Lithium upgrade on RT27-OB NW edition

I just finished upgrading my 3 Fireflies AGM batteries to a single Lithium Iron Phosphate (LiFEPO4 or LFP for short) house battery. A single 320Ah LFP battery.

The benefits of this upgrade for me over the Firefly AGM's:
* I left 160lbs of battery weight on the dock.
* I recouped two-thirds of my center cockpit lazarette space for storage.
* I acquired one-third more space in the port lazarette for storage.
* I can run the inverter for high wattage loads down to 20% SOC (minimal voltage drop).
* I cleaned up the wiring chaos from my bus bar installation.

This upgrade was not only expensive, it was very time consuming and extremely technical in nature. But I'm glad I did it. We took the boat out last weekend, two days of no shore-power, for sea-trial to test out the new house battery (and really, my entire electrical system).

I worked directly with Bruce Schwab at Ocean Planet Energy (paid engagement) on this upgrade. He provided design review, component selection assistance and validation, as well as oversight and installation review. A second set of eyes to make sure I didn't miss anything, as well as a fantastic technical resource I could ask questions to.

I'm also asking for your help. LaZina and I are working on a video (NW Edition upgrade to LFP) for our YouTube channel (Let's go channels surfing) and thought we'd solicit questions from you, to make sure when we record the video next week we don't leave out any important details.

I've just published to our web site a ton of photographs of the upgrade (a slide-show). It's a visual story of the upgrade. I also did a technical write-up and published the design drawings I created for this project (electrical wiring schematics, logical and physical wiring diagrams). I don't want an unsupportable boat. Thus, every change I make must be documented first, in detail. ABYC standards were also very important to me as I want to make sure my boat is safe and would easily pass a marine survey.

Ranger Tug (And Cutwater) offer (6) 100ah Dakota Lithium Iron Phosphate (LFP) on their Luxury editions with air conditioning, but not on their Northwest Editions. Channel Surfing is an RT27-OB Northwest Edition and came with AGM batteries. I went with a UL approved Lithioncs 320Ah single battery.

This is also the catalyst for another upcoming video we're working on which is to go over how the electrical system works on an LE and NW edition (factory standard).

Please drop any questions you have about this LFP upgrade and I'll be sure to answer them when we record the upcoming YouTube video.

Channel Surfing Upgrade to LFP
https://www.letsgochannelsurfing.com/lithium

Electrical Schematic
https://www.letsgochannelsurfing.com/_files/ugd/b6c9c0_c62cce46057c4a50b1a7ddf8bc5b5cfc.pdf

Port Lazarette - Port Side
https://www.letsgochannelsurfing.com/_files/ugd/b6c9c0_396b08a665d44ad58e2849aa670cee42.pdf

Port Lazarette - Starboard side
https://www.letsgochannelsurfing.com/_files/ugd/b6c9c0_8e4f977e41344232bfbe979594add5bb.pdf

Cockpit Overview/Layout
https://www.letsgochannelsurfing.com/_files/ugd/b6c9c0_e05fb51d6c2045739d0af5e004d42c3a.pdf

This is brilliant -- thank you for documenting these and sharing. I can only imagine how much trial and error you've saved people.

We're already looking at a solar and Lithium upgrade....

EDIT: Need to watch the video, only looked at the diagrams.... but did you move away from the Victron Skylla-IP65? Or did I miss something?

gregc":3h695v1r said:

This is brilliant -- thank you for documenting these and sharing. I can only imagine how much trial and error you've saved people.

We're already looking at a solar and Lithium upgrade....

EDIT: Need to watch the video, only looked at the diagrams.... but did you move away from the Victron Skylla-IP65? Or did I miss something?

Click to expand...

I replaced the Victron Skylla 70amp battery charger with a Kisae ABSO 60amp battery charger, dedicated to the house bank. The Kisae ABSO 20amp charger which came with the boat, I disconnected from the house bank. It only charges the engine and thruster batteries. I'll go over the reasons as to why in the upcoming video.

Very impressive. The quality of your documentation and workmanship is very professional.

One of your goals is to run the water heater from the inverter.
Was the limitation with the Fireflys due to a maximum current limitation or battery capacity?
Can the new single 12V battery provide more maximum current than the previous batteries in parallel?

In one of the pictures I see a coil of wire in the box with the 250A circuit breaker.
I am puzzled by this. Is the extra length needed for some reason?

In one of the pictures it looks like you are getting data directly from the Lithionics battery.
Does it have a built in Bluetooth interface, or is there another interface that makes this possible?
(I wish the Dakota batteries in my R27 LE could provide that information)

Does your Dolphin dinghy still fit in the center lazarette, or do you stow it somewhere else now?

Great work, and thanks for sharing!

Mark_H":13mlxpms said:

Very impressive. The quality of your documentation and workmanship is very professional.

One of your goals is to run the water heater from the inverter.
Was the limitation with the Fireflys due to a maximum current limitation or battery capacity?
Can the new single 12V battery provide more maximum current than the previous batteries in parallel?

In one of the pictures I see a coil of wire in the box with the 250A circuit breaker.
I am puzzled by this. Is the extra length needed for some reason?

In one of the pictures it looks like you are getting data directly from the Lithionics battery.
Does it have a built in Bluetooth interface, or is there another interface that makes this possible?
(I wish the Dakota batteries in my R27 LE could provide that information)

Does your Dolphin dinghy still fit in the center lazarette, or do you stow it somewhere else now?

Great work, and thanks for sharing!

Click to expand...

Thank you!!
I'll be sure to answer all these questions in the upcoming video.

I'll answer the question about the bluetooth interface now, though. Mainly because it's pretty darn cool.
Lithionics has it's own built-in battery monitor. Bluetooth to the battery via an app on my phone. The install requires a physical battery monitor gauge. But Lithionics doesn't mandate that you use their physical gauge. I already had a Victron BMV-712 installed so I continue to use that. But it's nice to be able to bluetooth connect to the Lithionics and see more detailed stats, such as voltage between the four cells.

Li3 also does one other fairly unique thing... they keep track of the following stats:
* Total Consumed Amp-Hours - Like an odometer.

* Aging Factor Temp - which is the amount of time the battery is operated at high temperatures. The algorithm is a sliding scale that adjusts for actual temperatures.

* Aging Factor SOC - The amount of time the battery sits at full charge and non-use. All batteries lose a small out life if they sit fully charged for long periods of time with no periodic cycling. The loss has been measured by some researches to be 3 percent of capacity loss per 6 months o high state of charge storage.

For warranty, this is how the customer and Lithionics can tell how well maintained the battery has been which makes their warranty objective (rather than subjective).

The NeverDie Battery Management System tech in the Li3 is pretty cool also. Run the battery down to 20% SOC is recommended for normal operations. However, if you take it to 10% SOC, the battery will shut itself off. <click>. Lights all go out. You can then press the on button for like, 3 seconds... the battery will power back on giving you the last 10%, however.... to prevent permanent damage to the battery it must be recharged immediately. But there's basically a 10% reserve, that also acts as a safety mechanism for the Li3 battery. That gives me a 32amp-hours in reserve. I probably won't ever need the reserve. But consider the situation where shore power is lost for an extended period of time while the boat is moored and the owner is away. This will prevent the battery from discharging to 0% SOC.

The battery has a small on/off switch located on the battery. This makes maintenance easy as I can actually turn the battery off and get 0 volts across the battery posts.

Thanks for posting this information and the Electrical Schematic. I am installing a solar charging system in my Mainship. I'm sticking with lead acid for the time being. I have plenty of room and the added weight is not really an issue in a 18000 lbs boat. It is something to consider though. I can't justify the additional $$$ for the lithium at this time. I don't know how long I will own the boat. I am setting it up now so the converting over would only involve a few wiring changes and DC to DC charger. I may still install it now depends on Budget. I have ordered two 335W 24V panels and a 100/50 Victron, I have 580 AH of battery (lead Acid) so 290 AH usable. Using lead acid batteries requires more solar to help full charge the batteries. Advantage of lithium you don't need to full charge as often as you do with Lead acid.

Thanks for the detailed explanation.
Looking forward to the videos.

BB marine":2q3l4pa6 said:

Thanks for posting this information and the Electrical Schematic. I am installing a solar charging system in my Mainship. I'm sticking with lead acid for the time being. I have plenty of room and the added weight is not really an issue in a 18000 lbs boat. It is something to consider though. I can't justify the additional $$$ for the lithium at this time. I don't know how long I will own the boat. I am setting it up now so the converting over would only involve a few wiring changes and DC to DC charger. I may still install it now depends on Budget. I have ordered two 335W 24V panels and a 100/50 Victron, I have 580 AH of battery (lead Acid) so 290 AH usable. Using lead acid batteries requires more solar to help full charge the batteries. Advantage of lithium you don't need to full charge as often as you do with Lead acid.

Click to expand...

670watts of solar... OMG. That'd be fantastic to have. 🙂

Space and weight is definitely an issue on the 27' and smaller boats. The RT29, C30, RT31, all come with 4 house batteries (440ah total (200ah usable)). The RT27-OB came with 220ah total (100ah usable). We consume between 90 and 120ah a day. 200ah usable battery capacity and around 300 watts or larger of solar seems to balance well here in the Pac Northwest.

Lithium helps a lot with the inverter for 120volt AC loads. The marketure says "All the volts, all the amps, all the time", as there's very little voltage drop with LFP when it's under load.

We were out 2 weeks ago on the boat for a weekend getaway. No shore power. 400 watts of solar, in early March, in the Pacific Northwest. We had fantastic weather, sunshine and blue skies. I was getting 1000 watt-hours a day. (about 80 amp-hours). And it'll only get better from here with each passing day as summer approaches.

In late January, in the fog (all day in the fog), I was able to capture 22amp-hours. Not much, but not zero either. September time-frame, rained all day, and I captured 49amp-hours. My high score last summer was 2,700 watt-hours (225ah). I love our 400 watt array. I wake up in the morning and check the battery monitor only to find the batteries are being charged.

Submariner":1qwhdrjs said:

Ranger Tug (And Cutwater) offer (6) 100ah Dakota Lithium Iron Phosphate (LFP) on their Luxury editions with air conditioning, but not on their Northwest Editions. Channel Surfing is an RT27-OB Northwest Edition and came with AGM batteries. I went with a UL approved Lithioncs 320Ah single battery.

Click to expand...

Martin,
I may be the odd ball R27, but my 2021(late 2020 build) came from the factory with three 200 ah Lithium batteries (one AGM starter, one AGM thruster), and two of the stock solar panels... Andrew was a dream to work with, I know they spent some time sorting out how to add the additional amp hours that I requested...

Cheers,
John

I will be following this with great interest.
LiFePo are less of a fire hazard than straight lithium batteries.
I have had lithium batteries short out internally during recharge and melt down in an impressive display of huge flames for such a teeny-tiny battery. Luckily, each time I was recharging on a cement floor and away from flammables.

Two questions come to mind just in general on this topic - not specifically aimed at the OP of this thread who is getting getting expert advice.
Has your boat insurance company been made aware of the installation and (in writing) approved it?
This question also applies to home and auto insurers for those who tow and home store their tug.
Does your marina have a rule on these batteries?
From my experience, you don't really understand how powerful and dangerous these batteries are when short circuited - even accidentally for only the tiniest fraction of a split second when something gets dropped and bounces off a hot terminal.
These batteries are mini-nukes in sheeps clothing. I am not saying they should not be used. I am usingg some. I am saying they are not your fathers Oldsmobile. Just be aware.

Submariner":1uh2cgzq said:

Lithium helps a lot with the inverter for 120volt AC loads. The marketure says "All the volts, all the amps, all the time", as there's very little voltage drop with LFP when it's under load.

Click to expand...

There is no doubt that the lithium battery is the future. Every article, installation manual, solar site that I have read or visited claims best results with solar panels, solar controller and Lithium battery combination. Flooded non-maintenance free is acceptable if properly maintained and fully charged. The weight to AH ratio is not desirable. We are venturing into a new style of boating and looking forward to the experience of a larger boat. I'm not sure if this is long or short term. I'm hoping for long term but we have to give it a year or so to see what we think. ( I have always been an open boat, center console boater and never owned the same boat for more than two years) Purchasing the C26 Cutwater in 2016 was a big change for me. I owned that boat longer than any boat in my 45 + years of boating and used it differently. It was the little boat that "COULD". 22 boats and counting, including the now Mainship Pilot 34. I was a two boat owner several times.

While the lithium for long term is the way to go unquestionably. I'm not sure what the long term is for me with my boat. I will get a feel for it going on the conservative side when it comes to batteries. The solar panels, MPPT solar charger controller, 3000W inverter, larger battery charger, cables, battery monitor will all be in place. The battery choice presently is (4) 100 ah group 31 flooded ,deep cell, cap top batteries (House and inverter bank) and (1) 4D 180 AH Flooded cap top thruster battery that can be combined with the house bank when needed. Two heavy duty Group 31 flooded maintenance free cranking batteries one for each engine. Total cost = 1300.00 for all new batteries. When price shopping for 4 lithium 100AH, and the three Lead acid for thruster bank and engines I was just over 5K.

I charge with two 55 amp alternators witch is slightly more output compared to the Yamaha outboard alternator. But if the batteries are combined through an ACR the voltage regulators on the alternators may cancel out one. This may be where a DC to DC charger may help. ( this will be up graded if I go with Lithium batteries along with Balmar alternators)

Your set up is awesome. It is an expensive upgrade with a payback only to you. I did a lot of upgrades to my C26 for years of cruising. The pay back could only be appreciated by My wife and I. We put many $$$ into the upgrades. The value of the boat did not increase because of the upgrades. I sold the boat and the new owner gets to enjoy those upgrades at no cost. I'm going to be a little more conservative this time around. My only reasons for pulling back on the lithium.

Great job on the upgrade!

GypsyMoth":pojpvcj4 said:

Submariner":pojpvcj4 said:

Ranger Tug (And Cutwater) offer (6) 100ah Dakota Lithium Iron Phosphate (LFP) on their Luxury editions with air conditioning, but not on their Northwest Editions. Channel Surfing is an RT27-OB Northwest Edition and came with AGM batteries. I went with a UL approved Lithioncs 320Ah single battery.

Click to expand...

Martin,
I may be the odd ball R27, but my 2021(late 2020 build) came from the factory with three 200 ah Lithium batteries (one AGM starter, one AGM thruster), and two of the stock solar panels... Andrew was a dream to work with, I know they spent some time sorting out how to add the additional amp hours that I requested...

Cheers,
John

Click to expand...

I am assuming with 600ah total you have the LE with air conditioning. I looked at upgrading to a pair of 200ah Dakota's first, before I went with Lithionics. I was playing Tetris with a drawn-to-scale picture of my center cockpit layout to see how I could fit them. The form factor of the Li3 was actually a huge selling point. The pair of 200ah Dakota's would have taken up most of my center cockpit storage.

Levitation":3gg0wwh9 said:

Two questions come to mind just in general on this topic - not specifically aimed at the OP of this thread who is getting getting expert advice.
Has your boat insurance company been made aware of the installation and (in writing) approved it?

Click to expand...

This is specifically why I hired Ocean Planet Energy to work with and paid them to review my design and consult with me over this upgrade. Insurance companies want to see a USA brand LiFEPo4 battery manufacture. They also require a professional installation (all ABYC standards must be followed). Bruce Schwab recommended I go with this specific Lithionics battery (the 320Ah UL approved model) for the UL approval as well.

To anyone reading this: If you've got an RT27-OB, this design will work on your boat and you're welcome to use it exactly as is. If you were to modify any part of it, an electrical review by a professional of your modified schematic would be required.

There are a lot of nuances with LFP. It's important to get it right. Just because something supports LFP doesn't mean it'll work for your installation.

BB marine":1qfputhq said:

Your set up is awesome. It is an expensive upgrade with a payback only to you. I did a lot of upgrades to my C26 for years of cruising. The pay back could only be appreciated by My wife and I. We put many $$$ into the upgrades. The value of the boat did not increase because of the upgrades. I sold the boat and the new owner gets to enjoy those upgrades at no cost. I'm going to be a little more conservative this time around. My only reasons for pulling back on the lithium.

Great job on the upgrade!

Click to expand...

Thank you!!

Our last boat we kept for 14 years. I finally sold my '97 pickup for a newer one 2 years ago. I tend to keep vehicles for a long time and wear them out. We expect that we'll keep our RT27-OB for many years as well. So upgrades near the beginning make sense as we'll get all the value out of them through use.

I also don't advocate anyone do any particular upgrade that I may have done. Everybody boats differently. Two boaters with the same exact boat can have very different boating lifestyles.