Radio with outboard?

Hi guys, I have a 1967 16ft crownline and it has 1971 Mercury 80 h.p. outboard on it. Last season I was at the sandbar with the radio on, now the boat doesnt have its own radio on it so i used a power convertor and ran my dewalt radio off the battery. Only used it about 4 hours, needless to say i was stranded at the beach. I plan on buying a radio for the boat and was wondering should i buy another battery for the radio or how should i go about this? Thanks

Re: Radio with outboard?

I think those inverters use a bunch of power themselves. A direct wired radio may have done better. Your best bet though would be two batteries and a battery switch. I'd probably run a starting battery and a deep cycle. This may be overkill for you and it would be for me too. I'd just use a battery powered boom box to eliminate the hassle

Re: Radio with outboard?

Does your engine have a functioning charging system? A radio's current draw is typically minimal but when you start routing it through an inverter you start consuming more than is necessary. A 12 volt radio would be a more efficient one to use, and unless you're cranking it's amp it would use very little juice. I've set up my whole boat with LED lighting and it's combined current draw is under 2 amps. My charging system puts out 7 or 9 amps so I have plenty to use liberally, and don't need extra batteries. It really depends on how much you would use power tilt, bilge pumps, lighting etc., but a simple radio isn't usually a great concern.

Re: Radio with outboard?

Anytime you try to get 120 volts AC from an inverter powered by a 12 volt source there is a 10:1 converstion factor involved. In other words if your Dewalt radio draws 1 amp at 120 volts AC, the 12 volt battery powering the inverter must deliver 10 amps each hour the device is operated. People commonly think just because the inverter has a 120 volt outlet that little battery will power something indefinitely. Definitely not the case. Inverters are about 85 - 90% efficient so there is only a 10% loss in that box. A 12 volt radio installed in your boat will operate for days on the single starting battery provided that battery is up to par and fully charged. If you install some sort of high power setup, then all bets are off and a separate battery is needed.

Re: Radio with outboard?

I have a second battery that is not charged by the motor, it powers the radio, a second fish finder and a 12V accessory plug. I charge it at the beginning of the year and a couple of times during the year. Use the boat a couple times a week during the season. The battery has never run down. It could also be used as a jump battery if the main battery had an issue.