Best 8d battery for full time liveaboard

In the process of putting in 2 new 8d batteries In the willard,its a full time liveaboard so batteries are used alot at night,gotta switch over to led lighting for interior,but want to get batteries that eventually will be hooked up to wind turbine,any thoughts and recommendations would be greatly appreciated

I put in 3 East Penn AGM 8Ds in 2014 and happy with them for both house and thruster banks.
I will not be replacing w 8Ds when needed. After doing some research and contacting both Trojan and East Penn they both confirmed that in their AGM line there is no starting or deep cycle performance difference between GC2s and GP 31s. This is confirmed by the specs as they spec CCA and AH capacities for both (unlike FLA).
I felt there was some potential benefit to having the same battys in both thruster/ start bank and my house so my decision is to use 2 GP 31 for start/thrusters and 4 GP 31s as a house bank. If one or two get weak/ die I MAY be able to avoid replacing all 4 or 6 by combining the remaining usable batty into one bank (of 2 or 4) and delay having to replace the other bank until more die. If I had 6V GCs for house and say GP 31 start I lose the flexibility.
Long story but bottom line my East Penn (Sams Club Duracell) AGM 8Ds are all doing well after 7 seasons so I'm happy with EP for their reasonable price.

Full River

You can get the power you need without going to the ancient heavy, big 8ds.

BTW Welcome to TF

I'd rethink installing 8Ds for your house bank- especially with the new technology available (carbon foam and LifeP04). The new tech batteries can be more deeply discharged, recharged quicker, and are much lighter than an 8D.

I have a tendency to say the higher end batteries are worth it. Bacchus says "Seven seasons". I am curious If they were being tortured all year long for 7 seasons would they still last??? I think East Penns are mid level batteries. But It is hard to argue with 7 seasons!!!! When it comes to Lead acid batteries(yes that does include AGM), I have learned that the heavier the better.....all other things being equal. IOW, more lead=better!!!! 2 Odyssey Group 31s might be easier to handle than an 8D and offer better performance.

My new LiFePO4s weigh 23 pounds, are rated for 3500 discharges and come with a lifetime warranty. No way I would put in 8Ds ever again.

Comodave said:

My new LiFePO4s weigh 23 pounds, are rated for 3500 discharges and come with a lifetime warranty. No way I would put in 8Ds ever again.

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I am no fan of 8Ds. But I have a hard time with the (ignorant)physics of LiFePO4 technology. Ultimately energy is heat.....or the other way around. It is hard to imagine 23 pounds absorbing the heat required of the task we are asking of them. Again....totally ignorant observation on my part.

I am certainly no expert on battery technology but the Lithiums are pretty amazing. Time will tell.

We have four lifeline 8D’s on our Lindell 36. Replaced them 2 years ago, after 17 years of service. They were still going strong but our generator run times were going up and seemed like we had got a reasonable amount of use out of them. We spend an average of 20 weeks per year on the hook, usually for a week at a time. I am sure there was a scientific way to determine replacement time, but my seat of the pants thinking was they had served their time. Anyway very happy with lifeline and if we have to honcho 4 8D’s in and out in another 15 years I won’t be to worried.

helm said:

We have four lifeline 8D’s on our Lindell 36. Replaced them 2 years ago, after 17 years of service. They were still going strong but our generator run times were going up and seemed like we had got a reasonable amount of use out of them. We spend an average of 20 weeks per year on the hook, usually for a week at a time. I am sure there was a scientific way to determine replacement time, but my seat of the pants thinking was they had served their time. Anyway very happy with lifeline and if we have to honcho 4 8D’s in and out in another 15 years I won’t be to worried.

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ONLY 17 years????!!!!! My point. I do think something needs to be said about how they are cared for. Mostly what kind of charger is looking after them. I see people on here saying they turn their chargers on when they get to the boat and turn them off when they leave. I can guarandamnteeyou those people are not seeing decent life out of their batteries. One of the things the better chargers have is an "Idle Mode". It is somewhat of a FOURTH stage of charging. If the batteries need a float charge, it will be applied. A continuous float charge by some battery chargers will kill your batteries over time. What charger were you using?

Edit: also you have four 8Ds in a 36 foot boat. That pretty much means you are not torturing your batteries and the reason they lasted so long.

LifePO4s are great. Light, long-life, and you can fully deep discharge them. Be careful, though, if they share duty as the starting battery for you engines, especially diesels. They have limited CCA (Cold Cranking Amps). They are perfect for a house battery if you can afford them. They have a higher up-front cost, but due to their long life end up being cheaper in the long run.

linked below is a thread entitled "My attempt to murder my Firefly batteries" in the sailing forum (Cruisers forum). The OP of the thread was an early in with Fireflies on his boat. He had a history of killing his lead acid batteries and wanted something which could withstand his abuse. If you read the thread its all self explanatory. He also has an Efoy unit on the boat. He has a classic sailboat with beautiful lines and he didn't want to visually wreck it by using solar panels.

Here is the opening lines to his thread:

Just an interesting story.

As I mentioned in other threads, if there is someone who can kill batteries, it will be me. I have a long history of murdering batteries badly! My challenge is to destroy the Firefly batteries in my boat by abuse!

They, however, have a different agenda!

https://www.cruisersforum.com/forums/f14/my-attempt-to-murder-my-firefly-batteries-221607.html

DBoat said:

LifePO4s are great. Light, long-life, and you can fully deep discharge them. Be careful, though, if they share duty as the starting battery for you engines, especially diesels. They have limited CCA (Cold Cranking Amps). They are perfect for a house battery if you can afford them. They have a higher up-front cost, but due to their long life end up being cheaper in the long run.

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Mine are a dedicated house bank. I have 3 starting batteries for the engines and genset. They were actually cheaper for me because I needed more room in the engine room for more house batteries but in order to get the room I would have had to buy a new self contained A/C system to replace the split system. Now the A/C can stay and I will have a larger house bank along with a new 120 amp alternator for less money than replacing/expanding my old 6 volt bank.

Read the article in the Library which discusses better alternatives to 8Ds. Most 8Ds are straight lead acid starting batteries and won't hold up well in deep cycle service.

David

OP, obviously there’s nothing wrong with FLA technology. Switching to lithium is not a simple nor a cheap thing.

However, I’d recommend you consider installing a bank of 2V industrial batteries instead of the 8D’s. You have a huge selection of capacities and weights to work with and they are generally rated to about 1500 cycles at 80% discharge, just about equalling lithiums, but at a fraction of the price.

Mako:

Could you give us a few examples of 2V industrial batteries with web links that would work in a marine house battery bank. One example I found was huge and comparing it to 6V golf cart batteries, was much more expensive: 28 cents per watt hour for a big 2V Trojan industrial battery vs 14 cents for 6V Trojan golf cart batteries. Prices were from the same seller- Arizona Wind and Sun.

In my experience due to the tremendous volume of golf cart batteries sold, their cost per watt is as low as anything you can find. They also require minimal jumpering, unlike 2V batteries.

See- https://www.solar-electric.com/trojan-ind33-2v-deep-cycle-industrial-battery.html and- https://www.solar-electric.com/trt16vo225ah1.html

David

Baker said:

I have a tendency to say the higher end batteries are worth it. Bacchus says "Seven seasons". I am curious If they were being tortured all year long for 7 seasons would they still last??? I think East Penns are mid level batteries. But It is hard to argue with 7 seasons!!!! When it comes to Lead acid batteries(yes that does include AGM), I have learned that the heavier the better.....all other things being equal. IOW, more lead=better!!!! 2 Odyssey Group 31s might be easier to handle than an 8D and offer better performance.

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I agree with a minor difference...
My part year season is what it is and may help batty life vs more active use. On the other hand I am unable to charge batty while in bed for the winter and no way I'm removing 8Ds to tend at home (as I used to with smaller boats & batty banks). So 6 mos w/o a charge isn't the best trestment and the original reason I went to AGM. With FLA I found a way to ignore batty maintenance sooner or later and was guilty of at least assault... not murder.
My philosophy re batty purchases is to attempt to balance performance, ease of use and economics. I absolutely agree that East Penns are in general a mid range batty. I do think they are a good value and readily available (Sams Club or a small truck shop I deal with).
No doubt there are "better" battys available but I question the payback for the higher $.
I am intrigued with LiFe but reluctant, at this point, to make the investment in time & $ to make the switch... maybe if I was 20 yrs younger and could hope to see a return in my boating or motorhoming life I'd feel different.
We all get to make choices and no one right answer for all. All I offer is what I've decided, my rationale of why and report my experience.

I installed fire fly batteries 18 months ago and have been more than pleased. I have about 930 amp hours of fire fly batteries and one battery bank which both starts the engines and provides house current.

I chose fire flies because I did not want to put lithium batteries in the engine room which in summer can get to 100 to 110°. Lithium batteries do not like high temperatures. Actually no battery likes high temperatures. But lead acid batteries and fire flies are a bit more resilient to such heat.

My batteries seem to maintain voltage even when they drop below 50%. This past summer the power pedestal on our dock malfunctioned. I had a dehumidifier hooked to a circuit powered by the inverter. The voltage dropped to 11 1/2 V by the time I learned of the pedestal issue. I was able to bring the batteries back to 100%. I am guessing that these are the last batteries I will have to put in this boat.

I replaced 8D start batteries with two group 31s. I replaced two 8D house batteries with 3 L-15, 4V batteries. All of these batteries comprise one large battery bank.

Before anyone talks about the danger of not having a dedicated start battery, I have to tell you I have two generators each with its own dedicated start battery.

+1 on not having dedicated starting batteries. IMHO, the boating world is rampant with "what if, what if, what if" for the extremely unlikely event. Same for those $1,400 dual Racor, space-hogging, rarely, if ever used, filter heads. As you no doubt have, I, too, have starting batteries for my generators which can be used (the generator) to recharge the house bank or the drive engines started with jumper cables if one must move immediately. Plus, a boatload of wiring and switches are absent with a combination starting-house bank. Yeah, but, yeah but .......

Gordon J said:

I installed fire fly batteries 18 months ago and have been more than pleased. I have about 930 amp hours of fire fly batteries and one battery bank which both starts the engines and provides house current.

I chose fire flies because I did not want to put lithium batteries in the engine room which in summer can get to 100 to 110°. Lithium batteries do not like high temperatures. Actually no battery likes high temperatures. But lead acid batteries and fire flies are a bit more resilient to such heat.

My batteries seem to maintain voltage even when they drop below 50%. This past summer the power pedestal on our dock malfunctioned. I had a dehumidifier hooked to a circuit powered by the inverter. The voltage dropped to 11 1/2 V by the time I learned of the pedestal issue. I was able to bring the batteries back to 100%. I am guessing that these are the last batteries I will have to put in this boat.

I replaced 8D start batteries with two group 31s. I replaced two 8D house batteries with 3 L-15, 4V batteries. All of these batteries comprise one large battery bank.

Before anyone talks about the danger of not having a dedicated start battery, I have to tell you I have two generators each with its own dedicated start battery.

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Another very happy Firefly user here. We've had them for five and a half years now, and like the guy who tried to kill his I've inadvertently done the same thing three times. They bounce back every time (though I am trying very hard to NOT do it again....

We only have four FFs (total of 440ah) as house and start bank, with a separate batt for the generator. I used to think that being able to discharge up to 80% or more and still maintain voltage was the biggest selling point to the Fireflys, but after a few seasons of use I determined the much faster charging profile of carbon foam is even better.

catalinajack said:

+1 on not having dedicated starting batteries. IMHO, the boating world is rampant with "what if, what if, what if" for the extremely unlikely event. Same for those $1,400 dual Racor, space-hogging, rarely, if ever used, filter heads. As you no doubt have, I, too, have starting batteries for my generators which can be used (the generator) to recharge the house bank or the drive engines started with jumper cables if one must move immediately. Plus, a boatload of wiring and switches are absent with a combination starting-house bank. Yeah, but, yeah but .......

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I fully agree with this philosophy. My current boat, Meridian did it "right". They have a whimpy house bank(I think it is something like 169Ah). They have a dedicated start battery for each engine(1 GRP31 each....for an 8.3 liter diesel). The have a battery for each thruster(1 GRP31 each....bow has about a 25 foot cable run....as you can imagine, Bow thruster performance sucks). And the generator is started off of one of the engine start batteries....I guess the theory being you could still start the other engine. There is also emergency paralell switches if that was ever needed. Plenty of redundancy one would think. But I think the reality of it is, each battery gets absolutely TORTURED doing its own little job over and over. And over time, I think this would defninitely affect the longevity of the each individual battery(bank). Whereas the "one big bank" philosophy, no batter gets tortured. Leave the generator out of the loop and there is your redundancy. On top of it all, super simple as fir as wiring goes and as far as maintanence and troubleshooting goes. Anyway, my batteries are signalling that they are tired. I will likely go back to a one big bank system.....leaving the bow thruster with it's own battery(s) and charger Since it will be a long way from the big bank.

Lostsailor13 said:

In the process of putting in 2 new 8d batteries In the willard,its a full time liveaboard so batteries are used alot at night,gotta switch over to led lighting for interior,but want to get batteries that eventually will be hooked up to wind turbine,any thoughts and recommendations would be greatly appreciated

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I would HIGHLY recommend going MORE batteries
The most common fail I have seen is people underestimating their usage and taking batteries down to 50% or worse and, in a year or two buying new batteries.

Ours never get below 80% (20% used) and I believe this, as well as ability to charge to 100% and some every day will make it a long lived battery bank.

Ours are inexpensive TBB branded AGM batteries, cant seem to get them anymore but they were sold to us by one of the larger Victron distributors so figured they must be OK - into their 4th year of full time off the grid usage and zero issue.

I don't get the fixation with not using more than 20% of the bank's capacity just to get a couple of more years use. My eight golf car FLA batteries, which double as starting batteries, are already nearly four years old and have been cycled down to 50%, and sometimes more, about 150 times. They will likely last another three or four years. As a test, last night at dockside, I ran on battery power all night. I removed 460 AH from a 932 AH bank, 50%. The charger fully re-charged the bank in 4.5 hours, not a particularly long time. Had I been cruising, there is no reason to believe the result would be any different. Perhaps my Victron SOC meter is lying to me.

Simi 60 said:

I would HIGHLY recommend going MORE batteries
The most common fail I have seen is people underestimating their usage and taking batteries down to 50% or worse and, in a year or two buying new batteries.

Ours never get below 80% (20% used) and I believe this, as well as ability to charge to 100% and some every day will make it a long lived battery bank.

Ours are inexpensive TBB branded AGM batteries, cant seem to get them anymore but they were sold to us by one of the larger Victron distributors so figured they must be OK - into their 4th year of full time off the grid usage and zero issue.

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oh to discover the moon be made of lithium!

catalinajack said:

I don't get the fixation with not using more than 20% of the bank's capacity just to get a couple of more years use.

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Not a fixation as such but it is how it ended up
We have 8 x 250ah
6 X 250ah would have been borderline imho
There are no shops on the water so I don't want to rape them and have premature failure
Batteries are cheap, easier to get them in one go when its easy to get them.

My eight golf car FLA batteries, which double as starting batteries, are already nearly four years old and have been cycled down to 50%, and sometimes more, about 150 times. They will likely last another three or four years

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If you lived aboard full time with no shore power like we do that would be more like 1450 cycles
How do you think they'd be holding up now?

.

As a test, last night at dockside, I ran on battery power all night. I removed 460 AH from a 932 AH bank, 50%. The charger fully re-charged the bank in 4.5 hours, not a particularly long time.

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Fully recharged?
Dont be to sure about that

Had I been cruising, there is no reason to believe the result would be any different

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It would be if all you relied on was genset or engine for charging, unless you run them right through the float cycle as well putting in minimal amps.

Perhaps my Victron SOC meter is lying to me.

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Quite possibly, they are an indicator imho, not truth

My victron says 100% SOC by midday yet solar appears to smash in amps for several more hours. On these days I wake up at 6am and voltage reads 24.3v and above 83% SOC
On days where there is little or no sun in the afternoon, so missing out on the "extra" even though the batteries SOC says 100% at 4pm the alarm is beeping at 6am and voltage reads around 23.1v but still above 80% SOC

Lostsailor13 said:

In the process of putting in 2 new 8d batteries In the willard,its a full time liveaboard so batteries are used alot at night,gotta switch over to led lighting for interior,but want to get batteries that eventually will be hooked up to wind turbine,any thoughts and recommendations would be greatly appreciated

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Northstar AGM’s are great batteries.
I have 4 , totaling 2000 reserve amp hours.
Only thing is that you MUST top off with a higher than normal voltage, per their specs
They are exactly the same batteries used in military tanks.
We have the standard refrigerator/ freezer and a Large dometic freezer.
Also the 3500 watt zantrex inventor runs a 42” tv, counter top ice maker.
ALL my lights converted to Led had the most impact on batteries amp draw. They are easy to replace and makes a huge difference in amp hour usage

Tanks and boats usage is vastly different. They don’t anchor out too many nights with refer running.

catalinajack said:

+1 on not having dedicated starting batteries. IMHO, the boating world is rampant with "what if, what if, what if" for the extremely unlikely event. Same for those $1,400 dual Racor, space-hogging, rarely, if ever used, filter heads.

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+1 Catalina.

Fear factor + extremism = “what if”

Our Fleming has 2 x 8D for engine starting and 4 x 8D for domestics. Having had her since 2003 we've used Lifeline and only changed them once after 12 years.