Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-18-2019, 05:13 PM   #1
Senior Member
 
lipets's Avatar
 
City: FL
Country: USA
Vessel Model: Benneteau Swift 42
Join Date: Jun 2019
Posts: 341
Question lithium ?

If you upgrade from say 4 12V wet cell to 100Ah lithium would you need 2 Lipo due to the lower discharge to 20% rather than wet having 50%
__________________
Advertisement

lipets is offline   Reply With Quote
Old 10-18-2019, 05:38 PM   #2
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23
Join Date: Aug 2012
Posts: 4,842
Yes, that is the theory and in this case I think it is valid. But lithium batteries cost 5 or more times what FLA batteries cost. You do save space and weight and if that is important enough to you to spend the extra money then, well ok.


David
__________________

djmarchand is offline   Reply With Quote
Old 10-18-2019, 06:03 PM   #3
Guru
 
Tom.B's Avatar
 
City: Cary, NC
Country: USA
Vessel Name: Skinny Dippin'
Vessel Model: Navigator 4200 Classic
Join Date: Jul 2009
Posts: 5,703
LiPo batteries are really better suited and are a better investment for sailboats that cruise for extended periods. The do give you more amp-hours for your dollar in the long run, but us powerboat types really donít see that return unless you hang on the hook for weeks and donít want to run your main or genset.
__________________
2000 Navigator 4200 Classic
(NOT a trawler)
Tom.B is offline   Reply With Quote
Old 10-18-2019, 07:29 PM   #4
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23
Join Date: Aug 2012
Posts: 4,842
Quote:
Originally Posted by Tom.B View Post
LiPo batteries are really better suited and are a better investment for sailboats that cruise for extended periods. The do give you more amp-hours for your dollar in the long run, but us powerboat types really don’t see that return unless you hang on the hook for weeks and don’t want to run your main or genset.
Really!!! At 5-10 times the price of FLAs per amphour rating or 3-5 times the price of FLAs per usable amphour, they would have to last at least 15 years to match FLAs on an amphour year metric.

I have never owned a boat for 15 years, so I am unlikely to ever find out if Li batteries can last that long .

David
djmarchand is offline   Reply With Quote
Old 10-18-2019, 08:25 PM   #5
Guru
 
ben2go's Avatar
 
City: Upstate,SC
Country: USA
Vessel Name: Dutch Barge Caroliner
Vessel Model: Selway-Fisher 45' Teign Luxe Motor
Join Date: May 2012
Posts: 2,566
I think this is a pretty OK video on lithium batteries.


__________________
What a pain in the transom.

ben2go is offline   Reply With Quote
Old 10-18-2019, 10:05 PM   #6
Guru
 
City: Hampton, va
Country: USA
Vessel Name: Didi Mau
Vessel Model: 2003 Ocean Alexander 456
Join Date: Jul 2015
Posts: 937
Get carbon foam batteries. I switched this summer and am so far impressed. Ill know morec after this spring when we return from Florida. Look up f firefly oasis batteries.

Gordon
Gordon J is offline   Reply With Quote
Old 10-19-2019, 06:44 AM   #7
Senior Member
 
lipets's Avatar
 
City: FL
Country: USA
Vessel Model: Benneteau Swift 42
Join Date: Jun 2019
Posts: 341
they are $500 for a 116Ah battery and 75lbs


two T-105's with 225Ah are <200 100lbs



Lithium 100Ah $650-$900 40lbs


If I had 6 T-105's ($600)I have 675 Ah at 50% discharge 340ah
300lbs



Foam I need 4 with 464Ah @ $2000 discharge 370
300lbs



Lit also 4 @ $2600 discharge about 320ah
150lbs

THe more I research this I think the Trojan T-105's are the clear winner




.
lipets is offline   Reply With Quote
Old 10-19-2019, 06:47 AM   #8
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,944
I hate to nit pick, but on a boat you would (should) only consider LFP (LiFePO4) batteries. Other Lithium Ion variants like LiPo are too volatile to be safe on a boat where you can't easily get away from it in the event of a problem. So if you are considering Lithium-Ion batteries, only consider LFP.


Setting the economics aside, thee are two huge operational benefits to LFP on a power cruising boat.


First is that you don't need to worry about when you last brought you batteries up to full charge, and whether you really got them all the way to full charge. This is the obsession of LAx battery operation, and it just doesn't matter with LFP. So instead of always thinking about managing your battery charge level, you can just focus on boating. To me, this is a huge improvement in daily operation of the boat.


Second is that the dreaded "absorption" phase of charging is non-existant. So instead of having a 2 to 3 to 4 hr tail on charging your batteries, something that really sucks when you are at anchor, LFP batteries will accept full charge current right up until they are full.


I have LFP batteries deployed in an off-grid house as a trial in advance to putting them in my boat, and I love them. They are worth every penny. Off solar, they are fully charged much sooner each day, leaving lots of solar power to run other things during daylight. And when the generator does run, my recharge time has gone from 7 hrs down to 2:30. They run cool, don't off gas explosive hydrogen, aren't full of acid that will burn you and everything around it, and aren't full of toxic lead. And depending on how you go about, cost per usable Ah or kWh of power is as low 1.5x the cost of quality AGMs.


I don't think I'll ever use a LA house battery again.
__________________
www.MVTanglewood.com
twistedtree is online now   Reply With Quote
Old 10-19-2019, 07:04 AM   #9
Senior Member
 
lipets's Avatar
 
City: FL
Country: USA
Vessel Model: Benneteau Swift 42
Join Date: Jun 2019
Posts: 341
the economics is against them IMO


My example $600 vs $2400-$4000


With solar on the T-105's they can last a very long time had them on an RV 7 years sold it they may still be use.


You don't mention failure of Lithium's a costly replacement if something goes wrong,


If they were less like $3-400 I would buy them and they will be in a few years
lipets is offline   Reply With Quote
Old 10-19-2019, 07:28 AM   #10
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,944
If the question is about the cheapest way to store power, itís likely flooded lead acid like the T-105s that you mention.

But if you also want maintenance free batteries, and to be freed from charge monitoring and management, there is a lot of additional value in AGMs and again more is LFP. But that comes at a cost, so you need to decide what matters to you.
__________________
www.MVTanglewood.com
twistedtree is online now   Reply With Quote
Old 10-19-2019, 07:44 AM   #11
Guru
 
catalinajack's Avatar
 
City: Edgewater, MD
Country: USA
Vessel Name: Catalina Jack
Vessel Model: Defever 44
Join Date: Nov 2011
Posts: 965
How deep may LiFePO baterries be discharged without reducing their life beyond reason?
Quote:
Originally Posted by twistedtree View Post
If the question is about the cheapest way to store power, itís likely flooded lead acid like the T-105s that you mention.

But if you also want maintenance free batteries, and to be freed from charge monitoring and management, there is a lot of additional value in AGMs and again more is LFP. But that comes at a cost, so you need to decide what matters to you.
catalinajack is online now   Reply With Quote
Old 10-19-2019, 07:54 AM   #12
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,944
Quote:
Originally Posted by catalinajack View Post
How deep may LiFePO batteries be discharged without reducing their life beyond reason?

Figure 80-90%, and figure on getting at least 2000 cycles out of them, and probably a good bit more. Lab testing consistently yields 2000 cycles with 100% charge/discharge. I've seen no concrete data on longer life spans because it simply takes too long. But even at 2000 cycles, that's about 6 years assuming you cycle every single day, which very, very few boats do. Even half that cycle rate I expect is uncommon. Most people using them are expecting 10-20 years.
__________________
www.MVTanglewood.com
twistedtree is online now   Reply With Quote
Old 10-19-2019, 08:34 AM   #13
Guru
 
City: Satsuma FL/Daytona Beach Shores
Country: United States
Vessel Name: No Mo Trawla
Vessel Model: Hurricane SS188
Join Date: Jul 2014
Posts: 2,184
TT, how many amp hours of LFP batteries do you plan to carry for your house bank on your new boat?
__________________
Buffalo Bluff Light 28
Donsan is offline   Reply With Quote
Old 10-19-2019, 11:47 AM   #14
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,944
Quote:
Originally Posted by Donsan View Post
TT, how many amp hours of LFP batteries do you plan to carry for your house bank on your new boat?

Something in the 1400ah @ 24V range. It's probably serious overkill, but without a solid understanding of the electric loads, I'd rather err on the side of too much rather than too little. And that's nameplate rating, so figure 80-90% of that is usable.


Part of the uncertainty is because I haven't finalized what batteries I'm going to use, and they come if different quanta of capacity. Plus I'm leaning towards a redundant setup with two banks, so the capacity steps are pairs of batteries.. Several vendors sell ~300Ah batteries, so a bank of 4 would be 1200 ah, and 6 would jump up to 1800ah.
__________________
www.MVTanglewood.com
twistedtree is online now   Reply With Quote
Old 10-19-2019, 11:50 AM   #15
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,944
Quote:
Originally Posted by Donsan View Post
TT, how many amp hours of LFP batteries do you plan to carry for your house bank on your new boat?

BTW, several people I know who have or are installing LFP are sizing to be able to run partial AC over night. That drives up the capacity required, and causes LFP systems to be bigger than what you might otherwise do with lead.
__________________
www.MVTanglewood.com
twistedtree is online now   Reply With Quote
Old 10-19-2019, 01:38 PM   #16
Senior Member
 
lipets's Avatar
 
City: FL
Country: USA
Vessel Model: Benneteau Swift 42
Join Date: Jun 2019
Posts: 341
Quote:
Originally Posted by twistedtree View Post
BTW, several people I know who have or are installing LFP are sizing to be able to run partial AC over night. That drives up the capacity required, and causes LFP systems to be bigger than what you might otherwise do with lead.

Way less $$ to crank up the Genn for AC
lipets is offline   Reply With Quote
Old 10-19-2019, 01:42 PM   #17
Senior Member
 
lipets's Avatar
 
City: FL
Country: USA
Vessel Model: Benneteau Swift 42
Join Date: Jun 2019
Posts: 341
Quote:
Originally Posted by twistedtree View Post
If the question is about the cheapest way to store power, itís likely flooded lead acid like the T-105s that you mention.

But if you also want maintenance free batteries, and to be freed from charge monitoring and management, there is a lot of additional value in AGMs and again more is LFP. But that comes at a cost, so you need to decide what matters to you.

I would use the word "cheapest" indicating inferior.


They have a big market share esp in solar


THey can be maintenance free, add solar to charge and auto water fills
lipets is offline   Reply With Quote
Old 10-19-2019, 03:58 PM   #18
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,944
Quote:
Originally Posted by lipets View Post
I would use the word "cheapest" indicating inferior.


They have a big market share esp in solar


THey can be maintenance free, add solar to charge and auto water fills

By "cheapest", I mean least expensive. It wasn't meant as a quality judgement.
__________________
www.MVTanglewood.com
twistedtree is online now   Reply With Quote
Old 10-19-2019, 06:13 PM   #19
Guru
 
City: Satsuma FL/Daytona Beach Shores
Country: United States
Vessel Name: No Mo Trawla
Vessel Model: Hurricane SS188
Join Date: Jul 2014
Posts: 2,184
Quote:
Originally Posted by lipets View Post
Way less $$ to crank up the Genn for AC

It could be depending on what conditions and scenario you use. In TT's case, the standard genny is 27.5kW. It probably burns 1.5gph at half load or say $4.50/hr for fuel. That is over $100/day for fuel. LFP makes a lot more sense to him than it does for say an 8kW genny that you might have on your boat.
__________________
Buffalo Bluff Light 28
Donsan is offline   Reply With Quote
Old 10-20-2019, 11:51 AM   #20
Guru
 
ben2go's Avatar
 
City: Upstate,SC
Country: USA
Vessel Name: Dutch Barge Caroliner
Vessel Model: Selway-Fisher 45' Teign Luxe Motor
Join Date: May 2012
Posts: 2,566
This subject can get as bad as the best anchor subject.
__________________

__________________
What a pain in the transom.

ben2go is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 08:56 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×