Update on Battery Choices

[Moonfish]

5 years ago we installed Firefly carbon foam batteries, and are very glad we did. I have inadvertently (stupidly?) dropped them down to 11 volts 3 times, and they still perform as new. We have four G31s, total of 440Ah. Up to 80% of that available. We made a video a year after installing them:

https://youtu.be/PrhapRFkt7o

 

[rslifkin]

On a power boat, in my mind, you're likely to do more hours of motoring in a day, so giant alternators to bulk charge as fast as possible become less important. And with a generator, you're unlikely to run an engine just for battery charging.

Small house banks are just to save money, as many powerboat buyers never leave the dock without the generator running for A/C and just marina hop.

The small shore charger is the biggest issue I see. I'd personally keep it to maintain the start batteries and then install a big inverter/charger for the house.

Personally, I get along pretty well with no inverter, a 40a shore charger (bigger would be nice), 400ah house bank and 2x 55 amp alternators. Adding solar would make it great (and it's in the plans), as I do my best to not run the generator just for battery charging. At the moment, unless I'm doing more than 2 nights without moving a couple hours, I can just run the generator when I need it for things and be fine. Charging while running it is basically a bonus. Solar would get it to the point where I'd almost never need the generator for charging batteries, just for running big loads like the water heater, stove, microwave, etc.

 

[jbinbi]

Thanks RSLIFKIN. With 550W of solar, I could leave my refrig on ALL the time. Didn't worry during the week when I was away, batteries always at full (I am in NE and talking about the boating season when we normally get lots of sun). Even with 2 rainy days in a row, no issues. While on the boat, we would use about 150-200Ah a day. Most of that was refrig and instruments (remember, a sailboat, so for 8 hours no power with all instruments going, I found they use about 9A/hr for 2 chartplotters, AP, AIS, wind, speed), I had all LED lights. Even if I just used the engines for 15 minutes to leave the harbor, if it was a sunny day, by noon I would have put 80-100A. So solar with a MPPT controller is terrific.

I too would not like to run a generator JUST to charge the batteries.

Sorry to go OT a bit. I think a chemistry that allows for quicker charging and a higher discharge than 50% makes sense, but some of the new boats with Li from the dealer are about 15k for 800AH for batteries/charger/controller. That is pretty expensive per Ah.

 

[Seevee]

5 years ago we installed Firefly carbon foam batteries, and are very glad we did. I have inadvertently (stupidly?) dropped them down to 11 volts 3 times, and they still perform as new. We have four G31s, total of 440Ah. Up to 80% of that available. We made a video a year after installing them:

https://youtu.be/PrhapRFkt7o

Moonfish,
Good info, saw the video, and spend a lot of time on Ocean Planets site and their videos.
So, understand one can get full amperage from them down to 80% discharge? How do you measure this?
So, 1 of their 12v 116a batteries would give 93ah.


If this is correct, the cost per AH is about the same as my Lifeline batteries, perhaps a sliver less. And the fact that 4 of them would give me 371 usable amps at $2172, or $5.85 per ah.


The Lifelines would take 6 batteries at 220 each to end up with 330a usable (at 50% discharge) at a cost of $1980 or $6 per ah.


This makes the Oasis a pretty good value, about the same price and 33% less space.



Have you run comparisons on the lithium?


Any special install issues?

 

[byrdric16]

My batteries live in the vented engine room. I have easy stand up access. I have 8 Dyno L16 commercial grade lead acid batteries for a total of 1500 amp hours or 750 usable amp hours. My last set went 10 years. Total coast of my bank is $2,000. That’s a lot of bang for the buc.

how often do you equalize?

 

[tiltrider1]

how often do you equalize?

I equalize only once a year. I should do it once before the season and once after but I often forget.

 

[ReedStr]

Plug for lithiums

This spring my agms gave up the ghost, i switched to battleborn lithiums, and I’m glad i did. Lithiums are a better match for cruising and their longer life justifies the higher price.

First though I should say if you’re willing to do the maintenance and don’t mind the weight TheN lead acid is by far the most economical.

Let’s start with some rules of thumb. For the same number of usable amp hours a lithium house bank will have half the rated amp hours, weigh 1/4 as much, be 1/2 as large, and cost 1.5x a high quality AGM battery bank. As a point of comparison a 30lb group 27 lithium has the same number of usable amp hours as a 110 lb 4D agm.

With respect to limitations you should charge them at .3C or less and keep them above freezing and less that 100F or you’ll shorten their cycle life. They also aren’t appropriate for bow thrusters or start banks. Too much load relative to bank size means short cycle ife and the possibility they’ll cut out at the wrong time.

For a house bank though they are a much better fit than AGM’s. With both lead acid and AGMs (which are lead acid batteries chemistry in Much better packaging) You’ll reduce cycle ife if you don’t charge them fully the lst 10% of which takes hours. Similarly if you leave them in partial SOC as is common for liveaboards and cruisers you also shorten their cycle life. Typically lead acid only get’s 300 to 500 cycles. 10 years if you don’t cruise much. 2 years if you live aboard on the hook. In contrast a lithium bank kept below 100F and charged between 20 and 80% will las 3000 to 5000 cycles or 10 to 15 years for a full time on the hook liveaboard. Since they cost 1.5x the price if agms you done need much of that cycle life to be a better value.

Some peole are concerned that they will cut out. This turns out to he a non issue. Keep them below 100f and Don’t overload them they won’t cut out. Others are concerned that they will burst into flames. This may be a problem for thehigh energy lithium chemistry used in cell phones and laptops but not the lifepo chemistry used in marine lithium. Lifepo lithium batteries are no more hazardous that lead acid.

I would say if you’re considering agms then you should consider a drop in lithium from a reputable manufacturer like battleborn. Assuming you have a decent charging setup the adjustments are straight forward and for 1.5x the price of agms you have a much longer lifespan and a much easier battery to work with.

 

[boathealer]

This spring my agms gave up the ghost, i switched to battleborn lithiums, and I’m glad i did. Lithiums are a better match for cruising and their longer life justifies the higher price.

First though I should say if you’re willing to do the maintenance and don’t mind the weight TheN lead acid is by far the most economical.

Let’s start with some rules of thumb. For the same number of usable amp hours a lithium house bank will have half the rated amp hours, weigh 1/4 as much, be 1/2 as large, and cost 1.5x a high quality AGM battery bank. As a point of comparison a 30lb group 27 lithium has the same number of usable amp hours as a 110 lb 4D agm.

With respect to limitations you should charge them at .3C or less and keep them above freezing and less that 100F or you’ll shorten their cycle life. They also aren’t appropriate for bow thrusters or start banks. Too much load relative to bank size means short cycle ife and the possibility they’ll cut out at the wrong time.

For a house bank though they are a much better fit than AGM’s. With both lead acid and AGMs (which are lead acid batteries chemistry in Much better packaging) You’ll reduce cycle ife if you don’t charge them fully the lst 10% of which takes hours. Similarly if you leave them in partial SOC as is common for liveaboards and cruisers you also shorten their cycle life. Typically lead acid only get’s 300 to 500 cycles. 10 years if you don’t cruise much. 2 years if you live aboard on the hook. In contrast a lithium bank kept below 100F and charged between 20 and 80% will las 3000 to 5000 cycles or 10 to 15 years for a full time on the hook liveaboard. Since they cost 1.5x the price if agms you done need much of that cycle life to be a better value.

Some peole are concerned that they will cut out. This turns out to he a non issue. Keep them below 100f and Don’t overload them they won’t cut out. Others are concerned that they will burst into flames. This may be a problem for thehigh energy lithium chemistry used in cell phones and laptops but not the lifepo chemistry used in marine lithium. Lifepo lithium batteries are no more hazardous that lead acid.

I would say if you’re considering agms then you should consider a drop in lithium from a reputable manufacturer like battleborn. Assuming you have a decent charging setup the adjustments are straight forward and for 1.5x the price of agms you have a much longer lifespan and a much easier battery to work with.

I currently have L-16 AGMs. Just out of curiosity, I compared my current house bank (pink row below) to Battleborn Lithium (green row below). Relion, and other manufacturers of both AGM and lithiums are in the same general price range for cursory online costs.

For nearly equivalent Ah, the lithiums appear to be a 40% savings in volume, 75% savings in weight, for nearly 2x the cost.

 

[Alisske]

I have used these for the last 15 years and been very happy. I replace the two batteries every 3 years on my 26 downeast a single Lehman 120 diesel.

Sort of a douche name, (“intimidator”) but then again, no one sees the butteries, lmao.

A

 

[GMS]

This spring we installed an 800ah LiFePO4 house bank built from raw cells. The project was a ton of fun and very educational, but it is NOT a causal endeavor. As mentioned above, you need to think in terms of a total system when dealing with LiFePO4 (IMHO).

We proceeded down this path for a number of reasons including all the typical reasons for going LI - fast charging, partial state of charge, near constant Voltage throughout cycle range, etc...

However, for us one of the most important factors was the ability to fit the batteries into a unique portion of previously wasted space on our boat. LI, especially when building a bank from raw cells, are very configurable in the space they occupy.

So far we are very pleased with the system, that included a new Victron Multiplus, a large frame alternator, and a WakeSpeed external regulator. These components were chosen based on the selection of a REC BMS (battery management system), which can control all charge and discharge sources to ensure the battery bank is well cared for.

in the end, if engineered properly and installed properly, I believe LI house banks are arguably safer than Lead Acid. Our system has multiple fail safes that are almost never present in a Lead Acid system (and no production of explosive gases). Obviously, the safety point is arguable and very dependent on the installation.

In the end, I only recommend going the LiFePO4 route if you are willing to spend the time (and/or resources) to do it right. Otherwise, stick with proven Lead Acid technologies.

One point of correction from above, LiFePO4 (as a chemistry) is capable of high C rates of charge and discharge if engineered appropriately (read proper BMS). LiFePO drop-in replacements are typically not engineered for high C rates due to the BMSs used - not to say drop-in replacements are bad, just engineered for a particular purpose (where .3 to .5 C is typical). Battleborns in particular appear to be excellent batteries for use in a house bank.

 

[ReedStr]

I think the difference is i got my battleborn’s for $850 each shipping included. Your thumbnail is anlittle fuzzy though and i could just barely make it out. It looks like you have $1049 each.

 

[Tator]

Chris,





Also, true about the charger (and the alternator(s))... need at least enough to charge 25% of the bank capacity. And solar could be a nice option, too.


Trojan website recommends 10-13% on FLA.

Tator

 

[Comodave]

I think the difference is i got my battleborn’s for $850 each shipping included. Your thumbnail is anlittle fuzzy though and i could just barely make it out. It looks like you have $1049 each.

Where did you get them for that price? On their website they show the $1049 price.

 

[IslandTractor]

I currently have L-16 AGMs. Just out of curiosity, I compared my current house bank (pink row below) to Battleborn Lithium (green row below). Relion, and other manufacturers of both AGM and lithiums are in the same general price range for cursory online costs.

For nearly equivalent Ah, the lithiums appear to be a 40% savings in volume, 75% savings in weight, for nearly 2x the cost.

If you use the G27 form Battleborn 100amp/hr batteries they are a bit cheaper at $949 each with exactly the same power as the GC2 form factor versions. The Battleborn price includes shipping too. Still a more expensive solution than your L-16 AGMs but with a much longer (10yr) warranty and easier handling it does make the Battleborns a bit more attractive.

And, for those of us who need more than the 400amp/hr that one set of L16 AGMs would cost but less than 800amp/hrs in your bank it allows the flexibility of a 500, 600 or 700amp/hr bank with substantial cost savings.

 

[Comodave]

We currently have 4 6 volt golf cart batteries as the house bank. 2 4D start batteries. All flooded lead acid. I was thinking of adding 2 more 6 volt golf cart batteries and replacing the old 4 at the same time. In looking online it looks like the 6 6 volts will cost about $1000 plus almost $300 in shipping. Maybe I could find a bit better deal but I have not really dug deeply into the prices yet. I have a Promariner 1260 servicing the 3 banks now. Looking at the Battle Born lithium batteries for the house bank 2 of them would cost just around $2000 and free shipping. They weigh 31 pounds each so I would loose a bunch of weight on the starboard side which is a good thing. With the lithium I would have a 200 amp hour house bank that I can use almost all of and recharge more quickly. Now I have a 440 amp hour bank that I can use 50% of. So for about $700 more I could go with lithium and save a bunch of space and weight, no more watering. Sounds like a plus except I would have to get another battery charger for the flooded start batteries. And a 10 year warranty with the lithium. What am I missing? Looks pretty appealing so far.

 

[boathealer]

We currently have 4 6 volt golf cart batteries as the house bank. 2 4D start batteries. All flooded lead acid. I was thinking of adding 2 more 6 volt golf cart batteries and replacing the old 4 at the same time. In looking online it looks like the 6 6 volts will cost about $1000 plus almost $300 in shipping. Maybe I could find a bit better deal but I have not really dug deeply into the prices yet. I have a Promariner 1260 servicing the 3 banks now. Looking at the Battle Born lithium batteries for the house bank 2 of them would cost just around $2000 and free shipping. They weigh 31 pounds each so I would loose a bunch of weight on the starboard side which is a good thing. With the lithium I would have a 200 amp hour house bank that I can use almost all of and recharge more quickly. Now I have a 440 amp hour bank that I can use 50% of. So for about $700 more I could go with lithium and save a bunch of space and weight, no more watering. Sounds like a plus except I would have to get another battery charger for the flooded start batteries. And a 10 year warranty with the lithium. What am I missing? Looks pretty appealing so far.

One thing you might consider is charging your remaining flooded batteries with a Victron dc-to-dc charger 12v to 12v (https://www.solar-electric.com/victron-energy-orion-tr-smart-12-12-30a-dc-dc-charger.html)

I use a 12 to 24 volt version of this charger to charge my thruster and anchor windlass battery bank. These are true multi-stage chargers not just combiners. It's really an elegant solution as you can focus all your charging efforts at just always getting the house bank up to 100%. Start batteries and my thruster batteries don't actually just charged that far and therefore won't put that much of a load on the house bank. It was a lot cheaper than a dedicated AC charger for me, and allows for ANY charging source - since they can all go to the house bank.

If you ever change the start battery chemistry to something else you can change the charging profile in the charger very easily and your overall system stays the same. The Bluetooth app is nice for checking the status of everything and configuring the charger.

 

[Wxx3]

In my winter's reading about batteries, one thing that stood out to me was that AGMs may not be the best choice for a house battery bank.

 

[Comodave]

Just got off the phone with Battle Born batteries. Looks even better. My concern was the web site says don’t use them below 24 degrees. We are on the boat all through the winter in the cold storage barn. I need power all winter. They said that the battery will stop providing power at -4 degrees and not accept charging below 25 degrees. That works for me as it rarely gets below -4 and I wouldn’t be working on the boat at those temperatures anyway. So I would have 200 amp hours to use below 25 degrees without recharging, that also works for me as all I need is lighting which is LED. I can leave the charger on and when the battery comes up to 25 it will start recharging. I would put in 2 100 amp hour batteries to start with and if they turn out to be too small I can add more within 3 years without any problems. In order to add more 6 volt batteries I would have to change out my split system A/C to a self contained unit. It would cost $2400 plus all the work to install it. So I save weight, have more usable power and save a bucket full of money... I guess I will be going with them. Oh, BTW, they have a 10 year warranty with the last 2 years being prorated. And they say really they should be usable for 12 to 15 years.

 

[Delfin]

I currently have L-16 AGMs. Just out of curiosity, I compared my current house bank (pink row below) to Battleborn Lithium (green row below). Relion, and other manufacturers of both AGM and lithiums are in the same general price range for cursory online costs.

For nearly equivalent Ah, the lithiums appear to be a 40% savings in volume, 75% savings in weight, for nearly 2x the cost.

For a few reasons, you need 1/2 the Ah capacity with a lithium bank compared to an LA bank. Changes things a bit....

 

[ksanders]

For a few reasons, you need 1/2 the Ah capacity with a lithium bank compared to an LA bank. Changes things a bit....

True and not so true.

Case in point...

Overnight I will use approx 400AH of battery capacity. That is my boat, my choices, my loads.

If I have a 800AH battery bank most of the time I will get up and fire up the generator, and I find my bank about 50% depleted.

But...

That is based on my being VEREY careful in regards to my recharge cycles.

What if...

What if I am that evening a little lax. What if my 800AH bank is only at 80% at bedtime. Perhaps we went out to dinner that evening. Perhaps we just got busy and plain ole forgot to run the generator.

I could stay up and recharge those batteries. I probably should, but...

Sometimes I admit that I drain my FLA battery bank below 50%.

That is frankly not an option if I was to have switched to a 400AH LIFEPO4 battery bank. I just do not have the reserve.

So...

While theoretically yes you can use a smaller battery bank with LIFEPO4 Vs FLA that is only thoretical. Sometimes Actual use dictates some reserve capacity.

BTW I got a full 10 years out of my last FLA bank and just bought a new one for less than $2,000. LIFEPO4 would have cost me ten dollars an amp hour.

Nope, I’ll stick with my tried and proven FLA batteries.

At 58 I do not have the life expectancy to even dream of cost justifying the price difference.

 

[ReedStr]

I called them direct and the offered it to me without much prompting.

 

[Delfin]

True and not so true.

Case in point...

Overnight I will use approx 400AH of battery capacity. That is my boat, my choices, my loads.

If I have a 800AH battery bank most of the time I will get up and fire up the generator, and I find my bank about 50% depleted.

But...

That is based on my being VEREY careful in regards to my recharge cycles.

What if...

What if I am that evening a little lax. What if my 800AH bank is only at 80% at bedtime. Perhaps we went out to dinner that evening. Perhaps we just got busy and plain ole forgot to run the generator.

I could stay up and recharge those batteries. I probably should, but...

Sometimes I admit that I drain my FLA battery bank below 50%.

That is frankly not an option if I was to have switched to a 400AH LIFEPO4 battery bank. I just do not have the reserve.

So...

While theoretically yes you can use a smaller battery bank with LIFEPO4 Vs FLA that is only thoretical. Sometimes Actual use dictates some reserve capacity.

BTW I got a full 10 years out of my last FLA bank and just bought a new one for less than $2,000. LIFEPO4 would have cost me ten dollars an amp hour.

Nope, I’ll stick with my tried and proven FLA batteries.

At 58 I do not have the life expectancy to even dream of cost justifying the price difference.

Having replaced a 1380 Ah AGM bank with a 600 Ah lithium bank three years ago, my actual experience is different than your theoretical calculation. I also enjoy recharging the bank in 2 hours rather than 5 of genset time.

 

[ksanders]

Having replaced a 1380 Ah AGM bank with a 600 Ah bank three years ago, my actual experience is different than your theoretical calculation. I also enjoy recharging the bank in 2 hours rather than 5 of genset time.

So you have 300Amps of DC charging capability

I do not. I have the largest inverter/charger I casn find which is 150 amps.

Every one of our boats is a bit different, and LOFEPO4 does not make sense for al of us.

BTW my calculations are not thoeretical. I average a bit over 70 mights on the hook a year and have had this same boat for over a decade.

 

[Delfin]

I recharge at 180 Amps, 24 vdc. If you are at s dock most nights, LiFePo4 isn't a good choice. At anchor a lot, definitely.

 

[CarlF]

If you've been happy with the Lifelines and got at least 5 years of life, why not stick with them? With a new boat there will be plenty of unknowns. Why add to that list of unknowns?

I switched from Lifelines to Firefly because I was getting less than 3 years out of the Lifelines - almost certainly from PSOC damage from anchoring out a lot and sometimes going over a month without a night in a marina for an overnight charge.

If the OP expects to anchor out a lot more with his new boat - he might want to look at Firefly's. I would never go back to Lifelines. But except for the PSOC issue - they were great batteries. If I spent more nights plugged in, I'd probably stick with them.

I thought about Lithium-Ion but it still feels best for those owners who really enjoy new technology and are willing to become somewhat expert in it. You average boatyard electrician isn't going to be any help if you have a problem with your Lithium batteries.

 

[ksanders]

I recharge at 180 Amps, 24 vdc. If you are at s dock most nights, LiFePo4 isn't a good choice. At anchor a lot, definitely.

Few boats have that kind of recharge capability, or are 24 volts. Only very large boats generally.

Actually I would argue that few boats with 12 volt systems and “normal” house batttery banks for a liveaboard size boat could benefit from the faster recharge rates possible with LIFEP04. The reality is chargers over 150 amps are pretty darn specialized and rare beasts on most boats.

The fact that your boat is 24 volts makes all the difference.

 

[boathealer]

For a few reasons, you need 1/2 the Ah capacity with a lithium bank compared to an LA bank. Changes things a bit....

1/2 Ah capacity is taken into account in the table I posted.

 

[ranger58sb]

I have used these for the last 15 years and been very happy. I replace the two batteries every 3 years on my 26 downeast a single Lehman 120 diesel.

They only last 3 years? Our AGMs lasted 12 years or so...

-Chris

 

[Darlin]

Hmmm. Batteries can be a big hassel.
Nothing more disturbing than hitting the start button and hearing a "thunk" and no start. I had 6 volt Trojan type batteries that failed in 2 yrs. Boat is in Mexico and they were not serviced over the summer. I replaced with no maintenance Optima blue top batteries. There are 15 batteries on the boat. 9 house, 3 start. One each davit, skiff and anchor windless. About $300 each. 9 are dedicated to house and supported by 50 amp charger as well as solar system. These batteries have been very reliable.

 

[Delfin]

Few boats have that kind of recharge capability, or are 24 volts. Only very large boats generally.

Actually I would argue that few boats with 12 volt systems and “normal” house batttery banks for a liveaboard size boat could benefit from the faster recharge rates possible with LIFEP04. The reality is chargers over 150 amps are pretty darn specialized and rare beasts on most boats.

The fact that your boat is 24 volts makes all the difference.

Bigger boats with 24 v use more current, smaller boats with 12 v less current, generally, so I can't see how that matters. If you are a liveaboard and plugged in, then you don't need Lithium, or if your cruising is from one dock to another, ditto. An inverter/charger is commonplace on trawlers, where charging is powered by a genset or shore power. If you end up using the genset, then of course less run time is a virtue. How could it not be? And if you are using a genset, then in addition to a fairly common 100 amp charging capacity from the inverter/charger, you can daisy chain Sterling chargers to get extra capacity. That is how I get 180 amps without the CAT running.

My installation used everything I already without modification, so was essentially drop in. I chose to add additional charging capacity, which was about a three hour job. 3,000 charge cycles from now, and a few thousand hours less genset runtime I'll let you know whether I'm still happy, because that would be the minimum lifespan I would expect.