Just completed upgrade from AGM to Lithium

[Nicholson58]

Originally Posted by SV__Grace

Maine Sail, I have a burning question for you as a real-life experienced user-

In transitioning from the AGM to Lithium owner/user mindset I'd love your recommendation for a practical, routine, every day/week/month charging protocol. Three questions-

1. How low should I routinely allow SoC to go before cranking up the generator?
(assume 0% SoC is 20% battery capacity)

2. When I crank up the generator, how high should I routinely allow SoC to go before turning it off?

3. Assuming the Mastervolt owner's manual is correct in their recommendation to bring their batteries to 100% SoC once per month or so, exactly when should I turn off the generator? As soon as it reaches 100%? When charging amps drop to float levels?

Thanks in advance for any real life guidance you can provide this LiFePo4 newbie!

No FLOAT with Li! Float applied to Lithium can seriously reduce life and even wreck cells. Follow my link above for Li on boats.

Further, if your BMS effectively disconnects the generator from the battery then your generator can be damaged (at least on my boat). There must always be a load connected. For this reason it is better to stop as the expert in the link states before 100%.

[Pete7]

Originally Posted by StephenOrmond

Also, your charger will need to be reprogrammed to shut off the float stage. Up to date chargers can accommodate that reprogramming, I’m told.

My Victron 100/20 MPPT with the latest software still has a float on either the standard LFP setting or your own custom setting. The only solution is to drop the float way down, currently at 13.3v

The minimum absorption time on the Victron DC>DC with the latest software is 1 hour. If you try to set a time in minutes it just defaults back to 1 hour. There may be a work around, I just haven't found it yet. thankfully shutting it down with the software, or huge great big switch does ensure I don't cook anything.

Pete

[rslifkin]

Originally Posted by Nicholson58

No FLOAT with Li! Float applied to Lithium can seriously reduce life and even wreck cells. Follow my link above for Li on boats.

Further, if your BMS effectively disconnects the generator from the battery then your generator can be damaged (at least on my boat). There must always be a load connected. For this reason it is better to stop as the expert in the link states before 100%.

In my mind, the alternator issue is easily solved. Have the alternator charge the start battery, then power is transferred from there (via whatever method) to the house bank. That way when the house bank disconnects, the alternator isn't unloaded, it just revers to keeping the start battery topped off.

[Nicholson58]

Alternators with external charge controls such as Balmar: old units can be reprogrammed with new software. New controllers should be purchased with Li software present. Alternatively, set the float voltage low and set the float time to zero.

Download software updates for your charger-inverter that accommodate Li. Some older units do not have this capability.

Wind and solar charge controllers may be fixed with software updates. Mine could only be set to minimum float voltage and float cycle time.

Trying, in the Caribbean, to successfully download and update the software on my four charging devices and protect my generator, or rather, the likelihood of at least one total unfixable failure was why we went with Firefly. I could visualize also several relays and automatic disconnects operated by the BMS as well. Way easier to do this in a first world country, reliable high speed internet, availability of phone and on line help.

[hpaabor]

I'm used to the "marine" version of things being more expensive but if I understand AH at all the 8000 AH battery in my car is worth about 4 times what I paid for entire car if I go by the marine price. Anybody bored enough to explain the apples and oranges in this comparison?

[newhaul]

Originally Posted by Nicholson58

Alternators with external charge controls such as Balmar: old units can be reprogrammed with new software. New controllers should be purchased with Li software present. Alternatively, set the float voltage low and set the float time to zero.

Download software updates for your charger-inverter that accommodate Li. Some older units do not have this capability.

Wind and solar charge controllers may be fixed with software updates. Mine could only be set to minimum float voltage and float cycle time.

Trying, in the Caribbean, to successfully download and update the software on my four charging devices and protect my generator, or rather, the likelihood of at least one total unfixable failure was why we went with Firefly. I could visualize also several relays and automatic disconnects operated by the BMS as well. Way easier to do this in a first world country, reliable high speed internet, availability of phone and on line help.

How is your generator at risk when running your shore charger as well as other 120/240 vac items when you are running it ?
I am sure that the shore charger is not the only thing you run your AC Generator for and they are self regulated wrt power output. The advantage of ac generators .
As to solar controllers and wind generators you are correct just set the end voltage ( in my case ) 13.6 vdc or a bit lower if you wish .
Best is to have an inverter charger combo . Mine is fully adjustable to even completely shut the float function down to less than 1 amp output. And with a 250ah or larger bank 1 amp doesn't even cover much above the self discharge rate.

Using a 50 amp b2b charger to control the charge from my fla start battery and my lfp house bank .

[Good To Go]

We too have just completed an up grade of our battery/solar arrangement however we have gone from 6 x 6v Crown 225's to 6 x 6v Golfmaster 105 Tubular batteries and installed 3 x 330w REC N series panels. So far (1st week) very pleased with outcome and no longer running the Genni each morning.

[MVDarlin]

You can buy a very nice genny for 10k.

[Senojev]

Just another perspective, admittedly from a dark side boater but a former sailor.

I have an 880 ahr bank of Lifeline AGMs in their 11th season. Charging includes a 200 amp alternator with 90% output at 1500 rpm, our normal cruising speed, a 160 amp charger, and 900 watts of solar. The boating season for us is around four months of anchoring out and another couple of months of short trips. Anchoring can be anywhere from two to ten days in duration.

Average daily usage is 240 ahr.

In eleven years our batteries have been treated well with them rarely getting down to 75% SOC and a discharge test last year showed around a loss of 80 ahr. Rarely is the battery bank not at 100% by end of day.

We do have a 9kw genset that has 600 hrs in 11 years and is used sparingly for hot water and more recently a 40gph water maker. Occasionally when sun is good and strong we use the inverter for heating water.

With a replacement cost of $3000 at today’s price, I find it hard to justify the switch to lithium with the current setup filling our needs.

[newhaul]

Originally Posted by Senojev

Just another perspective, admittedly from a dark side boater but a former sailor.

I have an 880 ahr bank of Lifeline AGMs in their 11th season. Charging includes a 200 amp alternator with 90% output at 1500 rpm, our normal cruising speed, a 160 amp charger, and 900 watts of solar. The boating season for us is around four months of anchoring out and another couple of months of short trips. Anchoring can be anywhere from two to ten days in duration.

Average daily usage is 240 ahr.

In eleven years our batteries have been treated well with them rarely getting down to 75% SOC and a discharge test last year showed around a loss of 80 ahr. Rarely is the battery bank not at 100% by end of day.

We do have a 9kw genset that has 600 hrs in 11 years and is used sparingly for hot water and more recently a 40gph water maker. Occasionally when sun is good and strong we use the inverter for heating water.

With a replacement cost of $3000 at today’s price, I find it hard to justify the switch to lithium with the current setup filling our needs.

Sounds like you have what works best for you but this thread is about switching from
AGM to LFP not I like my AGMs setup as is .

[more]

Originally Posted by tml

Lithium is I expect in my future but with T 105's at $125 times 8 = $ 1000 versus a multiple for Lithium patience is required.
Tom

Trojan T-105 190-200 amp hour- Deep Cycle Battery 6v

T-105 to 12V 265$ for 100amp ussuable energy - weight 56 kg - 400 cycle max
vs
crap 135ah lifepo4- usable energy 110ah - US $266.00- 11 kg - 2000 cycle min

life is 5 times cheaper vs trojan

https://www.aliexpress.com/item/1005...b4252b5eXIp153

[john manning]

To complete the description of your system for me can you tell me what AC devices you use routinely on your yacht.

I am currently rebuilding a yacht and thinking of going without generator. If I can keep AC usage down to 200A/Hr per day I can do this successfully.

[Captain Scott]

Originally Posted by MJH

I could not, would not spend $18,000 to upgrade my battery bank. There are other options. Enjoy your popcorn.

~ ~ _/) ~ ~ MJH

I am choosing options on a new boat being built for me now (Completion this December!) and have looked at most of the electrical options.... I will say this; if the faster charging numbers are accurate as stated in this thread, then the numbers say 1200 hours a year on your genny compared to 244. For me, the cost of a genny works out to about $1 and hour and then fuel is about $3 (.8 GPH x $3.75 a gallon) so at $4 an hour use cost (not counting for oil changes and other maintenance) that is a savings of $1000 a year. On the prices quoted you are looking at AGM at $7 a useable Kw compared to Lithium at $18.75 Kw or about 2.5 times price per AH. So 800ah compared is $5600 to $15000. So it could be a break even dollar wise, except this is the new technology and like horses verses cars (I am sure there were plenty of nay sayers then), I think the lithium will keep getting better and cheaper.

My plan is a couple of 150A alternators and a BIG solar array, no generator. I have already gone that way without lithium-ion (AGMs) and 85A alternators (which for me does not charge as well as my Xantrex shore power charger).

With a catamaran (a Seawind 1600) "light is fast". So another Lithium-Ion advantage. But the potential of having lunch as I pass under the Golden Gate Bridge and breakfast the next morning in Los Angeles appeals to me. Though that won't be for a while as I am starting out in the South China Sea. Anyone here sail in those waters?

Cheers, Scott

[Savanna]

Thank you SV Grace for your full and clear description of your experience. We too are greatly enjoying the benefits of a Lithium house bank. Hopefully the costs will continue to come down.

[Journeyman]

Originally Posted by Maine Sail

The data is certainly more accurate for LFP than it is for lead acid. We are one of the few marine electrical businesses that capacity test lead acid batteries (LiFePO4 too) and I can assure you that most lead acid batteries are flat a$$ dead before they even hit 250 cycles, let alone the 500 or 1000 as the data suggests.

My own LiFePO4 cells have now broken 2000 cycles, vast majority of the cycles to to 80% DoD but many of the cycles were to 0% SoC. The cells were manufactured on May 10th of 2009 (happy belated 12th birthday to my LFP bank) and still, today, 12 years later, exceed the manufacturers rated capacity of 400Ah.

I would challenge anyone to bring me even a single lead acid battery, used or never used/cycled that can still produce 100% of its rating 12 years after the date of manufacturing. Firefly is a clear stand out in lead acid but nearly as expensive as LiFePo4.

MaineSail,

Elsewhere in your writings you say "batteries don't die they are murdered".
That is, they are eventually or cumulatively abused by owners.

I think you will agree that over time lithium batteries are perhaps even more susceptible to this axiom. Just consider the complexity, and rule set confusion regarding their care in threads like this one.

I am not sure your testimonial to the robustness of lithium batteries over time is that relevant since your batteries are in the care of a battery expert.

I am trying to keep my eyes wide open as I consider replacing my 10 year old AGMs with a full spare-no-expense MasterVolt or Victron conversion.

What I am seeing right now is having a lithium boat looks like it might be a full time job. There are a lot of knobs and dials and wires and user practices to attend to with much wor$t consequences than AGM.

We are a "battery boat" that have run an all electric galley, electric outboards, 16 kbtu air conditioning at times, etc. etc. with only alternator charging into high CAR AGM batteries successfully for 10 years, and had to recover a couple of times from very bad abuse scenarios.

I will have my fingers crossed I can do as well with LiFePo4.