|Topic Review (Newest First)|
|08-05-2007 06:55 PM|
Originally Posted by trodzen View Post
This seems more expensive and complex than it will actually be, but it plays to the strengths of each battery type and its designated role on my boat, and it gets the batteries away from the engine and its heat.
|08-05-2007 12:50 AM|
Anyone looking for batteries in the se usa check out dcbattery.com in Miami. It's been years since I bought from them, but the price for Lifeline 8D AGMs was exactly half of West Marine Lifelines in Lauderdale at the time.
best - J
|08-03-2007 03:27 PM|
Preferably change them all, since mixing old and new batteries tends to be a bad idea regardless of chemistry when they are on the same charging source.
But some AGM batteries may have charging parameters that are so close to your wet lead, that it pays to check the specs. You may be able to use them together, especially if a "dumb" alternator is going to be the only charging device. Alternators with integral regulators actually aren't designed to do a good job at charging, they are designed to do a mediocre job which won't overcharge if you are running the engine all day.
|08-03-2007 03:12 PM|
Hey All, It's that time for me. I need to replace my house batteries (2 - 8D wet batteries) I am going to replace with AGM.
I don't care about all the calculations of recharge costs, etc. I'm going with AGM. I don't want any more holes in my favorite pair of holy-shorts.
My only question is, I have a happy little seavolt group 24 (? i think) wet cell starter battery. Everything I read says don't mix them. They are different banks and don't get cross connected at all, but they get charged from the same alternator. Do I need to change my starter battery too?
|08-01-2007 11:32 PM|
I was using his numbers from his chart, since you get very different numbers today perhaps that only tells us the real costs are subject to great changes. He's showing the Lifelines at 774 and the Surrettes at 493 if I read it correctly, 8D for each. Of course I think we all know battery prices can vary widely, depending on the shipping costs of lead and how close you can get up the distribution chain.
Lotta numbers in that model index, I'll try to look them over tomorrow.
|08-01-2007 09:09 PM|
HS...there is more to it than that...the calculation is NOT simply cost per amp hour over the life cycle based on purchase cost...it also figures in engine run time to charge etc. which is why the spreadsheet may turn out entirely differently for your boat and you can see all the inputs on the last sheet of his site here:
Example...his fuel cost for diesel is $1.50/gal. ...closer to 3 bucks now and if you have a big engine to run it uses more fuel per charging hour. If you charge on solar/wind...it turns out differently.
It is clear to me that FLOODED are cheaper in many or most circumstances but the typical long term cruiser may get both the benefits of AGM AND cost efficiency long term vs. flooded. Ya gotta enter the data for your own boat and battery choices to see if it works for you.
EDIT...HS...did a little research on the current Rolls/Surette marine batts and an 8d is $1600 bucks each and the model calls for two and is rated for 1500 cycles...even on your math basis that is $3200...1500 cycles and 650 amp hours.
Lifeline AGM...about $950 for 2x8d's and 1000 cycles and 510 amp hours.
That is a cost per lifetime amp hour of .00328 on the surette/rolls and .0018 cents for the Lifelines so YOUR lifecycle cost numbers with todays products from both companies favor the AGM's.
I would note that the current rolls/surette marine 8d's feature their unique 6 cell bolt together approach which is costlier to produce and has the advantage of being lighter to deal with and individually replaceable in the event of a bad cell. The warranty is also 7 years so all that is worth something as well...but on a pure "how much does it cost per amp hour over the life of the battery?" basis...the Lifelines win.
|08-01-2007 04:38 PM|
Cam, I'm afraid I don't agree with Vonwentzel's own charts, based on his own data. In the web page http://www.vonwentzel.net/Battery/01.Type/index.html
he shows Lifeline 8D AGM batteries rated for 1000 charge cycles, at an initial puchase cost of $1.57 per AH.
And he shows Premium Surrette at 3200 charge cycles, with an initial purchase cost of $2.00/AH.
Now, according to my math? If we further divide purchase cost (per AH) by the numer of cycles it can be used for, that's a total purchase cost of $0.00157 per AH for the Lifeline AGM, versus $0.000625 for the Surrette. (Note the extra decimal zero.)
The Surrette are then about 1/3 the price of the Lifeline AGM's, once the purchase price AND the number of discharge cycles are taken into consideration.
That doesn't mean AGM isn't the way to go--but it does mean he's left a very important multiplier out of his figures. (No doubt we're either related or missed the same year of math class.< G >)
|08-01-2007 02:55 PM|
|camaraderie||Yep CD...West is EastPenn/Deka right now. As usual...you can get the real thing cheaper elsewhere.|
|08-01-2007 12:57 PM|
I have gone thru several sets of batts over 20 years and have used all types, flooded, gel and AGM. I will not use flooded again although my last previous set I did give them a try again.
Can't stand the acid and the filling up with water and checking with a hydrometer. Too many ruin clothes!
The Prevailers were fine and now I am on to AGMs which are going strong after 3 yrs, but that is for weekend in season use only. The Gels worked for 3 years as a liveaboard.
I have moved up to 2-8Ds because I don't like to limit electric usage and have had solar cells to keep them topped off. I also use a separate Optima start bank.
I'm sticking with AGMs for now.
|08-01-2007 12:32 PM|
Thanks for bat info and links
The next step for me is to disect the wiring system. Great info thanks to all for your opinions and data. Now to counting coins.
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