Many marine batteries are bolted. I know that the Trojan T-105's and T-125s are bolted. Some batteries are available from the manufacturer in different configurations.
Battery advice for new-to-us Hunter 36...and why did these huge Northstar AGMs die so soon?
- Thread starter Kupe
- Start date
Per ABYC:
10.8.3 Battery cables and other conductors size 6 AWG (13.3 mm2) and larger shall not be connected to the battery with wing nuts.
I install systems for other people so, yes, I use a torque wrench. On my boat? Umm...sometimes.
Given that the weather here is cold, wet and miserable today, this of course raises the question of "how can the OP's charging system of 20A possibly damage his batteries ?"
Given that he arrives as a transient at a marina with electrical power, for 50% SOC batteries he will take something in the order of :
(360/2)Ahr. ÷ 20A = 9 hrs.
Maybe and extra hour or two for absorption and he's 100% SOC and ready to go. As far as a 72A or larger battery charger, he could fully charge at a marina in about 2.5 hours. Ideal if you want to charge up, fill with fresh water and skip out before paying your moorage
.We don't know anything about his alternator size. I'd put my money into something that'll give me more amperage while I'm motoring like an external alternator regulator to ensure I'm always well charged when I pull into that next anchorage.
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I'd rather be shot that use wing nuts on a battery. Hence, I always use nylocks.
I have a tendency to over tighten fasteners. I always want to give it that last little turn. In many cases that last little oomph results in costly errors in either time or money or both to fix. So I have armed myself with most sizes of torque wrenches for my boat and a good torque chart or say the data sheet from Trojan.
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I replaced my 3 lifeline 4-d's with 6 trojan t-105's and have no regrets. I paid about 900 for the 6 back in 2020. I also installed a flexible 175 watt solar panel on the deck to keep them topped up- my boat is on a mooring. When we cruise I throw another flexible 175 watt panel on the dodger or bimini while at anchor. When it's sunny I have plenty of power to run my fridge some 12v fans and the lights. I run the engine with a balmour 100A alternator occasionally to make hot water and supplement the solar. For me, it was cost benefit. I figure there's got to be a reason golf courses use them over other types so much. If you do go the flooded route make sure they are oriented correctly.
Installation & Orientation of Flooded Batteries on Boats - Marine How To
Port to Starboard Orientation This photo is simulating a sailboat heeling with flooded batteries. For years I’ve wanted to write this article, but until my friend Dave let me shoot this polycarbonate cased UPS battery, it was going to be tough to explain. As
marinehowto.com
I'm with Greg. 2 GC2 6 volt batteries that have a 230Ah capacity. That's 115 usable Ahs if keeping them above 50% discharged.
Mine just finished their 6th season. I'm in a slip and normally plugged in but 3 times I've abuse them by letting them be discharged below 50%. Once to 10V, once to 11V and just recently to 5V. My Sterling Ultra Pro 30Amp charger brought them back just fine and they still power my boat for 3 days while staying above 50% charge as they have the past 3 years.
There are many battery options and none of them is universally good. The right battery matches the owner's intended use. For day use, an occasional over night, and many nights in a marina with shore power, a pair of Group 27 or 31s would be just fine. Crossing the Pacific, you're going to want a different system.
So, for the OP, @Kupe (and anyone else thinking of changing their batteries) the first question to ask is, How am I going to use this boat? And then, how much energy do I need for how long when I'm away from shore power? What's my budget? Answers to those questions will go along way to building a functional electrical system that meets the owner's needs and budget.
So, for the OP, @Kupe (and anyone else thinking of changing their batteries) the first question to ask is, How am I going to use this boat? And then, how much energy do I need for how long when I'm away from shore power? What's my budget? Answers to those questions will go along way to building a functional electrical system that meets the owner's needs and budget.
Hi Kupe. I just finished replacing our two twelve year old 8D AGM deep cycle batteries (160 pounds each) with new sealed for life AGMs (172 pounds each). Cost was $916.10 each from All Battery Sales and. Service, a local Interstate battery dealer. Yes, they are very heavy, heavier than the old ones, but rated at 260 ampere hours each, as opposed to 240 for the old ones. The old ones were DECCA brand and performed very well over the years. These are Full River DC260-12LT and, hopefully, will last at least as long as the old ones.
It was a two man job. The hard part was lifting them into the clydesdale from our van and lifting them onto the steel rack shelf in the aft cabin. Used the main halyard to lift them from the clydesdale on the dock, swinging them into the cockpit, then lowered them down the companionway steps, then sliding them on cardboard into the aft cabin. Took about two hours to get the job done and another hour to connect them.
Our charging system consists of an Xantrex Freedom 20 (2000 watt) with a companion Link 1000 that does the job well, along with an 8KW Onan Genset. We normally consume about 50/60 AH per day depending on the season; more during the winter months when running the furnace. During our cruising season I run the Genset for about one and a half hours every other day to bring the house bank from a minus 100/120 AH to a minus 20 AH. This routine has worked out well over the years when many of our extended cruises can last over two months mostly at anchor. I keep shore power connected while in our slip.
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You will need to conduct a Power Survey to estimate your daily overall usage to compare against the batteries storage capacity and your opportunities to recharge. A fridge is a high power usage appliance, depending on the ambient temperature and how often is it opened it could easily consume upwards of 50A a day (24hr). Unless you are looking to upgrade your battery charger besides the cost of new AGM's, I would recommend four 6V deep cycle 225Ah batteries (Golf Cart Batteries) with each pair wired in series to get 12Vs and the two pairs wired in parallel to double their capacity. That should render a battery bank of 450Ah with a battery health safe usable capacity of 225Ah between recharges. Yes, there is a learning curve about matching your power needs, with sufficient power storage and the ways to recharge batteries. In addition learning about the batteries chemistry will lead to better product choices and proper maintenance for a longer service life. It's a juggling act.
Thank you and everyone again. I really am leaning toward the 4 Flooded Deep Cycle golf cart 6v batteries. Or possibly two Group 27 12v Flooded Deep Cycles...basically back to her configuration when new in 2004. The discussion here about sailing needs helped a lot. Moderate weather lake sailing in SE US...always on shore power except for maybe a couple two-night anchor outings a year.
What I also learned is that the huge Northstar AGMs were probably dead-men walking as soon as the previous owner installed them with the original charging system. I don't think my sailing needs justify the expense of new AGMs, let alone a new charging system. At least the FLA batteries have the advantage of being "the devil that you know"
So going to shop both- I think somebody mentioned Sam's or Costco as a good source of T105 golf cart batteries. I'll also check West Marine and some other local retailers for the Group 27 marine Flooded Deep Cycle options.
I've honestly slept better having found this group and the great welcoming and knowledgeable community!
Cheers!
Hey gang-
As a purely interim measure until I get new batteries, is there any consensus on these very popular car jump-starter packs just in case?
Thanks!
As a purely interim measure until I get new batteries, is there any consensus on these very popular car jump-starter packs just in case?
Thanks!
I take the attitude that a "just in case" can never be allowed to happen.
Once the boat is on battery power, the selector switch is used to isolate the starter battery, and it is then treated as sacred. I've also tested that our Yanmar 2GM20F will start after three days at anchor with about one revolution while using the house batteries which are down to 12.2V and 50% SOC. Actually after three days of sitting, the engine is still raring to start because the piston rings are still wet. And this is in bloody cold weather.
That's why I've looked at jump start packs before and figured I've got too many backups to have one on the boat.
If there is a BatteriesPlus nearby check them out. I bought my Duracell Ultra GC2s from them. The Duracell's are available in a range from 215 Ah to 255 Ah. For the price point I went with the 230 Ah batteries.
BTW, The GC2 fit in the footprint of a Group 27 battery.
West Marine just labels others batteries and ups the price. They don't have anything special.
As far as Group 27 Deep Cycle, they probably won't be true deep cycle and only have 80 to 90 Ah. Two GC2s will give you more total Ahs than two Group 27s and cost maybe $50 to $60 more.
Just a thought.
As @Ward H said, there is nothing special about WM batteries. They are made by East Penn who make batteries under a lot of labels.
On the MarineHowTo.com website there is an article on "Deep Cycle Batteries." Worth reading so you know what you're buying.
For the kind of sailing you'll be doing, the GCs are probably your best bet both in performance and cost. Be sure to measure to make certain they will fit and you should have a battery box for them to fit into. You'll also need a couple of jumper cables for the series connection. All that will cost less than one of the Northstar batteries.
On the MarineHowTo.com website there is an article on "Deep Cycle Batteries." Worth reading so you know what you're buying.
For the kind of sailing you'll be doing, the GCs are probably your best bet both in performance and cost. Be sure to measure to make certain they will fit and you should have a battery box for them to fit into. You'll also need a couple of jumper cables for the series connection. All that will cost less than one of the Northstar batteries.
please don’t do that! Do yourself and your wallet a favor and buy batteries from a battery supplier. Sams or Costco are also good sources. But don’t buy “marine“ batteries. The term is meaningless. In some cases, it implies so-called dual use batteries which are good for neither starting or house supply.
Those batteries need to be charged with a 14.7V absorption and the recommended charge current is .4C or 40% of Ah capacity They also require temp compensated charging The batts have most likely been murdered from chronic undercharging.
Our local store over prices their products, so elsewhere I go. All Battery Sales (Interstate) does a better job, IMHO.
Weighing in again.. I know I sound like a bit of a broken record…, sorry.
For relatively simple systems in mid sized boats, I really need to say that the 6v AGM batteries tick all the boxes (for me, in any case)
One of the biggest issues is weight, and the ability to install, move when necessary, etc. with ease
Cost is as reasonable as you could hope for.
If I were to use my 49 extensively off grid, perhaps I’d switch to fast recharge lithium. But, with an onboard genset, this doesn’t make sense.