Wednesday, November 5, 2008

Buying a Battery for Your Boat

A penny saved on this item

could mean many dollars lost

later on. Base your choice on quality and cost per month

A BATTERY is a utility item, hidden un­der the hatch or in some other inac­cessible place, out of sight and out of mind so long as the engine starts and the electri­cal system works. To most boatmen the battery is the algebraic "X," the unknown quantity, an obscure black box that may suddenly conk out-always at the most embarrassing time.

In buying a battery, the top grade is usually the most economical in the long run. There is no skimping on material, and being a bit oversize it stores more energy to start the engine under conditions that cause low-grade batteries to fail. The sav­ings in recharges and other service more than offset the additional cost of the quality battery.

When you buy a battery you will find there is an initial cost and an actual cost. The initial cost is the price you pay for the battery off the dealer's shelf. The actual cost involves what you pay initially, plus money paid for upkeep, measured against length of service received.

For example, a battery costing $30 and lasting three years without need of recharg­ing or other service costs about 84¢ a month. A gyp battery for $10 that lasts a year and needs two recharges during that time costs you about $1.08 a month. In

the latter case the cost and inconvenience of having the battery fail at sea are not included.

Since there are great differences between batteries, it's well worthwhile to select a battery with a well-known trade name rather than just any battery offered you. You will save money by buying a battery that has earned a name and a reputation in the battery field.

One mistake commonly made by the boatman in buying a battery is to buy one too small to do the job. In a car, lights, radio, and other accessories are used while the engine is running, and the generator supplies the necessary current. But in a boat, most of the accessories are used at anchor with the engine not running, and the battery supplies the power.

The electrical size of the battery is ex­pressed in terms of volts and ampere-hour capacity, such as 6 volt, 100 AH, 12 volt, 50 AH, etc. The ampere-hour capacity is based on a 20-hour discharge rate and is an indication of the battery's ability to deliver power continuously over a 20-hour period. It is the measure of the amount of working material put into the battery; that is, the number and size of the plates. A 100-AH battery will deliver 5 amps con­tinuously for 20 hours, 4 amps for a bit

longer than 25 hours, or 2 amps for con­siderably longer than 50 hours. But it will not deliver 50 amperes for two hours or 100 amperes for one hour. No boat should have a battery smaller than 100 AH, and preferably double that, in two batteries connected in parallel or in a dual-battery automatic system.

Sometimes the electrical size of a battery is expressed in terms of the number of plates in a cell or the total number of plates in the battery. But since there is no stan­dard for the size of the plates, such a rating has little value. Some gyp batteries have plates only half as long as the plates of a quality battery.

Most batteries are guaranteed for 90 days against defective workmanship and

Buying a Battery for Your Boat

material and for a period of months of service. Such guarantees are of the pro-rata type, which means that when a battery fails to give its guaranteed service the owner is entitled to buy a replacement battery at a reduced price, based on the service re­ceived. For example, a battery costing $30, guaranteed for three years, fails at 18 months. The owner would be entitled to a new battery for $15. Note that the guar­antee does not specify how well the battery will perform, nor does it protect the owner against the cost of recharging or other ser­vice. On such a basis a gyp battery, even though guaranteed for long service, can be costly. Better stick with the better-known brands.

Fundamentally, the buyer should be con­cerned with these things:

Will the battery operate the boat's elec­trical system satisfactorily? If it will not, frequent recharges will be necessary and you can be sure it will fail you at the time you need it most.

Will the battery serve dependably for a long time? If it won't you'll be faced with an early replacement, making -the cost on a per month basis prohibitive.

Does the manufacturer provide adequate service? When trouble occurs, the guaran­tee is not much good unless the manu­facturer can provide dealer service at the point where you need assistance. A battery with a guarantee backed by a nationwide dealer-service organization is highly desir­able.

In batteries, as in almost everything else, you get about what you pay for. A battery offered at an unusually low price is not necessarily a bargain. It may well be a bat­tery made to sell at that price, or even lower. The difference between a medium and a low-price battery may be only in capacity, the quality level of both being about the same. On the other hand, the low-price battery may be low in both ca­pacity and quality.

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