Hoping on the Right track but need some advice/help

[Jeremyduckworth]

Hello everyone Jeremy here new to the forum and to well all of this I've been researching reading and watching so many YouTube videos I feel like my brain might be fried. I have a 23' Duckworth Magnum Jet boat that I currently fish and take my wife and, on the way, (24 weeks along) baby girl out fishing and camping on I plan to start guiding out of this boat in the near future as well and have been wanting to complete a few projects prior to starting that. My boat is a 3/4 High top hard top with camper canopy 8hp Yamaha kicker motor and a 460 Kodiak ford inboard pushing a Hamilton 211 jet pump my current starting battery and house battery are both AGM I have no controller just a 1 2 both off switch and outside of alternator charging they get pulled out and hooked to a battery tender then put back in the boat. I have no way to run power out to where the boat is stored on the property without running 300 ft of extension cord and would rather not. What I am hoping to get some advice/clarification on is how to adapt my system to one add lithium house batteries I'm looking at 200-300AH system and keep the AGM cranking battery as I can't find any definitive answers on the newer lithium starter batteries and if they are actually safe for use with inboard boats. I see Australians adding lithium batteries to their vehicles all the time and loving them and I've seen where companies like Dakota and MTech have cranking batteries that are supposed to be rated to use with alternator charging on normal vehicle engines. if they are then I would like to go that route vs the dc-dc system I would also like to add solar to my hard top and be able to have that form of charging for the batteries as well as be able to run my 3000 watt inverter so I can add a mini fridge freezer to the boat I already have sink stove and toilet on board but want to ensure the Mrs. and little one will have everything they need to be comfortable. electronics wise as of now is pretty minor I run two VHF radios a Lorance fish finder and radar and all the lights through the boat are in the workings of being converted to LED just waiting on a few more to come in the mail. I see the 400 watts with alternator charging kit on the website and that really helped me have a good understanding of everything I had been reading and finding other places but what might other options be as well as things I might be missing. Also, for an understanding with the 460 the amount of time spent at idle is relatively a short period of time allowing the engine to warm up while getting away from the dock and into open water then it's spent at around 3000-3400 RPMs for all the rest of the time it's really running all fishing is spent with the kicker or without power. Any advice or ideas on how to proceed? As stated before if I could safely run the lithium cranking battery as well as house batteries that would be my preferred method otherwise keeping the AGM cranking battery and running lithium house batteries would be the route I'd take.
Thanks in advance for any and all help in the matter and if anyone is in eastern Washington and enjoys fishing let me know.

 

[JCSchwarb]

Hello everyone Jeremy here new to the forum and to well all of this I've been researching reading and watching so many YouTube videos I feel like my brain might be fried. I have a 23' Duckworth Magnum Jet boat that I currently fish and take my wife and, on the way, (24 weeks along) baby girl out fishing and camping on I plan to start guiding out of this boat in the near future as well and have been wanting to complete a few projects prior to starting that. My boat is a 3/4 High top hard top with camper canopy 8hp Yamaha kicker motor and a 460 Kodiak ford inboard pushing a Hamilton 211 jet pump my current starting battery and house battery are both AGM I have no controller just a 1 2 both off switch and outside of alternator charging they get pulled out and hooked to a battery tender then put back in the boat. I have no way to run power out to where the boat is stored on the property without running 300 ft of extension cord and would rather not. What I am hoping to get some advice/clarification on is how to adapt my system to one add lithium house batteries I'm looking at 200-300AH system and keep the AGM cranking battery as I can't find any definitive answers on the newer lithium starter batteries and if they are actually safe for use with inboard boats. I see Australians adding lithium batteries to their vehicles all the time and loving them and I've seen where companies like Dakota and MTech have cranking batteries that are supposed to be rated to use with alternator charging on normal vehicle engines. if they are then I would like to go that route vs the dc-dc system I would also like to add solar to my hard top and be able to have that form of charging for the batteries as well as be able to run my 3000 watt inverter so I can add a mini fridge freezer to the boat I already have sink stove and toilet on board but want to ensure the Mrs. and little one will have everything they need to be comfortable. electronics wise as of now is pretty minor I run two VHF radios a Lorance fish finder and radar and all the lights through the boat are in the workings of being converted to LED just waiting on a few more to come in the mail. I see the 400 watts with alternator charging kit on the website and that really helped me have a good understanding of everything I had been reading and finding other places but what might other options be as well as things I might be missing. Also, for an understanding with the 460 the amount of time spent at idle is relatively a short period of time allowing the engine to warm up while getting away from the dock and into open water then it's spent at around 3000-3400 RPMs for all the rest of the time it's really running all fishing is spent with the kicker or without power. Any advice or ideas on how to proceed? As stated before if I could safely run the lithium cranking battery as well as house batteries that would be my preferred method otherwise keeping the AGM cranking battery and running lithium house batteries would be the route I'd take.
Thanks in advance for any and all help in the matter and if anyone is in eastern Washington and enjoys fishing let me know.

Congratulations on your daughter. Exciting times…

You can safely substitute Lifepo4 batteries and use the same lead acid charging components. The only real difference if you get too far down on their SOC and need to wake them up. Try to keep them from 5%-95% and you will be fine, see voltage chart. The LFP battery is nearly as safe as lead acid. Try to keep dry. Adding a panel or two to the boat house matched at the same voltage to keep charged up would be a very low tech and high reliability setup eliminating your long cord run.

 

[Jeremyduckworth]

Excellent information thank you very much lithium all the way it is as I get the components for the solar array and get my mounts welded up I'll post the project as it goes. Now to select the propper cranking and house batteries.

 

[wholybee]

Fair warning. The above advice isn't quite true. Depending on your current alternator setup (likely stock) it will burn up and melt under the load of charging an LiFePO4 battery. The most straight forward and cheap solution is to get rid of the 1 2 both switch. Connect the alternator to the remaining AGM, and use a DCDC charger to charge the LiFePO4 from the AGM.

For faster charging there are more expensive solutions involving expensive alternators and regulators. Also, the "starting" rated LFP batteries still require a DCDC or expensive externally regulated alternator. They are not "rated" for alternator charging. The difference is that they have large intermittent current ratings for cranking. Normal drop ins might be safe for 100A. The starting are safe for 1000A.

Also, LiFePO4 will be damaged, or at least have a reduced life, from charging on float. For you, that means don't connect it to your battery tender. LiFePO4 batteries have almost no self discharge, so if it is full when you park it, and you come back a couple weeks later, it will still be full.

 

[Jeremyduckworth]

So how exactly do you explain how the majority of Australian off road companies are going to lithium batteries for all of their trucks diesel and gas and literally just pulling the battery from the truck plugging in the lithium and going out to the bush some even have a 15% discharge reserve for ensuring you have the cranking power for starting the vehicle they are running winches with the truck off and everything. I feel like the majority of the people who have run lithium in the vehicles havent had any issues as long as they used the proper battery for the application. some batteries are rated for higher alternators other for lower ones the invicta hybrid cranking batteries have been used for a few years now in extremely difficult situations and nobody has blown up an alternator. This is why I asked though to get opinions on the subject but real world experience would be best.

 

[wholybee]

Several reasons.
First, boats and off-road vehicles are not similar. An off-road vehicle has an engine compartment that is largely open to outside air, with a giant engine fan blowing that outside air around the engine compartment. A boat has and engine in a sealed engine compartment, with no fan.
Second, the alternator on a newer truck or off-road vehicle is going to be different than the alternator on a stock 460 ford in a boat. The former will have a built-in temperature sensor that regulates the alternator when it gets hot. A stock Ford 460 alternator does not. Lots of boaters DO charge directly with and alternator, but a more modern one, usually purpose built for the lower RPM use with less cooling that exists in a boat. Not a stock alternator from the 1970's.

Here is one example of someone that blew up 4 alternators because of swapping to Lithium without the proper precautions.

On my fourth alternator....??

I installed drop-in lifepo4 and the first failure they told me was bad diodes. paid for that repair and it happened again two weeks later. They finally sold me a brand new alternator. By week two that alternator basically caught on fire and the internals were totally melted.. They replaced it...

diysolarforum.com

Here is a video from Victron demonstrating it:

Here is a very in depth article on Lithium Batteries on boats:

DIY LiFePO4 Batteries On Boats - Marine How To

DIY LiFePo4 On Boats Last edit;3/26/23:The base of this article was written a number of years ago (2010) but this does not mean the information here is outdated. We have been keeping it updated and have added to it when ever we had the time. This article deals

marinehowto.com

 

[Jeremyduckworth]

I've had a lithium battery attached to my perkins diesel engine in a 1990 nissan patrol for over a year now with the original alternator my 460 ford is a 92' engine with an alternator that has tenperature sensor came from Duckworth that way back then and I dont know to many alternators produced anymore that dont come with an internal voltage regulator and temperature sensor I know mine is a 3 wire with temperature sensor USCG approved and 90 amp. I also dont know anyone who runs a Jetboat at the standard low rpm that sailboat and other motors tend to run. on plane for me is spent at 3400 rpm and WOT is 4200 rpm. So if in a jet boat and your spending a lot of time idling at 1000 rpms for a fairly long time with a stock way older 460 running a stock non new alternator then I could see the issue especially if your not matching the batteries to the alternator charging ability or using not specialty starting batteries I can understand it. There is also a huge difference in outboard compatible lithium cranking batteries as well as automotive engines which anyone who knows a 454 or 460 or other big block engines will tell you theres not much that hasnt been updated and is better especially in the electronics of the engines. Like EFI being on 460s through the early 90s till it was no longer produced in 97. But there has to be a reason why almost every major professional bass team is switching to full lithium as well as almost all of the custom built boats not sailboats but boats with inboard high output engines or outboards are making the switches as well. It's hard to compare apples to apples batteries from two years ago to now let alone alternator failures from ten years ago. Technology has been exponentially improved and almost all of the individual cases I've read for failures have been from years ago with way older technology or people just using the wrong battery all together. It's an interesting subject and one that I feel has multiple factors like running rpms a sailboat way less motor than my 485hp EFI ford 460 pushing a jet pump 34-4200 rpms.

 

[JCSchwarb]

I've had a lithium battery attached to my perkins diesel engine in a 1990 nissan patrol for over a year now with the original alternator my 460 ford is a 92' engine with an alternator that has tenperature sensor came from Duckworth that way back then and I dont know to many alternators produced anymore that dont come with an internal voltage regulator and temperature sensor I know mine is a 3 wire with temperature sensor USCG approved and 90 amp. I also dont know anyone who runs a Jetboat at the standard low rpm that sailboat and other motors tend to run. on plane for me is spent at 3400 rpm and WOT is 4200 rpm. So if in a jet boat and your spending a lot of time idling at 1000 rpms for a fairly long time with a stock way older 460 running a stock non new alternator then I could see the issue especially if your not matching the batteries to the alternator charging ability or using not specialty starting batteries I can understand it. There is also a huge difference in outboard compatible lithium cranking batteries as well as automotive engines which anyone who knows a 454 or 460 or other big block engines will tell you theres not much that hasnt been updated and is better especially in the electronics of the engines. Like EFI being on 460s through the early 90s till it was no longer produced in 97. But there has to be a reason why almost every major professional bass team is switching to full lithium as well as almost all of the custom built boats not sailboats but boats with inboard high output engines or outboards are making the switches as well. It's hard to compare apples to apples batteries from two years ago to now let alone alternator failures from ten years ago. Technology has been exponentially improved and almost all of the individual cases I've read for failures have been from years ago with way older technology or people just using the wrong battery all together. It's an interesting subject and one that I feel has multiple factors like running rpms a sailboat way less motor than my 485hp EFI ford 460 pushing a jet pump 34-4200 rpms.

Mercury recently published a field notice permitting LFP’s usage with their products as long as the CCAs and another specification was considered. Search this board for that article reference.