Lithium Ion Batteries

Not a 35000 lb trawler, but a 15000 lb catamaran trawler. There are 3 electric cats out there now, one crossed the Atlantic with a average speed of 5.5 kt on 10 KW of solar panels. Another has covered 6000 nm cruising Europe on 8 KW of solar and the 3rd only has 6 KW of solar, good for 3.9 kt. That is 3.9 kt for 24 hours, harvested from 5.5 hours of solar exposure.
transatlantic21: The world's first crossing of the Atlantic on a solar boat

Boat - SolarWave

Island Pilot DSe Hybrid Intro

Pretty cool.

Speed increases require an exponential increase in power. Explains why tankage that gives 300 nm range at 12 kt will give 1200 nm at 6 kt. Drop speed below 6 kt and you only use 10 hp of that 120 hp diesel. Drop to 5 kt, and now your in electric/battery propulsion arena. The PDQ 34 is a perfect candidate for diesel-electric propulsion. With just 2.5 KW of solar and 75 KW-hr of batteries, your able to make a 100 nm passage, hang on the hook for a week and make another 100 nm passage. Basic Caribbean cruising. Should you have a short weather window, fire up the (2) 75 hp diesels and increase your speed from 4 kt to 16 kt and then pay for that speed at the fuel pump. There are many boats that are being designed around diesel/solar/electric right now that I'm trying to keep track of. My last ship used (7) 4.6 MW diesel gen sets to power (6) 5000 hp electric thrusters, displaced 32,000 tons. It is the way of future cruising thanks to the advances of LiFePO4 cells and their price drops along with solar panels dropping in price from $5 per watt to $1 per watt. The investment now has a fast return, whereas just 5 years ago you couldn't recoup the investment in fuel savings.

We have recently installed a 1,000 AH/48v LiIon battery on our hybrid catamaran, Sunshine. Since the goal is to use renewable energy as much as possible for both "hotel" loads AND propulsion, this is the only really viable battery to use. Our AGM batteries (16 each, 12v, group 31) had the same mass and 40% of the capacity. So far, we are quite pleased with the installation and for the last two months, the boat has been "off the grid," charging only from her solar array. We feel strongly that one can use lithium batteries to allow for generator-free anchoring - no longer will you be unwelcome in the sailboat anchorages!

Reuben,

In the beginning I used AGM for my EV racing, much better charge acceptance than LA, and could lay down the amps for discharge. I too have converted to the LiFePO4 cells, what a difference. These are the cells of the future for diesel-solar-electric propulsion. A small project I finished last year was an electric kayak powered by (8) Winston 100 a-hr cells. I was expecting a good range increase over a group 27 LA that gave me 16~18 nm range but was amazed at the 80 nm range I have now. Testing these cells have proved that 100 a-hr rating is more conservative than the 20 hour (0.05C) of LA. I get 100 a-hr at 1.0C only going to 80% DOD.

I am very curious why you chose the 1000 a-hr cells at 92 lbs per cell rather than the 700 a-hr cells at 47 lbs? Run two banks of the 700 a-hr cells (32 cells) for almost the same weight as a single bank (16 cells) of the 1000 a-hr cells. Was it a good deal from Balqon to go that route or did you like the packaged 4 cells to a bank for the cells being banded?

Oops, just been informed on the Cruiser's Forum that Balqon had a typo on the weight. The 1000 a-hr cell is 77 lb, not 94 lb.

BTW, welcome to the forum sir, you are famous in my book.

Bob,

Thanks for the followup - I chose the 1,000 ah cells for simplicity and they fit perfect (after a bit of sawing and yanking out of cabinets). Balqon was good to deal with (I had previously visited both Thunder Sky and CALB in China - I liked their cells) - the BMS still needs some tweaking - my main issue is that when power to the shore charger (Elcon) is shut off, the battery shuts down, too. Just needs a program change.

The other surprise issue I had was upon connection to the bus, the solenoids were welding closed. Turns out the capacitors in the two inverters were at issue. So an engineer friend of mine suggested a "slow start." So we wired a resistor across the solenoid terminals that would be activated once we turned the battery on - then a delay relay would actually activate the solenoid several seconds later, once the capacitors were fully charged.

The next job I have is to delay the turning on of the Mean Well power supplies until the solenoid has closed since they are each 500w and use a good bit of current.

Finally, when I get updated relays for the Steyrs, I will need to control their charge/discharge via the BMS, too.

At least I'm not without something to do.

So...

We're not hearing much from those who so sharply criticized the idea of a hybrid trawler. It seems like someone is having luck with the technology.

Pretty cool stuff. I'm afraid to ask what this must cost though.

Interestingly, LiIon batteries have a lower cost of ownership than lead acid, including AGM. Even though the initial cost is significantly higher, there are so many more available cycles, that the cost per cycle is much less. If you're lucky you get 500 cycles from a high-quality AGM battery such as Odyssey (what we initially used). A well maintained LiIon battery can get 3,000, 5,000, upwards of 7,000 cycles.

Let's talk about the intangibles.

1. You can sit at anchor indefinitely in the Florida Keys, living aboard with all the comforts without ever running an internal combustion motor or burning a single gallon of fossil fuel.

2. While at anchor there is no generator noise nor exhaust.

3. You can move anchorage to anchorage at modest speeds without firing up the diesels

4. Energy from the sun keeps your food refrigerated, makes ice from fresh water you've made on board from the sea water, runs your TV and home theater and charges your dinghy motor. NOT BAD.

I see no reason a hybrid yacht cannot be engineered with a similar size and price of the popular Ranger Tugs.

Reuben,

Some folks have had minor teething issues changing over to LiFePO4 cells on the Cruiser's Forum (a sister forum for sailboat cruisers). Once worked out, the common feeling is "Lead is Dead".

Here is a link to a 2600 post thread on LiFePO4 cells as house banks LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks - Page 174 - Cruisers & Sailing Forums

Also, I have found a dinghy that will easily plane with a Torqeedo outboard, a nice catamaran, air entrapment hull design. I did my thesis on minimum wetted surface vessels at CMA, back then we only had fast ferries. LITE SERIES - Takacat.com

My concept for years has been the cruising boat as a mother ship with the PV array providing for all domestic loads that would include an all electric galley, all the way to a 1650 watt BBQ, plus charging all the water toys, dinghy, kayak, and underwater diver tow. My kayak with its long, narrow hull, only requires 32 w-hr per nm. The BBQ will cook (4) 1 3/4" steaks for under 800 w-hr.

No more propane or gasoline.

rjtrane said:

Interestingly, LiIon batteries have a lower cost of ownership than lead acid, including AGM.

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That's dependent on the application though. I just bought a new house bank ($1256) and that will last me another 5 years say.

My boat would never see 3,000 or 5,000 cycles. I can guarantee they won't even see 500 cycles in a 5 year period.

rjtrane said:

Let's talk about the intangibles.

1. You can sit at anchor indefinitely in the Florida Keys, living aboard with all the comforts without ever running an internal combustion motor or burning a single gallon of fossil fuel.

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I'm not a live-aboard in the Florida Keys. And if I were a live-aboard here cruising the inside passage year round, solar is tough and how would I heat my boat?

rjtrane said:

I see no reason a hybrid yacht cannot be engineered with a similar size and price of the popular Ranger Tugs.

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If the market in the sun drenched areas of the world would support it I suppose. It might be a bit more challenging up here.

I know the technology is feasible, but the business case won't closed with the price of technology up this way.

SomeSailor said:

So...

We're not hearing much from those who so sharply criticized the idea of a hybrid trawler. It seems like someone is having luck with the technology.

Pretty cool stuff. I'm afraid to ask what this must cost though.

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The technical success of hybrid light catamarans has been noted before on TF and well covered in the boating press. Cost, it really doesn't matter for many who enjoy the pursuit of ingenuity and new things. Remember too a plane did a non stop around the world some time ago with solar arrays. Bob and Reuben are indeed Li battery savvy and put their money where it counts in this regard, they are to be applauded.

But this thread is about the 99.99% of us who own heavy monohulls, many of whom do quite fine with LA batteries for the house bank.

Reuben, the Sunshine State is a great place for your vessel. How would it do cruising in the PNW well North of Seattle?

Since you mentioned Odyssey AGM, this was an early project,
My dad and nephew in the picture


The motor is a B&S Etek, that can handle at peak rating 400 amps @ 48 volts.

I used to race with the gas scooters, but they got tired of getting beat and had a race that was 50 miles long on old route 66 in Arizona. My (4) Odyssey PC 680's only had a range of 6 1/2 miles, so I built a battery trailer for extended range with (6) 8 volt flooded batteries. Weight for those batteries and trailer was 490 lbs, but with the full torque available at 1 rpm that an electric motor has, no problem starting out.

sunchaser said:

Remember too a plane did a non stop around the world some time ago with solar arrays.

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I heard one is going to try it across the US next month, but as far as I know no one has made it around the world on PV.

Even the one going across the US will be leaving in May and not arriving in New York until late July.

When you relegate batteries as just a house bank and still use propane for your high energy loads, LA will do OK. But think outside the box. I used to work for the oil industry, and believe me they are not nice people. I don't want my cruising/retirement years to be dictated by their whims. If you don't care for DIY and roll your own, there are companies that provide a complete turn key diesel-electric package like Steyr that Rueben employed and many others that allow adapting to your current drive train. The idea for typical Caribbean cruising is 100 nm passages punctuated by a week in some pristine anchorage, then another passage. Reuben's cat trawler can do this, and with retro fitting, most other trawlers could do this with proper battery sizing. And when you use the LiFePO4 cells in this scenario they really shine.






BTW, the above systems will allow you to do away with the heavy AC gen set, as they can generate plenty of DC to directly charge the batteries and with inverters, a AC gen set is redundant. When you use DC you have a choice of rpm you can run at, unlike the frequency demanded rpm of 1800 or 3600 for 60 cycle and 1500 or 3000 for 50 cycle. Just let the inverter to this.

Bob I will say you guys have piqued my interest with this thread. I own a GEM2 NEV that I use for commuting around town at 25MPH and it is a kick to drive. My LA batteries are at the end of their life cycle and was considering upgrading to AGM before reading this thread.

Now you guys have me thinking it's time to research the new lithium battery options for my 72 volt 5 HP application. I cycle my batteries 5 times per week in this application plus weekend trips with the wife to the grocery store. It is nice driving past the gas stations. Thanks for the thought provoking thread.

deckofficer said:

I used to work for the oil industry, and believe me they are not nice people.

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Really, some may disagree. In fact some I know think it is a great business to be in with bright people galore. Name a business, hobby or profession, and one can find those who will run it down or praise it.

Bob - that scooter project shows me you're as nuts as I am!

Craig - your scooter would need 22 cells of LI to build up 72 volts. Add a BMS (battery management system) and charger and you're ready to go. How many AH is your current battery? You are a definite candidate for LiIon.

SomeSailor said:

I heard one is going to try it across the US next month, but as far as I know no one has made it around the world on PV.

Even the one going across the US will be leaving in May and not arriving in New York until late July.

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You are correct, I thought Burt Rutan had some arrays on his wings in 2005, guess not. Solar is just too inefficient as compared to pure petro for flying.

rjtrane said:

Craig - your scooter would need 22 cells of LI to build up 72 volts. Add a BMS (battery management system) and charger and you're ready to go. How many AH is your current battery? You are a definite candidate for LiIon.

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I'll have to look it up at home as I'm no where close to the level of electronic savvy as you guys. My 2 seat car is made by Global Electric Motors and employs 6 12volt LA batteries. It also has an integrated charging system that will probably need an upgrade too from what I've read.

Craig,

I have basically the same kind of NEV, though built in China and designed to look like a Smart Car. It uses (10) 100 a-hr LA and a 8.5 KW AC motor. Since the States have different speed laws for NEVs (most are 25~35mph with a couple at 40 mph) the factory uses a programmable controller so the retail seller can set the speed for the state it was sold in. If you don't set it, the top speed is 53 mph. Since it looks like a Smart Car, I just drive it on all surface streets and dismiss the California regulation of no NEVs on roadways with a posted speed above 35 mph.






Reuben,

You mean you do goofy things like build a scooter that instead of the typical 750~1000 watt motor, you use one capable of 19,000 watts? To date if my scooter was a rodeo bull it would have a perfect record, as 5 family/friends have tried to ride it and all 5 wound up losing control of it, even after my careful preflight with them about all torque available at 1 rpm. One friend dislocated his shoulder, so I stopped letting anyone else ride it. I raced my Corvette to 40 mph and won on that scooter.

CPseudonym said:

Bob I will say you guys have piqued my interest with this thread. I own a GEM2 NEV that I use for commuting around town at 25MPH and it is a kick to drive. My LA batteries are at the end of their life cycle and was considering upgrading to AGM before reading this thread.

Now you guys have me thinking it's time to research the new lithium battery options for my 72 volt 5 HP application. I cycle my batteries 5 times per week in this application plus weekend trips with the wife to the grocery store. It is nice driving past the gas stations. Thanks for the thought provoking thread.

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LFP is a good match for this and "almost" but quite a drop in. Probably 23 or 24 100Ah cells.

1) work out the mechanics of installation and security.
2) bottom balance, that means prior to install fully discharge every cell to 2.5-2.6V.
3) charge until the highest cell reaches about 3.45V, no more than 3.5V
4) make sure all connections are clean and secure

The bottom balancing will eliminate the need for a BMS. When one cell reaches end of charge they all will. You stop, but won't drive any cells below the point of no return. Mote this is for EV, not a House bank on a boat.

After the first couple of charges, the highest cell will remain the same, probably for a long time, but you should double check this every 3-6 months after the installation.

The biggest challenge will be finding a way to end the charge with the highest cell at 3.45 to 3.5V. If your 72V charger is well regulated and adjustable, you can terminate upon reaching the right voltage. It might require adding or deleting a cell to get it right. Or use a Junsi Cellog on the highest 6 cells with the alarm output rigged to disconnect the charger with a latching relay.

See:

http://www.jun-si.com/EnProductShow.asp?ID=96

Good luck! You should end up with snappier performance too. Bob

All the above is correct. What ever rating in a-hr of the LA's you will probably have the same range with 1/2 that rating due to how different they are rated. Plus acceleration will be better due to shedding 270 lbs. A lot of folks say you need a BMS, I'm not one and agree with Ebaugh on a bottom to top balance of the cells, then your good to go. For me this was a slow process, first I discharged my pack in series to the knee, then rewired all the cells in parallel for the balance charge from my variable power supply. I was charging at an average of 4 amps @ 3.9 volts, so each pack took close to 100 hours to charge in parallel. If you decide to go with (24) of the 60 a-hr cells, that same bottom to top balancing at the charge rate I used (4 amps) will take 15 days of charging. But after I balanced, I don't need a BMS, and that is worth it to me.

Because I didn't want to un-band my cells I just made up jumpers for the parallel balance charging.


The top charger was built for fast charging 12 volt LiFePO4 batteries, weighs only 8 lbs and puts out 50 amps. The bottom is my lab power supply that I used for the parallel charging.

I mean the following question in the most polite and sincere way.

Is there a link to a website you guys can provide that provides a LI tutorial for dummies like me?

I almost understand about every third term you guys use

Craig,

Just ask, that would be much quicker than the 2600+ posts on the Cruiser's Forum dealing with using LiFePO4 cells as a house bank.
LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks - Cruisers & Sailing Forums

Thanks Bob. I'll post some questions after doing some more research on my requirements.

In the meantime are there any California suppliers for the batteries and chargers?

My source has been Balqon in Harbor City, California. Be sure to check their clearance sales on older stock, these prices are better than any other source.
Balqon - Advanced Transportation Solution

CPseudonym said:

Thanks Bob. I'll post some questions after doing some more research on my requirements.

In the meantime are there any California suppliers for the batteries and chargers?

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I need to retract one of my previous suggestions, using the CellLog in the previous post. They work for a marine house bank, but used as I originally suggested will load the cells unevenly in your 72V application. To shut off the charger, you are going to have to use bank voltage, or monitor every cell, not just the high ones. My mistake...sorry.

The cells are available from Balqon and perhaps Calib Power USA in SOCAL. There is a EV dealer in the Bay Area NORCAL, Thunderstruck Motors and also I think that is where Alliance Renewable Energy is located. In Phoenix there is Elite Power Solutions, and in Flagstaff with another location somewhere in California is Electric Blue Motors. An Internet search will find websites for all mentioned, or I can post one if needed.

Make sure you know your supplier before you send them money, it is not uncommon for them to want cash or a wire transfer for payment. It's one of the Achilles heels of LFP at the moment. I have done business only with Electric Blue Motors, who is a distributer for Elite Power and was very satisfied. I was in Grenada at the time and had them ship 48 cells to me....

If you need a new charger, these dealers may be able to help. But EV chargers are pricy, and there may be some simpler alternatives for a small 72V pack. I will think about it, but you could also join and post a question on the DIY Electric Car forum. There are more knowledgeable guys over there that might be able to offer a suggestion.

If price were no object, I'd use CALB FI series cells. You should be able to get them from Calib Power or via the Internet from EVTV Motor Verks. If Balqon has what you need in stock, they will probably be the least expensive.

CPseudonym said:

I mean the following question in the most polite and sincere way.

Is there a link to a website you guys can provide that provides a LI tutorial for dummies like me?

I almost understand about every third term you guys use

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Larry posted the link in another thread, but I have a write up on how to use Lithium Phosphate in marine house bank applications. If you look at our blog site at:

http://marazuladventures.wordpress.com/

On the right side of the home page ind Bobs Articles is a link that takes you to short blog post with a link to a 12 page or so PDF file article I wrote that covers my installation and things that need to be considered from a marine perspective.

There is also great information on EVTV.ME and the DIY Electric Car Forum, but nothing exactly like a single overview Im aware of.

Pro BMS

Here are my thoughts regarding using LI as your house bank (essentially that is what we are doing).

I like the idea of a BMS - it gives you information on all the cells. The main way to protect your investment is to keep the individual cells within spec this means running them down too low and/or over charging - EACH CELL.

The BMS we installed (custom engineered from Balqon) has a remote display at the helm. It not only shows the pack voltage (total battery, in our case 48 v nominal), but high cell voltage, low cell voltage, charge/discharge rate in amps, cell temp, total amp hours available (and as a percentage), and BMS temp.

Additional pages on the BMS allow for manually connecting/disconnecting the battery from the bus - connecting/disconnecting charging devices - connecting/disconnecting load devices. It also "specks" via CanBus to the Elcon 3kW charger.

But most importantly, it will disconnect charging devices should ANY cell approach its upper limit (in our case 3.8v) AND disconnect the battery from the bus should any cell reach 3.9v - after this, the cell starts to damage itself. It works in a similar manner on the discharge side, with disconnecting loads .1 v before disconnecting the battery itself. This is the only way the battery can keep from damage unattended.

One big surprise to me (not, I'm sure to the EEs out there), was upon connecting the battery to the bus, we kept welding contactors closed, thus preventing the battery from disconnecting from the bus. Turns out the capacitors in the inverters were causing a voltage surge. A simple resistor wired between the contactors and a delay relay to close the on/off solenoid (after the capacitors were charged) solved the issue.

And, on a boat, you are most likely going to have an inverter. And will want some sort of safety mechanism to disconnect the battery. Reading total voltage of the pack will not do the job by itself - all it takes is one cell at 3.0v to keep the reading of a 12v battery at 13.4v even though one cell could be 4.0v while the other two are at 3.2v each. This is not your grandfather's LA battery!

BMS would equal Battery Management System?