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These have probably been answered before but this time I promise to pay attention. Three questions. 1) What is the best combination of batteries, 1 starting 1 deep cycle, two deep cycles, 1 starting 1 dual purpose? 2) If the oil and filter were changed at the end of last season, is it necessary to put fresh oil in now? 3) Is it best to run the boat before putting new plugs in to burn off the fogging oil? The engine is a 5.0 liter Mercruiser I/O. Thanks!!
 

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1/ 1 Starting and 1 deep-cycle. Both will then be optimized for their intended purpose. The starting Batt is built with thin grids so to develop quick hi-amperage bursts to better spin a hot engine, the Deep-cycle is build with heavier grids to better provide a steady lower-amperage draw over time, thus perfect to run either electronics or lighhting with the engine off. Plus, the deep-cycle will better withstand a big drain-down and be able to bounce back without any adverse effects. Again, better as the aux or house batt. Use the right tool for the job and both will live longer.

2/ No.

3/ Yes.

rgds, Leprechaun
 

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More Battery Questions

Leprechaun:
you appear to know your batteries. Where did you learn all that information? I would like to know more about batteries.

Is it better to charge them before using them or to wait for the boat to charge them?

Can I add acid to make them better?

Who makes the best ones?
How old can my battery be and still work? How do I know how old it is?

It was in the boat when I bought it.

what should I do with the old one if it does not work?
 

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"Where did you learn all that information?"

>>>> A lifetime of boating screw-ups and reading all I can on anything and everything on boating/fishing. Plus being a long-time Snap-on tools dealer didn't exactly hurt either.

"Is it better to charge them before using them or to wait for the boat to charge them?"

>>>> You can do a few different things here:

1/ Just put them back in the boat and hope for the best - not my top choice

2/ Throw them a charger on them for a few hours to build up the latent energy - better, still not the best choice

3/ Take them off the boat and have them
load-tested by a competant automotive garage that owns a heavy-duty battery load tester known as an "AVR". Anyone that makes the $1500+ investment in this instrument will have demonstrated to you his commitment to learning how to properly diagnose weak batteries. - this is the BEST choice and the one I push to my friends and on another boating board on which I moderate.

If you want me to go into the science and procedure of this testing I will - but it might suffice to say that an AVR is a H/D load-tester that uses a carbon-pile to apply current-burning resistance to a battery. It is typically set to eat up 50% of the available amperage over a specified period of time - those specs are usually provided by the battery manufacturer and are typically posted on the top lable on the battery. For example - an 800CCA battery (Not marine cold cranking amps - another whole thing) would be loaded to 400 amps over say 20 seconds and the remaining voltage would then be read. If it drops to lower than 9.7V, the battery is said to be "dead" or prone to fail soon and that battery must be replaced.

In the above paragraph I mentioned using automotive CCA's and not marine CCA's as the appropriate rating of that battery. Why? - Because automotive CCA's are measured at 0-deg F while the made-up term Marine CCA is measured at 32-deg F - a huge difference in the staying power of a battery under load. So the marine battery manufacturers can put a big labee on the front of their battery that reads "1000 Amps" and people that don't know better snap it up as it says right on its case that its more powerful than that 800 CCA automotive battery. Its really not the buyer's fault - just the battery trade playing fast and loose with the facts. I suppose they figure that the typical boater owner doesn't do alot of boating when the temp is below 32-deg F - don't forget, that's where water freezes, so they feel they can get away with devising a less-demanding and quite deceptive rating system. One that overstates the subject battery's capabilities. Dn't be taken in by this scam.

So in actuality, what I'm saying is that an automotive battery rated at 850CCA is most probably much more powerful than a "Marine" 1000CCA battery. No big mystery here, but like I said, most of the public is unaware of this situation when they go out to buy batteries. Not you though, not anymore.

Now there is something else you should know.

The improper use of an AVR by an unscrupulous individual will indeed kill the most robust battery - He can just drain it down to whatever voltage level the crooked garage owner cares to bring it to. He can make any perfectly good battery fail by either increasing the carbon-pile load or increasing the test time well beyond what the battery manufacturer specifies.

So what I'm saying is to be careful who you select for this testing - a good guy will be fair and honest with you, a bad dude will screw you for two new $100 batteries before you know what hit you. Just like pretty much everything else in life, an AVR can be tool for good or evil. Just get a recommendation before you hand over your batteries for testing.

"Can I add acid to make them better?

>>>> Better in what way? Do you mean more powerful? Nope - it doesn't really work that way. A battery's electrolyte is composed of diluted acid in a very specific solution or ratio of water to acid. This is commonly tested with an inexpensive tool called a "Hydrometer" which will float to a specific height in the open battery cell's hole and that height is calibrated, based on the acid level in the solution. This property is actually know as the "Specific Gravity" of the solution and while frankly, I've forgotten the exact number you are shooting for, a properly-charged battery will have a specific gravity of "X" while a partially charged or a battery with a diluted electrolytic solutionwill have a specific gravity of less than that "X". Frankly, most dedicated auto/marine battery hydrometers have the "Good", "Marginal" and "Bad" zones clearly marked and the hydrometer will tell you in about 5 seconds what both the state of charge and the quality of the electrolyte is.

"Who makes the best ones?
How old can my battery be and still work? How do I know how old it is?"


>>>> Those are really the $64,000 questions - the answer depends on the level of care that they have received, the amount of useage and the overall quality of the components the batts are constructed of.

Here's my thinking on these questions and I've been doing this a while - I get 3 seasons out of my batteries. Doesn't seem to matter what brand I buy - I'm so freakin' hard on them that even 3 seasons is pushing it. Doesn't seem to matter the brand - I've used Delco, Interstate, Douglas, Exide, Sears Diehards, SeaHawk, and even the high-priced Optimas - all seem to go 3 years and that's it.

Now this might be a function of the amount of starting as well as the deeply cold winters that I fish into as far as the starting batt. And the fact that I leave my 10" CRT fishfinder on all day long (Its like a little 12V television - draws about 75 watts all by itself). Plus the radar is always in standby, the VHF, two GPS's and autopilot (In standby) are always on, if I'm off the dock, motor running or not. Not to mention deck and running lights if I'm fishing at night.

Now couple that with the fact that the battery box situation on my boat will only accept the smallish Group-24 battery size and I feel that if I get 3 full seasons, I'm doing good.

Currently I have a pair of the West Marine house-brand batteries in there - starting and deep-cycle. I find them to be no better or worse than any of the others I've used - and if you catch the sale at West marine you can grab them up for $59 - 69 apiece. Not too shabby.

"what should I do with the old one if it does not work?

>>>> You leave them with the store you buy the new replacement batteries from. They are required by law to accept the dead batteries, but are also permitted to charge you an "Environmental Fee" for them to pay for the disposal. Typically that fee could be around $5 each, West marine hasn't charge me that fee as of yet. Its baloney anyway as those old used-up batteries are worth money to a recycler - and therefore the store scores twice - once by charging you the fee and again when the recycler picks up the deadies for lead recovery. Like I said, I've never been charged this fee by West Marine. Or Boater's World either for that matter.

Hope I didn't make things more confusing for you.

rgds, Leprechaun

(This post edited by Leprechaun on 04/14/2003)
 

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My .02

I'd like to add my .02, if nothing else, it's good to have a difference of opinion.. I haven't had nearly the experience as Lep, so take it as you wish.

I like 2 "deep cycle + starting". They are basicly deep cycle w/ a good CCA. The reason for this is I use bothe batteries the same. Before leaving the dock, I check to be sure bothe are charged & then use only one. The next trip out, I switch & use the other battery. They bothe get even use & one is nearly guarenteed to be charged at all times, as it was charged at the dock & I'm not using it.

This is a 21 foot outboard powered boat.. with something bigger, I might go w/ 4 batteries and a more complicated system, one that has "house" & "starting" batteries.. I do have 2 circuits; a "house" and "engine", but that's more for safety reasons - I can cut the engines off of power & still run pumps & lights etc.. or I could use a weak battery for electronics, while keeping another fully charged w/ engine.

Jon
 

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No issues with any of the above - its a different approach to the same problem, but I have no love for those dual "Neither fish-nor-fowl" batteries. You don't seem to get the best of both worlds that way - rather they give me only marginal performance in either application. I have never has those things last as long as dedicated application-specific batteries.

Oh and I DO have the two batteries rigged with two separate battery switches on two paralleled circuits that can be combined if needed... Its really the only way to go for a more complex set of boat electrical systems to give me the redundancy that I require for peace of mind.

rgds, Leprechaun
 
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