Topic Previously Titled: Do you wish to see lithium batteries added to class rules?
When J/109 batteries need replacing, the only class-rule option today is lead-acid. By 2020, nearly 90% of large yacht owners had chosen lithium, and the technology was already making its way down to 40-foot racing boats (Yachting World). In 2021, 20% of Chicago J/109s presented to the measurement committee with lithium systems, apparently unaware that the rules allowed only lead-acid. As of 2025, lithium now holds more than a 38% share of the marine battery market by total dollars. A small group of owners met after the class meeting to discuss what it would take to update the rules to allow lithium with zero racing advantage and clear safety standards. To move forward, we need 20 owners to express interest in considering this rule change. If you’d like to be counted toward that threshold, please add your name to the bottom of this thread.
Thank you,
Dan
Seeking 20 names to support future vote on lithium batteries. Add your name
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Dan Corcoran
- Posts: 336
- Joined: Sun Jan 29, 2017 4:32 pm
Seeking 20 names to support future vote on lithium batteries. Add your name
Last edited by Dan Corcoran on Mon Oct 27, 2025 7:26 pm, edited 1 time in total.
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Dan Corcoran
- Posts: 336
- Joined: Sun Jan 29, 2017 4:32 pm
Re: Do you wish to see lithium batteries added to class rules?
Please reply if you wish the class to invest technical efforts into expanding battery rules beyond lead acid into Lithium. I thought I heard at least 4 people desire this for cruising their sailboats. Others might simply not want their next 10yr battery investment to be lead acid again.
Please also write here, if lead acid is good enough. Your comments are welcome also.
Please also write here, if lead acid is good enough. Your comments are welcome also.
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Dan Corcoran
- Posts: 336
- Joined: Sun Jan 29, 2017 4:32 pm
Re: Do you wish to see lithium batteries added to class rules?
Bill, I would like to propose the following Lithium Battery rule change to the technical committee for consideration in the upcoming business meeting.
“Lead is Dead” (see article). Our owners should not be constrained from switching to LiFePO4 when their Lead Acid batteries expire. Such LiFePO4 batteries are clearly more economical than Lead Acid over the life of a boat.
https://marinehowto.com/drop-in-lifepo4 ... -consumer/
The proposed rule changes take in the following considerations:
• The work of the measurer is minimized as described in the document. Optionally it can be reduced further.
• The class is promoting that owners safely upgrade their J/109’s in an ABYC E-13 compliant manner plus additional precautions, rather than performing a dumb LiFePO4 drop-in style upgrade.
• Any potential weight benefit is offset by a requirement for (2) batteries (Both LiFePO4, or a LiFePO4 plus Lead Acid) and that the weight of other components required for a safe LiFePO4 upgrade (and) that the Lithium Ahr capacity is off-set by a weight multiplier of 0.50, e.g. a 200 Ahr LiFePO4 counts as 100 Ahr, will eliminate all weight advantage.
Best regards,
Dan Corcoran
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J/109 Proposed Class Rule Change
By Dan Corcoran, September 8, 2024
Proposed Change to Measurement Checklist
Lead Acid Battery Standard Option (unchanged)
* 2 x lead technology batteries minimum combined capacity 150Ah
LiFePO4 Battery Option (added)
* 2 batteries minimum combined capacity of (0.50 x LiFePO4 capacity) + Lead Acid capacity, of 150Ah.
* Documentation of Class Compliant LiFePO4 Installation. Documented upgrade checklist on boat ready for class inspection, of safe LiFePO4 upgrade plus J/109 Class requirement that boats can quickly recovery from a total failure of a single battery/Battery BMS.
* Documentation at the electrical battery switch that clearly explains how to configure the J/109 to bypass a failed battery.
* 20% of boats to be chosen randomly, need to demonstrate for the measurer the 109 crew can start the engine on each battery without the other, including a demonstration on the battery monitor that the alternator output is reaching the good battery and house loads.
Documentation of J/109 LiFePO4 Installation
A compliant installation of LiFePO4 Batteries must have all the capabilities listed below as attested to by a competent installer and the boat owner, available to show the measurer at all national events.
The simple replacement of Lead Acid batteries with “Drop In” LiFePo4 batteries is expressly disallowed without the additional upgrades listed below and/or in the ABYC E-13 standard.
The intent of the following requirements is to reduce the opportunity of a J/109 with LiFePO4 having a weight advantage over those with Lead Acid AND to allocate the saved weight towards additional electrical system that will ensure every LiFePO4 equipped J/109 has an additional capability to operate fully and safely in the event of any one battery BMS failing, and to reduce the risk that an electrical storm at the time of a race will completely a J/109, as theoretically could happen in response to an electrical storm EMP pulse during a race or delivery to race venue.
[ ] An installer of sufficient knowledge and competency in boat electrical systems has made an ABYC E-13 compliant upgrade. List added components here: _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
[ ] Describe here how the J/109 can operate from Battery 1 (start engine, receive alternator output, supply house loads), with all other batteries disabled. Battery 1 is labeled ______________ Battery 1 manufacturer & model # _____________________ Battery 1 chemistry is _____________
__________________________________________________________________________________________________________________________________________________________________________
[ ] In the event Battery 1 failed, or is about to fail, the user receives the following ABYC E-13 alarm as follows : ______________________________________________________________________. The user can silence the alarm by __________________________________________________________. In the event the BMS for this battery has failed, the user will be alerted the battery and/or BMS failed as follows (e.g. the user won’t be caught unaware): _____________________________________.
[ ] Describe here how the J/109 can operate from Battery 2 (start engine, receive alternator output, supply house loads), with all other batteries disabled. Battery 2 is labeled ______________ Battery 2 manufacturer & model # _____________________ Battery 2 chemistry is _____________
__________________________________________________________________________________________________________________________________________________________________________
[ ] In the event Battery 2 failed, or is about to fail, the user receives the following ABYC E-13 alarm as follows : ______________________________________________________________________. The user can silence the alarm by __________________________________________________________. In the event the BMS for this battery has failed, the user will be alerted the battery and/or BMS failed as follows (e.g. the user won’t be caught unaware): _____________________________________.
Such upgrade to achieve the above included (all must be included to meet class rule):
[ ] If no Lead Acid Batteries, each of Two LiFePO4 batteries must be individually capable of starting engine while supporting house loads (or) If One battery is Lead Acid, One LifePO4 battery must be capable of starting engine while simultaneously supporting house loads (or) Two Lead Acid batteries are separately available for starting engine.
[ ] An additional 2/0 or larger electrical cable has been run from battery switches to the engine compartment to isolate the engine starter from the alternator output. The engine starter can select which of two or more batteries to start from.
[ ] Document the engine has been successfully started 5x from battery 1, after first being discharged 50% (if LiFePO4 battery) or 10% (if Lead Acid battery)
[ ] Document the engine has been successfully started 5x from battery 2, after first being discharged 50% or 10% (if Lead Acid battery)
[ ] Either, all batteries are of the same chemistry or additional components were used to insure the correct multi-state charging of each battery chemistry is successful. Those components included: _____________________________________________________________________________
[ ] The battery switch used for selecting which battery starts the engine, MUST NOT HAVE A BOTH OPTION. It such a “both” battery combiner capability is desired, there must exist a separate dedicated combiner switch sufficiently wired and fused to combine a discharged battery to a charged battery safely.
[ ] In the event a battery fails, alternator output can be directed either manually or automatically to a good battery. Describe here how that occurs ________________________________________________
[ ] The alternator must be protected from a sudden loss of one, or all batteries, with an alternator protector. Describe alternator protector product, model number, and location here ___________________________________________________________________
Attested by:
Boat Owner ______________ Signature _____________________ Date: __________________
Installer Name ______________ Signature _____________________ Date: __________________
“Lead is Dead” (see article). Our owners should not be constrained from switching to LiFePO4 when their Lead Acid batteries expire. Such LiFePO4 batteries are clearly more economical than Lead Acid over the life of a boat.
https://marinehowto.com/drop-in-lifepo4 ... -consumer/
The proposed rule changes take in the following considerations:
• The work of the measurer is minimized as described in the document. Optionally it can be reduced further.
• The class is promoting that owners safely upgrade their J/109’s in an ABYC E-13 compliant manner plus additional precautions, rather than performing a dumb LiFePO4 drop-in style upgrade.
• Any potential weight benefit is offset by a requirement for (2) batteries (Both LiFePO4, or a LiFePO4 plus Lead Acid) and that the weight of other components required for a safe LiFePO4 upgrade (and) that the Lithium Ahr capacity is off-set by a weight multiplier of 0.50, e.g. a 200 Ahr LiFePO4 counts as 100 Ahr, will eliminate all weight advantage.
Best regards,
Dan Corcoran
----------------------------------
J/109 Proposed Class Rule Change
By Dan Corcoran, September 8, 2024
Proposed Change to Measurement Checklist
Lead Acid Battery Standard Option (unchanged)
* 2 x lead technology batteries minimum combined capacity 150Ah
LiFePO4 Battery Option (added)
* 2 batteries minimum combined capacity of (0.50 x LiFePO4 capacity) + Lead Acid capacity, of 150Ah.
* Documentation of Class Compliant LiFePO4 Installation. Documented upgrade checklist on boat ready for class inspection, of safe LiFePO4 upgrade plus J/109 Class requirement that boats can quickly recovery from a total failure of a single battery/Battery BMS.
* Documentation at the electrical battery switch that clearly explains how to configure the J/109 to bypass a failed battery.
* 20% of boats to be chosen randomly, need to demonstrate for the measurer the 109 crew can start the engine on each battery without the other, including a demonstration on the battery monitor that the alternator output is reaching the good battery and house loads.
Documentation of J/109 LiFePO4 Installation
A compliant installation of LiFePO4 Batteries must have all the capabilities listed below as attested to by a competent installer and the boat owner, available to show the measurer at all national events.
The simple replacement of Lead Acid batteries with “Drop In” LiFePo4 batteries is expressly disallowed without the additional upgrades listed below and/or in the ABYC E-13 standard.
The intent of the following requirements is to reduce the opportunity of a J/109 with LiFePO4 having a weight advantage over those with Lead Acid AND to allocate the saved weight towards additional electrical system that will ensure every LiFePO4 equipped J/109 has an additional capability to operate fully and safely in the event of any one battery BMS failing, and to reduce the risk that an electrical storm at the time of a race will completely a J/109, as theoretically could happen in response to an electrical storm EMP pulse during a race or delivery to race venue.
[ ] An installer of sufficient knowledge and competency in boat electrical systems has made an ABYC E-13 compliant upgrade. List added components here: _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
[ ] Describe here how the J/109 can operate from Battery 1 (start engine, receive alternator output, supply house loads), with all other batteries disabled. Battery 1 is labeled ______________ Battery 1 manufacturer & model # _____________________ Battery 1 chemistry is _____________
__________________________________________________________________________________________________________________________________________________________________________
[ ] In the event Battery 1 failed, or is about to fail, the user receives the following ABYC E-13 alarm as follows : ______________________________________________________________________. The user can silence the alarm by __________________________________________________________. In the event the BMS for this battery has failed, the user will be alerted the battery and/or BMS failed as follows (e.g. the user won’t be caught unaware): _____________________________________.
[ ] Describe here how the J/109 can operate from Battery 2 (start engine, receive alternator output, supply house loads), with all other batteries disabled. Battery 2 is labeled ______________ Battery 2 manufacturer & model # _____________________ Battery 2 chemistry is _____________
__________________________________________________________________________________________________________________________________________________________________________
[ ] In the event Battery 2 failed, or is about to fail, the user receives the following ABYC E-13 alarm as follows : ______________________________________________________________________. The user can silence the alarm by __________________________________________________________. In the event the BMS for this battery has failed, the user will be alerted the battery and/or BMS failed as follows (e.g. the user won’t be caught unaware): _____________________________________.
Such upgrade to achieve the above included (all must be included to meet class rule):
[ ] If no Lead Acid Batteries, each of Two LiFePO4 batteries must be individually capable of starting engine while supporting house loads (or) If One battery is Lead Acid, One LifePO4 battery must be capable of starting engine while simultaneously supporting house loads (or) Two Lead Acid batteries are separately available for starting engine.
[ ] An additional 2/0 or larger electrical cable has been run from battery switches to the engine compartment to isolate the engine starter from the alternator output. The engine starter can select which of two or more batteries to start from.
[ ] Document the engine has been successfully started 5x from battery 1, after first being discharged 50% (if LiFePO4 battery) or 10% (if Lead Acid battery)
[ ] Document the engine has been successfully started 5x from battery 2, after first being discharged 50% or 10% (if Lead Acid battery)
[ ] Either, all batteries are of the same chemistry or additional components were used to insure the correct multi-state charging of each battery chemistry is successful. Those components included: _____________________________________________________________________________
[ ] The battery switch used for selecting which battery starts the engine, MUST NOT HAVE A BOTH OPTION. It such a “both” battery combiner capability is desired, there must exist a separate dedicated combiner switch sufficiently wired and fused to combine a discharged battery to a charged battery safely.
[ ] In the event a battery fails, alternator output can be directed either manually or automatically to a good battery. Describe here how that occurs ________________________________________________
[ ] The alternator must be protected from a sudden loss of one, or all batteries, with an alternator protector. Describe alternator protector product, model number, and location here ___________________________________________________________________
Attested by:
Boat Owner ______________ Signature _____________________ Date: __________________
Installer Name ______________ Signature _____________________ Date: __________________
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Dan Corcoran
- Posts: 336
- Joined: Sun Jan 29, 2017 4:32 pm
Re: Do you wish to see lithium batteries added to class rules?
Exploring a Lithium Upgrade Path for J/109s – Who’s With Me?
I’m still very interested in developing an upgrade path to LiFePO₄ (lithium) batteries for J/109s. So far, I feel like I’m standing on an island, as owners don't speak up and swap out lead acid for class events.
Here’s why I’m writing:
- Looking for allies: If you share this interest, let’s connect ahead of the annual meeting to discuss a proposal for class rule updates.
- Reminder for those already experimenting: If you’re running lithium for cruising but swap back to lead-acid for class events, please remember that J/109's (or any boats before 2023? for that matter) are not designed for them. “Drop-in” batteries are not truly drop-in; they require an additional 2/0 cable run from the battery switches to the engine compartment, charging system upgrades, DC-DC charger additionan, an additional battery switch, and fuses to avoid serious safety and performance issues.
- Sharing resources: I’m linking a new article from Panbo on the updated ABYC standards. These changes matter because:
. There’s now official E-13 support for mixed chemistry (e.g., lithium house bank + lead-acid starter battery).
. Certain standard battery switches must be replaced or augmented if they’re being used to combine two battery types.
. T-class fuses, depending on the size of your battery, are now mandatory.
“Lead is Dead.” When your current batteries expire, you will want to consider moving to LiFePO₄. They’re not just better, they’re more economical than lead-acid.
If you’re considering this, please read these excellent resources. They cover critical upgrade steps for J/109 owners, such as charging system changes, managing BMS shutdown risks, preventing dead banks in dual setups, and why T-class fuses are a must:
- Be an Educated Consumer: LiFePO₄
https://marinehowto.com/drop-in-lifepo4 ... -consumer/
- Easy LiFePO₄ Conversion
https://marinehowto.com/easy-lifepo4-conversion/
- New ABYC Standards on Batteries & Electrical Systems
https://panbo.com/abyc-publishes-update ... standards/
Bottom line: Lithium is everywhere. Make sure your boat isn't a hazard for sure, but also let’s update our class rules so Lithium users need not swap for lead acid batteries for class events, which has its own cost and time requirements for busy owners. Perhaps the best class rule (proposed in prior post), is one where Lithium batteriers are allowed as long as the necessary T-class fuses and system changes are also made for the safety of our racing crews, like in the case of a lithium shutdown a simple ability to start the engine from the alternative battery that is ABYC compliant. Who else wants to start this conversation?
I’m still very interested in developing an upgrade path to LiFePO₄ (lithium) batteries for J/109s. So far, I feel like I’m standing on an island, as owners don't speak up and swap out lead acid for class events.
Here’s why I’m writing:
- Looking for allies: If you share this interest, let’s connect ahead of the annual meeting to discuss a proposal for class rule updates.
- Reminder for those already experimenting: If you’re running lithium for cruising but swap back to lead-acid for class events, please remember that J/109's (or any boats before 2023? for that matter) are not designed for them. “Drop-in” batteries are not truly drop-in; they require an additional 2/0 cable run from the battery switches to the engine compartment, charging system upgrades, DC-DC charger additionan, an additional battery switch, and fuses to avoid serious safety and performance issues.
- Sharing resources: I’m linking a new article from Panbo on the updated ABYC standards. These changes matter because:
. There’s now official E-13 support for mixed chemistry (e.g., lithium house bank + lead-acid starter battery).
. Certain standard battery switches must be replaced or augmented if they’re being used to combine two battery types.
. T-class fuses, depending on the size of your battery, are now mandatory.
“Lead is Dead.” When your current batteries expire, you will want to consider moving to LiFePO₄. They’re not just better, they’re more economical than lead-acid.
If you’re considering this, please read these excellent resources. They cover critical upgrade steps for J/109 owners, such as charging system changes, managing BMS shutdown risks, preventing dead banks in dual setups, and why T-class fuses are a must:
- Be an Educated Consumer: LiFePO₄
https://marinehowto.com/drop-in-lifepo4 ... -consumer/
- Easy LiFePO₄ Conversion
https://marinehowto.com/easy-lifepo4-conversion/
- New ABYC Standards on Batteries & Electrical Systems
https://panbo.com/abyc-publishes-update ... standards/
Bottom line: Lithium is everywhere. Make sure your boat isn't a hazard for sure, but also let’s update our class rules so Lithium users need not swap for lead acid batteries for class events, which has its own cost and time requirements for busy owners. Perhaps the best class rule (proposed in prior post), is one where Lithium batteriers are allowed as long as the necessary T-class fuses and system changes are also made for the safety of our racing crews, like in the case of a lithium shutdown a simple ability to start the engine from the alternative battery that is ABYC compliant. Who else wants to start this conversation?
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Vento Solare
- Posts: 445
- Joined: Wed Dec 31, 1969 8:00 pm
- Location: Newport, RI
Re: Do you wish to see lithium batteries added to class rules?
Dan,
I am including an excerpt from the J/109 Class Constitution regarding rules changes. I have added emphasis for the procedure you may use to propose a change. For ease of administration, an email chain from 20 members will suffice as a substitute for a proposal in writing. Just make sure that the email includes the proposed wording for the change and an affirmative by the voting member. There has been no change in the opinion of the Technical Committee, Executive Board or J/Boats on allowing anything but lead technology batteries. The 2025 NA Measurement Checklist has a battery inspection item listed.
Should you desire to discuss this at the annual meeting, I suggest forwarding (or post in this thread) the specifics of whatever you desire to discuss. Since the annual meeting has a fixed agenda and duration, if the discussion can not be completed in a timely manner and there is interest expressed by those attending the meeting, we may schedule a follow on session so that those interested may participate in the discussion.
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7.0 Changes to Class Rules
7.1 The J/109 Class Association is committed to stability in the J/109 Class Rules governing racing. Therefore, rules amendments should be limited to circumstances dictated by safety, material advances in technology, changes mandated by national authority, World Sailing, or clearly advantageous changes to measurement or racing rules.
7.2 Amendments to the Class Rules may be proposed in writing by 20 Voting Members, the Technical Committee, the Executive Board, or the Copyright Holder.
a) Proposed amendments to be considered for the next Annual Meeting shall be submitted to the Secretary not later than August 1 of that year.
b) Proposed amendments of an exceptional and urgent nature may be considered by a special meeting of the Executive Board. A two-thirds majority of the Executive Board shall be required to convene a special meeting. Such a special meeting shall be conducted not less than 30 days, nor more than 60 days after a proposed amendment has been submitted to the Secretary. All proposals shall be posted on the J/109 website to permit review and discussion by the membership.
7.3 Proposed amendments will be considered at the Annual Meeting or a special meeting of the Executive Board. The Executive Board shall also determine the effective date of each proposed amendment, should it be adopted. Each proposal receiving at least a two thirds vote by the Executive Board shall be submitted to Voting Members for approval.
I am including an excerpt from the J/109 Class Constitution regarding rules changes. I have added emphasis for the procedure you may use to propose a change. For ease of administration, an email chain from 20 members will suffice as a substitute for a proposal in writing. Just make sure that the email includes the proposed wording for the change and an affirmative by the voting member. There has been no change in the opinion of the Technical Committee, Executive Board or J/Boats on allowing anything but lead technology batteries. The 2025 NA Measurement Checklist has a battery inspection item listed.
Should you desire to discuss this at the annual meeting, I suggest forwarding (or post in this thread) the specifics of whatever you desire to discuss. Since the annual meeting has a fixed agenda and duration, if the discussion can not be completed in a timely manner and there is interest expressed by those attending the meeting, we may schedule a follow on session so that those interested may participate in the discussion.
-----------------------------------------------------------------------
7.0 Changes to Class Rules
7.1 The J/109 Class Association is committed to stability in the J/109 Class Rules governing racing. Therefore, rules amendments should be limited to circumstances dictated by safety, material advances in technology, changes mandated by national authority, World Sailing, or clearly advantageous changes to measurement or racing rules.
7.2 Amendments to the Class Rules may be proposed in writing by 20 Voting Members, the Technical Committee, the Executive Board, or the Copyright Holder.
a) Proposed amendments to be considered for the next Annual Meeting shall be submitted to the Secretary not later than August 1 of that year.
b) Proposed amendments of an exceptional and urgent nature may be considered by a special meeting of the Executive Board. A two-thirds majority of the Executive Board shall be required to convene a special meeting. Such a special meeting shall be conducted not less than 30 days, nor more than 60 days after a proposed amendment has been submitted to the Secretary. All proposals shall be posted on the J/109 website to permit review and discussion by the membership.
7.3 Proposed amendments will be considered at the Annual Meeting or a special meeting of the Executive Board. The Executive Board shall also determine the effective date of each proposed amendment, should it be adopted. Each proposal receiving at least a two thirds vote by the Executive Board shall be submitted to Voting Members for approval.
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Dan Corcoran
- Posts: 336
- Joined: Sun Jan 29, 2017 4:32 pm
Re: Do you wish to see lithium batteries added to class rules?
Yes, I would like to present this year. Here are my thoughts on timing and content:
- 2 min - Introduction. Who I am, benefits include lower boat ownership cost, faster charging / usable potential from same number of Ahr battery capacity, lower run time on diesel engines to recharge batteries extending engine life, reduced weight penalty for three and larger battery banks desirable for cruising.
- 3 min - With photographs make the point that drop in batteries are dangerous alone, but J/109's (like any other fiberglass boat) can be upgraded to support additional battery chemistries. Rather than electrical diagrams, I would illustrate with photographs of what it looks like when making a proper installation of mixed battery types and TPPL batteries (almost equivalent installation precautions as Lithium, due to their high current potential).
* photo of battery compartment with T-fuses
* photo of where additional 2/0 cable would be run
* photo of battery switch change
* photo of DC-DC charger seperating battery chemisties, e.g. Lithium and Lead Acid
* photo or shore charger that would need to be changed or replaced, balmar mc-614 that needs to be configured.
- 3 min - Assure the audience of owners not interested in Lithium, that this represents no performance advantage racing. The additional wiring and parts of a safe installation (as opposed to drop-in) has no weight advantage in a 2 battery configuration. Suggest that if the technical commitee is unconvinced of weight savings, perhaps because of a future lithium battery product that weighs less, where a weight could be added.
- 1 min - Close asking for support of leadership and owners in 2026 for a 1/1/2027 effective rule change, offer to take questions after answer questions after the annual meeting completes. Ideas for making the inspection fast and efficient, would be a question for after the meeting.
total 9 minutes
Questions I anticipate, after annual meeting
Fear that our boats were not designed for this
* From a fiberglass structure point of view, there is nothing to be designed in. It's all electrical, and electrical components can be modernized and replaced far easier on the 109, then any cruising boat I owned. Vs. lead-acid batteries, Lithium needs a dry location, our J/109's have that.
* It’s true the J/109 wasn’t originally built with Lithium in mind, just like it wasn’t built for modern electronics, bigger electric loads, NMEA-2000 networking, or wireless devices.
* Lithium is just another modern alternative that can reduce charging stress on engines and allow larger consumer loads for cruising, etc.
Fear of Fire
* The chemistry we’re talking about—LiFePO₄—is not the same as the batteries that make headlines for fires. It’s specifically designed for stability, even under severe abuse.
* Consumer devices on our boat, even temporarily, have a greater risk of severe abuse while underway.
* Consumer devices, crew might charge on our boats, are even more dangerous if they are charging when knocked over underway. They have less capable battery management systems for preventing battery thermal runaway.
* ABYC has published guidelines for safe installation that is widely adopted
Fear of Class Liability Risk
* The reality is that liability comes from ignoring foreseeable risks, not from setting reasonable safety standards. Our proposal will not endorse any brand or force anyone to switch, it simply adopts widely recognized standards, like ABYC E-13, for those who choose to install Lithium. This is no different than requiring proper lifelines or PFDs. By doing this, we’re addressing a known safety issue proactively, if you want Lithium you have to play by at least these rules (follow ABYC rules; add wiring, alternator protection, etc. that 109's should get) so for example on a race course lightening causes many boats BMS's to become powerless, all can start engines and at least retire safely to the marina.
* State in the rules, "Lithium battery installations are permitted provided they comply with ABYC Standard E-13. The owner is solely responsible for ensuring compliance with all applicable regulations, and compliance with this rule does not imply that the organizing authority assumes any liability for the safety of the installation."
* When building the measurement checklist / standard, do not use electronics diagrams. Owners can share diagrams like they do for installing in-haulers that could potentially have safety shortfalls, but have no real risk of liability for sharing.
Dan
- 2 min - Introduction. Who I am, benefits include lower boat ownership cost, faster charging / usable potential from same number of Ahr battery capacity, lower run time on diesel engines to recharge batteries extending engine life, reduced weight penalty for three and larger battery banks desirable for cruising.
- 3 min - With photographs make the point that drop in batteries are dangerous alone, but J/109's (like any other fiberglass boat) can be upgraded to support additional battery chemistries. Rather than electrical diagrams, I would illustrate with photographs of what it looks like when making a proper installation of mixed battery types and TPPL batteries (almost equivalent installation precautions as Lithium, due to their high current potential).
* photo of battery compartment with T-fuses
* photo of where additional 2/0 cable would be run
* photo of battery switch change
* photo of DC-DC charger seperating battery chemisties, e.g. Lithium and Lead Acid
* photo or shore charger that would need to be changed or replaced, balmar mc-614 that needs to be configured.
- 3 min - Assure the audience of owners not interested in Lithium, that this represents no performance advantage racing. The additional wiring and parts of a safe installation (as opposed to drop-in) has no weight advantage in a 2 battery configuration. Suggest that if the technical commitee is unconvinced of weight savings, perhaps because of a future lithium battery product that weighs less, where a weight could be added.
- 1 min - Close asking for support of leadership and owners in 2026 for a 1/1/2027 effective rule change, offer to take questions after answer questions after the annual meeting completes. Ideas for making the inspection fast and efficient, would be a question for after the meeting.
total 9 minutes
Questions I anticipate, after annual meeting
Fear that our boats were not designed for this
* From a fiberglass structure point of view, there is nothing to be designed in. It's all electrical, and electrical components can be modernized and replaced far easier on the 109, then any cruising boat I owned. Vs. lead-acid batteries, Lithium needs a dry location, our J/109's have that.
* It’s true the J/109 wasn’t originally built with Lithium in mind, just like it wasn’t built for modern electronics, bigger electric loads, NMEA-2000 networking, or wireless devices.
* Lithium is just another modern alternative that can reduce charging stress on engines and allow larger consumer loads for cruising, etc.
Fear of Fire
* The chemistry we’re talking about—LiFePO₄—is not the same as the batteries that make headlines for fires. It’s specifically designed for stability, even under severe abuse.
* Consumer devices on our boat, even temporarily, have a greater risk of severe abuse while underway.
* Consumer devices, crew might charge on our boats, are even more dangerous if they are charging when knocked over underway. They have less capable battery management systems for preventing battery thermal runaway.
* ABYC has published guidelines for safe installation that is widely adopted
Fear of Class Liability Risk
* The reality is that liability comes from ignoring foreseeable risks, not from setting reasonable safety standards. Our proposal will not endorse any brand or force anyone to switch, it simply adopts widely recognized standards, like ABYC E-13, for those who choose to install Lithium. This is no different than requiring proper lifelines or PFDs. By doing this, we’re addressing a known safety issue proactively, if you want Lithium you have to play by at least these rules (follow ABYC rules; add wiring, alternator protection, etc. that 109's should get) so for example on a race course lightening causes many boats BMS's to become powerless, all can start engines and at least retire safely to the marina.
* State in the rules, "Lithium battery installations are permitted provided they comply with ABYC Standard E-13. The owner is solely responsible for ensuring compliance with all applicable regulations, and compliance with this rule does not imply that the organizing authority assumes any liability for the safety of the installation."
* When building the measurement checklist / standard, do not use electronics diagrams. Owners can share diagrams like they do for installing in-haulers that could potentially have safety shortfalls, but have no real risk of liability for sharing.
Dan
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Dan Corcoran
- Posts: 336
- Joined: Sun Jan 29, 2017 4:32 pm
Seeking 20 names to support future vote on lithium batteries. Add your name
(Note: This reply provided by Dan Corcoran in order to gain consensus for Lithium Batteries does not imply endorsement by the Technical Committee)
October 2025 Annual Meeting Lithium Topic - When it’s time to replace your J/109 batteries, the only option currently allowed under class rules is lead-acid. But change is coming if you vote for it. Will 2026 be the year you get that choice?
In October 2020, Yachting World quoted manufacturers of large yachts as saying they were almost exclusively using lithium, and that the technology was trickling down to 40-foot racing boats. Now in 2025, depending on the source, lithium batteries have gained 35% of the marine battery market as owners look for more power per pound, longer battery life, and other benefits.
The benefits for J/109 racers include less engine run time to charge batteries, especially helpful with B&G electronics suites. You can temporarily achieve some of this benefit with Firefly and Odyssey Extreme batteries, but their performance typically declines quickly after about a year. With Lithium, the improvement is permenant. For J/109 racer/cruisers, switching to lithium can save 60 lbs or more compared to filling your entire battery compartment with lead-acid.
After the class meeting, a group of six owners discussed what it would take to update the rules to allow lithium batteries in a way that:
* Creates no racing advantage
* Promotes safe, ABYC-compliant installations
* Reflects the growing number of boats already equipped with lithium from a prior non-racing owner
In 2021, 20% of Chicago J/109s showed up to the nationals already having lithium systems that don’t comply with current rules.
To make lithium a reality for everyone, we need 20 owners to raise their hand and signal interest in a safety-focused rule change. Hitting that number unlocks a future formal vote.
If you want the choice to upgrade on your terms, or simply believe in fair, future-ready class rules, add your name and help us reach the 20-owner threshold.
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My Personal Interest:
I’m ready to upgrade and currently waiting on the class rules to change. In 2022 I made the key safety upgrades required for lithium on my boat including installing larger fuses, other protective measures, and fully isolating the two battery banks to ensure reliable starting power even if the house bank turns off to protect itself.
If you want the choice to upgrade on your terms, or simply believe in fair, future-ready class rules, add your name and help us reach the 20-owner threshold.
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Supporting Publications: Lithium is no longer an edge case in marine industry.
https://j109.org/docs/2021_j109_annual_ ... tation.pdf
https://marinehowto.com/drop-in-lifepo4 ... -consumer/
https://www.practical-sailor.com/marine ... mall-boats
Lithium Acceptance in the Marine Industry (2020–2025)
“Arcona, for instance, says up to 90% of their larger yachts now leave the factory equipped with them. Equally, the technology is increasingly embraced in the racing world, whether at the top end on IMOCA 60s and Fast 40s, or smaller IRC yachts competing in RORC’s offshore races.”
https://www.yachtingworld.com/gear-revi ... ics-128151
https://www.fortunebusinessinsights.com ... ket-106582
https://market.us/report/marine-battery-market
October 2025 Annual Meeting Lithium Topic - When it’s time to replace your J/109 batteries, the only option currently allowed under class rules is lead-acid. But change is coming if you vote for it. Will 2026 be the year you get that choice?
In October 2020, Yachting World quoted manufacturers of large yachts as saying they were almost exclusively using lithium, and that the technology was trickling down to 40-foot racing boats. Now in 2025, depending on the source, lithium batteries have gained 35% of the marine battery market as owners look for more power per pound, longer battery life, and other benefits.
The benefits for J/109 racers include less engine run time to charge batteries, especially helpful with B&G electronics suites. You can temporarily achieve some of this benefit with Firefly and Odyssey Extreme batteries, but their performance typically declines quickly after about a year. With Lithium, the improvement is permenant. For J/109 racer/cruisers, switching to lithium can save 60 lbs or more compared to filling your entire battery compartment with lead-acid.
After the class meeting, a group of six owners discussed what it would take to update the rules to allow lithium batteries in a way that:
* Creates no racing advantage
* Promotes safe, ABYC-compliant installations
* Reflects the growing number of boats already equipped with lithium from a prior non-racing owner
In 2021, 20% of Chicago J/109s showed up to the nationals already having lithium systems that don’t comply with current rules.
To make lithium a reality for everyone, we need 20 owners to raise their hand and signal interest in a safety-focused rule change. Hitting that number unlocks a future formal vote.
If you want the choice to upgrade on your terms, or simply believe in fair, future-ready class rules, add your name and help us reach the 20-owner threshold.- - - - - - - - - - - - - - - - - -
My Personal Interest:
I’m ready to upgrade and currently waiting on the class rules to change. In 2022 I made the key safety upgrades required for lithium on my boat including installing larger fuses, other protective measures, and fully isolating the two battery banks to ensure reliable starting power even if the house bank turns off to protect itself.
If you want the choice to upgrade on your terms, or simply believe in fair, future-ready class rules, add your name and help us reach the 20-owner threshold.- - - - - - - - - - - - - - - - - -
Supporting Publications: Lithium is no longer an edge case in marine industry.
- Lithium Batteries in J/109s (2021) — 20% of the Chicago fleet
https://j109.org/docs/2021_j109_annual_ ... tation.pdf
- March 2024 — MarineHowTo
https://marinehowto.com/drop-in-lifepo4 ... -consumer/
- April 2025 — Practical Sailor
https://www.practical-sailor.com/marine ... mall-boats
Lithium Acceptance in the Marine Industry (2020–2025)
- October 2020 — Yachting World
“Arcona, for instance, says up to 90% of their larger yachts now leave the factory equipped with them. Equally, the technology is increasingly embraced in the racing world, whether at the top end on IMOCA 60s and Fast 40s, or smaller IRC yachts competing in RORC’s offshore races.”
https://www.yachtingworld.com/gear-revi ... ics-128151
- January 2025 — Fortune Business Insights
https://www.fortunebusinessinsights.com ... ket-106582
- January 2025 — Market.US
https://market.us/report/marine-battery-market
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MochiFanta
- Posts: 3
- Joined: Mon Nov 11, 2024 6:45 pm
Re: Seeking 20 names to support future vote on lithium batteries. Add your name
Count me in to allow Lithium.
Mochi Fanta
USA125
Mochi Fanta
USA125
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Vento Solare
- Posts: 445
- Joined: Wed Dec 31, 1969 8:00 pm
- Location: Newport, RI
Re: Seeking 20 names to support future vote on lithium batteries. Add your name
Mochi Fanta - I know the previous owner raced one design extensively. I have not seen the boat since he sold it. Do you do one design racing?
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Dan Corcoran
- Posts: 336
- Joined: Sun Jan 29, 2017 4:32 pm
Re: Seeking 20 names to support future vote on lithium batteries. Add your name
I was asked to look into what the J/105 fleet is doing. Some information:
1. No class rules prohibition.
2. On-line article about the change here for a J/105 sailboat , Thank you to X.X for bringing this to my attention. https://www.sailingscuttlebutt.com/2024 ... g-results/
* Don't expect the weight savings unless you are similiar to the author having a house bank larger than the 109 class rules minimum. In the proposed class rules for lithium there will be no weight savings if you are already at the low end 150Ahr total two battery lead-acid low weight configuration.
1. No class rules prohibition.
2. On-line article about the change here for a J/105 sailboat , Thank you to X.X for bringing this to my attention. https://www.sailingscuttlebutt.com/2024 ... g-results/
* Don't expect the weight savings unless you are similiar to the author having a house bank larger than the 109 class rules minimum. In the proposed class rules for lithium there will be no weight savings if you are already at the low end 150Ahr total two battery lead-acid low weight configuration.
Re: Seeking 20 names to support future vote on lithium batteries. Add your name
Thanks for the interesting conversation during the class meeting. I honestly had not looked much into it previously. In doing some reading as this season winds down - I would support a future vote on lithium.
Like everything new, it seems like this is an evolution, and when done correctly, the results seem positive and most of the cons in terms of safety have been resolved. I believe it is worth a conversation about the option of switching in the future and some of the 105's (and the industry) are heading down the same decision path during future boatyard projects.
Cary James
Sunny Side - USA 37
Like everything new, it seems like this is an evolution, and when done correctly, the results seem positive and most of the cons in terms of safety have been resolved. I believe it is worth a conversation about the option of switching in the future and some of the 105's (and the industry) are heading down the same decision path during future boatyard projects.
Cary James
Sunny Side - USA 37