If I hooked up 2 amps would I need to buy a separate battery?

Should I get another boat battery and On Board Battery Charger?

• We recently bought our first boat. Its an outboard 16 ft 1989 Sea-Ray. We are new to boating and have a few questions we need answered before memorial day weekend! We bout the boat in Feb. this year and took it out for a short trip in April on a small lake and it started right up and ran great after never charging the battery. Its now almost June and am wondering if we need to recharge the battery before we take it out again. And I am seriously considering getting an On Board Battery Charger and another battery but money is kind of tight. Ive done some research on them and I know how they work but Im just wondering if its really necessary to get all this right now or if I could just buy a new battery and switch it over if one battery goes dead instead of installing an on board battery charger. We do have a stereo that will be hooked up and a fish finder but that's about it no trolling motor or anything. Also if any one has any info on transomsupports and if they are worth it that would be great. Like i said we have an outboard and plan on trailering it at least 150 miles each way a couple times a month. Im wondering if it is really needed or if I could wait on that too. Thanks for any help im just a little confused and just want to have a stress-free day out on the lake!!

• Answer:

  Your outboard has an alternator to keep the battery charged while the main engine is running. The sonar will draw almost no current, but the stereo...depends on how much power it uses, and how long you spend anchored up in "party cove" with the tunes blasting vs running up & down the lake (which will recharge the battery). Also, the output of your outboard; some older motors have only 4- or 6-amp alternators, but modern V-4 & V-6's output 35 or more amps. You can always experiment by playing the stereo in the driveway and measure the battery voltage with a voltmeter and crank the motor every so often. Then you'll know how long it takes the radio to drain the battery to the point of not starting the motor. The trick to rope-starting a very large outboard is to remove half the spark plugs (makes it twice as easy to start), crank it and let it idle up to operating temp -- a warm motor should start with just a fraction of a crankshaft rotation. Shut it off, reinstall the plugs and away you go. You can use a marine deepcycle battery (or a dual-use cranking/deepcycle) for cranking (as long as it has enough cranking amps for your motor), and it will give you better service than a cranking battery. Don't use an automotive battery -- they aren't made to take the abuse of the boating environment. 12V batteries self-discharge over time, and storage at less than full charge is the main cause of premature battery failure, so you should either get a bench charger and recharge the battery every couple or three weeks between uses, or else an onboard charger with a "float" or "maintain" mode (*not* a 1- or 2-amp "trickle-charger") that can stay plugged in 24/7 -- the onboard charger is the ideal way to maintain a battery. ~~~~~~~~~~~~~~ if by "transom support" you mean a "transom saver" to hold the motor while trailering, yes by all means use one. You can wait on it, however -- if you have enough clearance to trailer with the motor vertical, that's best. Otherwise, you have to secure it in the tilted up position -- the power tilt is *NOT* sufficient to hold it for trailering, and neither is the "tilt lock" mechanism. if you mean your transom is soft, there's nothing you can do but replace the entire transom -- fastening a support to rotten wood is really no support at all.