Re: Another battery question
Here is the standing recommendation for marine batteries for your type of boat:<br /><br /> Outboard center-console boats need dual-use batteries, with one for starting and one to run the electronics. <br /><br />If you use one starting and one deep cycle, it is a step up from this recommendation, but at a higher cost for the deep-cycle battery.<br /><br />There are three types of technology used to make lead acid batteries. Each type has its own charging profile. You should not mix battery types for starting and deep-cycle applications IF you are using a single battery charger for all your batteries. If you use two types of batteries, you need two chargers. Battery types:<br /><br />Wet Cell or Flooded the same batteries technology of the critters we have in our cars. The marine version is beefier but is still the least expensive per A/Hr to own and operate. They require regular maintenance, have the highest self-discharge, but are very forgiving of charging irregularities. Charging cycles: 800-4500 (2650 average).*<br /><br />AGM a maintenance free battery using the newest technology. It has a low self-discharge rate. Also not as sensitive to charging irregularities. The interior construction yields a battery that is not susceptible to failure with overcharging. AGM deep-cycle batteries are also great for starting applications. Batteries can be mounted sideways. Cost about twice a wet-cell per A/Hr to own and operate. Should be charged with a 3-stage charger. Charging cycles: 1000-5000 (3000 average).*<br /><br />Gel basically a wet-cell battery with the electrolyte turned to jelly. Another sealed, maintenance free battery that can be used at any angle. Very low self-discharge rate. Most sensitive to charging profile
most battery chargers should not be used on this battery...needs a charger designed for Gels. The battery cannot be equalize due to over charging causing serious, irreparable damage. The most expensive battery per A/Hr to own
almost 4xs that of a wet-cell. Charging Cycles: 800-2000 (1400 average).*<br /><br />* The number of charging cycles is determined from published data and reflects when the battery was used by some techno-boy under ideal conditions. Do not expect to get these numbers on your boat.<br /><br />Rickdb1boats advice for the biggest battery you can afford is good advice!!! It may appear a bigger battery is a wasted resource
it is not. Heres way: the lower limit of the deep cycle battery is considered 50% of its 20-hr rating (A/Hrs). If you get a 100 A/Hr battery, plan on being able to use only 50% of that
50 amps, at any time
but using less is better. The life of a battery is determined, in part, by how many amps it has to cough up and how often. The deeper it is discharged, the unhappier it is, the shorter its usable life will be. The less a deep cycle is discharged, the happier it is and the longer it will last.<br /><br />This is the useful number of cycles for a high-end AGM marine deep-cycle battery (Concorde Lifeline) and a wet-cell marine deep-cycle battery (Surrette/Rolls series 4000) based on the depth of discharge. These are 12v batteries.<br /><br />Dischg..Conc...Rolls<br />------..----...-----<br />10%.....5000...unpublished)<br />20%.....2850...2000...5000**<br />30%.....1870...1700<br />40%.....1250...1490<br />50%.....1000...1280...3200**<br />60%.....810.....1120<br />70%.....640.....960<br />80%.....500.....800<br />90%.....400.....700<br />100%...340.....590.....1500**<br /><br />**These big numbers are for the Rolls series 5000 battery. It is either 4v or 8v and expensive, but has a 15-year+ useful life. Your typical off-the-shelf 6v CG battery has a similar profile. As you can see, if you have serious deep-cycle applications you would likely bennifit from useing a brace of 6v golf cart batteries wired in series. They last longer, perform better, and cost the least per A/Hr in the long run.
