New Boat: Lithium Now or Later

[donradcliffe]

The 30,000 quote you got is likely from a builder who has not done Lithium before and wants you to pay for him to learn how to do it.

The Mastervolt system design is pretty old school and not user friendly. Having a system like that is like owning a Mercedes. If anything goes wrong you drop the boat off at the workshop and write a big check two weeks later.

[Statistical]

Originally Posted by stormalong

I agree entirely with Adelie's post. That is what I did 30 years ago and it works well. In addition, most of the time you are operating a windlass the engine will be running and most of the power will come from the alternator. Also, even though it is a 1500 watt electric motor you will rarely use that much power.


As for the decision to go LFP, IMO don't do it.

My reasoning is that battery technology is rapidly changing. Different chemistries will be coming out in the next few years that will be better. The global demand for electric vehicles is driving a huge amount of R & D.

FLA is long proven technology. I use 6 Trojan T-105s for 660 AH at 12 volts. I have 390 watts of solar and two alternators. My loads include refrigeration and a windlass. I get about ten years from a battery bank. The batteries are seldom discharged more than 20%.

Considering the cost and potential obsolescence, again, IMO it is a poor investment.

I can't imagine a worse line of thinking. A LFP ready boat isn't really LFP ready it is future ready. It will have digitally programmable chargers, inverters, solar charge controllers, and external alternator regulators. If something newer and better comes along in 5-10 years then you will adjust your equipment to use that.

The big challenge with LFP over the last 20 years isn't new hardware. If you buy a boat with brand new victron boxes switching to LFP is trivial. The big issue has been "legacy" equipment which were hardcoded to assume lead acid batteries. The expensive part isn't new batteries it is new everything to work with those batteries. However any boat with legacy hardware hardcoded to lead acid tech isn't going to play nice with whatever super duper battery tech is next. The some cost of upgrading hardware & batteries will apply.

"Better" is also naive way of looking at things. Chemistries are compromises. NCA/NMC have roughly double the energy density of LFP. Does that make them "better"? They are also far more likely to result in your boat burning down to the water line.

One new chemistry on the Sodium ion which promises to be cheaper but it also has worse charge characteristics and energy density compared to LFP. It is more a lead acid killer than an LFP killer. Still even if sodium ion does become the "go to" option for cruisers the key is modern programmable hardware so you can just adjust it from LFP charging parameters to SI charging parameters.

T-105 limited to 20% discharge cost more than an LFP bank limited to 80% discharge.

[sailingharry]

Originally Posted by Statistical

I can't imagine a worse line of thinking. A LFP ready boat isn't really LFP ready it is future ready. It will have digitally programmable chargers, inverters, solar charge controllers, and external alternator regulators.

I would go a step further. Any robust cruising boat with a viable electrical system is ready for not only lfp, but anything else that comes along. The two big hard spots are alternators and inverter chargers. If you have more than a couple of hundred ah, maybe it takes as much as 400ah, of lead batteries you will have already fried your factory alternator (and hated every day you used it until it fried!) and gone to an externally regulated alternator with temperature sensing. You will have upgraded to at least a 2kw inverter charger to get a decent shore power charger, and it will naturally come with programmable settings. You have probably already upgraded from the 100W solar panel with a fixed pwm controller, because you need enough power to last more than a weekend.

The boats that have problems are people with one or two group 27s, or a pair of golf carts, running a small solar array, and a factory alternator, and want to run with the cool kids with all their power hungry systems. They will need a new alternator, a new inverter, a big solar array, and all the new power hungry accessories (fridge, autopilot, big screen chartplotter, induction cooktop, etc) that they intend to drive. But even without LFP, that upgrade would have required all that fancy stuff. You can't put 200ah of daily consumption back into an AGM Bank with legacy equipment.

[jordanbigel]

Originally Posted by stormalong

As for the decision to go LFP, IMO don't do it.

My reasoning is that battery technology is rapidly changing. Different chemistries will be coming out in the next few years that will be better. The global demand for electric vehicles is driving a huge amount of R & D.

Sorry, if you had actually used LifePo4 you would never say this. Operating a cruising boat with LifePo4 is a life changing experience.

Perfect is the enemy of good - keep waiting for perfect and you have missed the boat completely.

[SV__Grace]

We refit our 1985 20 ton ketch with 100% Mastervolt, expensive, but love it.

Started with AGMs, which worked fine for us before we started cruising and living on the hook full time, then became a PIA and upgraded to Mastervolt lithium house bank and love it as well- far superior for solar/wind and minimizing generator use.

Being expensive, working well with solar/wind and preferring partial SoC, lithium batteries only make sense (to me) for full time cruisers. If you live on land and take your boat out for day sails, weekenders, even week or two vacations, you don't need lithium and are wasting your money and risking degrading your batteries by keeping them on shore power the majority of the time.

Like most boat decisions, the best choice is for how you intend to use your boat.

Originally Posted by SV-Viento

New 40' mono build for weekend to multi month cruises. Demand side of system will have fridge, full electronics with radar and autopilot, etc but at this time no AC or water maker. These items will be serviced by house bank either FLA or Lithium LiFePo.

Other demands loads include windlass, electric headsail furling, and electric primary winches and starter to be serviced by Separate AGMs via DCtoDC relays.

Shore power, 2 alternators (one to starter and one to house and AGM loads). Future solar is also planned.

THE QUESTION: should we have the House System Set up with lithium now or later and the real question is cost. The entire system is a Mastervolt system. To add Lithium, the builder charge is close to 30K. But my simple math indicates we can add later for roughly half of that. What are we missing? and should we simply move forward with it now or later?

[Statistical]

Originally Posted by SV__Grace

Being expensive, working well with solar/wind and preferring partial SoC, lithium batteries only make sense (to me) for full time cruisers. If you live on land and take your boat out for day sails, weekenders, even week or two vacations, you don't need lithium and are wasting your money and risking degrading your batteries by keeping them on shore power the majority of the time.

LFP should not be degraded by being on shorepower unless the chargers are configured wrong. LFP are used in cars and they are only ever on "shorepower".

At this point though for the DIYer LFP are pretty close to AGMs even for the day sailer or weekender. The big challenge isn't the batteries it is the charging sources. If someone has an internally regulated alternator and some lead acid only charger from 1986 that isn't going to work and upgrading all of that adds some not insignificant cost.

[Pizzazz]

We need a FAQ on lithium power systems, here is a start:

- LiFePo is better than FLA and most people love it. The only downside is that you can't start your engines with lithium batteries, so you need to have separate starting batteries

- FLA's are proven, very tolerant and sufficient for most people. It is true that voltage sags with deep discharge but most marine equipment is designed to handle it. Except for the voltage sag, it is exactly the same if you have 200 AHr batteries that you replace every two years or 400 AHr batteries that you replace every four years

- It is best to have separate batteries for start and house and on larger boats for windlass and bow thrusters.

- Quality LiFePo cells cost around $120/kW (wholesale) and that price has been stable last few years. The remainder of the cost is in packaging, BMS and other bells and whistles. These overhead costs are coming down over time. Shop around or wait.

- Charging LiFePo from solar is easy (lots of options) but not so easy from the alternator. It is really silly to have a large bank, a large alternator and a small 30A DC-DC charger. So, you need to upgrade the alternator charger. The rest of the system is standard.

- 12V is simpler and cheaper but 24V is really much more efficient, especially at the alternator level and the solar mppt charger level. It should be considered for any boat over 40 ft that has significant electrical needs.

MV Ithaka

[Statistical]

The 24v angle is worth considering for the OP. Going from 12V to 24V is a pain in the butt far more than going from FLA to LFP. At a miniumum you need new charger/inverter & alternator. Depending on the model you may also need new charge controllers. The DC panel likely will need an upgrade or partial replacement (or a new 24V panel and keep the existing 12V panel).

If it is reasonable cost upgrade you may wish to consider going 24V now. Electrical demands on boats tend to only go up.

[SV Coronado]

I bought my boat new and stuck with the factory AGMs and genset for charging out of the factory. After a year, we installed 1,600Ah of LiFePO4 and 2,400W of solar. The system I installed is all Victron and far superior to the crap the builder would have installed for twice the price. As tough as it was living off of lead acid and genset, it taught us to be power conscious and gave us strong opinions on what we needed vs. nice-to-haves.

[smac999]

Originally Posted by SV-Viento

You ask good questions and I wasn't sure how much detail to provide up front

The Base FLA house system would have 620Ah.
The Lithium system would have 460 ah.

The alternators are each 115a one is externally regulated the other is not The externally regulated alt is programmable and Lithium compatible.

The inverter charger is also programable and lithium compatible although in theory it could be specified larger and is if we purchase the lithium upgraded system.

The alt and inverter setup will be the save either way. You will want the ext reg with either. Just the programming changes. If you have mastervolt inverter / charger. And other stuff dc-dc? . You probably what their alt reg. And their batteries. So they all talk.

So just check the price of mastervolt lith batteries. They are expensive compared to others.

[SV-Viento]

Originally Posted by smac999

The alt and inverter setup will be the save either way. You will want the ext reg with either. Just the programming changes. If you have mastervolt inverter / charger. And other stuff dc-dc? . You probably what their alt reg. And their batteries. So they all talk.

So just check the price of mastervolt lith batteries. They are expensive compared to others.

Lots of good thoughts still coming in this thread including the above - thanks to all. Also some of the side banter is popcorn worthy

So This is the path we are trying to sort out with builder. Verifying externally regulated Mastervolt alt and upsizing Mastervolt inert/charger. This will give us a system ready for Mastervolt batteries in future allowing the whole system to communicate more easily and ultimately be more reasonably priced.

[EFSAustria]

I think there ist a big missunderstanding in the whole discussion. Can you specify what exactly is covered by the 30 K? I am missing the business end of the whole story i.e. the solar conversion! Is this included? Than there ist a point in going into the details of your situation. Have run the whole show 2 years ago on my Lagoon 380 and spent a Lot of time and more than 30K Euros in for 900 amph Victron and 1.4 KW Solbian solar. With what I know now and prices down significantly I could do the same job for 30 to 40 % less! I any case, do the Installation right now! But you have to dig into this thing, from the nature of you question I can make out that you are at the very beginning of understanding the job. And you have to know what you need, or you are taken for a wild ride, like I was...
You can contact me on my mail, If you want to avoid strange comments from people who are posting every other day without having every seen a boat from far away...

[Evergreen]

Later

[Fuss]

Originally Posted by Pizzazz

We need a FAQ on lithium power systems, here is a start:

- LiFePo is better than FLA and most people love it. The only downside is that you can't start your engines with lithium batteries, so you need to have separate starting batteries
MV Ithaka

Really, I can’t start my engine with Lifepo4….really, I have to have separate lead acid batteries!!
Why??

[Statistical]

Originally Posted by Fuss

Really, I can’t start my engine with Lifepo4….really, I have to have separate lead acid batteries!!
Why??

It would be more correct for him to say MOST LFP battery banks can't reliably deliver the required current to start a motor. It isn't universally true. If you have a battery capable of the required CCA to turn over that starter it doesn't care that they are LFP flavored electrons.