage capacity is insufficient to meet your needs. Whole range of strategies to achieve a balance - reduce consumption, increase storage capacity, increase charging capability and so on. Inevitably there is no one best solution and the trick is arriving at the balance that keeps you on the board.

As I suggested with my reference to Ryan and Sophie it is possible to meet the requirements for his boat with lead acid as many others have shown. One of the reasons why lead acid is preferred is because existing systems can be expanded and improved at lower cost than switching to lithium. Of course if one is starting from a blank canvas there is merit in going lithium IF overall it meets perceived needs better - or like you choose to use electricity for services like cooking that others might choose to use alternatives.

As with all technical developments, Lithium (like electric propulsion for boats) will remain at the margins until it is demonstrably superior to existing systems and enters the mass market. No signs of that yet - can't recall any mainstream boat builder offering it even as an extra.

 

[Kelpie]

Do you plan to use wind self steering across the pond?

Yes, we do.
I also plan to install an Aquair which will feed the FLA bank.
I am also going to set up a way of switching the nav circuit to be either FLA or lithium. At the moment we find the autopilot takes a lot out of the FLA on long passages, and I have to be careful not to drop below 50%.

 

[Refueler]

Something that crossed my mind after seeing the 'cross pond' bits and possibilities of distant cruises ....

Its fine cruising 'developed' areas - where any problem with the Lithiums can be sorted - but start going further afield - what happens then ? The old Lead Acid is known worldwide even in poorest / least developed locations.

I know its extreme - and for majority - its weekend or maybe longer coastal stuff - so not an issue.

The matter of discharging cells partially on leaving the boat ... with LiFe / LiFePo4 - this is actually not so important as with LiPo - where leaving full charged damages the cells. Its why dedicated Lithium chargers have Storage mode to bring LiPo cells down to storage level (3.7 - 3.85V per cell). LiFe / LiFePo4 cells can be left near full charged ready for use .,.. with minimal degradation.

 

[Zing]

It's funny what you see as advantages.
Can you install lithium for less than £500 all in. If not it's not cheaper.
Longer life for a cheap system? Jury is out on that. Let's see what happens in 5 years time.

Safer or as safe? I don't think so. My lead batteries won't burn.

Half the weight. Give you that one

Discharge losses. Who cares. It doesn't matter

No Peukerts loss. Ditto above.

No voltage drop. Ditto above. Never had a problem.

Faster charging. Ditto above. We charge on solar. Never on a gen.

no 10. Not sure what that means.

No 11. Nothing to manage on lead. Charging automatic on Victron reg.

Maintenance. Give you that one. Top up Trojans once per month.

So bottom line. I have to top up with water and my lead batteries are heavy. Not convinced lithium offers much for the average sailior.

Many of these advantages are interrelated.

Cheaper by cost per year per unit of useable capacity is what I am referring to (sorry, but I was trying to be concise) and that is a function of their long life and reliability and cost. Of course I can buy a lithium battery for less than £500, but it would be better to spend a little more. Cheaper in the long run and better in use.

Losses do matter if you struggle with solar power for example. For some that 20% or so round trip loss may break their solar sufficiency.

My lithiums won’t catch fire. I don’t have the type that do. Plus I won’t stab them with a 2“ stake. Yours on the other hand can catch fire (explode to be precise) as they have you said. They can also crack and spew sulphuric acid all over the boat. It happened to me once. I maintain they are safer if you get the right ones.

Peukert, discharge losses, voltage drop and ability to discharge fully all combine to give my no.10. It also interplays with the low management issue. No. 11. They are just so much more forgiving in use. It means you can arrive at a destination with almost flat batteries and still do stuff. Power the bowthruster at full power, ditto the windlass to do a couple of anchor resets in deep water for example. You can avoid these problems with lead and that goes then to the management effort issue. You say you have not had a problem with some of these issues. With lead I certainly did. Not with lithium.

I forgot another advantage. No capacity loss with time. Leave six months on the hard without paying for power, with the safety of an isolated battery and no charger running.

I appreciate for many people, you included it seems, they don’t offer much. The real test is what would I choose next time. I’ve had both types twice over and like the advantages of lithium a lot. My fifth set will be lithium without any hesitation. For me, lead is dead.

 

[ashtead]

Many thanks to all who have contributed - I will be following how my pontoon neighbour gets on with his new batteries -they spend much more time away at anchor than we would certainly but whether they have longer cruising plans I don’t know. Luckily we manage happily with our AGM even when venturing down to West Country or France . A decent stainless arch with solar panels seems a better investment to investigate.

 

[Zing]

Something that crossed my mind after seeing the 'cross pond' bits and possibilities of distant cruises ....

Its fine cruising 'developed' areas - where any problem with the Lithiums can be sorted - but start going further afield - what happens then ? The old Lead Acid is known worldwide even in poorest / least developed locations.

I know its extreme - and for majority - its weekend or maybe longer coastal stuff - so not an issue.

The matter of discharging cells partially on leaving the boat ... with LiFe / LiFePo4 - this is actually not so important as with LiPo - where leaving full charged damages the cells. Its why dedicated Lithium chargers have Storage mode to bring LiPo cells down to storage level (3.7 - 3.85V per cell). LiFe / LiFePo4 cells can be left near full charged ready for use .,.. with minimal degradation.

I have 4 banks of parallel cells, so considerable redundancy. If I have a cell failure I will isolate a bank.

You should ideally still discharge LiFePo4. I left mine at 50% recently.