LiFePO4 (LFP) battery poll

[Don L]

I am just a sailboat, but went LFP last Dec when I 2.5 year expensive FireFly batteries went bad. I have 4 x 100ah $300/ea drop in withy BMS Power queen batties I got off Amazon for $1319 total including shipping and tax. They have been working great on a full time cruiser currently in Bahamas and have never had shore power. I made no physical changes to my electrical and just reprogramed the alternator regulator and solar controlled.

Best thing about them is they accept all the current I can throw at them till they get almost fully charged and the biggie for a full time cruiser, don't have to fully that if I don't fully charge them each day that it is damaging.

Who knows if they live up to the hype, but if they make it 5 years I will consider it great.

 

[Delta Riverat]

When I need to replace the 2 batteries in the house bank I will go with LiFePO4 and a suitable inverter/charger. The 3 starter batts (2 engines and generator) will remain lead acid.

 

[Mambo42]

Am finishing up the complete re-wiring of the boat, should be finished next week. I now have a complete Victron system on board and in June the AGM batteries will go out (500 Ah at 24 v) and will be replaced by 1400 AH at 24 V winston cells.
That system will be charged by 2 x 200 A Delstar alternators, 2 x wakespeed WS-500 regulators and 3.2 Kwp Solar panels, plus a 6.5 Kva Cummins generator (which will only be used in case of emergencies).
End goal is to be able to run the boat completely of solar and lithium batteries without the need of a generator.
It has been a 3 month job by 2 electricians, took out 21 large bags of old cables and they found multiple fire hazards or worse.........fires waiting to happen (but luckily did not). Now the boat is safe again, ready for the next 20 years at least.
Will post some pictures of the before and after soon.
Tomorrow the boat will go out for the first test run after almost 6 months on the dry. Also needed new engines, so it was a bit of a spending spree, but unfortunately was necessary.

 

[Greg QS]

Just starting the install. Wafting for the batteries to arrive
Battteries are ordered eg4 12v 400ah x 6
Victron multiplus, cerbeo gx, option for solar
wakespeed 500
links shunt and busbar system

 

[Mako]

Greg, with a vessel of your size, I'm surprised that it's wired for 12V, or are you series-wiring the batteries? 20kW of stored energy is excellent, hopefully enough to run at your stateroom aircon all night, nice and quietly.

 

[Greg QS]

Yes it 12v for almost everything. To late to change. Hoping to get days of power and the occasional ac overnight

 

[mvweebles]

I'm jealous. Ton of battery storage (2400ah). Question: guessing the victron has 120 amp charger 0.05C charge which is pretty low. What other charging sources - guessing pretty large alternators?

Peter

 

[Greg QS]

OOOH baby. Just got the call the bats are coming next Tuesday. Will be adding solar , hopefully this summer or fall, have a 8x11 area to work with. The one engine has a 350 amp 12 v alternator. I am adding a wakespeed 500 to condole it. Mts out of Maryland also noted the same thing. The idea (for now) is i can get through 2-3 days with no genset. Our normal run is 7hr to and from the anchorage. Or as you know when traveling you have long hours of run time at 125a Victron and 350amp alternator cooking away .

My other reason for the large bank is to short cycle the system. If the bats "claim" 7k cycles at 80% . If i short cycle the bats due to large system , all batteries say they get longer life.

I am setting the boat up for live aboard, hopefully allowing me to get from Jump to Jump without running the genset, or at least minimizing it. The ability to run ac in the master overnight. As of right now we run the genst 24/7 when away from the dock. Diesel is a little better right now but even 4 bucks a gallon , 1/2 gallon an hour is 12 gal a day . dosent sound like much but that is $48 bucks a day sitting there. 96 bucks a weekend. $366 a week.

 

[rslifkin]

8x11 is a decent area for solar. Depending on the exact space limits, what panels you use, etc. you can likely get as much as 1.5 - 1.6 kw of panels up there. Assuming minimal shading, that'll get you in the ballpark of 6 - 7 kwh per day in good weather.

 

[Greg QS]

Cost wise. Around 10 k investment. ( but i need to spend 6k to replace my existing bats)
So if you take the 10 k and figure 48$ a day of use It will take 208 days to break even. We anchor out every weekend in the summer about 5 months , that's 40 days. We take the boat for 2 weeks a year add up to 14 more days, 54 total At that rate the batteries will pay for themselves in 3.8 years. In fuel savings alone. Ok lets say 5 years.

 

[Greg QS]

8x11 is a decent area for solar. Depending on the exact space limits, what panels you use, etc. you can likely get as much as 1.5 - 1.6 kw of panels up there. Assuming minimal shading, that'll get you in the ballpark of 6 - 7 kwh per day in good weather.

I will use top of the line. I do have some things up there that will shade . Radar and light mounts and domes. The solar company said they now have panels with individual diodes that take out the shaded individual cells. Not dropping the rest of the panel. These are planned for the install.. Are they more? yes , but really not much more.

I take this stuff like computers. Buy the best Teck you can now, It will be more useful for longer into the future.

 

[Mambo42]

I will use top of the line. I do have some things up there that will shade . Radar and light mounts and domes. The solar company said they now have panels with individual diodes that take out the shaded individual cells. Not dropping the rest of the panel. These are planned for the install.. Are they more? yes , but really not much more.

I take this stuff like computers. Buy the best Teck you can now, It will be more useful for longer into the future.

Good idea to limit the effect of the shading. One thing you may want to consider is to either put each panel on a separate MPPT controller or group the panels together in such a way that they shade together or not at all.
I have panels that are divided into 3 sectors. If one of those sectors is shaded it won't affect the panel as a whole. Only the sector that is shaded will be affected.
I did remove and moved a lot of equipment to reduce shading (even moved the flag ), now I have 8 panels on 5 MPPT controllers. Based on the old panels I knew where the shade was, so knew which panels could be in series and which ones could not. After all, if panels are in series and only one part is shaded, it will affect the whole serie. But series will raise the voltage and therefore the efficiency of the panels.
So, with optimum series the MPPT controllers optimize the output of these series and although they are expensive, they are worth it, I would advise implementing them in your solar system.

Am curious to hear your experience whether the claim of the producer of your panels is correct or not. Is the effect of the shading indeed less as they claim ?

 

[Mambo42]

OOOH baby. Just got the call the bats are coming next Tuesday. Will be adding solar , hopefully this summer or fall, have a 8x11 area to work with. The one engine has a 350 amp 12 v alternator. I am adding a wakespeed 500 to condole it. Mts out of Maryland also noted the same thing. The idea (for now) is i can get through 2-3 days with no genset. Our normal run is 7hr to and from the anchorage. Or as you know when traveling you have long hours of run time at 125a Victron and 350amp alternator cooking away .

My other reason for the large bank is to short cycle the system. If the bats "claim" 7k cycles at 80% . If i short cycle the bats due to large system , all batteries say they get longer life.

I am setting the boat up for live aboard, hopefully allowing me to get from Jump to Jump without running the genset, or at least minimizing it. The ability to run ac in the master overnight. As of right now we run the genst 24/7 when away from the dock. Diesel is a little better right now but even 4 bucks a gallon , 1/2 gallon an hour is 12 gal a day . dosent sound like much but that is $48 bucks a day sitting there. 96 bucks a weekend. $366 a week.

I had exactly the same reasoning. If you need to run the genset basically all the time it consumes a lot of diesel, which reduces your range and does cost quite a bit of money. Not running the generator saves money and increases your range. It is a simple A, B, C and althoug the investment in Lithium and solar is quite high, I will earn it back pretty fast.

Great to hear someone else had the same thought process.

 

[cafesport]

So last May I added a small lithium bank which could be recharged in a day by solar or if cloudy by its own charger. This bank’s energy is used overnight to fully charge or to maintain two offline agm house banks via a dc to dc charger. This keeps the agm house bank very very happy. It can also provide the energy to run equalization cycles during the day once the lithiums get to be fully charged. The lithium bank has now gone through a little over 220 cycles. The only issue I’ve had was an intentional over discharge test which cost 3.6 amps of capacity. Oh and I’m not thrilled about the heat generated by Victron’s dc to dc chargers.

 

[Greg QS]

Good idea to limit the effect of the shading. One thing you may want to consider is to either put each panel on a separate MPPT controller or group the panels together in such a way that they shade together or not at all.
I have panels that are divided into 3 sectors. If one of those sectors is shaded it won't affect the panel as a whole. Only the sector that is shaded will be affected.
I did remove and moved a lot of equipment to reduce shading (even moved the flag ), now I have 8 panels on 5 MPPT controllers. Based on the old panels I knew where the shade was, so knew which panels could be in series and which ones could not. After all, if panels are in series and only one part is shaded, it will affect the whole serie. But series will raise the voltage and therefore the efficiency of the panels.
So, with optimum series the MPPT controllers optimize the output of these series and although they are expensive, they are worth it, I would advise implementing them in your solar system.

Am curious to hear your experience whether the claim of the producer of your panels is correct or not. Is the effect of the shading indeed less as they claim ?

According to the manufacture of the panels. There panels eliminate the need for the multiple MPPT's. The extra cost of the panels out weighs the extra MPPTs and wiring.

 

[Don L]

I don't feel separate mppt controllers are needed regardless.

 

[rslifkin]

Splitting up the panels across multiple controllers can help, but it depends on the panels and how they're mounted. If they're high enough voltage panels that you don't need to run multiple in series, then splitting them up is good, especially if the panels may be shaded unevenly or are angled differently. In my case, I have 2 large panels that are angled a bit differently due to deck camber. Putting them on separate controllers was almost exactly the same cost as using 1 larger MPPT. Only difference was a few extra feet of wiring.

 

[Mac2]

OOOH baby. Just got the call the bats are coming next Tuesday. Will be adding solar , hopefully this summer or fall, have a 8x11 area to work with. The one engine has a 350 amp 12 v alternator. I am adding a wakespeed 500 to condole it. Mts out of Maryland also noted the same thing. The idea (for now) is i can get through 2-3 days with no genset. Our normal run is 7hr to and from the anchorage. Or as you know when traveling you have long hours of run time at 125a Victron and 350amp alternator cooking away .

My other reason for the large bank is to short cycle the system. If the bats "claim" 7k cycles at 80% . If i short cycle the bats due to large system , all batteries say they get longer life.

I am setting the boat up for live aboard, hopefully allowing me to get from Jump to Jump without running the genset, or at least minimizing it. The ability to run ac in the master overnight. As of right now we run the genst 24/7 when away from the dock. Diesel is a little better right now but even 4 bucks a gallon , 1/2 gallon an hour is 12 gal a day . dosent sound like much but that is $48 bucks a day sitting there. 96 bucks a weekend. $366 a week.

You might want to consider your livaboard status when purchasing your solar equipment. You get about a 30% tax break on all equipment used for your solar system if your boat is your primary home.

 

[rslifkin]

You might want to consider your livaboard status when purchasing your solar equipment. You get about a 30% tax break on all equipment used for your solar system if your boat is your primary home.

For the federal tax credit the boat doesn't need to be a primary home. Some of the state credits require that, however. Because of that I was able to take the federal credit but not the NY state one for the solar install on our boat.

 

[Brooksie]

Having pulled people from a burning boat, I would not even sail aboard a boat w/ them

 

[guy with a boat]

Having pulled people from a burning boat, I would not even sail aboard a boat w/ them

A boat with what? People?

 

[Greg QS]

The new stuff is super safe. Temp sensors in the batteries that shut them down. My new ones have mini fire extinguishers inside as a last chance fail safe.

LiFePO4 batteries are very stable and will not catch fire or explode. There is a slight risk of damage to the alternator but most of the time the electronics in the boat will protect components from damage and will warn you with error codes or shutdown systems completely.

 

[Iggy]

Splitting up the panels across multiple controllers can help, but it depends on the panels and how they're mounted. If they're high enough voltage panels that you don't need to run multiple in series, then splitting them up is good, especially if the panels may be shaded unevenly or are angled differently. In my case, I have 2 large panels that are angled a bit differently due to deck camber. Putting them on separate controllers was almost exactly the same cost as using 1 larger MPPT. Only difference was a few extra feet of wiring.

Maybe micro inverters can help in this?

 

[Iggy]

A boat with what? People?

Thats what I was wondering?

 

[Iggy]

The new stuff is super safe. Temp sensors in the batteries that shut them down. My new ones have mini fire extinguishers inside as a last chance fail safe.

LiFePO4 batteries are very stable and will not catch fire or explode. There is a slight risk of damage to the alternator but most of the time the electronics in the boat will protect components from damage and will warn you with error codes or shutdown systems completely.

If the setup is done correctly and depending on how its setup. Meaning, there are many ways to do this. One of the ways presents no risk to the Alt. Other ways you connect a device to protect the Alt.

 

[rslifkin]

Maybe micro inverters can help in this?

It's a similar concept, but the micro inverters give AC output, the MPPTs give DC to directly charge batteries. So the micro inverters wouldn't necessarily fit as well into a boat solar system.

 

[Iggy]

It would cut down on the wiring and the MPPTs. But I get it, you want the 12v output and not the 120V output. But it could power a 120V shore charger and make for a simpler install.

I would have to think more about it. Off the top of my head, your right.

 

[dannc]

It would cut down on the wiring and the MPPTs. But I get it, you want the 12v output and not the 120V output. But it could power a 120V shore charger and make for a simpler install.

I would have to think more about it. Off the top of my head, your right.

I was looking at solar panels with micro inverters years ago for a house installation. For a house, the micro inverters made some sense, but I was concerned with the micro inverters being attached to the panel, being on the roof and having to deal with the heat. Seems like in the last year or two, I read something in passing that the PV manufacturer was having issues with the micro inverters. Just replacing them would be a PITA since one would have to go up on the roof, remove the panel, replace the inverter, put it all back together and then repeat on 9-14 panels.

On a boat I suspect this would not be such a problem if the micro inverter failed but it is something to consider along with the inverter's ability to handle the boat environment.

Later,
Dan

 

[twistedtree]

Having pulled people from a burning boat, I would not even sail aboard a boat w/ them

You should read up on the differences between LFP (LiFePO4) and other lithium ion battery chemistry’s. LFP is arguably safer than the lead acid batteries we have been using the past 100 years.

 

[Mako]

A boat with what? People?

[emoji3]