Lithium batteries - are they worth it?

In time perhaps, just not yet, I don't want to be the first mouse to the trap. That said, if you have a generator and run it hard once a day to charge the bank, do the washing, make water etc and have induction cooking then might make sense. For everyone else, well nice science project if you have the cash to burn.
 
I use many different forms of Lithium batterys each day literally ... LiPo, LiFe.

I have special chargers and all the gear .... would I pay the money for them on a boat ... no. There would have to be a really good reason to spend out so much money on batterys with the required charge control systems etc.

I'll stick with my 2nd hand Lead Acids .... which give me years of service. At 20 - 30 Euros a battery (80 - 100A/hr) ... why change ??
 
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If money is no object AND you run deep cycle nearly every day AND the ability to recharge more efficiently from multiple sources is important... maybe. If you also need light weight (performance multihull) and have limited space, more likely. But very few boats meet all of the requirements.

They make sense for cell phones, but not so much for ballasted boats.
 
We fitted 400Ah of LiFePo4 lithium batteries last winter together with associated Battery Management System, control relays, contactors, charging controllers etc. We are very happy with them, charging is much quicker, more capacity available, much lighter, longer "expected" lifespan. I did all the design, installation, setup and commissioning so I know exactly what is going on. By going the DIY route the cost of Lithium is comparable to proper deep cycle lead acid batteries (eg Rolls), it is definitely more expensive than standard LA batteries normally fitted to boats.

Lithium is not yet "mainstream fit and forget" for boats, you need to have a good understanding of the whole system to get the best out of it. It is not worth it for a boat that spends most of it's life in a marina with regular shore power and only a few longer spells away from dock. We are full time liveaboards and have not plugged in to shore power for nearly 12 months, we have loads of solar, large alternators and large inverter to power watermaker etc. We are completely power self sufficient and the Lithium batteries are a significant part of that solution.

Conclusion - Lithium is great for long term liveaboards who are electrically knowledgeable, otherwise they can be a very expensive experiment.
 
Planning for DIY LiFePO4

Recent thread. As said above, and at the start of the linked thread I think they are currently best suited to long-term cruisers or liveaboards with at least 10 years of boating life in them and an electrically nerdish tendency.
 
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The only reason to switch to lithium is energy density. So if you are racing then you can reduce mass by a tiny fraction or if you are space limited you can increase your capacity. If you are neither then there is no reason to switch.
 
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crisjones said:
We fitted 400Ah of LiFePo4 lithium batteries last winter together with associated Battery Management System, control relays, contactors, charging controllers etc. We are very happy with them, charging is much quicker, more capacity available, much lighter, longer "expected" lifespan. I did all the design, installation, setup and commissioning so I know exactly what is going on.
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Many 12v lithium batteries are now being offered with integral battery management systems, so they are virtually a straight swap for conventional lead-acid batteries, and no specialist knowledge or extra equipment is needed. PBO did a test report fairly recently which you can read online - Lithium batteries for boats reviewed – 12 of the best lithium boat batteries tested - Practical Boat Owner

At the end of the day though, they're still quite pricey.
 
Buck Turgidson said:
The only reason to switch to lithium is energy density. So if you are racing then you can reduce mass by a tiny fraction or if you are space limited you can increase your capacity. If you are neither then there is no reason to switch.
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Energy density is a big gain, but not the only one and not necessarily the most important one for liveaboard cruisers. Here's a list from the useful Nordkyn design site.
  • Lithium batteries don’t suffer from low charge or deep discharge (down to a limit) and easily offer more than twice the usable storage for the same nominal capacity.
  • They charge much faster; they can literally absorb all of the available current until almost full.
  • They are near 100% current-efficient, 1Ah in means about 0.997Ah out: they waste very little energy. This also means no lengthy, wasteful absorption during which good electricity is turned into heat and gases.
  • They hardly suffer from cycling in marine applications.
  • They hardly self-discharge over time (provided they were never abused).
  • They provide a noticeably higher and much more constant system voltage during discharge, over 13 volts.
  • They are much lighter, much less toxic than lead-acid cells, fully sealed and don’t generate explosive gases, even internally.
  • They last many times longer than a lead-acid bank while providing much higher performance throughout, provided they are treated correctly.
 
pvb said:
Many 12v lithium batteries are now being offered with integral battery management systems, so they are virtually a straight swap for conventional lead-acid batteries, and no specialist knowledge or extra equipment is needed. PBO did a test report fairly recently which you can read online - Lithium batteries for boats reviewed – 12 of the best lithium boat batteries tested - Practical Boat Owner

At the end of the day though, they're still quite pricey.
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So called 'drop-in replacement' LFP batteries are being offered by many firms. I think there are dangers in this and I think PBO should know better and should describe the need for a lithium system rather than a lithium replacement. A battery management system (BMS) is best thought of as like a fuse on an electrical circuit. A BMS is just one part of a complete lithium system. It offers catastrophic level protection only, to protect the battery from being destroyed. Fair enough if there are no big consequences - such as using it in an RV or to power up a trolling motor. In fact these might be perfectly adequate batteries for that. But there is a big difference for sailors. Let's say you are motoring along and the alternator is charging the battery. It will do so very fast as there is much lower internal resistance in these batteries and no long absorption phase as in lead acid. So it would be easy to overcharge. That's OK, the manufacturers might say, as there is a high voltage disconnect in the BMS to protect the battery and, of course, you would definitely want your eye-wateringly expensive new battery to be protected. But what happens to the rest of the electrical system when the battery is suddenly removed? The high voltage spike may take out the alternator, solar chargers and all those expensive marine electronics. No mention of this is made at any point in most advertising. (In fairness to this article it does mention charging by B2B which would protect the alternator from a high voltage spike but one forum member using the B2B found it inadequate and prone to overheating.) Responsible marine installations are the fully integrated ones (like the mega-expensive Victron system,) or careful DIY installations starting from bare cells where the load and charge circuits can be separated so that an overcharged battery can still allow load, or an overly discharged battery can still be charged . There can be workarounds - using them in a hybrid system with a lead acid, the use of a battery to battery charger, or other kind of alternator protection but these are complex solutions and not fully satisfactory, and definitely not in the sprit of the 'trouble-free drop-in replacement' trope.

Because integrated BMSs are designed to offer last line of defence the high and low voltage cut-offs are beyond the limits for ordinary daily use if people want to get a long life. So there has to be a good monitoring system (and preferably alarms) which allow the battery to be managed before the extreme parameters of the BMS are reached. Chargers need to be specific to LFP, they must not allow floating above 13.6 volts. Many chargers with Lithium settings are now seen as way too high. My Sterling A2B had a LFP setting of 14.6 boost and 14.4 volts float! Sterling no longer recommend this! Many people charge to 13.9 or 14.0 and then shut down the charger. So mains and solar chargers that are fully user-programmable are needed.

The author of the PBO article is remarkably casual about charging ... "The only stipulation is that the charger must deliver a maximum voltage of 14.4V, typically a gel lead-acid setting." (My emphasis.) This entirely neglects the commonly accepted prohibition against floating LFP batteries. The first of the authors below (who does know what he is talking about) mentions someone advised to use an even lower gel setting of 14.2 volts and ruined their batteries since the option on that charger included a very lengthy absorption phase. He writes ...

"The problem with the GEL setting installation, revolved around absorption DURATION, not the voltage. 14.2V is a perfectly safe LFP charge voltage. The problem was the duration the cells spent at 14.2V. The 14.2V the absorption duration was 4 hours long, with no way to change the length of the absorption cycle-timer. On top of a 4 hour absorption, the chargers charge rate, which was very low in comparison to the banks Ah capacity, his cells were actually hitting 100% SoC before the voltage even got to 14.2V. Continuing to charge beyond the 100% SoC point can lead to lithium plating."

And not a single mention in the article of temperature limitations. Charge the battery below freezing point? Permanent damage. Use them regularly at 30C+? Drastically shortened life.

I hope I've made my main point - buyer beware ... anyone interested should, in my view start from these articles and research the subject as much as they can.

LiFePO4 Batteries On Boats - Marine How To

Lithium battery systems | Nordkyn Design

The other great source of information and advice is the 'Lithium Batteries on a Boat' Facebook group with over 4,000 members and there are several long threads on the Cruisers Forum if you have the patience.
 
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crisjones said:
We fitted 400Ah of LiFePo4 lithium batteries last winter together with associated Battery Management System, control relays, contactors, charging controllers etc. We are very happy with them, charging is much quicker, more capacity available, much lighter, longer "expected" lifespan. I did all the design, installation, setup and commissioning so I know exactly what is going on. By going the DIY route the cost of Lithium is comparable to proper deep cycle lead acid batteries (eg Rolls), it is definitely more expensive than standard LA batteries normally fitted to boats.

Lithium is not yet "mainstream fit and forget" for boats, you need to have a good understanding of the whole system to get the best out of it. It is not worth it for a boat that spends most of it's life in a marina with regular shore power and only a few longer spells away from dock. We are full time liveaboards and have not plugged in to shore power for nearly 12 months, we have loads of solar, large alternators and large inverter to power watermaker etc. We are completely power self sufficient and the Lithium batteries are a significant part of that solution.

Conclusion - Lithium is great for long term liveaboards who are electrically knowledgeable, otherwise they can be a very expensive experiment.
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Sounds good. Do you have a circuit diagram you'd be willing to share as I think that might illustrate the point about the need for a lithium system?
 
lw395 said:
There was a thread a while back you might search for.
Richard-something who lives on a canal barge nr Manchester has them.
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:)

I have my old LA bank, which is still attached to the inverter so, if I want to charge my razor, or the Dyson, or the toothbrush, or use the printer, or the lawn mower, strimmer, brush cutter, and a few other AC things, I use the inverter, and deplete the LA bank. For a variety of reasons, they only charge from the alternator, so I have to run the engine and, because of their nature, I have to get them back up to 100% soon after use. It takes a long time, and is irritating.

By the end of next week, I should have a way of easily switching the 240V charger and solar to charge the LA bank, rather than the Li bank but, even then, it has to be done very soon after use, and will take a long time and be irritating :)

There will come a point where I get the inverter connected to the lithiums, so the LAs will be merely a back up, and be fully charged more or less 24/7.

So the freedom to use and charge, (always at the max available, with no reducing to tail current), when convenient is one huge advantage and cost saving. When I say convenient, a full charge, (95% or so), lasts about 5 days of full time living aboard, (8 days with one 250w solar panel and some sunshine). I was charging the LAs at least every 2nd day, and the last 10% took ages every time.

Mine were second hand, having been new in 2006. If they last as long as they might do, (many years), they will have been cheap to buy and set up, as well as being cheaper and much more convenient to run.

Only time will tell but, so far I'm loving them.

As a matter of interest, about a month before I bought them, I posted that, as a destroyer of batteries, there was no way I would ever risk the money needed for a Lithium Bank :) or :(
 
I’ve had a home made pack of Winston cells for 7 years now. I’d recommend them. The things I like the best are the constan voltage, right from full to flat. The absence of big voltage drop on heavy current draw. Fast charging, so less time charging. Light weight. Longer life. Basically they are better in almost every way and because of the long life are no more expensive.

The downside is you can destroy them more easily than lead with over-charging or over-discharging, so you have to be careful.
 
Ignoring the OP's request for first hand experience. I figure I'll bite the bullet and fit a lithium system when I trash my current set. Live / work aboard kills lead acid quickly, even when you are pretty careful with your usage.
 
seadog30 said:
There have been many reports of fires in computer and phone Lithium bateries. What about the dangers of the much larger batteries in a boat ?

Phil
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There are several lithium chemistries. The batteries used in marine applications - LiFePO4 (LFP for short) - are much more stable than the battery in your phone. This is worth a watch ...

 
At $600US for a set of four Trojan T105s its hard to justify the cost of lithium batteries. They may have lots of attributes but my boat is set up for lead. Conversion to LifePO4 is not cheap. How to turn off the alternator so you dont blow diodes is just one additional problem that doesnt come cheap. It will be worth considering when I need new batteries next time but for now lead is cheap and it does the job
 
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