Changing house bank from AGM to Lithium on an older Outremer 55

[fxykty]

We have a 2003 Outremer 55L, a performance cruising sailing catamaran that we’ve owned for four years. In that time we’ve sailed weekends and holidays locally and had several passages and extended cruising periods in the South Pacific. We are preparing to leave New Zealand this year for extended cruising and have decided to change our AGM house bank to Lithium for three reasons based on our time with the current system:

• Avoid voltage drops due to high loads such as our windlass
• Maximise our solar, wind and alternator generation through better charge efficiency and not affected by extended partial state of charge
• More useable capacity, to enable AC water heating via inverter and an all-electric galley so we can remove propane as primary and fixed-installation cooking fuel (avoiding heat, moisture, danger and hassle of propane)

Note that reducing battery weight is not a factor, but a happy byproduct of our battery chemistry choice.

This thread is intended for people who are considering a change of battery chemistry and may be interested in our conversion. This will be a DIY battery build assisted by professional system design and a licensed marine electrician for key parts of the installation. Questions and comments are welcome.

This first post is to describe our starting point and the new components that we’ve decided on so far. We’re currently about half way through the system design, which is being done by Cameron Murray of Trans Marine Pro https://transmarinepro.co.nz/. TMP is located in Opua, New Zealand. The next post will show the completed system design.

The boat currently has a relatively standard electrical system with not much changed from the time it was built. I’ll only show the battery, charge and AC load components as there won’t be any changes downstream of the DC load bus:

• Lead acid house bank, 6x 110Ah Victron Energy AGM 12V batteries
• Starboard and port 12V start batteries (AGM)
• Generator 12V start battery
• Mastervolt Chargemaster 70/3 charger
• Mastervolt Mass Sine 12/2000 inverter
• Mastervolt Mastershunt 500A
• Mastervolt Masterview Easy monitor, control and display
• GE Mase IS 4.0 AC generator (2.9kW continuous output - added in 2013)
• 2x Leece-Neville 8MR 90A alternators, converted to external regulation for Balmar 614 regulators and a Balmar Centerfielder 2 to manage the two outputs
• Victron Energy Smart Solar MPPT 150/100 regulator fed by 3x 330W panels in series (over the davits)
• Superwind SW350 wind generator with SCR 12V charge controller
• 750W 230V heating coil for water heater
• 16A 230V shore power input (generator output is currently routed via the shore power’s ship/shore switch, as only one AC input is possible with the current charger). Note that shore power is only used when we’re hauled out, as our berth doesn’t have power and we don’t use marinas.

New components already purchased:

• 4x Winston WB-LYP700AHA battery cells. These will be mounted in series to create a 4S 12V 700aH battery Shenzhen Smart Lion Power Battery Limited. These were bought ex-factory from Julia Yu Sky Power International
• Tao Performance BMS https://www.taoperf.com/main-menu/tao-bms/. Bought direct from company director
• Victron Energy Quattro 12/5000/220-100/100 inverter/charger https://www.victronenergy.com/invert...argers/quattro
• Victron Energy SmartShunt 500A shunt https://www.victronenergy.com/batter...-battery-shunt
• Victron Energy Cerbo GX monitoring and control https://www.victronenergy.com/panel-...oring/cerbo-gx
• 2x Balmar Digital Duo Charge DDC-12/24 battery combiner/chargers https://balmar.net/products/digital-duo-charge/

[Emmalina]

There are lots and I mean lots of threads on Lithium !

[Insolent]

Hi Fxykty,

Thanks for sharing. Nothing wrong with one more thread. I for one am interested since it might be particularly relevant in terms of the boat you have. Do you have an approximate budget for the parts? I presume labour will be predominantly your own.

Cheers,

Mike

[fxykty]

Originally Posted by Insolent

Hi Fxykty,

Thanks for sharing. Nothing wrong with one more thread. I for one am interested since it might be particularly relevant in terms of the boat you have. Do you have an approximate budget for the parts? I presume labour will be predominantly your own.

Cheers,

Mike

Total budget is just under NZD 20K, with professional labour and services about 1/3 of that. So far the only invoice we’ve paid is NZD 5,015.03 for the batteries and shipping. They were USD 1/Ah.

Running total (NZD): 5,015.03

[hzcruiser]

Looks like a well designed system indeed!
If the AGM's are still ok, have you considered keeping all or some of them in parallel to the LFPs in case the LFP cut out due to over/under voltage or a brief current spike that might trip the only battery you would have left on board otherwise?
Cruising with just one batt of 4 big 700Ah cells seems to be putting all your eggs in one basket.

[fxykty]

Originally Posted by hzcruiser

Looks like a well designed system indeed!
If the AGM's are still ok, have you considered keeping all or some of them in parallel to the LFPs in case the LFP cut out due to over/under voltage or a brief current spike that might trip the only battery you would have left on board otherwise?
Cruising with just one batt of 4 big 700Ah cells seems to be putting all your eggs in one basket.

We’re keeping two start batteries in AGM for the three engines - one generator and two motors. These batteries can be paralleled and used for emergency DC power. The old house batteries still have some useful life in them despite their 7 years of age and we will sell them off cheap - absolutely no point keeping them from a space and weight point of view.

[hzcruiser]

That's good if you can still sell them.

[GordMay]

Originally Posted by fxykty

Total budget is just under NZD 20K, with professional labour and services about 1/3 of that. So far the only invoice we’ve paid is NZD 5,015.03 for the batteries and shipping. They were USD 1/Ah.

Running total (NZD): 5,015.03

This AM:
$5,015.03 New Zealand Dollar equals $3,625.39 United States Dollars.
1 New Zealand Dollar equals 0.72 United States Dollar.
1 New Zealand Dollar equals 0.92 Canadian Dollar.

[fabgo]

This should be an interesting thread. Looking forward to see the complete design.

[fxykty]

Originally Posted by GordMay

This AM:
$5,015.03 New Zealand Dollar equals $3,625.39 United States Dollars.
1 New Zealand Dollar equals 0.72 United States Dollar.
1 New Zealand Dollar equals 0.92 Canadian Dollar.

Yeah, the NZD has been going up against the USD over the past 5 months since I paid the invoice. Oh well, only USD 3,269.00 back then.

[fxykty]

Removal of existing equipment started!

• Mastervolt components: charger, inverter, shunt, display, network bus, all the connecting cables
• AGM house bank batteries: 6x 32kg
• Propane galley: 2 burner hob and propane oven, plus the gas hoses, solenoid, and 2x 20kg aluminium gas bottles
• Generator start battery
• Port water tank (moving)
• Shorepower breaker and switch
• 2x Mastervolt BatteryMate 1602 isolators/combiners
• Lots of long cable runs from the house bank area to the port engine bay. Some of these will be replaced, but we've gotten rid of about half

We've been able to sell the Mastervolt equipment and batteries as a set to another boater - the equipment all works and the batteries, while they sag under load, still have over 95% capacity and should be fine for another few years, especially as the new owner is on shore power. Hopefully someone will want the propane galley as a set and the battery isolators/combiners.

Port water tank was removed as that's where we want to put the new battery bank and all the associated components - underneath the salon main seating. This location means we can easily access the batteries and everything else from the top. In addition, the DC fuses are located immediately above this area (behind the seat backs). We will move the water tank to the original house bank battery location - this area is under the navigation table and can only be accessed from the front. While this does move the tank 1.1m outward, it basically weighs the same when full as the batteries and inverter that were in that space that it's replacing. The new batteries plus inverter/charger will weigh about half as much and will be close to the centreline.

Port tank in place, under the salon seat


Empty tank location in foreground and empty house bank location under the navigation table


Our plan is to start the installation of new batteries and equipment week after next (still waiting for our Quattro to arrive from Australia, sigh). Unfortunately, we'll be decommissioned for the AC races, so will have to watch from shore and screens only. We want to be done in a couple of weeks so that we can have a shakedown cruise over the Easter long weekend.

(BTW, we just sold our house and will move the boat to a live aboard berth after Easter. Goodbye party is booked (12 June) and we plan to leave for Australia in the next weather window after that. There's a bit of pressure to get all the jobs, of which this electrical upgrade is only one, done while we still have full time incomes.)

[fxykty]

System design. This was made for us by Cameron Murray of Trans Marine Pro https://transmarinepro.co.nz.



Notes:

1. We want to be able to run instruments and other DC loads if the LYP bank is cut off for whatever reason, hence the emergency override (to ignore the BMS cutoff and keep the LYP bank involved) and the alternative emergency parallel (which will provide DC power from the engine start battery(ies) when the charge and discharge contactors are closed by the BMS)
2. High voltage cutoff (HVC) (and low voltage cutoff (LVC)) is managed by the BMS and it will send warning signals to the various DC regulators/charge sources. In particular, this means that if our alternators are charging the LYP house bank they will be protected in the case of HVC via the signal to the field relays
3. LVC warning signal will be sent to the Quattro to shut off the inverter
4. The two contactors on the positive charge and positive discharge buses enable the BMS to cut off the respective bus in a high voltage or low voltage event. Note the contactors will be in normal open position, so any failure will open the contactors
5. New equipment is the Victron Energy Quattro, Smart Shunt, Cerbo GX, Balmar Digital Duo Charge x2, Tao.Performance BMS. The rest shown on the diagram is already there
6. Generator start battery will be removed and will start from the port engine battery
7. Cerbo GX will be viewed via it's web interface to start. We will be replacing our existing Raymarine e95 MFD with a Raymarine Axiom Plus 9RV so can manage the Cerbo data there. Time will tell whether we need a dedicated display such as the Touch 50
8. Tao.Performance BMS https://www.taoperf.com has a small panel that shows status, plus a wifi monitoring and control interface. It will be interfaced via CAN Bus to the Cerbo, so the Cerbo interface can be used as well
9. We've added a contactor to the wind generator regulator as a just in case, as it autimatically switches output from the battery to its load resistor when there are no more amps required. As it outputs constant voltage, we've set that to 13.9V

Running total: NZD 14,305.91

• 5015.03 Battery cells shipped to Auckland
• 8934.75 Victron Energy and Balmar equipment, including fuses, contactors, relays and VE direct cables
• 737.00 Tao.Performance BMS and shunt
• 1190.00 System design, pre-charge and pre-balance of the battery cells as a 4S 12V battery pack
• 299.13 Baumatic 2 burner induction hob 3.5kW
• 130.00 Breville Toast and Roast Pro 1.65kW 28L (we may sell this one and get the 22L Breville Smart Oven Pro as it's smaller width will enable us to use it in our propane oven cavity, while the wider Toast and Roast Pro won't have enough clearance to use it in the cavity - should have measured first, doh)
• -2000.00 Received for removed charger, inverter, shunt, fuse, easy view, masterbus, cabling, and batteries

Note, costs are GST exempt as we have foreign registration and NZ Customs TIE (Temporary Import Exemption)

[fxykty]

Oh boy, like any boat related job this is taking much longer, sigh.

Spent the last couple of weeks in the evenings pulling cables out - all the AC cables (not to current code, and we’re redesigning the circuits) and the DC and AC cables from the engine rooms to the house bank. We removed almost 100kg of cable! We will replace with almost 150kg of new cable, as the specs are bigger (e.g. 120 sq mm instead of 70 sq mm for the long alternator cables). Fewer cables as we’re rationalising the wiring with the new design, but bigger wires.

We’re up to about $4K in new cabling and associated bits. That bill will come later.

Two new 16A (230V) cables for induction hob and oven, plus a couple of 10A galley outlets on their own circuit for small appliances. Extended the AC circuit in the guest hull (which had only one outlet in the aft cabin) to the head and to the sewing room (converting the front cabin to something more useful).

Removed the generator start battery and prepared to wire to the port engine start battery. Added an emergency parallel switch between the new positive discharge bus and the engine start batteries, in case the house bank gets cut off by the BMS. No inverter of course, but DC loads will be covered.

We were able to sell our old house batteries and the entire Mastervolt system as a set for $2,000.00. We also sold the 28l oven and replaced with a 22L Breville Smart Oven Pro - it fits the cavity better and we will be able to use it without pulling it out. The two equaled each other in cost so no effect on the budget.

Bought a 7” touch screen with HDMI and USB power on the back for connection to the Cerbo GX, $149.00. Already have the 2m extension USB and HDMI cables.

Running total NZD 12,454.91

[Paul L]

Running total went down cause you sold the old stuff?

This Lithium upgrade looks like it will end up costing about as much as 6 AGM bank replacements. That would cover something like 24 to 60 years of cruising. I used to work at a large aerospace firm. Our motto was Economy at any cost

I'd sure like to move our boat to Lithium, but it is just hard to justify the overall cost when I include the stuff we'd want to replace/upgrade.

[fxykty]

Originally Posted by Paul L

Running total went down cause you sold the old stuff?

This Lithium upgrade looks like it will end up costing about as much as 6 AGM bank replacements. That would cover something like 24 to 60 years of cruising. I used to work at a large aerospace firm. Our motto was Economy at any cost

I'd sure like to move our boat to Lithium, but it is just hard to justify the overall cost when I include the stuff we'd want to replace/upgrade.

Yes, it’s going to be a lot to swallow. In the four years we’ve had the boat leading up to our departure we’ll have spent about 1/3 of our purchase price in maintenance and upgrades. This electrical system upgrade is a relatively small part of that.

We have an initial 10 year cruising plan and are willing to spend some of our capital while we are still working to bring much of the boat’s systems up to current spec. We’ve done the same with replacing and upgrading most of the running and static rigging, mechanical systems, and new white sails.

An equivalent usable capacity AGM battery bank would have cost us almost as much as the lithium cells we bought, partly due to the high cost of AGMs down here as opposed to what I’ve seen in the US. Of course we have to add another third of the cost of the cells for BMS and the components to turn cells into batteries. But we don’t have to add an extra 320kg in battery weight, let alone find the space for them.

Our shore power connection and general AC wiring was 18 years old and not even close to modern codes, so replacing all that is a safety item. One day we’ll replace the DC circuit board too, but since it’s all the low amperage stuff we won’t do it during this job. The higher amperage DC wiring is being replaced.

The Mastervolt system was OK, only 7 years old, but flakey (has required two system resets of the charger at the NZ distributor just in the last year), so upgrading that system is a functional replacement.

Lead acid has severe voltage drop at higher loads, and we wanted to stop having to run an engine or generator to run higher DC loads like the windlass or water maker. Switching to an electric galley and getting rid of propane (hot and humid) was another goal. Third goal is to have more efficient charging via existing alternators, generator, wind and solar is a big benefit, lowering our diesel run times by at least half.