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Copacabana · 28-03-2019, 09:22

Quote:

Originally Posted by alamoana

Dear all, I am on Rolls 4000 series FLA batteries for just over 18.5 years, on a mooring. I have never plugged in to shore power. Only run a genset less than one hour per week to make sure it runs and top off batteries. I have had solar for the last 1.5 years. I managed the charging via alternators with an Amplepower SARV3 regulator, and a SCM-55 x 2 modules controlling the charge from the genset. I can thus strongly recommend Rolls 4000 series FLA. I have no experience with the other types.

18.5 years on the same set of Rolls? That's amazing, especially considering you didn't have solar except for the last 1.5 years. I wish I could get Rolls batteries here- they certainly seem worth the extra price for the quality and durability. Even the price isn't that much more than regular golf cart batteries:

https://www.solaris-shop.com/surrett...ooded-battery/

2 of these would be perfect for my boat.

sainted · 28-03-2019, 09:47

You don't say how many 8D batteries comprise your house bank. If its two, you can usually fit six Trojan T105s in the same space. That'll give you a 660 amp hour house bank. T105s are 6v golf cart batteries and offer good bang for the buck. You can also buy good quality golf cart batteries at Sam's Club, often for substantially less than Trojans.

Like others have said, I don't like AGM batteries for house applications because they do very poorly when not completely charged after each cycle.

John on the website morganscloud.com (inexpensive subscription required) has an excellent discussion of the pros and cons of AGM batteries for house service. He uses Lifeline 8D AGMs and he worked closely with the manufacturer to figure out how to get the best service life from them.

Scott

sailorF54 · 28-03-2019, 09:56

Quote:

Originally Posted by GordMay

Compare weights. Heavier is better.

Best advice ever !

ShoreFun · 28-03-2019, 10:06

I am still on the learning here on the boards.

I come from car stuff and antique cars. My brother is a mechanic on Mercedes in an third party repair shop.

So the high end Interstates tend to do the best from the car stand point. By best well I was taking 8 year old used interstates and using them for 2 to 4 years in my car. My brother has a 1931 Model A with no regulator and gets 8 to 12 years on various batteries. A return to Interstate was one battery and I think currently he has 1/2 a 12volt AGM at like 8 years (getting weak). One cell was bad and he just cut off that half. He also get like 10 years on a an Optima battery.
One the other end, I got batteries from Sam's and found they like to fail at 3 years like clockwork. I had them in my F250 pickup and my 1930 Model A Ford. I now only buy high end Interstates for my car batteries.
I am not saying Interstate are the correct batteries for a boat. I am just using them to contrast good batteries with cheap batteries. I have read enough to know there are a bunch of considerations you must make when deciding on a battery for your boat.

The other critical part for a boat is correct charge management. You can have the best batteries in the world and if you do not allow them to be properly charged they will fail fast. I have run across several articles explaining proper charging. It is easy to not charge the batteries properly even with the proper equipment.

It seems some extra money up front in the charge storage and generation can have a long term payoff.

But I may not know what I say. I just have a Hunter 170 and I have yet to be on the water.

MJH · 28-03-2019, 10:08

Quote:

Originally Posted by ob44

I am replacing my house batteries (Trojan 8D AGM 230 AH) and am looking at West Marine (8D AGM 245 AH made by East Penn). Does anyone know whether one is better than the other?

Practical Sailor Magazine tested some AGM batteries in March 2006 but they were not 8Ds. Trojan 27 was Best Choice, Mastervolt 31 next, followed by Deka, made by East Penn, as the Budget Buy. Optima for a small sailboat.

How long did your Trojan 8D AGMs last?

West Marine has a 20% off sale on their AGMs (East Penn) through March 31, 2019.

~ ~ _/) ~ ~ MJH

cottonsail · 28-03-2019, 11:30

Couple of years ago Practical Sailor did a comparison battery test. West Marine compared poorly. Trojan was king of the hill.

john61ct · 28-03-2019, 11:58

Quote:

Originally Posted by ShoreFun

high end Interstates tend to do the best from the car stand point.
…
got batteries from Sam's

Starter batts and true deep cycling are different worlds.

The only batteries good for deep cycling sold in Sam's (or pretty much any big box) are the FLA GCs labelled Duracell and actually made by Deka.

Best value in the world at $1 / Ah @12V

Interstate does not make batteries, just a relabelling marketeer / reseller, its units are mostly made by JCI, and meh quality or worse for deep cycling purposes.

Pelagic · 28-03-2019, 12:00

Quote:

Originally Posted by ob44

I am replacing my house batteries (Trojan 8D AGM 230 AH) and am looking at West Marine (8D AGM 245 AH made by East Penn). Does anyone know whether one is better than the other?

How long have you had your Trojan 8D AGM 230?

I have had mine for only 3.5 years and 3 of the eleven have already failed..... Very disappointed!

**roverhi** · 28-03-2019, 12:23

8D batteries originated as large Diesel engine starter batteries. Most are not deep cycle but high output short term drain batteries. There are some deep cycle 8D's, think Trojan is one manufacturer, but most are just large car batteries. I wouldn't go with an 8D simply for their size and weight. Don't need a hernia changing a battery. Would go with 6v deep cycle FLA batteries as they are cheap, relatively easy to schlep about, tolerant of deep cycling, bad charging practices, and long lasting if you keep the water level up.

john61ct · 28-03-2019, 14:08

Quote:

Originally Posted by roverhi

Most are not deep cycle but high output short term drain batteries. There are some deep cycle 8D's, think Trojan is one manufacturer

No, only Rolls & Dyno, in FLA.

These are AGM, so pseudo deep cycle at best.

And yes FLA GCs are best value

Exile · 28-03-2019, 14:43

Quote:

Originally Posted by roverhi

8D batteries originated as large Diesel engine starter batteries.

Speaking of (although way off-topic), my boat came to me with an 8D deep cycle dedicated to starting the engine only, along with a dedicated engine alternator. My engine is a 4-cyl., 80hp Westerbeke which, according to the manual, requires 400-600 CCA for starting @70ºF. While I know CCA is not used as a spec for deep cycle batts., my G24 genset start battery is rated at 870 CCA. So if my small G24 is more than enough to start my engine (compensating for cable voltage drop & other variables), then surely the 8D is overkill, no? At some point I'd like to combine it with the other two 8D deep cycles I use for my house bank. Seems wasteful to have it dedicated to engine start only. Or am I missing something?

**roverhi** · 28-03-2019, 15:40

Quote:

Originally Posted by Exile

Speaking of (although way off-topic), my boat came to me with an 8D deep cycle dedicated to starting the engine only, along with a dedicated engine alternator. My engine is a 4-cyl., 80hp Westerbeke which, according to the manual, requires 400-600 CCA for starting @70ºF. While I know CCA is not used as a spec for deep cycle batts., my G24 genset start battery is rated at 870 CCA. So if my small G24 is more than enough to start my engine (compensating for cable voltage drop & other variables), then surely the 8D is overkill, no? At some point I'd like to combine it with the other two 8D deep cycles I use for my house bank. Seems wasteful to have it dedicated to engine start only. Or am I missing something?

A largish 12v car type battery worked in both my 300D turbo Mercedes and they put out over a 100hp. 8D may be overkill for your 80hp engine. On the other hand do know that Westsail combined two house banks together for starting the upgraded engine in the W42. That was a Perkins of around 70hp IIRC.

Exile · 28-03-2019, 15:54

Quote:

Originally Posted by roverhi

A largish 12v car type battery worked in both my 300D turbo Mercedes and they put out over a 100hp. 8D may be overkill for your 80hp engine. On the other hand do know that Westsail combined two house banks together for starting the upgraded engine in the W42. That was a Perkins of around 70hp IIRC.

AFAIK, a dedicated 8D for engine starting was original to the boat. So while it may indeed be overkill, on the other hand who am I to question the original design? In fact, my boat originally came with a 70hp engine, and some with 55hp. Fwiw, I did wire my fuel polisher to this start battery so at least there is some (minimal) draw, and tying it in to the house bank is not as easy as it sounds. What I may do is simply run a positive cable from the engine batt. to the house bank with a switch. That way I can draw off the engine batt should I suffer a failure from the house bank. I already have it wired the other way (with a relay switch) so I can draw on the house bank should the start batts for either the engine or the genset need a boost.

One of those boat systems that I think could be improved on, but if it ain't broke . . . .