1ea. start and house bat or 2 house batteries?

[Todd]

I can see the good argument for why sailboats should have a sealed battery. A lot of the deep cycle batteries are not sealed what are your thoughts on this? I have had good luck with the twin 6 volts as well. It looks like the T-105 has a screw-on cap for maintenance so I was thinking it is near-sealed as long as the battery is installed in the correct upright position. Still having sticker shock though!

[NiceAft]

I've noticed in this thread that some have mentioned that they carry a portable jump starter.

I am assuming they are referring to the type that you plug plug into an A.C. outlet so as to recharge for the next use. It is my understanding that unless you either keep them constantly in a charged state, they will no longer function when you need them. I unfortunately went through two of these before I learned that. Because I did not maintain a fully charged state, they fully discharged, and then would not take a charge. I now keep my portable charger constantly plugged in; as per instructions. The alternative is once a month recharge the unit until fully charged again.

Ray

[Sumner]

.. Still having sticker shock though!

Thousands of sailboats have the T-105's in them.

I've put off buying batteries for the Endeavour until we are actually going in the water but did buy two T-105's down here (FL) 2 years ago for the Mac and they were $93 then and have gone up a little to $103 now (with exchange). Lots of golf courses here and that drives the cost down. Look for people selling them to golfers for a good price.

Good article by Maine Sail ...

http://www.pbase.com/mainecruising/deep_cycle_battery

Sumner

============================
1300 miles to the Bahamas and back -- 2015

The MacGregor 26-S

The Endeavour 37

Trips to Utah, Wyoming, Idaho, Canada, Florida

Mac-Venture Links

[Todd]

.. Still having sticker shock though!

Thousands of sailboats have the T-105's in them.

I've put off buying batteries for the Endeavour until we are actually going in the water but did buy two T-105's down here (FL) 2 years ago for the Mac and they were $93 then and have gone up a little to $103 now (with exchange). Lots of golf courses here and that drives the cost down. Look for people selling them to golfers for a good price.

Good article by Maine Sail ...

http://www.pbase.com/mainecruising/deep_cycle_battery

Sumner

Great article! I feel much more informed now.

[1st Sail]

Looking for a good primer to research batteries I started here.
https://themarinebattery.com/#B00ACNO2AO

I most likely will go with 2 12v batteries, switchable via the Perko. I prefer a switchable battery bank vs 2 6v in series (presumably less expensive than 2 12v) as a stupid preventer. I have a 1 in 3 chance of selecting an inappropriate battery supply configuration 1, 2, 1&2.

Lithium! There are plenty of articles on Lithium. Several articles are leaning toward Li as a less expensive investment long term. I found the stats on discharge rates Li vs AGM significant. I am reading everything I can google. I think Li is worth consideration. In terms of available power and recharge rates Li beats AGM. You can no longer use Amp/hr as a determinate of available power. When you factor battery use, power consumption, recharge time (solar, generator, outboard), discharge limits (AGM 50%, Li 80%), discharge delivery rates, an Li equivalent to an AGM wins by a significant margin. Of particular note is the Li recharge rate. AGM's take significantly more power to top off whereas Li recharge to 100% is near flat. That translates in to a significant 24hr use cycle. Running a frig, anchor light, GPS anchor monitor, cabin lights, tv, laptops after sun down on Li alters the recharge strategy. Charging via solar, generator, OB has a significantly shorter recovery period and requires less total power generation to recovery. Li discharge / recharge cycles are quoted 1000-2000 vs AGM. Some articles quote Li use life up to 10yrs. Time will tell.

The big ? is will be keep our Mac long enough to recapture the initial cost.

[kadet]

The big ? is will be keep our Mac long enough to recapture the initial cost.

Or use it enough to justify the cycle count. On a trailer sailer used a few times a month vs a live aboard I happily take my AGMs to 80% discharge so I gain nothing over LiFePO4. Deep Cycle AGM also has low internal resistance and can be charged with very high apps initially for fast charging and I use a 40A 3 stage AC charger for this.

Batteries that are only shallow cycled continually to 5% or less will usually not last as long. This happens because at very shallow cycles, the Lead Dioxide tends to build up in clumps on the positive plates rather than an even film. Lithium might help here but again cost vs use.

I got 5 years out of my old sealed calcium lead acid batteries for $180 I expect to get 8+ years from my AGMs for $450 for the same amount of power from LiFePO4 it would have cost me over $1400 and would not have worked with my charging setup. So to recoup that investment those LiFePO4 would have to last 24 years. And the way battery tech is improving I will probably reinvest in better tech before the 8 years is up like Li2O2 or nanowire or aluminium air or...

Lithium requires additional cost in special monitoring and charging equipment due to the risk of death of the batteries from over discharge/charging. The sums just don't add up yet. LiFePO4 is still too expensive for a bank in a non-liveaboard boat if even then.

[Tomfoolery]

Or use it enough to justify the cycle count. On a trailer sailer used a few times a month vs a live aboard I happily take my AGMs to 80% discharge so I gain nothing over LiFePO4. Deep Cycle AGM also has low internal resistance and can be charged with very high apps initially for fast charging and I use a 40A 3 stage AC charger for this.

And that's why I use flooded marine 'deep cycle' batteries, from Walmart. Charged with the OB when using the boat, and my Marinco 5+5A stationary charger, they seem to stay up fine. My older battery is 6 years old now, and the new one was last season, so I have a 5 year stagger going on. We'll see how long that first one lasts, but one of the two that came with the boat lasted 5 seasons before I replaced it, and I have no idea how old it was when I got the boat. But even at 5 years of life, it's still $20 per season per battery, so like bottom paint and OB maintenance (which costs more per year), it's just part of the cost of ownership. For how I use the boat, of course. YMMV, of course.

[1st Sail]

For me AGM's win this one. There are a few reviews out there from individuals whose batteries failed within 1-2 yrs. One has to wonder if it is from misuse or mfg defect. For the majority of reviews the lifespan is in the 5-8yr range with proper care. Everyone that has contributed has had great performance overall.I'm sitting on 10yrs of intermittent trailer/sailor use on a maintainer. I agree with Kadet and Tomfoolery. I'm still a trailer/sailor at heart for a few more years. Also there is an abundance of proven affordable technology available to maintain and monitor AGM battery systems.

Thanks to all for your insight and valuable feed back!

[Highlander]

Or use it enough to justify the cycle count. On a trailer sailer used a few times a month vs a live aboard I happily take my AGMs to 80% discharge so I gain nothing over LiFePO4. Deep Cycle AGM also has low internal resistance and can be charged with very high apps initially for fast charging and I use a 40A 3 stage AC charger for this.

And that's why I use flooded marine 'deep cycle' batteries, from Walmart. Charged with the OB when using the boat, and my Marinco 5+5A stationary charger, they seem to stay up fine. My older battery is 6 years old now, and the new one was last season, so I have a 5 year stagger going on. We'll see how long that first one lasts, but one of the two that came with the boat lasted 5 seasons before I replaced it, and I have no idea how old it was when I got the boat. But even at 5 years of life, it's still $20 per season per battery, so like bottom paint and OB maintenance (which costs more per year), it's just part of the cost of ownership. For how I use the boat, of course. YMMV, of course.

I agree Tom
I,ve got 8yrs out of my flooded marine batt,s one the original start bat & a deep cycle both r grp24

I,m gonna replace them with wally mart batts both deep cycle grp27 as I believe someone on here said they will fit under the step ladder

J

[Sumner]

If you are doing multiple day cruises and want the most from your batteries I'd take the time to understand what Maine Sail has posted on the subject of what is sold as 'deep cycle' batteries...

"Main Sail --- Does this mean a Group 24, 27 or 31 battery can't and won't work? Absolutely not, it just means that when compared to a battery that is actually designed, built and intended for deep cycling activity, such as golf car or sweeper scrubber or fork truck batteries a Group 24, 27 or 31 flooded battery simply is not the same, cycle-wise, despite the "sticker" suggesting to a buyer that it is."

http://www.pbase.com/mainecruising/deep_cycle_battery

Sumner

============================
1300 miles to the Bahamas and back -- 2015

The MacGregor 26-S

The Endeavour 37

Trips to Utah, Wyoming, Idaho, Canada, Florida

Mac-Venture Links

[NiceAft]

Sumner,

I'm sorry to say that I don't know what the heck you just posted.

In simple English, what are you saying. It's not you. It's me, and I don't apologize for it.

Ray

[Todd]

I would be ok doing the twin 6v over the twin 12v. Here is why:
- you can get the Duracell version GC2 which is the same as the West Marine for ~$85 x 2 (half the cost) It is a real deep cycle so has the 225 a p hour rating and the better cycles. (Per the article)
- at least for me I can get them right here at our SamsClub in the high desert so readily available-no mail order shipping costs
- right down the street is Costco where for a meager $60 bucks I purchased one of these new portable battery charger/emergency jump packs. Its Lithium and in fact does hold its charge. It is really great tech. The size of a hard drive from the 90's. I had an opportunity to try it on my completely dead 5.0 liter motor....not even the dash lights would turn on. It started that car in 30 seconds, no exaggeration. I got it for my boat as the emergency start pack. Now I know it will start the BF60.
-BF60 has a pull start option and has the rope inside the engine cover.
-I dont have to remember to put the battery selector on a specific battery.

[kadet]

Here is why I wouldn't use Trojan T105s over proper deep cycle AGMs.

The true measure of the worth of a Lead Acid Battery is its weight as the lead plates are what determine its robustness and true cost/worth the rest is just cheap acid and plastic, lead is what costs the $$$ and gives the deep cycle perfromane.

A T105 weighs 28kg for 6V 225AH at 20hrs so you need 2 in series for 12v so 225AH for 56KG

The AGMs I use are rated at 12V 125AH at 20hrs for 36.5kg so 2 in parallel gives 250AH for 73KG here they also cost about $40 less per battery compared to T105s - I would love to get a T105 for just over $100AUD

T105s are still wet cell so they can spill when heeled, they are slow to fully charge and if one dies you only have a 6v system. They also should not be discharged below 50%.

AGMs are true SLA can be mounted at any angle, they can be discharged to 80% they can be high amp charged and if one dies you still have a 12v system.

[grady]

I am a fan of the AGM's also. You will need to educate yourself on proper charge voltages. Especially in high temperatures. Unlike a flooded battery if you overcharge it and boil some electrolyte out you just put more back in. A AGM uses verry little electrolyte and you can not replace it. If you boil out some electrolyte you have just reduced the capacity of the battery.

[Sumner]

Sumner,

I'm sorry to say that I don't know what the heck you just posted.

In simple English, what are you saying. It's not you. It's me, and I don't apologize for it.

Ray

I'm just quoting a part of Maine Sail's article on why some of the batteries that are sold as "deep cycle" batteries are not "true deep cycle". You need to go to his site (follow that link) for a complete review,

Sumner

============================
1300 miles to the Bahamas and back -- 2015

The MacGregor 26-S

The Endeavour 37

Trips to Utah, Wyoming, Idaho, Canada, Florida

Mac-Venture Links