Anyone with homemade lithium battery bank?

[twohapence]

Originally Posted by TreblePlink

I would never use lithium batteries on a boat. Their main advantage is energy density (low weight) - and that is rarely critical on a boat. BUT from a safety standpoint, Lithium and water do not mix, unless you like flame.

So how do you feel about Hydrogen and Oxygen? Or 20 molar sulphuric acid? One can explode with devastating consequences and the other can cause severe burns and blindness. Add a little water to concentrated sulphuric acid and you get boiling acid flying everywhere.

Do you have petrol for your outboard? Or propane/butane for your stove? If not would you go back to a coal burning stove for cooking and heating?

None of us would ever go to sea if we weren't prepared to accept some risk and Lithium in the form of LIFEPO4 with or without Yttrium fits my risk appetite just as well as lead acid batteries. But with greater rewards.

[snokid]

ABYC compliance is going to be the biggest problem. No soldered connections allowed for power.

throwing that into the wind 18650's will do the job no problem just look on youtube look up powerwalls plenty of land lovers doing just what you are talking about safely.

I dive with 18650's exposed to water haven't had one catch on fire yet!!!

If I was to do it I would start with new cells though.

For the people who aren't in the know.... you have a bunch of basically aa batteries in parallel each of those batteries is fused incase of a problem. then you series each of those banks till you get to the voltage you want. in multiples of 4.2v.

all those hoverboards caught fire because of how they were charged. overcharge and you will have a fire!!! short and you will have a fire!!! charge with too much current and you will have a fire!!!!


That said there's no need to go to all that work. AGM's are pretty cheap easy to install and maintain...

Bob

[senormechanico]

Originally Posted by TreblePlink

I would never use lithium batteries on a boat. Their main advantage is energy density (low weight) - and that is rarely critical on a boat. BUT from a safety standpoint, Lithium and water do not mix, unless you like flame.

At least it's self extinguishing..., and it's not going to make me go back to lead.

[mitiempo]

Originally Posted by TreblePlink

---

What type of "Lithium" batteries did Boeing have thermal problems with?

Boeing used lithium cobalt.

[Zil]

Have you read through this comprehensive discussion? http://www.cruisersforum.com/forums/...nks-65069.html

[john61ct]

Yah take notes so you don't need to run through it twice 8-)

[CatNewBee]

18650 Lithium cells are a No-Go on a boat. Way too dangerous.

I am planning to built a Lithium battery of the Yellow Winston Thundersky prismatic cells (LiFeYPO4), they have very little Lithium and are considered fire-safe. A good BMS is a must have when using Lithium - if you want a reliable and durable solution.

Also you have to take a lot of precaution when building the system for a rugged environment regarding corrosion protection of the poles and bridges between the cells.

There are drop-in lithium batteries, ready to use and with internal BMS out there, but I would prefer an own build. If you have all monitoring, balancing and protection logic external, you can fix problems easier while under way - at least temporary - until you arrive to the next harbor and you can build bigger blocks / capacities.

BTW - the Wynns are funny, entertaining, brave and adventurous - but honestly - technically they are still greenhorns and have little scientific background when it comes to electricity. They learn quick and build up confidence on what they are doing and they are smart to not overestimate their skills and ask the professionals for advice and help when needed.

So yes, Lithium has advantages - but there are many flavors in Lithium technology for different use cases.
At the moment LiFeYPO4 seems to be the best solution for the water and RV usage regarding fire protection, energy storage, charge / discharge characteristics and reliability even below the freezing point in contrast to LiFePO4.

[CatNewBee]

May be a good casual reading:

NFPA Research on Li Fires

[deluxe68]

Originally Posted by leboyd

Even if the Wynns made $10,000/week on YouTube or however one makes money, unless you're a good friend of the OP, how do you know they are in a different league? Not everyone who cruises or lives aboard are dirt poor. If they are buying a new '45 top-of-line boat, they could easily spend $500k. $7-10k for 2 or 3 batteries isn't very much.

They may be dirt poor and buying an old boat for $30k, but I wasn't making any recommendation or suggestion whether they could or could not afford those batteries. I was pointing out the Lit batteries are a solid technically viable battery for sailboats.

Haters gotta hate.

Not haters, they simply read the OP where he said he would spend up to $1000.

[roland stockham]

Originally Posted by getyourbone

Hello!

Very new here. Wife daughter and I are about to move onto a 45 ft sailboat. I am looking into increasing the battery capacity as I am sure "we" will find a desire to use more electronics and comfort items (Air Conditioning, hair dryer, curing iron etc...) than the previous owners of the boat.

Anyone care to comment

Thanks,

Steve

I know almost nothing about lithium tech except that for me it is out of the question because of price. I have seen a large high power system used on a cat that seamed to work well but they had 1kw of solar panels accross the aft deck to charge it. And I do mean 1kw, that was what I saw on the meter not the rated capacity! Have you given any thought to how you are going to keep up with the charging demands. Once you get beyond a certain point running a genset becomes a simpler and more sensible option with a smaller electrical system for when demands are lower. Worth doing an energy budget that also looks at time. If you only need high power for 1hr a couple of times a day that can suggest different options than if you just look at total watts per day. Also I would suggest not rushing into changes. When you first move onto the boat you will still have a 'shore' lifestyle. It take a while to adapt and you may find you power need are a lot lower 6 months in.

[CatNewBee]

Well it depends on the budget, the power needed and the charging options on board.

A very simple calculation. Lets say you need 100Ah per day and want to be on batteries for 2 days until you need to re-charge - so usable energy storage will be 200Ah.

With wet Pb / GEL / AGM you will need a total capacity of 400Ah (Pb batteries shoud not be discharged below 50% otherwise they will lose capacity and fail)

LiFePO4 / LiFeYPO4 can be safely discharged to 20% so You'll need 240Ah as a battery, that will be 4 times lighter than the Lead-Acid block.

So with Pb Batteries you need a charger of 10% or 1/10 of the capacity for the charge, that means you need a 40A charger. This can be a 220V/12V charger running on generator or the generator of the engine, that delivers the 40A. For completely charging the 200Ah used you will need 5-8 hours, because the higher the charge level, the lower the charge current.

Now the LiFe(Y)PO4: they can be charged with up to 3C or 3x the Ah capacity, so you can charge the 240Ah battery with up to 720A and charging can be finished in 20 minutes. (calculated power for charging up to 8.6kW) Assume you have a genset wit 5kW, it could deliver 400A @ 12V and you have a Victron 3000W Inverter / charger with 160A charger + a separate Lithium Charger 120A, this would total to 280A) jou would charge the battery in 45 minutes at 1.2C what is considered safe and ensuring a long life of the Lithium battery pack.

Well - it is a difference if you run your gen for a whole day or less than an hour to have energy for 2 days.

Assume you have 3 solar panels with 100Wp on your roof, it would contribute to round about 1200Wh or 100Ah / day (estimation is 4x the Wp for a day in Wh), so you could top-up your batteries without the need of the generator at all in both scenarios.

So Lithium is great but expensive and makes gen usage short, also delivers far more Amps if needed for inverter usage, solar can help staying quiet.

With the right sizing LiFe(Y)PO4 is the way to go for live-aboard 24/7 - 365days usage and circumnavigation, for casual weekend or seasonal sailing lead acid is still the better choice. Solar helps keep the batteries happy too.