Think I need new House Batteries for my Mark II

[Chuck.Philips]

I neglected my old house batteries on our 2005 Mk II and let them go dry.  After adding distilled water, I get some charge out of them but they seem to lose power based upon readings from my Xantrex 2000 more quickly now when I'm on the hook than they did last summer. The batteries are 5-years old. Has anyone replaced their batteries on their Mark II and really like what they have purchased enough to recommend them?  Our house batteries are located under the dining settee cushion. We don't use much power on the hook other than the refrigerator (all the time) and a few lights for an hour or so.  We use a Honda 2000 to recharge when necessary.  I have already changed the starting battery as it tested "need to replace" at a local boat shop.  The bad batteries seem to have affected my inverter as well--I can't get it to start from the panel.  It will only work when I manually press the "invert button" on the actual device.

Advice would be appreciated.

Chuck
"Forever Young"

[Ken Juul]

What size and type are you looking for?

[Stu Jackson]

Chuck, the tech wiki includes this very good discussion of battery types

http://www.c34.org/wiki/index.php?title=C34_Battery_Selection

The Mark IIs, IIRC, came with 4D (or 8D?) batteries which were huge and heavy.  Many skippers moved to lighter 6V golf cart batteries.  You could also go to 12V Group 31 batteries which are lighter also.  The 4D and 8D batteries are not true deep cycle batteries anyway, as reported repeatedly by Maine Sail.

This is from the Electrical Systems 101 topic:

What is a Deep Cycle Battery? (from Maine Sail's website)

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

Your boat, your choice.   

[David Comando]

Hi Chuck.
When I got my 1987 C34 it had 4, six volt golf cart batteries used for the house bank. they lasted another 8 years. When they wouldn't hold a charge any longer I replaced them with 4 Dekka, six volt golf cart batteries, and a Smart gauge. They are still going strong 4 years later. I check the water level every couple of months, more frequently in the hot summer days. I highly recommend this set up.

[KWKloeber]

Chuck,

Describe a little but about how you use the boat, recharge, etc.  That will dictate what the best battery type would be.

kk

[Jim Hardesty]

Describe a little but about how you use the boat, recharge, etc.  That will dictate what the best battery type would be.

Words of wisdom from kk.  I don't like to give much advice on batteries for that reason.  Just want to say the original battery setup works just fine with my use.  Mostly plugged in at a dock occasionally a day or two overnight at anchor.  That includes inverter for coffee maker and microwave.  Unlike my Hunter friends I don't carry a generator to charge the batteries every few hours.  It's my 6th season on my Penn batteries, they are showing some age (using the microwave) but still good for my usage.  Maybe replace next year.  Yes, they are big and heavy.  But, only when they get changed out.

Don't know if I helped you with your decision.  Just wanted to put in my 2cents.  Talking batteries is much like a political discussion, some are very opinionated. 

Jim

[KWKloeber]

Also -

Alt capacity - 51 amp?  72 amp?  ie, how quickly can you replace used A-Hs while motoring?

Tied to a shore charger?  Mooring?  Depend on solar? ie, when/how long does it take to replace A-Hs

Equipment?  ie, microwave, high use power?  LED lighting?

Use - day sailor?  Crusing?  Weekends on a hook?  ie, capacity needed before recharging?

what is really needed is an energy budget (I think Stu has one online), then the answer is more easily determined as "which battery?"

It's like asking "How large a gas tank should I have on my vehicle?"  It depends!

ken

[Stu Jackson]

what is really needed is an energy budget (I think Stu has one online), then the answer is more easily determined as "which battery?"

Yes, the energy budget is in the Elec Sys 101 topic.

But, not quite: The answer (in choosing a deep cycle battery for your HOUSE bank) is only in how big the bank needs to be.

Look, you can buy cheap batteries, you can buy the wrong type (i.e., dual purpose, which are fit for neither purpose!!!), or you can buy true deep cycle batteries.  That discussion was provided, in great detail, in my earlier post.

Whatever battery type you choose (wet, gel, AGM) the energy budget determines the SIZE of your bank, NOT the type.

[KWKloeber]

Whatever battery type you choose (wet, gel, AGM) the energy budget determines the SIZE of your bank, NOT the type.

A good/complete budget tells more than just net A-H needed to hold in reserve before replenishing.   

example - If an owner only day sails, is tied to a shore charger, doesn't use a reefer (or has a holding plate type,) no high capacity loads, uses no nav lights, bla bla bla -- then deep cycling isn't an issue.

If however, say deep cycling is an issue, but the A-Hs used is low versus the recharge capability (time to replenish the charge), except say once a month when s/he hangs on a hook---  then deep discharge (ie slowly killing the battery( may be likely, and an AGM might be more appropriate than a flooded call because they can withstand a deep discharge better. 

The budget can define more than just the net A-Hs at the bottom line -- looking at line items and reading between them paints a picture of usage that could be considered in choosing a battery.

kk

[Stu Jackson]

1.  A good/complete budget tells more than just net A-H needed to hold in reserve before replenishing.   

2.  example - If an owner only day sails, is tied to a shore charger, doesn't use a reefer (or has a holding plate type,) no high capacity loads, uses no nav lights, bla bla bla -- then deep cycling isn't an issue.

3.  If however, say deep cycling is an issue, but the A-Hs used is low versus the recharge capability (time to replenish the charge), except say once a month when s/he hangs on a hook---  then deep discharge (ie slowly killing the battery( may be likely, and an AGM might be more appropriate than a flooded call because they can withstand a deep discharge better. 

4.  The budget can define more than just the net A-Hs at the bottom line -- looking at line items and reading between them paints a picture of usage that could be considered in choosing a battery.

1.  How can that be?  An energy budget ONLY tells you what you think you may need, of course tempered by perhaps using a battery monitor or ammeter to CONFIRM your budget.  Gee, just like your household BUDGET and the reality of your checkbook at the end of the month!    :D:D

2. "-- then deep cycling isn't an issue."  Buying a starting type battery to use even for this daysail type of use, that also requires a deep cycle battery, is a complete waste of $$.  Sure, the choices are as outlined in my previous posts, but anybody who buys an automotive battery and does this kind of sailing will be distinctly poorly served because his battery LIFE will be zilch.  Why not spend the same $$ for something that actually works?  Buy a deep cycle battery for your house bank even if you ONLY daysail.

3.  This is a more complicated subject than that, although I understand Ken's admirable intent.  I highly recommend that those who are new to this subject read up on the Electrical Systems 101 topic, because, quite frankly AGMs are, for example, usually horrible for sailboat applications, as discussed by Maine Sail in the AGM threads in that 101 topic.  It is a subject that each and every skipper needs to learn about for himself.  Saying "AGMs can "fix" your charging issues" is not proper.  They have distinct drawbacks, because their ability to accept charging REQUIRES heavier sources and wires.  Please, please remember, it is called an electrical SYSTEM because only ONE single component cannot make up for the possible deficiency of the rest of the parts.

4.  I continue to maintain that an energy budget can ONLY tell you what you INTEND to use, hence the word "budget."  Confirm it if you will with a battery monitor, but, quite frankly, what you RETURN to any battery bank by charging is based SOLELY on battery acceptance, ALSO DISCUSSED IN  the Electrical Systems 101 topic.  http://c34.org/bbs/index.php/topic,5977.0.html

Ken's contributions, including this one, are valuable, to point out the big issues facing us all about our boat electrical systems.  Thanks.

[KWKloeber]

As long as we're going by the numbers here's why I say that a good and complete budget can tell more than simply the bottom line.

First, I think I see some confusion -- a "Budget" doesn't inherently mean "precisely accurate" (at one extreme,) nor "wild-ass guess" (at the other extreme,)  It's just an income-expense statement of "what I am going to spend" (amp-hours out) vs "income" (A-H replenishment.)  A budget can be VERY accurate (I know EXACTLY what my income or my rent is) or it can be a wild-ass guess (or anywhere in between.)   The more accurate you can define it, the better the information to drive decisions. I have my loads measured to the 1/10 amp, and they do not change.   The variable is how I use the boat, and for a given usage I can be VERY accurate as to A-H s consumed.  The variable we might look at is "worst reasonable case" when looking at decision points for what battery.  Any budget should be a management tool (I spent more on fuel this month, so I need to cut back on entertainment, not "Gee, I wonder if I will overdraw the checking account come the 31st."  (or, I'm spending more hours on the hook because I just retired, so I need to offset that by installing LEDs,)

1.  If my budget says "rent," then I know inherently I don't need to worry about unanticipated house maintenance expenses.  If it says "morgage", well then....... that tells me something else.  Same with any budget -- reading between the lines reveals something (or can reveal something.)

2. Auto battery is a false choice.  It's not a binary choice between, say, rewiring and buying 6-volt deep cycle golf carts or using auto batteries.  I said deep cycling isn't an issue -- not that one would NEVER EVER use 25% or 30% of capacity -- but it isn't the every-day, prime consideration, and isn't the main driver of the decision of battery type.   

For example A, if a budget showed that all one ever does is day sail (and really A-Hs used 95% of the time was for engine starting,) a a cheap Wally flooded cell "deep cycle" (which we know isn't) that gives all needed for starting, and the once or twice a year overnight, might be all that's needed -- and be hundreds of dollars ahead in the long run over buying true deep cycle batteries -- golf cart or otherwise (that one never needs or will see the benefits of.)

For example B, if all one EVER does is start the engine, motor to the start line, weekend day race (never night lights) and return under power and plug in, then that for that situation buying a true deep-cycle battery would be a much greater waste of money in both the short term and long run.

3. I had not implied that is the ONLY decision data point -- as I said, reading between ALL the lines gives info and direction as to what battery might be appropriate.  Yeah, a gel would be a better choice, but it was meant as an example of using more than just the bottom line to formulate decisions -- not a recommendation to buy one or another for any given boat usage profile.  As Stu laments, there's complications and many considerations, but THE POINT was, more data is always better than considering only part of the data.  There's no absolutes and there's hardly ever one single decision point that drives a decision.

4. See the preamble. Budget neither inherently means "guess" nor does it mean "precision." 
Here's why I say that reading between the lines can give more info than just the bottom-line "net"? Using the example budget (electrical 101), if "overnight" are all zeros, and offshore are all "zeros," that tells me something about how the boat is used, and that can be one of many decision data points.  If reefer is "zero" (ie, have a holding plate) that gives me info that might help drive a decision.  It's not all about the bottom line (let's say its 90%) but if that's all one wants to look at on a budget (and ignore other good and valuable information,) then that's their choice!  And yes, "acceptance" does rule the roost!!

kk

[mainesail]

an AGM might be more appropriate than a flooded cell because they can withstand a deep discharge better. 

The reality is that, with only a few exceptions such as the new Firefly AGM, all AGM batteries should be cycled no deeper than 50% in a typical sailboat/PSOC application and they do not last any longer than a comparable quality flooded deep cycle battery.. The shallower the cycling the better for all lead acid batteries...

GEL batteries and the new Firefly Carbon Foam AGM will cycle the longest when going beyond 50% DOD but any proper deep cycle battery can be discharged to 80% DOD, this is a design criteria for a deep cycle battery, but they won't last very long doing so, especially in a PSOC operation.

The only battery I know of that I would routinely advise any customer of regularly taking below 50% DOD is the Firefly AGM.. If you want the best life out of an AGM or GEL battery they need to be installed as a "system" otherwise they just burn a bigger hole in your wallet.

I like and install a LOT of AGM batteries but they are ALWAYS installed as a system. I am installing $1900.00 worth of AGM batteries in about two hours but they system architecture, wind, solar, massive alternator, temp sensors, massive inverter charger etc. , all fully custom programmable, is already in-place and is a sound design. This is s system worth spending AGM money on.

For the OP it sounds like sticking with good old deep cycle flooded batteries would be the best fit because it sounds like the system design is not suitable for AGM or GEL.. 6V or 12V flooded golf cart batteries will represent the best dollars to cycle life ratio for the money.

[KWKloeber]

RC  Do you find any significant difference between East Penn and Johnson (and their store branded)?

Ken

[mainesail]

RC  Do you find any significant difference between East Penn and Johnson (and their store branded)?

Ken

I am not a big fan of any of the JCI sticker brands. East Penn builds a great GEL battery, decent deep cycle golf line up and decent flooded batts. Their AGM line is quite disappointing.

[Mick Laver]

Hi Chuck
Lots of great advice here as usual. You mentioned you had a Xantrex so you already have an empirical "energy budget." How many Amp-Hours do you consume per day on the hook?

They're not very sexy, but we've been very happy with our 4 Trojan 105s. They give us 450 AH (which is probably 50 more than you currently have), they'll easily fit in the same space, and our last set lasted 8+ years. We use about 70 AH per day at anchor, so the Trojans give us about three days before we drag out the Honda.