Lithium Install on a MkII

[KeelsonGraham]

Has anyone here done a lithium installation on a Mk II?

I'd like to do a complete Victron set up with 2 x 200ah batteries, smart BMS, Phoenix 12/2000 inverter and a smart charger, but I'm struggling to think of spaces for fitting all the different components. The batteries wouldn't be a problem, but the inverter is a big beast.

[Stu Jackson]

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The batteries wouldn't be a problem, but the inverter is a big beast.

KG, in 1998 I installed a big, heavy Heart Interface Freedom 15 I/C.  I, too, was struggling with location.  At the very same time, Capt. Al Watson in Connecticut was doing the same with his Freedom 10.  I was in California and we "met" each other on this C34 website before the forum began in 2001, so we did it by email.  We agreed that the most opportunistic location was under the nav station desk.  Both of us chose to mount it on the sloping side of fiberglass on the outboard side.  On our Mark I boats that is NOT the hull, but a completely separate wall of fiberglass before the hull with a large air gap between.  Since then I have read about some skippers using the wall between the hanging locker and under the desk, too.  We chose that location because it was close enough to the battery box to run the heavy cables from the I/C through the macerator compartment, under the cabin sole, to the battery box.  Here's Al's writeup from the old Projects page in the pre-forum static website: https://www.c34.org/projects/kindred-spirit/inverter.html

The very best primer for lithium systems is Maine Sail's on his marinehowto website.  https://marinehowto.com/drop-in-lifepo4-be-an-educated-consumer/

Cruisersforum.com also has a good lithium section, trust contributor "jedi" above all others, he knows his stuff.  https://www.cruisersforum.com/forums/f166/

Please be warned:  The amount of misunderstanding of basic battery technology, even before the complexities of LiFePO4, is simply astounding.  Many people didn't understand how wet cell batteries got charged, what acceptance is, or how alternators and regulators work, even before LFP.  Couple that with LFP and BMS and you end up with the blind leading the blind asking increasingly inane and ridiculous questions.  So, when reading on this subject, carefully consider the sources; the good ones like Maine Sail and jedi are worthwhile.  Most people asking seem to have avoided Maine Sail's 101 completely, and keep reinventing the wheel.  I also continue to get a kick out of people putting in huge LFP banks with tremendous acceptance rates and then limiting their charging ability by funneling it down with wonky small 30A dc-to-dc charger, when a 400 ah LFP bank could easily absorb 150A all the way from 20% to 95% SOC.  Why bother?

[KeelsonGraham]

Thank you Stu. I was thinking about the chart table locker and wondering about the cable run. It sounds like the Mk II is very different from the Mk I.

I've read that article and, frankly, I think it's safer (for me) to find an electrical engineer to do the installation.

Before that I just wanted to try to work out where everything could go.

[waughoo]

I am looking at a somewhat similar set up.  I am curious why you want a separate charger.  Victron makes a multiplus 12v/2000w/80amp inverter/charger.  This saves at least one pice of equipment to find a place for. 

The 2k W multi in my build will live at the VERY back of the hanging locker to allow it to still work as a hanging locker.  From that spot to the battery box, 4/0 wire will carry sufficient ampacity for the device.

The c34's batter box is frustratingly small.  I do believe two of the 200ah batteries from victron will fit in the box.  The hard part will be the fusing.  The victron lynx bms connected to a lynx distributer will not fit ANYWHERE in the batt box with batteries installed.  Thus, you'll need to get creative with how you arrange it all in there, or perhaps move some of that equipment out of the batt box.

The last item to consider is your insurance company.  I found that my current carrier would allow LFP batteries but that a receipt from a marine electrician who installed the battery was required along with the equipment being sourced from a supplier with a US presence.  That would not be too hard to accomplish with victron.  Finally though... the insurance company would increase my policy amount by 35% !$@$@#!!

I have spoken to my broker and she believes she has found another company that will work, but I am still sorting that out.

[KeelsonGraham]

Hi Alex,

I've looked at the Multiplus, it's a very large bit of kit and my worry is the cable length required to run to somewhere it can fit nicely.

The insurance aspect is definitely troubling me. I've been looking for a qualified electrician to do the job for me.

Having read MaineSail's article and a ton of other stuff, I'm starting to think that this isn't a viable project. There are just so many ways to fry the hugely expensive components.

[waughoo]

To me, it is a significantly safer system than a lead acid or an agm system due to canbus enabled batteries and charge sources.  The issue though is that most boat's charging infrastructure is old enough not to have the correct charge profiles for LFP which dictates a fair amount of infrastructure upgrades to get the boat set up for LFP.  After that is done though, the benefits are huge.

As for the multi vs the Phoenix, they will require the same wire gauge to opperate (2000w Phoenix inv and a 2000w multi use the same cabling).  I also believe that the Phoenix is approximately the same size as the multi (It was a long time ago that I compared them though).  I honestly doubt there is any reason to separate the inv and charger for your install.  It will complicate things and require you to find more space to mount components.

What I have been doing is upgrading the infrastructure piece by piece so that I can then switch from lead acid to LFP and only have to change the charge profile in the chargers (multi, ws500, and mppt solar if I have any by then).  It allows me to spread the cost and disruption out a bit over time.

[Noah]

Don't mean to hijack this thread, as I own  a MKI , but thought I would jump in for perspective and to check for flaws in my thinking. I have a one-year-old, 460A FLA (4 Trojan 6v) house bank and FLA start battery on an echo charger. I could change my house bank to LFP and swap echo for DC/DC to start battery—my battery charger has the LFP profile as does my Balmer regulator. I also have a 2,000 inverter, all with big "new" wiring and proper fusing. BUT...to what end? My shore power charger is only 40A, my alternator is 95A, and I do not have solar. So, unless I decide to go long distance cruising (which I don't) and want to add high charge-rate output equipment (bigger alternator, which would be a tight fit for anything substantially larger), a bigger shore charger (maybe), and add a solar arch or Bimini with solar, I don't think I would significantly benefit. I think I will just have to stick with my current system and run my engine to charge at sea or at anchor. I get about 3 days at anchor before I need to run the engine for an hour or so, to top back up. Pretty old school but, it will have to do for me under my current thinking. Am I missing anything in my logic?

[Stu Jackson]

Noah,

No, you're not missing anything.  The choice of going to the LFP option is, I believe, primarily How You Use Your Boat.  And you have addressed that quite well.

The advantages of LFP battery technology are:  1)  greater USEFUL storage in the same ah capacity - LFP batteries can "use" between 100% down to 20% of their rated capacity, whereas wet cell technology can only use half;  2) lower voltage sag as SOC declines;  3) ability to absorb much HIGHER recharge rates.

#3 is why Maine Sail notes that the supporting electrical generating capacity part of your SYSTEM is a critical component of any LFP upgrade.  Absent higher capacity alternators properly controlled this important part of LFP technology is essentially wasted.  That's why, for example, I mentioned the use of low amperage dc-dc chargers as a silly way to deal with LFP.

Noah's comments are a perfect example of addressing a Balanced Electrical System.

Alex's post addresses it well also.  His choice makes just as much sense for the way he plans to use his boat.

[waughoo]

Don't mean to hijack this thread, as I own  a MKI , but thought I would jump in for perspective and to check for flaws in my thinking. I have a one-year-old, 460A FLA (4 Trojan 6v) house bank and FLA start battery...

Noah,

You are in the position of being able to switch to LFP due to having updated/current charge sources, but not really needing to.  The benefits to you are somewhat nil as you are perfectly happy with what you have.  Nothing wrong there (as Stu says).

For me, I want to be able to be on anchor for multiple days WITHOUT running the engine again until I decide to change to another spot.  If for some reason I NEED to recharge at anchor, I want the ability to put a lot of charge in with a short run period.  I HATE noise at anchor so being able to be quiet is king for me.  Even if one has a big alternator and a lead acid bank, the resistance of lead acid limits how much charge you can put back before the current is reduced.

My additional issue is voltage sag with loads.  In watching my current lead acid bank, I routinely have 11.8v powering pumps and things which is just not good for the equipment and at that voltage, the equipment draws more watts.  The last time I was out on the boat, I could not get the furnace to light the glow plug due to voltage sag causing a cut out in the light up procedure.  Because it tries a couple times, the effect of this is the burner getting sooted up making it harder to light next time.  To resolve the cold I was experiencing (it was January at anchor for a quick overnight close to home), I had to start the engine to get the battery voltage up and then it would start the furnace.  While it was on, the battery could power the fans, fuel pump and circ pump (without the engine running), but once the burner shut off, I had to restart the engine again to get the voltage up.

I'll admit the above is also partly due to the age of the batteries, but this is something that just DOESN'T occur with a LFP battery bank.  The pack voltage is so incredibly stable for the duration of usable AH's that it is almost like having a DC conditioner providing power.  This is even true with LARGE inverted loads.  For me this is a big benefit of LFP.

As for the safety comment, as one has all these multiple charge sources working together, having a canbus enabled network for the chargers, consumers, and the bms allows the battery to tell all the chargers and consumers what to do.  The thread we've done a lot of discussing about recently was the shore power and alternator charging at the same time.  With a multi-plus battery charger (shore connected), and a WS500 alternator regulator all talking together on the same canbus with the batteries, the batteries would just tell the regulator, "no thanks... I'm full, please stay at idle).  This is the safety I am referring to.  Additionally, the canbus connection can avoid load dumps from unannounced disconnects etc.  This is not true with a drop in battery, but when they are all meant to work as a system, these safety features are part of the gig.  For me, this is a BIG improvement over the lead acid set up.  It is an elegantly designed system that has a lot of sophisticated networking that happens in the background so I can just enjoy the benefits without having to be that sophisticated monitor when out on vacation!

So... do I need a LFP house bank?  Well, I suppose I don't NEED one, but it sure would... strike that... WILL make cruising my boat the way I use it so much more pleasant with regards to what is important to me.  Plus... I sure do love a good technically challenging project! 

[Ted Pounds]

Thought I'd throw this blog out:

https://www.litime.com/blogs/blogs/battery-management-system?_pos=1&_sid=946d3f521&_ss=r

A good friend of mine replaced his 6 8V FLA batteries in his golf cart with one 48v LFP battery.  He is raving about the difference.  No maintenance and no worries about SOC (other than is there enough to get home 😉). With LFP you can go with half the amp hours because deep discharge is not a problem.  Also, if you can, it's better to go with one battery because the built in BMS will take care of balancing the individual cells.  With multiple batteries you will have to periodically charge them individually to keep them balanced....

[Noah]

How does he run his 12V equipment?

[Ted Pounds]

How does he run his 12V equipment?

Good question.  In his case it's just lights for driving at night, two headlights and two taillights.  He took all four and rewired them in series to run off the 48 volts.  Another option, which I will do on my golf cart, is to buy a 48v to 12v converter.   They're available on Amazon among other places for around $21.

[robbjd]

Keel, I did a LiFePo conversion the second season we had our Mk2. I have two Expion 100 Ah Gp27 batteries mounted on their triple battery mount tray, and an AGM starting battery mounted beside them. I installed a Victron Cerbo GX with a Touch 50, a 500 amp smart shunt, a Smart solar 100/30 MPPT solar controller, a Orion TR smart 12/12-30 DC/DC charger, and I use a Blue Smart 12/15 IP65 charger to top up either battery set when needed. The Expion batteries recommend a maximum charge current of 50 amps, but I never need more than the 15 amps provided by the 12/15. The batteries and shunt are installed under the seat in front of the sink, The DC/DC charger and Blue smart charger are under the sink with the charger plugged into an outlet that I installed when I removed the original charger. We have an 1800 watt inverter that came with the boat under the starboard seats, and a 230 watt solar panel mounted on our davit arch. The Cerbo, MPPT controller, breakers, and a Vesper AIS are mounted in the small cabinet forward of the chart table. By replacing the 6v batteries I have shed about 25 Kgs.

[Jim Hardesty]

I've been thinking about buying this.   
https://www.eblofficial.com/products/ebl-2000w-portable-power-station

Advantages for me, self-contained, fast charging with shore power or my Honda generator (2hours), solar possible, fits under nav table

Disadvantage for me, not integrated into boat, wouldn't hook up to start boat or charge from engine.

Saw it here.  There's many posts on Lithium batteries, it's a work in progress for them so some information is outdated and updated in later posts.
https://www.youtube.com/watch?v=HlZ_9SJeeVE&list=PLsT7_jPsZM5pFpq8RX0oxjibknM2Gz361&index=91

My question for the more knowledgeable, how long will it run my Engle freezer? It uses 1.2 amps, estimate it runs about half the time to keep food frozen hard.

I would appreciate any comments pro and con to help me make a decision.
Jim

[KWKloeber]

Jim

It's "listed" at 2096 Wh or at 12v that's 175 amp hours. 
1.2 amp is about 14 watts for the freezer. 
2096 watt hrs / 14 watts x 2 = about 150 hours, OR at 50% on-time = about 300 hrs/12 days running the freezer.

But there's no indication at what output amperage rate the watt-hours rating is calculated.  i.2a isn't high so I'd think that the Wh capacity would be reasonable (IF the w-hr number was actually tested and is correct and not exaggerated.)  EBL is a pretty good company in my very limited experience using it's batteries. 
IIWMB I'd probably reduce the capacity by 25% and ass/u/me that you'd get 9-10 days on a full charge.     

-Ken