Batteries

[Seevee]

Looking for an update on batteries.

So, looks like the current choices for most of us trawler folks are, in order of purchase price:

Plain lead acid
Cheapest to by, high maintenance, short life

AGM
Minimal maintenance, needs smart charging, and it cared for last long.
AGM foam, Oasis Firefly
Also minimal maintenance, high claims for longer life, more discharge flexibility and a better value.

Lithium
Expensive to purchase and charging is critical. Need to monitor carefully. However, very long life, large flexibility in discharge capability, very fast charging (but need expensive high output alternators and regulators). Light weight and space savings. Arguably the best if you're keep your boat for a long time.

Thoughts and questions?
I'm thinking of the Oasis if the claims can be verified. Question: They say larger discharge capability, but can the voltage be held longer so one really gets more use from the battery? And, is there truth that they really need to be topped off for charging at least once a week?

Lithium sounds great, but at a cost just for the alternators, serpentine belts kit, and regulators, it's close to $4500, plus the high cost of the batteries, gets VERY pricey.

 

[Simi 60]

Lo

Lithium
Expensive to purchase and charging is critical. Need to monitor carefully. However, very long life, large flexibility in discharge capability, very fast charging (but need expensive high output alternators and regulators). Light weight and space savings. Arguably the best if you're keep your boat for a long time.

Lithium sounds great, but at a cost just for the alternators, serpentine belts kit, and regulators, it's close to $4500, plus the high cost of the batteries, gets VERY pricey.

Why do you need to spend all that on alts etc?
Surely it's cheaper to simply run the Genset.

And LFP us not appearing that over the top
It is compared to the deal I got on our last set of AGM, but they are fading after 5 years of solid use and replacement now of another brand of AGM will cost 100% or more than last time.
That increase in price brings it up to more than LFP cost and if LFP longevity matches the claims we will be well in front.

 

[DavidM]

I wouldn't call FLA batteries high maintenance, short life. I checked the water level every couple of months and added water every 3-4 months. They would last 7-10 years. Sams, etc 6V golf cart batteries are still the cheapest usable amp hour for the buck.

David

 

[C lectric]

I think from your comment about FLA that you are simply lumping several different types together unfairly.
There are FLA starter batteries which in HOUSE service will not last long IN HOUSE service
There are Deep cycle batteries, and I MEAN deep cycle batteries that are really deep cycles and assuming reasonable treatment and proper sizing will far outlast starter types.

THe so called starter/deep cycles are NOT DEEP CYCLES.

There are GOLF carts , 6 volt, types which are deep cycles made by the millions and the purchasers demand good service life assuming of course they are given decent treatment. They also last well given decent treatment.

Of course the others hold their voltage better and can be discharged deeper to a point. Referring to Gels, AGMs, Fireflys.

All of them require a GOOD charger capable of being adjusted for the particular type of battery. All of them require a full recharge each cycle for best life.

I won't go into LiFePO4 as to me they are still in the area of too much bit fiddling although I am aware, well aware , of them.

A lot depends upon the use you intend to make of them. SHort trips, frequent plug in or generator use AND cost can often make the GOOD FLAs a good choice even now.

So do some more RESEARCH and look hard at your intended useage and expected service life.

And to be a bit more out look at solar if you have enough sun in your area to make the panels worthwhile. I live in a poor sun area and yet my 260W are doing a great job. In winter the panels won't help much but then we no longer use the boat in winter.

 

[rgano]

My cramped engine space with aluminum fuel tanks close by favors something which would not emit too many acidic fumes. I chose to continue with the AGMs I inherited with the boat and added more of them to make a second bank for the house.

 

[firehoser75]

I think from your comment about FLA that you are simply lumping several different types together unfairly.
There are FLA starter batteries which in HOUSE service will not last long IN HOUSE service
There are Deep cycle batteries, and I MEAN deep cycle batteries that are really deep cycles and assuming reasonable treatment and proper sizing will far outlast starter types.

THe so called starter/deep cycles are NOT DEEP CYCLES.

There are GOLF carts , 6 volt, types which are deep cycles made by the millions and the purchasers demand good service life assuming of course they are given decent treatment. They also last well given decent treatment.

Of course the others hold their voltage better and can be discharged deeper to a point. Referring to Gels, AGMs, Fireflys.

All of them require a GOOD charger capable of being adjusted for the particular type of battery. All of them require a full recharge each cycle for best life.

I won't go into LiFePO4 as to me they are still in the area of too much bit fiddling although I am aware, well aware , of them.

A lot depends upon the use you intend to make of them. SHort trips, frequent plug in or generator use AND cost can often make the GOOD FLAs a good choice even now.

So do some more RESEARCH and look hard at your intended useage and expected service life.

And to be a bit more out look at solar if you have enough sun in your area to make the panels worthwhile. I live in a poor sun area and yet my 260W are doing a great job. In winter the panels won't help much but then we no longer use the boat in winter.

I am with you on all counts for this one.

Most batteries in a marine (pleasure boat) application have a shorter than "optimal" life due to owner abuse. I cannot speak to lithium, as to how much abuse they can take, but FLA and most other types will not tolerate very well regular operation in a partial state of charge. My understanding of FireFly is that they will accept PSOC better than most. Improve your treatment of what ever battery type you think best meets your needs. One of the best ways to achieve the necessary regular 100% recharge is with solar. If you can't "fit" enough solar capacity on your boat (due to space or other reasons), put the largest panel(s) you can and use them to top up the batteries after your AM generator run. Shore power or very long run times are required to achieve 100% charge (6 hours approx. depending on charger capacity meaning if you have a very small charger it could take longer)!
The best "bang for your buck" are the Sam's Club 6 V golf cart FLA. Check the water once a month (takes 10 minutes with a fairly large bank) and add water as needed. If access for this is a problem, go AGM. If you want to spend a bit more, but be more "forget about it", and not be so concerned with getting that 100% recharge, then go FireFly.

 

[darkside]

Through my work I own perhaps two hundred deep cycle FLAs.
We always used to specify Trojan golf carts but the last few years we have tried maintenance free, sealed, deep cycle, lead acids. So far they seem to last as long, or longer than Trojans. They are used in construction industry in scissor lifts.
Having said that I have specified LFP for my current boat in build.

 

[ksanders]

I got a full decade out of my last FLA bank and dded water every couple months during our cruising season. That takes all of 30 minutes, and it's nice to actrually look at connections once in a while that carry a couple hundred amps, just to make sure they look good.

860 amp hour bank cost me in 2020 around $1300 and I paid another $175 for some strong people to do the heavy lifting after I undid all the connections.

Pretty good service for the dollar.

 

[Simi 60]

.

860 amp hour bank cost me in 2020 around $1300 and I paid another $175 for some strong people to do the heavy lifting after I undid all the connections.

Pretty good service for the dollar.

12 or 24v?

 

[rsn48]

I have linked this video several times as folks ask similar questions such as yours. Its a longer presentation by Jeff Cote but you will be quite knowledgeable about batteries and boating when you are done. This talk was presented at the 2020 Seattle Boat Show:

 

[FF]

No question FLA batts do not get the best treatment on cruisers as the last 15% or so takes "forever" to get charged , although solar helps.
A 100% charge daily is hard to keep up.

The easy way to have FLA "live longer and prosper" is to oversize the bank by 15% to 20% so after years of normal use /abuse they will still perform as well as a standard sized bank did when new.

7 or 8 years instead of 5 or 6 is easily worth the 15% extra the extra bank size costs when new.

An SOC meter is also a great help.

 

[ranger58sb]

Plain lead acid
Cheapest to by, high maintenance, short life

AGM
Minimal maintenance, needs smart charging, and it cared for last long.
AGM foam, Oasis Firefly
Also minimal maintenance, high claims for longer life, more discharge flexibility and a better value.

Lithium
Expensive to purchase and charging is critical. Need to monitor carefully. However, very long life, large flexibility in discharge capability, very fast charging (but need expensive high output alternators and regulators). Light weight and space savings. Arguably the best if you're keep your boat for a long time.

Thoughts and questions?
I'm thinking of the Oasis if the claims can be verified. Question: They say larger discharge capability, but can the voltage be held longer so one really gets more use from the battery? And, is there truth that they really need to be topped off for charging at least once a week?

From reading, there's AGM, and then there's AGM. Odyssey and Lifeline (and maybe Northstar, perhaps Victron?) seem to have great reps at $$$$, most others at $$, so-so.

From experience, we had great success with Odyssey; 11-12 years each bank, something like that. I eventually changed one of those banks to Lifeline 6Vs -- to increase capacity in roughly the same physical space and to service an inverter -- but didn't have those long enough to rate from personal experience.

Edit: I meant to say why we went to Odyssey in the first place. Our main 12V battery banks were dual-purpose; each bank started one engine and serviced approx. half of the house loads. And the physical battery space was optimized for 3x Group 31s. Comparison shopping -- cranking amps, capacity, etc. -- led me toward Odyssey PC-2150s... and they worked out well for our situation. (Much later, I figured out a way to stuff 4x GC2s into one of those areas, but in a way that made service physically impossible. That eventually led to the Lifeline GPL-4CTs, given that two pairs were also deemed sufficient to start that engine.)​

Note Odyssey and Lifeline have different charging profiles, so that new inverter was actually an inverter/charger servicing the bank of Lifelines.

Lots of cruisers on the other forum complain about AGMs because they're not often near shorepower. That hasn't ever been an issue for us; we're seldom away from the dock for more than 2 weeks or so at a time.

There are several Firefly threads on the other forum; apparently they're getting some love... even at $$$$$... especially due to their reported PSOC tolerance. You could review some of those...

In our case before, servicing batteries wasn't easy... and just getting to one bank now is a real chore... so we tend toward AGMs to ease some of the contortion pain. But reading suggests FLAs are still best bang for $ if you can and do service them properly.

-Chris

 

[rslifkin]

For AGMs, Northstar and Odyssey are both quite good, but expensive. They're probably the best bet if you need short bursts of high load, however, as they hold voltage better under high loads than most other deep cycle types.

Beyond those, there are Firefly if you need more PSOC tolerance, and then the other good quality deep cycle AGMs (which are more like an AGM version of a good flooded deep cycle). Those include Lifeline, Fullriver, Rolls, and probably a few more, but not the dual purpose batteries typically sold as "deep cycle". Some of those types are good batteries, but not for real deep cycle house usage (I do use them as starting batteries, however).

In my case, one of my big reasons for adding solar was to be nicer to my batteries by allowing them to get topped off almost every day when we're away from shore power. My house bank is a pair of deep cycle 6v AGMs (currently Fullriver DC400-6).

 

[jleonard]

I am facing a similar decision with my travel trailer. To me I think deep cycle 6 V are still the way to go. I've learned how to maintain them and I get 7 years or so out of a bank and I don't have to start replacing charging equipment.

 

[OldDan1943]

The American Tug comes standard with 3X4D AGM batteries. 2 house and 1 start battery. The generator start is a group 24 AGM, isolated from the other batteries and charger. I added 1 more 4D battery to the house bank for a total of 600amps. I have the standard 150amp alternator on the main engine. 40amp charger. Also I added 2X130watt solar panels. Finally, I have a 6kw NL generator. Oh, I like my generator. LOL
I guess I could change a different battery chemistry but why bother. I make no attempt to live off the grid. I like my generator SMILE I do have an electric stove and over and microwave so unless I am having a cold breakfast, start the generator.
If I can go over night with juice for the lights, bilge pumps (dry bilges so the bilge pumps dont normally run at all) run the 12vt fridge and microwave my first cup of old coffee, I am happy.
If I get 4 years off the 4X4D batteries, I am happy. As a habit, I change all batteries at the same time, including my generator battery.
I have the traditional battery parallel switch..... If the ME start battery goes belly up, turn the switch and the house bank is added to the start battery bus. I moved the bow thruster from the start battery to the house bank after discovering the Cummins shuts down on low voltage. I guess I could have turned the magical battery switch to add the house bank to the start battery. Who thinks of such things when trying to dock. SMIRK

NOW, the only weak link is, if the gen battery goes flat. Perhaps an additional switch connecting the house bank to the generator start or perhaps 20ft long jumper cables? Oh well, let's hope that does not happen.

 

[rslifkin]

NOW, the only weak link is, if the gen battery goes flat. Perhaps an additional switch connecting the house bank to the generator start or perhaps 20ft long jumper cables? Oh well, let's hope that does not happen.

Does the gen already have an on/off switch for its battery? If so, I'd just replace it with a 1-2-both-off switch and add a link to either the house or the engine start battery. Ideally, everything should have an option to select a backup source of starting power.

 

[OldDan1943]

Does the gen already have an on/off switch for its battery? If so, I'd just replace it with a 1-2-both-off switch and add a link to either the house or the engine start battery. Ideally, everything should have an option to select a backup source of starting power.

rslifkin, I totally agree with you OR I could hook it into the charging circuit or maybe carry one of the 'new technology', handy dandy, solid state, little tiny booster batteries?

 

[ksanders]

12 or 24v?

12

 

[jleonard]

NOW, the only weak link is, if the gen battery goes flat. Perhaps an additional switch connecting the house bank to the generator start or perhaps 20ft long jumper cables? Oh well, let's hope that does not happen.

I carried a set of 25 foot jumper cables for over 20 years and never had to use them LOL

 

[dhays]

I have L16 AGMs that have worked pretty well for my house bank.



If I had easier access to the batteries, I would have gone with 6v GC batteries. Used and abused them for years on my sailboats and they worked really well. They would work well for my current boat, but I'm simply too lazy to crawl around to water the batteries.

 

[Moonfish]

Thoughts and questions?
I'm thinking of the Oasis if the claims can be verified. Question: They say larger discharge capability, but can the voltage be held longer so one really gets more use from the battery? And, is there truth that they really need to be topped off for charging at least once a week?[/I]

We have had Oasis Firefly batteries (4x Group 31) for more than 6 years now. They are our house bank and main engine start batts, so they get plenty of abuse. Not to mention I have inadvertently tried to kill them four times now by forgetting to turn the charger back on and running them down under 11.5 volts. But they bounce back every single time and perform as advertised.

Yes, they are great in a partial SOC, but I really appreciate that they charge much quicker than standard AGMs or FLAs. I can't explain the science behind their charge acceptance qualities, but Bruce Schwab at Ocean Planet Energy can.

This summer we're finding the faster charging and partial SOC performance has been extremely helpful, as our primary generator (NextGen 3.5) has been on the fritz. So we've been using our back up genny, which is a Honda 2000. On average, we've been running the Honda about 1.5-2 hours a day, not only keeping the batts charged, but running an AC fridge in the galley and an AC chest freezer on the aft deck (we also alternate those 2 electric hogs on the inverter a few times a day). While on the hook and using the Honda, I set our Magnum Inverter/charger to only output 50% to the batteries. If they weren't the Firefly carbon foam batts I don't think it would work nearly as efficiently. Of course, yes, if we had all lithium gear it would be even better, but we don't.

In three weeks we used just under 5 gallons of gas, so the charge/power regimen we've been using has been pretty efficient.

Regarding your last question, I've not heard of them needing to be topped off weekly. In fact, I believe that they recommend against a constant float charge when not in use. When Nigel Calder first started testing them on his boat he left them in a partial SOC for a few months. He was summarily impressed with their performance upon recharging. However, that was many years ago and before he helped invent the Integrel super alternator system...

 

[OldDan1943]

I carried a set of 25 foot jumper cables for over 20 years and never had to use them LOL

Yea, for my N46 I carried some mighty long jumper cable made of welding cable. I gave them away. This AT is now set up pretty good except for the one weakness.

 

[Rossland]

Sterling Power from England have posted a bunch of youtube videos and this one is on this subject:

 

[FoxtrotCharlie]

Have been very satisfied with our four Trojan 6v's for house bank. Runs house, plus our 3000w inverter. 160amp alt on starboard on engine keeps them topped off easily. If needed the genny takes care of them also. Old timey 8D's for cranking. Overkill for my Lehman 135's.

 

[Seevee]

We have had Oasis Firefly batteries (4x Group 31) for more than 6 years now. They are our house bank and main engine start batts, so they get plenty of abuse. Not to mention I have inadvertently tried to kill them four times now by forgetting to turn the charger back on and running them down under 11.5 volts. But they bounce back every single time and perform as advertised.

Yes, they are great in a partial SOC, but I really appreciate that they charge much quicker than standard AGMs or FLAs. I can't explain the science behind their charge acceptance qualities, but Bruce Schwab at Ocean Planet Energy can.

This summer we're finding the faster charging and partial SOC performance has been extremely helpful, as our primary generator (NextGen 3.5) has been on the fritz. So we've been using our back up genny, which is a Honda 2000. On average, we've been running the Honda about 1.5-2 hours a day, not only keeping the batts charged, but running an AC fridge in the galley and an AC chest freezer on the aft deck (we also alternate those 2 electric hogs on the inverter a few times a day). While on the hook and using the Honda, I set our Magnum Inverter/charger to only output 50% to the batteries. If they weren't the Firefly carbon foam batts I don't think it would work nearly as efficiently. Of course, yes, if we had all lithium gear it would be even better, but we don't.

In three weeks we used just under 5 gallons of gas, so the charge/power regimen we've been using has been pretty efficient.

Regarding your last question, I've not heard of them needing to be topped off weekly. In fact, I believe that they recommend against a constant float charge when not in use. When Nigel Calder first started testing them on his boat he left them in a partial SOC for a few months. He was summarily impressed with their performance upon recharging. However, that was many years ago and before he helped invent the Integrel super alternator system...

After all the comments and info I've gotten, I believe the Oasis will be my next battery choice. The lithiums are just WAY too expensive for the benefit, especially when I'd have to spend clost to $5K just for alternators/regulators and belts.



Been happy with my Lifeline AGMs. Currently have the West Marine (Penn) batteries and they are just ok... so hope to get 3 or 4 more years then dump them.

 

[Seevee]

Sterling Power from England have posted a bunch of youtube videos and this one is on this subject:

Interesting video..... but worthless. Why not tell us what the batteries CAN do, not what they can't.

 

[Bacchus]

NOW, the only weak link is, if the gen battery goes flat. Perhaps an additional switch connecting the house bank to the generator start or perhaps 20ft long jumper cables? Oh well, let's hope that does not happen.

I was in the same situation and took another TFers suggestion when doing some batty wiring mods.
Replaced the gen batty on/off sw with a 1-2-all and added a jumper to my house bank. Same foot print & bolt holes so direct replacement.
If gen batty is low I can add charge, if dead can start gen with house.

 

[High Wire]

I carried a set of 25 foot jumper cables for over 20 years and never had to use them LOL

Right with you there. Versatile problem solver wherever needed.

 

[Simi 60]

The lithiums are just WAY too expensive for the benefit, especially when I'd have to spend clost to $5K just for alternators/regulators and belts.


.

Gone up in price?
It was $4500 in the first post

Again I ask,
Why do you need to spend all that on alts etc?
Surely it's cheaper to simply run the Genset

 

[OldDan1943]

Gone up in price?
It was $4500 in the first post

Again I ask,
Why do you need to spend all that on alts etc?
Surely it's cheaper to simply run the Genset

Just guessing, he forgot the tax, travel time, shop fees, environmental fees?

Ideally, he wants to charge the batteries while underway???