Battery-Alternator-Voltage
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=24941
Printed Date: November-19-2024 at 9:44am
Topic: Battery-Alternator-Voltage
Posted By: Link
Subject: Battery-Alternator-Voltage
Date Posted: February-20-2012 at 3:29pm
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Teachable Moment time:
My cousin is a car guy, runs a parts store. He knows most everything there is to know about cars. Last year he was down for a week and used my ’89 Sport. I was at work one day when he called and said my battery was not putting out enough voltage. Long story short, he bought a deep cycle marine battery and put it in the boat. He also replaced the alternator. Today I am reading up on the forum and there are several posts saying that deep cycle marine batteries are bad. Can someone explain to me why? And should I replace it immediately? Also, is there any difference between a car and marine alternator? The boat read 12v on the positive side of the battery, but the gauge shows around 10v. Could easily be a bad gauge since it fires right up every time, but the posts I read have me doubting myself now and thinking the alternator might be the wrong one. Can someone school me on the topic? I am a routine maintenance kind of guy, not a mechanic. Thanks! ------------- 1989 Sport Nautique |
Replies:
Posted By: crobi2
Date Posted: February-20-2012 at 4:07pm
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Deep cycles typically give up cranking amps for the ability to deeply discharge and not destroy the battery. Since in most of our boats you just need the battery for cranking, a high quality cranking battery is all you need. If you are blasting a 2000 watt stereo amp, you probably need a second battery and modified charging system anyhow.
Alternators for boats are supposed to be ignition suppressed (oftentimes just a screen) to keep the fuel fumes in your bilge from blowing up. Because of the moisture, the wiring gets corroded at connections, so this could be responsible for a low reading at your gauge. Also, it has been alleged that sometimes the main wire to the dash is too thin. You might just want to check and clean all of your dash connections. I did it after we got our boat - took around an hour or so. When the alternator is working, it should be supplying almost 13.5 - 14 volts to the battery. ------------- C-Rob 2000 SAN |
Posted By: TX Foilhead
Date Posted: February-21-2012 at 6:03pm
| I would worry more that he installed an automotive alternator than a deep cycle battery. Marine alternators also ramp up the voltage a little different than a car because of the sustained RPM's in a boat they see on a boat. |
Posted By: Bri892001
Date Posted: February-21-2012 at 6:17pm
| Do you remember what your dash gauge read before? I would just go by what voltage you get at the battery. There's a few reason's your dash gauge may read differently. Well, one main reason, and that it undersized and potentially corroded wiring/connections going to your dash and in your dash. |
Posted By: Link
Date Posted: February-21-2012 at 6:30pm
Seems like it always read 14 Volts. I probably didn’t pay much attention to it after he replaced it last year. It was toward the end of the season, and the boat had new alternator/battery so I didn’t pay much attention. This year when I charged the battery and took the boat out, I noticed it reading lower than the normal 14 Volts. I get a 14v reading at the battery. Shouldn’t I be getting 14.6V? I am not sure I should really be too concerned, but I just want to have the correct setup. (I am learning as I go and use the site to school me on the right way to do things!) ------------- 1989 Sport Nautique |
Bri892001 wrote:Posted By: Link
Date Posted: February-21-2012 at 6:36pm
I recall him saying after he replaced the alternator that he was still not sure if it was charging correctly. Would this be because the one he put on was not marine? I don’t know how the two are different, but with the voltage reading on the low side at the dash, it reminded me of what he said after putting the alternator in. ------------- 1989 Sport Nautique |
Posted By: TRBenj
Date Posted: February-21-2012 at 7:02pm
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Its unlikely you ever had a charging issue in the first place. Our year boats are notorious for undersized wiring to the dash, causing a voltage drop. Put a larger load on the dash and the voltage reading will drop further (blower, lights, etc). This problem gets more obvious as time goes on, as wires and connections corrode. To really fix the issue, you should clean your connections, replace any worn out breakers, and run extra power and ground wires from the engine to the dash.
I would put the original alternator back on. If its gone, then make sure what you have on there now is rated for marine use- its a safety issue. Marine electrical components (distributor, starter, alt) need to have spark suppression built into them to prevent the ignition of gas fumes in an enclosed space. I would also ditch the deep cycle battery. Theyre meant for trolling motors and large stereos (small current draw over a long period of time). You dont need a marine battery for our boats- a good starting battery (large current draw over a short amount of time) works best. A Group 65 battery fits in the battery box nicely. ------------- |
Posted By: 8122pbrainard
Date Posted: February-21-2012 at 7:27pm
You had better ditch your cousin too!   ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Jllogan
Date Posted: February-21-2012 at 7:29pm
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ha ya cousins what do they know? Seems like the only thing I ever learned from cousins is what not to do by their bad examples. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: 8122pbrainard
Date Posted: February-21-2012 at 7:30pm
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The cousin doesn't by chance have a Autozone franchise does he? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Jllogan
Date Posted: February-21-2012 at 7:33pm
Oh Pete, you stole that one from me, I almost made that comment but thought it was below the belt. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: 8122pbrainard
Date Posted: February-21-2012 at 8:20pm
Justin, I've been know to be blunt at times!! Maybe I should edit my post and put some smileys in ? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Link
Date Posted: February-22-2012 at 12:55pm
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Give me a cousin who spends his own money to fix something (even if done wrong) over the little brother who leaves it on E every time he uses the boat!
...and no, it is Advanced, not Autozone.  ------------- 1989 Sport Nautique |