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claudioita asked

Help for upgrading an existing maritime setup (boat), to Lifepo4

Hi, I have the following setup on a boat

- Multiplus Compact 12/2000/80-30, so a 12V system

- Cerbo GX

- 3 pieces Smartshunt 500A

- 5 pieces Smartsolar charger MPPT 100/30

- 1700W solar panels (never saw a production higher then 1,1KW in summer due to shading I think)

- 750Ah battery bank (not Lithium), i think 5 packs, for servicing the boat

- 2 battery engines, one for starter each engine

- AC-in 220V shore power when docked in a Marina

- Fischer Panda i15000 (15kw) Generator when away from gris/land


So far so good, but wish to upgrade to Lifepo4, between 15Kwh and 20Kwh

So below the questions

A) Looking at SOK 206Ah Marine grade 6,7 or 8 pieces, or Epoch 460Ah Marine grade, 3 or 4 pieces. or Victron 330Ah 4 or 5 pieces (although Victron way more expensive). Any thoughts ecommendations?


B) A dealer suggested the following additional equipment to get

- 1 piece Lynx Smart BMS 1000 (M10) (is it needed, what for?)

- 2 pieces Lynx Distributor (M10) (is it needed what for?)

- 2 pieces DC-DC Battery charger Orion XS Smart Buck Boost 50A Non-isolated (don't understand what is for)

- 2 pieces Cable VE.Direct - USB adapter

- 1 or 2 pieces Quattro 12/5000/220-100/100

- and of course 4 better 5 pieces 330Ah Victron Lifepo4 (he sells only Victron)

- sell the Multiplus

He strongly recommends two Quattro because the recharge of the battery (since solar panels will not manage to charge fully) will be at 480A, and doesn't recommend only one because at 240A will use the generator too long time to recharge the batteries (not very convinced about this but...


What do you guys think of all the above.

My first reaction was that his offer was overkill, and then to save money, but accept all considerations, also spending more money.

So ideally my first thought was to go with SOK or Epoch Lifepo4 batteries (50% cheaper) and only 1 Quattro for having 5KW output, and for recharging faster the batteries with the generator (now my Multiplus I think it's 80A and it feels slow, but 240 should be enough, no?), but again I ask here for advice from you experts.


Any thoughts, recommendations?


Thanks in advance






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Sarah avatar image
Sarah answered ·

Hi @claudioita, some help with your questions. For context who so much battery storage? This is only really useful if you have an electric cooking or want to run A/C.

1) the smart BMS is the recommended BMS for the Smart Victron LiFePo batteries and the potential load which your designer has assuredly estimated.

2) the Lynx distributors are an excellent way to fuse the batteries and charging/load resources and provide simplified cable and current management.

3) the Orion XS is a DC-DC charger for charging the lithium batteries from the alternator. They control the charging power (up to 50a per engine) and with a future purported software upgrade will include DVCC which means they can be managed by the BMS.

4) if you need the sort of battery capacity that you are quoting then two Quattro’s would be beneficial.

As I mentioned earlier you really need to look at your load and what it consists of. Overall my thoughts would lean to upgrading to 24 volts for the Quattros and retain a portion of your 12 volt batteries for the DC system which could be charged from the 24 volt bank using a DC charger. Biggest power draw on 12 volt system will be typically be windlass, bow thruster, and winches (if present).

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claudioita avatar image claudioita commented ·
1-2) ok so the smart BMS and Lynx distributor are needed only for Victron batteries I understood well?

3) wonder which system is now charging the batteries now from the alternator (have to check)

4) an option could be to install one Quattro, see how it goes and then add a second, if needed, later, correct?

Victron batteries are almost double price, so if I can avoid the extra cost, I will.


Why upgrade to 24V, which are the benefits? From my understanding all DC systems in the boat are 12 V, at a glance it seems to me a big hassle to have a 24V Quattro instead of 12V


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claudioita avatar image
claudioita answered ·

Hi, @Sarahhanks for your comments, will respond in detail later.

In regards of power consumption the boat has 7 A/C, although rarely used all together, but based from other owner experience 15KWh is the minimum to have a night with A/C on without turning generator on.

Complete loads are

7 A/C (it's enough 2 - 3 concurrent all night long)

water heater,

4 fridges,

water maker 12V,

charger of efoil (2Kw 220V) (1-2 hours usually once per day or two)

occasional hair dryer,

induction cook top (not present at the moment, but perhaps will be in future),

Compressor fir scuba equipment (not present but perhaps in the future)

electric tender platform (don't remember consumption),

coffe machine 220V (very important :))

Lights

Starlink router

Electric winch

Windlass.


Of course I can turn on generator, and/or the engine when needed (I do that now to avoid draining of the batteries of my current system), and also with the upgraded system the generator will need to be turned on to recharge the batteries (since I produce at most 6-7Kwh of solar per day)


In essence I need to find the best balance, between amount of batteries, time for recharge them, ideal generator uptime.

Hope is all clear


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Sarah avatar image Sarah commented ·

Hi @claudioita thanks for the info. Given the scenario you are describing you really will need to consider moving to either 24 or 48 volt house batteries. It all depends on how frequently you are on shore power and what you want to operate when you are on batteries without using the generator. Generators are great and when you have a 15 kva generator (which can run a house from) you don’t need to think about it much. Moving to battery only usage, even if only overnight, is a big step that you want to investigate thoroughly with your system designer. Personally I would caution more than a 3 kva load at 12 volts. Have a read o wiring unlimited https://www.victronenergy.com.au/upload/documents/The_Wiring_Unlimited_book/43562-Wiring_Unlimited-pdf-en.pdf which will help to explain the different voltages. Sarah.

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claudioita avatar image claudioita Sarah commented ·
Well in winter time the boat is almost always in the marina with shore power. In summer almost never, since I am self sufficient (water maker, generator, solar) so I try to avoid marinas at all cost and prefer anchoring in safe and beautiful bays.

Ideally use generator limited time, more then ideal not at night. During night time the loads are 2-3 A/C, Starlink, a Camera, water pump of toilets when used, some lights, TV in evening, the fridges that are always on, chargers ofu electronics (tablets, laptops, phones)

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iand avatar image
iand answered ·

The maximum charge current of that Quattro is 220A so even 2 would only give you 440A not 480A -- and this is only at 25C and below, from experience I'd knock at least 10% off that (400A), and maybe more unless you can guarantee a cool air feed to it. 5kW charging into the batteries is going to mean rather long running times from a 15kVA generator (12.7kW nominal).

I have a Quattro 48/10000 with 140A spec for maximum charging current (7kW) but never see more than about 125A charging current for any length of time, and this is in a cabinet on the boat with an added external fan to blow cold air from outside into it.

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jjduke avatar image
jjduke answered ·

i will echo @Sarah 's answer and provide some input on the 24 or 48v energy storage solution over 12v.

Using 24 or 48v in your solution will provide more efficient inverter/charger and greatly reduce your wire sizes for the large currents you will need for the 2-3 aircons overnight unless you want to run the generator to do this. The efficiency isn't just about more power per stored kW, it is also about the heat produced from the inefficiencies in the inverter/chargers. they are also less expensive for the same charging and inverting rates. (the 5kVA quattro charge rates at same temp (see datasheet column 2) are 2.8/3.07/3.58 kW for 12/24/48 V quattros)

Your 15kWh-24kWh hour storage range actually seems small for 2-3 aircons overnight but they may be smaller/more efficient than my experience and you do have both large solar charging (6-7kWh on sunny day) and a large generator.

As @IanD points out, the generator would be really comfortable producing 10-12kW and a single Quattro 12/5000/220-100/100 will sustain a 2.8kW charge rate @ 25°C. you should plan to derate this by at least a 10% margin) As the charger gets hotter, the charging rate will be throttled. That plays into the efficiency tradeoff. With a 24v or 48v inverter/charger, you generally can do better than the 12V systems.

Also, your wiring will be much smaller (read: less expensive) because the wiring will be carrying less current. You will find with the 24v or 48v solution that the 500A Lynx BMS and M8 distributors will work and be more cost effective.

You said you weren't convinced about having 2 quattros. If you use the boat the way you currently do--small inverter for DC-AC use, but rely heavily on the generator for most AC needs, you will miss a huge benefit of LFP. It is, for sailors (and motorboaters), a completely different paradigm. For example, I don't have a generator but have 20+kWh of battery storage which I use to run the aircons and other AC loads overnight. I recharge through solar (less than yours) and the a large (5 kW-24V) alternator on the 50hp diesel--effectively the propulsion engine is also my generator, but it works because when we anchor, we are always under motor power for at least an hour before anchoring and an hour leaving the anchorage.

You likely will have other AC loads when the generator is running but having dual 5kVA quattros in parallel will get you a comfortable 5.0kW charge rate (less generator time). That said, the 8kVA Quattos (24v or 48v) will give you faster charging, more inverting headroom and seem like the sweetspot in the price per kW charge and kW load. Your generator, when running will be happy under load, and you will run it less.

You may also find that you can use your engine alternators for supplemental charging (the likely purpose of the quoted Orion XS dcdc chargers) and for redundancy. (they are only 12v-12v right now, but there are other solutions to dcdc charging.)

The battery energy storage cost difference has been drastically reduced recently. The Victron Smart LFP is a tried and tested solution (almost 2 seasons with mine). They just work and are reliable. What convinced me to go full Victron was when my wife asked about resale of the boat, safety and insurability. I had to think about the "extra cost" from a potential buyer's point of view: would I prefer to buy a boat with Victron batteries, or a boat with some other batteries? My answer was that I would discount any LFP batteries other than Lithionics, MG or Victron to almost 0 (euro/pound/dollars) and include an electrical refit price in my offer. YMMV


[edit: I didn't address the 24-12v, or 48-12v concern/ " hassle" for 12v DC loads. To me, it's a non-issue. Here's why: there are very inexpensive (and very effective) dcdc converters which can take 24 or 48V and convert/condition the power to a specific voltage (say 13.2v) for your 12V DC distribution panel or any other DC loads. I have 2 70A output (total 140A) 2412 dcdc converters (confusingly called Orion converters) which provide plenty of power to the 50A DC circuit breaker panel, AND either of my 12v winches (not on the panel). The converters are switchable and just do their job providing constant voltage conditioned current. I think this actually has solved some electronics issues (old Raymarine wind/speed/depth instrument signals dropping offline on the chartplotter at weird times, narrowed down to voltage sag when we used a winch when the engine wasn't tunning...been solved for 2 years just by having conditioned 13.2v power to the instruments.) ]


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iand avatar image iand commented ·

My series hybrid narrowboat has a similar system, there's only a single 48V LFP battery bank (35kWh) together with a Quattro 48/10000 and a Kohler 9kVA generator. Bow thruster is 48V straight from the battery (only needs 25mm2 cabling even for a long run), the rest of the boat uses a clean regulated 24V (1/4 size cables compared to 12V) via an Orion DC-DC converter, and there's a small 12V DC-DC converter to keep the generator start battery charged.

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claudioita avatar image claudioita commented ·
Thanks a lot for many useful information. I have to dig in more on the question of voltage, my knowledge is limited, will start to study it (little free time unfortunately).


But a big questions comes to my mind, I guess all my equipment is 12V (I know for sure the water maker, I guess also the lights, the fridge, the windlass, probably the winch and so on), if I use a 24 or 48V inverter/charger what do I need to do for all my appliances?

I guess also the battery bank that I am going to buy has to be with the appropriate voltage (24 or 48), correct?

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claudioita avatar image claudioita commented ·
Which DcDc converter do you recommend? Better stay with Victron, if yes which models, or?
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claudioita avatar image claudioita commented ·
Ok, you and @Sarah agree I should move to a 24V system (perhaps 48?), in order to reduce wiring sizes (or to avoid over heating of current wiring) but I don't understand the following : if I have then to convert almost all from 24 (or 48) to 12, then what's the difference? I mean the DcDc converter will stay usually in the same place (in my case the port engine room of my catamaran) where the battery packs and inverter are located, and from which all electric cabling departs already.... Hope my doubt is clear (?)
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jjduke avatar image jjduke claudioita commented ·

you may have read my comment before i edited it to address the DC voltage conversion issue/hassle.


As I said, i use (2) 24-12 Orion 70a DCDC converters in parallel for this. My main 12v DC panel (lights, fans, electronics, navigation, bilge pumps, refrigerator, propane solenoid, macerator pumps, etc) is rated for 50A total using a 4awg cable to it. I have other large amp draw winches (90a peak which i do see occasionally on the halyard winch) which are also supplied 12v (really 13.2v) from these converters but on their own 1/0awg through individual circuit breakers. Essentially, you leave the 12v circuits alone. just put the converters as the 12v power source and they are provided with 24v (or 48v) power from the batteries.


The Orions are pretty small but work amazingly well and are inexpensive. I have more 12v power than I need (140a continuous) but i also have "margins" to keep things cool and efficient. Also, conditioned power supply doesn't have voltage sag under load. the Orions put put the same voltage when the batteries voltage sags. (you may see 12v lights dim and electronics may act strange when there is heavy loads and inrush currents when the inverter kicks to power high current devices (aircons) without conditioned power. it's a side benefit but real for the electronics. Of course, you could use 12-12 dcdc converters to get this benefit, too.)

I think you will find if you spreadsheet it out, the 24v (or 48v) system will give you more energy storage for less; more power for loads and charging for less (faster charging=less runtime on generator and more inverting power=less need to supplement inverters with generator, if needed); and the high current limitations of 12v is halved/quartered (big current=big wires and fuses).


I hope that answers the question. (the doubt was clear ;-)

[For me--in a C42-- 24v was the sweet spot. I use the engine as a generator. A 360A 12v (alternator needed 4/0 cables) was not going to be an easy or economical install. The185a 24v alternator i chose (same alternator, wound differently but is more efficient) could have used 1/0awg cables but i used 2/0 for margin. The 48v alternator would have been even more efficient (130a) and i now wish I had gone with 48v but battery space is very constrained. 24v bank was the best I could do for future battery capacity upgrade.]


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Sarah avatar image Sarah claudioita commented ·

Having a dual 24/12 volt system certainly is more complicated. But it is really the only way to to have an inverter onboard that is larger than 3 KVA (at 12 volts the current can be up to 250 amps). Which has only really become feasible on boats using Lithium batteries. For many the motivator to move to 5 KVA inverters has been a transition to electric cooktops from gas and to use the A/C overnight (in either case without using the generator).

Furthermore, In most cases the inverter is the most significant source of energy load and charge (water heater, kettle, induction cooktop, A/C, coffee maker, hair dryer etc). At 24 volts a 5k inverter will draw up to 200 amp. This may be for long sustained periods of time and the 24 volt battery bank needs to be sized accordingly. It is unlikely that you will have any other 24 volt appliances.

Of the 12 v equipment the most you will likely draw is 100 amps for the windlass which is only on when raising/lowering the anchor, other than that the water maker will likely draw around 30-40 amps when it is operating. The remaining 12 volt equipment load is generally not significant. The 12 volt battery can be much smaller than the 24 volt battery and topped up using the DC-DC charger. When released the Orion XS 24/12 would be ideal.

The wiring unlimited text explains a lot of this in more detail. https://www.victronenergy.com/blog/2019/09/03/wiring-unlimited/

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kevgermany avatar image kevgermany ♦♦ claudioita commented ·
Personally I'd go 48V in your situation.

Main reason is charging efficiency and running the heavy loads to the Quattro(s). Much less power loss through the wiring as well due to the lower currents. Some really nice 48V LFP batteries out there as well.

The 48V to 12V is well covered and as it seems your existing wiring is OK, there's little impact.

This is the way I've gone on my boat, 48V for the electric motor. Converters to give 12V for the things that need it.


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claudioita answered ·

So synthetizing, I should get

- 24V inverter/charger (2 24V Multiplus II 3000 or 5000, or 1 or 2 24V Quattro) which shall I get?

-24V power bank, let's say around 20KWh (also 24V correct??)

- a bunch of 24/12 converters as needed in the boat (don't know how many are needed in current settings)

- when something 12V motor breaks, replace it with 24V


But what about alternator and engine battery (I have two engines, 60hp each, one engine with a 12V battery, the second with the service battery bank), will I need to adreess that too?


What about solar controller (I have 5), will have to address that too?

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