Older boat/ motor and New Electronics

[phx5kegsman]

I have a 78 Johnson 115 V4 on the back of my 82 Ranger 330V. I have put much (probably too much) time and money into both of them. Both boat and motor perform well. The bought came to me with a Humminbird Helix 9 at the bow, and I have added a garmin Echomap 9 with side and downscan. Both are hooked up to my house battery, which also serves as my cranking battery. Other accesories connected to this battery are the bilge pump, gauges, horn, etc. I also have navigation and stern lights, which rarely get used. No, for now. My concern is weather or not the charging system on my old motor can keep up with all of these toys. If I'm not mistaken, I believe the rectifier on my motor puts out 10 amps. I have no idea how many amps newer outboards put out. Am I ok to run both fish finders for most of the day? Or, will I have to stop fishing every hour or two to run the boat around to charge the battery? I know that this old motor was not designed with these gadgets in mind and it is what it is. should I be running my gadgets on a seperate battery?

 

[flashback]

Yes

 

[matt167]

I think the flashers and paper chart fish finders of those days ( their name escapes me at the moment ) took more power than modern fish finders. Truth is with a second house battery and automatic switching if you so choose will work fine

 

[dingbat]

I run 9" chart plotter, 9" fish finder, VHF, CD, NMEA 2k network and wash down. A grp. 27 battery couldn't keep up a full 8 hour day with 30 amp output and an hour of run time

Keep in mind that you only get 10 amps for every 1 hour of run time above 1500 rpm

Multiply your run time (above 1500) X 10 amps and there is your net gain in power.

 

[phx5kegsman]

That explains a lot! The lakes that I fish are not very big, so I don't spend much time above 1500 rpm throughout the day. There's been a few times when I wasn't sure I had enough juice to start my motor. And those old two strokes don't always start right up on the first crank, lol! Can anyone give a little more info on a "second house battery and automatic switching"? I've never heard of that before.
When I acquired the boat, I figured that I would be able to upgrade to newer motor. Boy, was I wrong! You can't even find a decent later model two stroke in my area. And the prices on four strokes are just insane! I'll just have to make do with what I've got, for now. Thanks for your help

 

[matt167]

You typically use a battery selector switch for multiple batteries. There are switches that will switch for charging automatically

 

[dingbat]

That explains a lot! The lakes that I fish are not very big, so I don't spend much time above 1500 rpm throughout the day.

I fish a pretty big pond. Anywhere from 1/2 to 2.5 hour run to the fishing grounds. It's the 6 to 8 hours of trolling that gets me

There's been a few times when I wasn't sure I had enough juice to start my motor. And those old two strokes don't always start right up on the first crank, lol!

Mine is pretty good. Rare to not start on the second crank with temps above freezing. Once warm, a quick turn of the key and I'm off.

Can anyone give a little more info on a "second house battery and automatic switching"? I've never heard of that before.

Here is what I use with two (2) grp.27 deep cycle batteries.

Add-A-Battery Kit - 120A - Blue Sea Systems

Simplifies switching and automates charging for a complete two battery bank solution.

www.bluesea.com

When I acquired the boat, I figured that I would be able to upgrade to newer motor. Boy, was I wrong! You can't even find a decent later model two stroke in my area. And the prices on four strokes are just insane! I'll just have to make do with what I've got, for now.

I guess it depends on where you live what you consider expensive. Probably 25 of them on Facebook market place in a 50 mile radius of here (Baltimore)

 

[phx5kegsman]

Not much in central California, lol!

 

[stevedan]

That explains a lot! The lakes that I fish are not very big, so I don't spend much time above 1500 rpm throughout the day. There's been a few times when I wasn't sure I had enough juice to start my motor. And those old two strokes don't always start right up on the first crank, lol! Can anyone give a little more info on a "second house battery and automatic switching"? I've never heard of that before.
When I acquired the boat, I figured that I would be able to upgrade to newer motor. Boy, was I wrong! You can't even find a decent later model two stroke in my area. And the prices on four strokes are just insane! I'll just have to make do with what I've got, for now. Thanks for your help

Same in my area, ended up buying 1996 force engine and with a little work got it running, but has been the only motor I have seen so far (craigslist) in my area of North Carolina for 70 HP to 90 HP that is not over $1000.00 and a 4 stroke on a 1985 boat, is out of the question..

 

[dingbat]

Same in my area, ended up buying 1996 force engine and with a little work got it running, but has been the only motor I have seen so far (craigslist) in my area of North Carolina for 70 HP to 90 HP that is not over $1000.00 and a 4 stroke on a 1985 boat, is out of the question..

Craig's list is a bust anymore.
Most have moved over to Facebook Market Place

 

[flashback]

I like dingbats bargain barn! Best deals ever...

 

[airshot]

Just add a second battery, when your done for the day put it on a charger/ maintainer until your next trip. I use a group 31 deep cycle to run everything except starting the big motor. Lights, radio, ship/ shore radio, fish sonar, aereator, bilge pump, horn etc can run all day with power left over. Now you will save your starting battery so you can always get back in. Outboards are designed to maintain the starting battery, not designed to charge deep cycle battery in a short time. Run two batteries and be safer.