KISS Ocean Passage Lithium Setup

[DDabs]

Hello everyone,
I am in the process of rewiring/re-electrifying my vessel for a transatlantic passage, and thought I'd post a bit about what I'd like to do and ask for some opinions on the matter.

Background- I have been researching the past few months everything regarding lithium batteries, so I am aware of most of all the basics. This thread is mainly to get more information on my personalized setup.

The boat/setup:
The boat is a 50' aft cockpit, fiberglass sloop. The systems on board have been designed to be extremely simplistic and reliable. Most systems are manual, and the only big draws on the atlantic crossing will be autopilot and refrigeration.

I am pulling five 4D batteries out of the boat. I have usually always had golf cart batteries on my boats, with my last boat using 6 in series for a bank of around 675 ah. My current boat with the 4d's has a bank of close to 1000ah.

The proposed replacement setup:
I want to replace the 5 4D batteries on board with a bank of two 200ah lithium batteries. I have been contemplating building vs. buying, but in any case I am planning on two 200ish ah batteries. I know the DIY route has a 260ah option, so if I go DIY i will be using two of those.

Two lithium batteries, one single FLA battery for a starting battery. battery-battery charger for the alternator, since I am using an OEM yanmar hitachi, i think 80 amps?

Solar will be 3 100w panels on the dodger/coachroof, plus a wind generator.
Solar panels will be fed into their own individual Genasun charge controllers, and then to the battery bank. The wind generator I assume gets tied into the house bank as well?

The missing items now that I haven't researched as much are:
a shore power charger and inverter setup, in case I need to run an appliance at sea. On an ocean passage, I don't see needing an inverter, especially on my boat (I have no major appliances). I will be carrying a Honda 2000 portable generator in case all else fails.

Anyways, just wanted to get a thread started and I appreciate anyone's opinions. I apologize for the messy thought process.
David

[fxykty]

You’re planning to replace a 1000ah lead acid battery bank with 400ah or 520ah of LFP? That seems pretty small, as you don’t really use 80% of the LFP capacity on a daily basis. OTOH, your charging capabilities don’t really allow for a larger battery and your usage is low so that could be plenty of capacity. You can discount the wind generator - reasonable power output when sailing upwind or in big winds, but pretty much nothing when you’re anchored or berthed.

What happens after the passage? Will you be in marinas with shore power? Will you or family or guests want to run AC appliances?

[DDabs]

The 1000 ah bank wasn't really my design- it was what came with the boat when I bought it. My Caliber 40 using its 675 ah LA bank was more realistic for me because I cruised the Caribbean for 9 months using that setup paired with 420W of solar and it worked great. The major systems on that boat were the same as my new boat- just refrigeration and autopilot. The Caliber was using chartplotter and radar a lot more often in the Caribbean than I will be using during the transatlantic passage. I think 400 ah of lithium should be more than enough.

After the transatlantic, the plan is to take the boat to Italy where she will be berthed. No need for AC appliances for the family or guests. The boat was made to sail and so that is what she does! That is the spirit of the requirement for this battery build- the simpler the better for me.

David

[DDabs]

So far my potential setup would be:
-(2) 206ah SOK batteries
-(3) 110w sunpower flexible panels
-(3) genasun gv-10 mppt controllers
-1 starting SLA AGM battery
-victron orion B2B charger

I am still researching options for a wind generator/hydrogenerator to make up for the lack of solar. I don't want to do an arch and I do not have a bimini. I could perhaps put more panels on the foredeck but id rather not run wiring from that far forward

[wingssail]

Originally Posted by DDabs

So far my potential setup would be:
-(2) 206ah SOK batteries
-(3) 110w sunpower flexible panels
-(3) genasun gv-10 mppt controllers
-1 starting SLA AGM battery
-victron orion B2B charger

I am still researching options for a wind generator/hydrogenerator to make up for the lack of solar. I don't want to do an arch and I do not have a bimini. I could perhaps put more panels on the foredeck but id rather not run wiring from that far forward

Whether or not this will work depends on the loads your refer and autopilot put on the system (and don't forget the sailing instruments). I think the battery capacity may be sufficient if the refer is small and efficient, (or the water you are sailing in is cold).

What I'd focus on is the recharging ability of 330watts of solar. This will give you around 150 AH on a sunny day (more or less). Pretty close to your probable needs. In my case I depend on a high output engine driven alternator with a good regulator to top off the batteries if the solar does not do it. It's hard to match 80-100 amps for an hour of running the engine.

Secondly, Do not under estimate the importance of good BMS and charge management for each cell and some very granular monitoring. You'll need to know exactly what is going on with your batteries, temps, SOC etc.

[DDabs]

As far as the solar panels- I cannot justify spending $800+ on flexible 100w solar panels from Solbian or Solara. These two companies make their panels in Italy and Germany, and demand a much higher premium. I am sure the quality is better- but it isn't justifiable. That leaves me with crappy Chinese Amazon panels. Based on the build quality, most of the panels seem to be made with the same material, just different junction boxes. Sunpower and Topsolar are two Amazon sold panels that seem to use really nice, completely waterproof junction boxes. Topsolar is $140/panel and Sunpower is $210.

[Hermia II]

If you use the same alternator for both starting battery and LiFePo4 you could use the Matsrevolt Charge Mate Pro 40 to limit the output from your alternator to 40A. Otherwise you'll quickly broil it. The OEM alternator is not made for continuous high output. Also make sure the regulator is set to max 14.4v.
Charging is delicate. Voltage may not exceed 14.4v, your BMS must make sure that the different cells are balanced, it must prevent overcharging, your regulator must have a LiFePo4 charging algoritm, since LiFePo4 don't charge as Lead/Acid batteries, and so does your shore power charger (or charger/invertor).
My recommendation is to spend a little more and stick with one manufacturer for the batteries, BMS, Charger/inverter and monitoring. I have installed Victron which is complicated but that's because it needs to be. Match that to a Balmar 220A alternator with the Balmar MC618 regulator. Then you have a robust system.
If you however like to keep it simple, I strongly recommend remaining with fresh Lead/Acid batteries. It's much better suited for marine use.
God only knows what will happen to my LiFePo4-installation when I get close to my next thunder storm.

[donradcliffe]

Flexible panels will disappoint you in a year or two. More solar is WAY better than a wind generator. I sailed RTW on 500 ah of gel batteries with the same loads, and that was plenty of storage capacity. Think about a big independent alternator/regulator for the house bank, it will give you shorter engine hours and more redundancy. You will need a shore power charger matched to the output of your honda generator. An inverter charger is an option to consider, but get one where you can adjust the charging rate to keep from tripping the honda.

https://www.cruisersforum.com/forums...ger-16312.html

[CarlF]

With flexible panels it's all about the warranty. You'll be lucky if they last two years in southern latitudes. Unfortunately, for a cruiser it's not always convenient to get warranty panels shipped to you. I've had Solbain panels fail in the same length of time - but for the price you pay they can afford the warranty replacements.

If you are putting the panels on a bimini use twin wall polycarbonate panels to reduce the flexing of the panel.

https://www.youtube.com/watch?v=onMZ_dRSFUs

[DDabs]

With the stock 80A alternator hooked up to a SLA AGM start battery, won't I be OK in terms of the alternator being happy? It will dump into the starting battery when the engine is running and then I can choose to use the battery to battery charger if needed.

As far as the MPPT controllers, the Genasun modules are rated for Lithium batteries and you can even order a custom unit with the voltage preset. The lithium model they have should work fine with the SOK battery. I chose SOK batteries because based on Will Prowse's review, the cells/BMS are accessible and seem to be pretty well put together, all for not much more than it would cost to build my own battery. So although the BMS may not be the best, it will suit just fine.

Sticking with Victron everything was also an option for me... but honestly their batteries are on the upper end of the spectrum and I have heard that their MPPT controllers have very small connection ports and everything is also built in India. I am sure the quality is decent however I am looking for as durable and reliable as possible. This is why I like the Genasun equipment.

Flexible panels on the dodger and coachroof are going to be expected to be replaced after a year or so. I am not buying them as a long term power sustainability option- this is primarily for Ocean passages.

[DDabs]

The SOK batteries state the rate of charge should be 14.6V. The Genasun controllers come with a charge rate of 14.2. Is this tolerable? It is an additional $40 to have the controllers programmed to 14.6. I guess this is where the programmable Victron units take the win. Also- it says the recommended charge rate is 40A. Will I be ok using a 20A charger on my single 30A shore power connection?

[mitiempo]

Originally Posted by DDabs

The SOK batteries state the rate of charge should be 14.6V. The Genasun controllers come with a charge rate of 14.2. Is this tolerable? It is an additional $40 to have the controllers programmed to 14.6. I guess this is where the programmable Victron units take the win. Also- it says the recommended charge rate is 40A. Will I be ok using a 20A charger on my single 30A shore power connection?

You could use a larger charger.

The Victron solar controllers would be best in my opinion. Fully adjustable in every parameter.

[Hermia II]

14,2 is fine, 14,6 is too high. You could use a larger charger, but 20A is not a technical problem.

[DDabs]

Pardon my ignorance- but can I run a larger charger than 20A from the shore power? I figured 30A was my max if I only have one single 30A shore power connection. I'm sure once I get to the Med, I won't be able to use that anyways, so I may need to think about that.

I have come to a few hard decisions:
-batteries I am leaning towards the company lythbattery, who will build me two 230ah batteries with Daly BMS. Grade A cells. $2000 shipped to my door. This seems like my best option at this point. I will have a 460ah house bank. starting battery will be a 12v AGM FLA. I have not decided on the starting battery yet and could use suggetions. Do most people use a starting battery, or a dual cycle in case of a shutdown of the main house bank?
-solar panels have been acquired- I went with the company Soltronix, who makes semi flexible panels right here in the USA. Their junction boxes are nice and sealed and the build quality seems much better than what is on amazon. price is $379/panel for 100w. Pricier than amazon, not as much as a $800-1000 solbian panel.
-mppt- still up in the air about victron mppt's. I really like the genasun gv-10 controllers but I want to be able to see whats going on. What is the best way to do this?

[Moontide]

If you want to spend the $ the water generators (ones that look like lower leg of an outboard) are almost impossible to beat when sailing. Can easily keep up with your loads and have the advantage of working at night. Much higher output than any wind generators I've seen (well, except of course the giant ones on shore).



Have you considered fixed panels hanging on the pushpit or lifelines? Can get higher output but one side will probably be shaded when sailing. Not as pretty but much more efficient.



As others have said, I would shy away from any of the flexible panels due to durability.


I would think 400 ah of LiFePO4 would be plenty. I have 900 watts of solar with 6 GC batteries and my boat is a power hog. Have worked fine with 3-4 reefers/refrigerators, AP, couple of computers and other cruising BS. I do stay in a bet further south than an Atlantic crossing entails.