LiFe PO4 ...?

[Trident]

Bear in mind that true deep cycle LA batteries such as Trojans have excellent life. We have many sets of liveabord friends who get over 8 years out of a set as liveaboard in the Tropics where heat is doing them no good at all. If you can believe their published graphs, they out perform most AGMs at a fraction of the price

Agreed - I have friends in the Med who claim 15 years from well taken care of Trojan 6v
Perhaps worth reminding people that there are lead acid and lead acid - the very thick plates and high quality build of Trojan (Rolls I believe are similar?) give much better life than most but you have to top up the water and treat them well.
I have to say though Geem, that when I bought 8 Trojans in the UK for my last boat (so in 2013 I think - they were most definitely not a fraction of the price of some AGM - except that 1 1/4 x is actually a fraction ) - I guess they may be less in the US and there about where they are made but regardless an excellent choice for cruising and live aboard but still surpassed by LifePo4 now in every respect (especially weight as I still wince at the memory of loading 8 Trojans aboard)

 

[geem]

Agreed - I have friends in the Med who claim 15 years from well taken care of Trojan 6v
Perhaps worth reminding people that there are lead acid and lead acid - the very thick plates and high quality build of Trojan (Rolls I believe are similar?) give much better life than most but you have to top up the water and treat them well.
I have to say though Geem, that when I bought 8 Trojans in the UK for my last boat (so in 2013 I think - they were most definitely not a fraction of the price of some AGM - except that 1 1/4 x is actually a fraction ) - I guess they may be less in the US and there about where they are made but regardless an excellent choice for cruising and live aboard but still surpassed by LifePo4 now in every respect (especially weight as I still wince at the memory of loading 8 Trojans aboard)

Out here in the Caribbean, they are the base offering in many chandlers. You see Lifeline AGMs as well. Thr difference in price of Trojans in significantly less. There isn't the choice of batteries out here as most are imported from the USA. I guess heavy lead cost a bit to ship. We paid circa £125 each for our Trojan T105REs in Puerto Rico, 4 years ago.

 

[Tranona]

Right so forget lead carbon & go AGM or lithium if upgrading from lead acid seems to be the concensus. Thank you & I hope this is useful to the OP as well...

(FWIW my usual tactic is to just buy whatever lead acids Tayna have on special offer at the time...)

For many coastal cruisers with modest DC requirements ordinary LA are fine. They are easy to use, reasonably tolerant of misuse and typically might give a life of 5-7 years - probably longer than most people actually own a boat! The key thing is to keep the house and start banks separate but with linked charging from the alternator, plus a bit of solar if the batteries are left for longish periods without charge. AGMs come into play as demands rise and people have longer time horizons as with similar usage patterns a life of 10 years is common. Heavier users like liveaboards can also do well with AGMs (or better deep cycle like Trojans) by having larger banks and better charging like more solar or a generator to avoid deep discharging. Lithium comes in because you can reduce the physical size of the bank or increase your usage of electrical items like cooking with electricity. The downside is cost and complexity, although this is changing and not a barrier to those who have longer time horizons built into their decision making.

 

[Kelpie]

More research required then but I wasn't suggesting they'd perform as well as lithium.

Lithium aside looking up some specs for 110ah batteries:

Lead Acid £100 - 300 cycles (50% discharge)
AGM £160 - 600 cycles (50% discharge)
Lead Carbon £190 - 1500 cycles (50% discharge)

No doubt all the above are exaggerated or might only be achieved in perfect lab conditions but surely there's some element of truth? They're also claimed to suffer less from sitting with a partial charge and to charge more quickly....

And the equivalent in DIY lithium is about £100 (based on £420 for 280Ah, giving 224Ah useable, compared to the 55Ah usable of a 110Ah lead acid).

But with 2000+ cycles (some claim 6000+; the pioneer of LFP on boats, Rod Collins, is up to 14yrs now with no loss of capacity).

I agree that it's probably overkill for people who use their boats at weekends and a couple of holidays a year, especially if that involves lots of motoring. But for those who need the best value possible, lithium is already way out in front on cost alone, let alone the benefits of faster charging etc.

 

[geem]

And the equivalent in DIY lithium is about £100 (based on £420 for 280Ah, giving 224Ah useable, compared to the 55Ah usable of a 110Ah lead acid).

But with 2000+ cycles (some claim 6000+; the pioneer of LFP on boats, Rod Collins, is up to 14yrs now with no loss of capacity).

I agree that it's probably overkill for people who use their boats at weekends and a couple of holidays a year, especially if that involves lots of motoring. But for those who need the best value possible, lithium is already way out in front on cost alone, let alone the benefits of faster charging etc.

I don't disagree, but the initial cost of convertion to lithium can be high. If you don't have much solar, don't have an alternator that can charge lithium directly (and can deal with the BMS shuttung down and not blowing your alternator diodes), want to charge other batteries as well, such as bow thruster, generator, the cost can add up as much ad the lithium battery

 

[Tranona]

And the equivalent in DIY lithium is about £100 (based on £420 for 280Ah, giving 224Ah useable, compared to the 55Ah usable of a 110Ah lead acid).

But with 2000+ cycles (some claim 6000+; the pioneer of LFP on boats, Rod Collins, is up to 14yrs now with no loss of capacity).

I agree that it's probably overkill for people who use their boats at weekends and a couple of holidays a year, especially if that involves lots of motoring. But for those who need the best value possible, lithium is already way out in front on cost alone, let alone the benefits of faster charging etc.

But only if you have the knowledge and prepared to DIY - and have the solar (both hardware and environmental conditions) to fully utilise its properties.

For the typical UK based coastal cruiser it is simply not relevant as you can buy batteries for delivery the same day, which will drop straight in and give more than adequate performance. The ultimate cycles is irrelevant. 60 days on board a year discharging to 50% SOC is "heavy" usage - 30 years with lithium, compared with typically 10-15 years with basic AGMs. How many people have that sort of time horizon?

Very different with your kind of setup and usage regime.

 

[geem]

But only if you have the knowledge and prepared to DIY - and have the solar (both hardware and environmental conditions) to fully utilise its properties.

For the typical UK based coastal cruiser it is simply not relevant as you can buy batteries for delivery the same day, which will drop straight in and give more than adequate performance. The ultimate cycles is irrelevant. 60 days on board a year discharging to 50% SOC is "heavy" usage - 30 years with lithium, compared with typically 10-15 years with basic AGMs. How many people have that sort of time horizon?

Very different with your kind of setup and usage regime.

The problem is we just don't know. Calender aging is likely to kill them before they meet their design cycles. Nobody has had them long enough to know the effects of calender aging. We do know that if you have them in a constant 40degC environment they don't last more than 5 years.

 

[Tranona]

Yes, a bit like engines in yachts. Few will ever get near the design life of the engine. They die of lack of use, poor maintenance and neglect. Same with batteries of any type. The more you use them in an appropriate way the more likely you are to be able to exploit their theoretical lifespan. Few people keep their boats long enough to get enough reliable data on life spans.

 

[Kelpie]

But only if you have the knowledge and prepared to DIY - and have the solar (both hardware and environmental conditions) to fully utilise its properties.

For the typical UK based coastal cruiser it is simply not relevant as you can buy batteries for delivery the same day, which will drop straight in and give more than adequate performance. The ultimate cycles is irrelevant. 60 days on board a year discharging to 50% SOC is "heavy" usage - 30 years with lithium, compared with typically 10-15 years with basic AGMs. How many people have that sort of time horizon?

Very different with your kind of setup and usage regime.

I don't disagree, and said as much myself.
But for anybody who is fed up replacing lead acid batteries every few years, lithium offers a cheaper solution in the long term, if you understand a bit about it.
I'm going to quibble a bit about your 'environmental conditions' for solar to work with lithium. In fact because of better charge acceptance and not needing to get to 100% SOC, you can happily run lithium with considerably less solar than lead acid needs.
You will need to use an MPPT, but I would think most boats using anything other than a trickle charge are already going to be doing that.

 

[Kelpie]

I don't disagree, but the initial cost of convertion to lithium can be high. If you don't have much solar, don't have an alternator that can charge lithium directly (and can deal with the BMS shuttung down and not blowing your alternator diodes), want to charge other batteries as well, such as bow thruster, generator, the cost can add up as much ad the lithium battery

That's a case of looking at what you already have and what features you need.

My case is unusual, I readily admit. I priced up both a deep cycle lead based system and a lithium one, and lithium came out substantially cheaper.
I was adding new PV+MPPTs which are the same regardless of battery type.
In theory I could have reused the existing fuse and isolator if I'd gone LA, but in practice it needed upgrading anyway.

I bought a secondhand DC-DC charger which was about the only item that was lithium-specific, that was £100. But I've never actually used it because I just don't need to charge from the alternator.

Because my lithium battery was about £400 cheaper than the deep cycle batteries I was going to buy instead, this easily covered the extras, with a bit left over.

Far removed from typical weekend use of course. I just don't like people to think that they can't afford lithium.
I met someone recently who was quoted €20,000 to have his catamaran upgraded to lithium. I don't think he believed me when I explained my costs

 

[geem]

That's a case of looking at what you already have and what features you need.

My case is unusual, I readily admit. I priced up both a deep cycle lead based system and a lithium one, and lithium came out substantially cheaper.
I was adding new PV+MPPTs which are the same regardless of battery type.
In theory I could have reused the existing fuse and isolator if I'd gone LA, but in practice it needed upgrading anyway.

I bought a secondhand DC-DC charger which was about the only item that was lithium-specific, that was £100. But I've never actually used it because I just don't need to charge from the alternator.

Because my lithium battery was about £400 cheaper than the deep cycle batteries I was going to buy instead, this easily covered the extras, with a bit left over.

Far removed from typical weekend use of course. I just don't like people to think that they can't afford lithium.
I met someone recently who was quoted €20,000 to have his catamaran upgraded to lithium. I don't think he believed me when I explained my costs

We have met several cruisers with more money than sense who have gone that route. Same kind of crazy cost using Victron or Mastervolt kit. It makes no sense to me. They don't buy into the system and have no knowledge about it how it works. We're heard recently that one guy with such a system had a massive power failure and was clueless how to fix it or what was wrong. They resort to the 'plastic spanner'(AKA credit card fix) and have to wait for a Victron specialist to show up and fix it for them.

 

[Kelpie]

We have met several cruisers with more money than sense who have gone that route. Same kind of crazy cost using Victron or Mastervolt kit. It makes no sense to me. They don't buy into the system and have no knowledge about it how it works. We're heard recently that one guy with such a system had a massive power failure and was clueless how to fix it or what was wrong. They resort to the 'plastic spanner'(AKA credit card fix) and have to wait for a Victron specialist to show up and fix it for them.

The opposite of Practical Boat Owner.

 

[Graculus]

I don't know where you are located buy may be worth having a word with Ed Shiers at About - Four Counties Marine Services He knows what he is doing (I have watched him for a while) and has an instagram site which shows his work on an almost daily/weekly basis.

Thanks but I think I'm too far away, down south

 

[geem]

I just had a look at our daily energy use on our lithium battery bank. The average consumption is 115Ah per day at 24v so in 12v money we are using 230Ah per day on average. This is all done on solar apart from the odd day or two per month when we exercise the diesel generator. We could never have done this with our lead bank

 

[Kelpie]

I just had a look at our daily energy use on our lithium battery bank. The average consumption is 115Ah per day at 24v so in 12v money we are using 230Ah per day on average. This is all done on solar apart from the odd day or two per month when we exercise the diesel generator. We could never have done this with our lead bank

How much diesel do you think you're saving?

 

[geem]

How much diesel do you think you're saving?

Our diesel generator was only used to run the watermaker. It is a very fuel efficient generator and watermaker combo, so not that much. We hardly use gas now but the combined saving is not insignificant. I think I did work out that the combined saving would pay for the lithium in about 8 years. Pretty good