# Leaf batteries for sailboat house batts



## witzgall (Aug 23, 2011)

Hi all,

My wife and I live aboard our sailboat, a 44' ketch. On our previous boat, we had a 400ah L12v LIFEpo4 bank that served us very well. Over the two years of cruising up and down the east coast and to the Bahamas, we were a rare breed using this technology. Now, this has changed and many others have embraced their use.

Our current boat is a 24v boat. This is for house power, used for the lights, instruments, refrigerator, windlass, starting, etc.

Our charging sources are the alternator (adjustable regulator) generator/charger and solar. We can control all charging sources well.

Now you have the background. I am interested in the Leaf batteries, but the voltages are a bit off of what I would like to see. On our 24v system, we can safely use from about 29.5v to 22v, so seven cells in series would be perfect, but not doable without opening up all of the modules, something that does not appeal to me.

Without opening up the modules, I think we could use the leaf modules 3sXp to get the capacity we want, and then discharge only to 3.5v at the cell level, and charge to 4.15v, discarding some pack capacity on the top end and lower end (where we would not go anyways on a LIFEPO4 setup). This would put us from 24.9v to 21v. The voltages are lower than I would like, but most of the gear on the boat would work just fine at these voltages. The only thing I worry about is the windlass, but typically only use that with the engine running, so it may not be a problem.

The highest current draw is the starter for a second or so (engine starts in about 1 second) and the windlass at perhaps 50-70a. 

I would carefully top balance them before install, and I don't imagine the need for additional balancing at these fractional c-rates. How are those of you using these cells "Outside" of a Leaf balancing? Mini-BMS appropriate?

I am soliciting opinions as to the feasibility of such a use?


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## pgt400 (Jul 12, 2008)

I've been bulk charging to 90 volts....discharging no more then 50 ah. 11S1P modules. So far the cells stay within .025v of each other... .050 at the module.


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## onegreenev (May 18, 2012)

Taking apart the Leaf Modules is not going to happen. They are built in such a way you would ruin them trying to un-glue them. Don't bother trying. Be careful, these are steel cases and can rust. Might consider the standard LifePO4 because of the plastic cases. Id be concerned in a salt water environment. If you can keep them safe and sound get the new Lizard Leaf Modules instead of the early versions. With low voltage setups maybe the early ones would be good if you parallel many for high amp hours. 

Pete 

But don't tear them apart.


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## witzgall (Aug 23, 2011)

Yes, I agree about taking them apart. Concerning the cases, that is something I would have to think about , but the compartment they would be in is rather dry. I could always paint the exposed surfaces. There are lots of reasons LIFEPO4 would most likely be a better choice, except price. 

Lizard battery? I googled that, do you mean a 2013 or newer? Are the cells themselves different?


I was drawn to the LEAF batts over the Volt cells because of a perceived difference in their discharge curves. It looks to me like the Leaf's are a more steady taper in voltage, and the Volt's fall down into the sub 3.65v range too early in their discharge. Of course, If I could take apart a volt batt and re-configure to parallel cells more easily, that would be a huge plus.

Chris



onegreenev said:


> Taking apart the Leaf Modules is not going to happen. They are built in such a way you would ruin them trying to un-glue them. Don't bother trying. Be careful, these are steel cases and can rust. Might consider the standard LifePO4 because of the plastic cases. Id be concerned in a salt water environment. If you can keep them safe and sound get the new Lizard Leaf Modules instead of the early versions. With low voltage setups maybe the early ones would be good if you parallel many for high amp hours.
> 
> Pete
> 
> But don't tear them apart.


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## Karter2 (Nov 17, 2011)

onegreenev said:


> Taking apart the Leaf Modules is not going to happen. They are built in such a way you would ruin them trying to un-glue them. Don't bother trying. Be careful, these are steel cases and can rust. .


Hmm?.. No personal experience on this but....
From other posts by folk who have dismantled these modules, they comment that the cases are Aluminium (clear coated) rather than steel, and the cells are not glued together.
Also, it has been shown possible to re terminate the cells into a 4s, 1p configuration without removing them from the module cases. Although not a job for the novice.!


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## onegreenev (May 18, 2012)

witzgall said:


> Yes, I agree about taking them apart. Concerning the cases, that is something I would have to think about , but the compartment they would be in is rather dry. I could always paint the exposed surfaces. There are lots of reasons LIFEPO4 would most likely be a better choice, except price.
> 
> Lizard battery? I googled that, do you mean a 2013 or newer? Are the cells themselves different?
> 
> ...


Not sure exactly when the Lizard Modules were introduced but they are better than the first two years. So 2013 sounds right. I'd for sure pick these over the Volt modules. Price is good. Just make sure they are high and dry. Not being able to properly take a module apart to reconfigure sucks.


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## witzgall (Aug 23, 2011)

I too thought they were aluminum before the previous post here, that is better for us.

Concerning re-terminating, are you taking about the guy who dismantled them and rewired on youtube? If so, I would not want to do it that way. These need to be rock-solid, I would need to be able re-orient them so that the + and - all lined up for the paralleling, and again for the series, so that the tabs could be mechanically clamped. Imagine being hundreds of miles out to sea in your home and finding a short that would leave you without power or much worse.



Karter2 said:


> Hmm?.. No personal experience on this but....
> From other posts by folk who have dismantled these modules, they comment that the cases are Aluminium (clear coated) rather than steel, and the cells are not glued together.
> Also, it has been shown possible to re terminate the cells into a 4s, 1p configuration without removing them from the module cases. Although not a job for the novice.!


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## piotrsko (Dec 9, 2007)

witzgall said:


> I was drawn to the LEAF batts over the Volt cells because of a perceived difference in their discharge curves. It looks to me like the Leaf's are a more steady taper in voltage, and the Volt's fall down into the sub 3.65v range too early in their discharge. Of course, If I could take apart a volt batt and re-configure to parallel cells more easily, that would be a huge plus.
> 
> Chris


*
Comes as a complete surprise to me*.

at HUGE discharge rates, they drop fast, but I have a pack right now that is at 1/2 discharge and it is at 3.75. only reason i'd use a leaf pack is that good low time packs are easier to come by than a cheap 4 year old wrecked volt pack. the volt packs come as 6s3p and 12s3p sub packs except for manifolding about the same size as a 12v FLA of same capacity..


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## bigmotherwhale (Apr 15, 2011)

witzgall said:


> Hi all,
> 
> My wife and I live aboard our sailboat, a 44' ketch. On our previous boat, we had a 400ah L12v LIFEpo4 bank that served us very well. Over the two years of cruising up and down the east coast and to the Bahamas, we were a rare breed using this technology. Now, this has changed and many others have embraced their use.
> 
> ...



If i had a leaf pack i wouldn't use it for powering the lights pump etc 
i would probably install an electric motor and solar panels and or wind turbine and use it to power the boat, you could even keep the engine and use it as a simple hybrid saving fuel costs.

It seems like a waste of high discharge cells when you could get away with a cheaper higher capacity lower discharge rated pack that is better suited to your needs.

saying that, the pack could easily be split into modules, and a suitable BMS installed.


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## hmincr (Jan 20, 2012)

I have 2012 Leaf cells. They ARE stuck together with a blue plastic separator. The cans are aluminum. I cut them open to get the cells unstuck, so I could slide the group of cells out. 

I used WD40 sprayed in between the cells and used a piece of hard plastic, with a sharpened and rounded edge, to VERY slowly push between the cells and blue separators. IF this is done slowly and carefully, using sufficient WD40, the cells come apart easily with NO wrinkling of the foil pouches. I can't emphasize enough, PROCEED SO SLOW IT HURTS. You COULD wrinkle the cells. Then, I rearranged the cells to prevent shorting out the tabs from cell to cell, and soldered #10 very thin flNE strand wires to the tabs, to make the 5S1p packs. Added heavy pieces of plastic as tab/wire separators, and coated all connections with Liquid Tape. That is one fine invention. 

I sprayed the cleaned off separators and cells with a spray contact cement, and pressed the cells together. On the + and - tabs of the 20S 1P pack, I drilled through the heavy copper tabs (that are crimped/soldered to every battery tab), and bolted on the battery leads that ran to the terminal strips and to the controller. 

I made a wooden open top box frame, and made fibreglass pouch boxes, open on one flat side, with all sides flanged, and padded the edge with carpet underlayment foam, for support. I bolted the cell groups, 5S each, back to back with a double layer of laminated door skin 3/32" thick each, to make a 3/16" thick plywood separator that was bolted inside the frame of my homemade Bicycle/motorcycle. I put a through bolt trough the plywood, and used some VERY stuff wood we have here, as pads just a little smaller than cell size, and bolted 2 sections of car leaf spring that I drilled a center hole in, on each side of the bike, and supplied sufficient force to compress the cells.

This gave me a width of 4" total, so I could pedal the bike/moto, if I needed to. Down here in CR, pedals means it's a bicycle, no matter how powerful or fast you ride on the roads. 

I now have a Chevy Volt battery, that I am mounting an 18S or 20S pack in that same frame, that I modded a little. That gives me 3Kwh pack. I should be able to ride to town 8 miles each way, up some serious hills and regen some, back into the battery, for now. 

Leaf cells will be wired up in 12-24V battery for house use. Power Co. SUX down here.

Next project is a leaning tadpole Bicycle/motorcycle. This one I am modding, should get me around locally just fine.


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## dcb (Dec 5, 2009)

modifying 1 (and only 1) module to be [email protected]~3.75v isn't too bad, you don't have to dissect the whole thing but you can cut the aluminum carefully off the end and cut through one of the bus bars to break the series connection then sort out how to parallel what is left (solder if not too much current draw is fine).

then you can put 6 unmodified modules in 2p3s(6s?) and add this to it and have 120ah.

I would leave it in the aluminum case though. Most modders are looking to put them all in series for ~15v/module, but you are looking to put them all in parallel @~3.75v, 

lots of info in this thread and various dissections:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=52162


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## Caps18 (Jun 8, 2008)

I would ensure that you have two ways to prevent an overcharge from happening. If you aren't on your boat on a sunny day, you don't want your solar controller failing and sending high voltage to these batteries.

http://www.voltaicsystems.com/blog/solar-charger-tutorial-part-4-battery-protection/


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## onegreenev (May 18, 2012)

Karter2 said:


> Hmm?.. No personal experience on this but....
> From other posts by folk who have dismantled these modules, they comment that the cases are Aluminium (clear coated) rather than steel, and the cells are not glued together.
> Also, it has been shown possible to re terminate the cells into a 4s, 1p configuration without removing them from the module cases. Although not a job for the novice.!



Yes, you are correct. The cases are aluminum but the spacers are steel and can rust. The spacers are also for between module support. If you could build the cheaply or cast them cheaply you could make some out of aluminum. I'll post a video on what these are like stuck together.


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## Karter2 (Nov 17, 2011)

Anyone contemplating a permanent marine installation of this sort would need to check/change many details to ensure a reliable and safe result.
Lots of fasteners and brackets would ideally be changed to marine grade stainless or similar.
However, I doubt there are many unprotected steel components used in the Leaf pack with modern anti corrosion processes rendering serious rusting a thing of the past. I suspect those steel spacers would be nickel or Aluminium electroplated as a minimum, but likely with a secondary coating also.
How long does a modern steel exhaust system last ?


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## witzgall (Aug 23, 2011)

Yes, there are many considerations to make a safe installation on a boat. I am the service manager of a yacht servicing business, and we see poorly or worse dangerous installations done by well intending but unskilled/unknowledgable owners all of the time.

I would also not ever recomend anything but a commercial battery system for anyone that asks me, because if they have to ask, then that is what they need. 

The idea of running at lowrr voltages is not going to work, i am afraid, as the alternator regulator i wanted to use will not work in these lower ranges, i thought it would.

Chris



Karter2 said:


> Anyone contemplating a permanent marine installation of this sort would need to check/change many details to ensure a reliable and safe result.
> Lots of fasteners and brackets would ideally be changed to marine grade stainless or similar.
> However, I doubt there are many unprotected steel components used in the Leaf pack with modern anti corrosion processes rendering serious rusting a thing of the past. I suspect those steel spacers would be nickel or Aluminium electroplated as a minimum, but likely with a secondary coating also.
> How long does a modern steel exhaust system last ?


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## aeroscott (Jan 5, 2008)

sailors sometimes use a hand controlled regulator(rheostat) .just add a low and high cutoff relay.


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