Volts vs. Amps gauge

eireton

Cadet
Joined
Apr 7, 2001
Messages
7
I'm sure this goes to "OLD SCHOOL"... But someone, Please help...!<br /><br />Amps = current being drawn.<br />Volts = Potential differential.<br /><br />On a running boat what is more important to monitor? If the AMP gauge is positive, isn't that always a good thing? Why does the voltage gauge help someone (except for false potential)?<br /><br />If I had one gauge... What one would help me most???!!!<br /><br />-Ed
 

corm

Lieutenant Junior Grade
Joined
May 12, 2000
Messages
1,241
Re: Volts vs. Amps gauge

Hi Erie,<br />In two of my boats I have volt meters, both outboards. So I know the battery condition from running accessories,radio, locator, lights,ect. in my IO I run both so I know the alternator is charging and that the battery is holding the charge. I got stranded on Lake Pepin with a battery that had a bad cell in it. As luck would have it <br />my secondary battery had a bad cell also. I carry jumper cables in this overnighter to help others in need. Was I lucky there was some one else camping by us that I could get jump started
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. So after that I installed a volt meter along with the amp meter. If I could have only one it would be the volt meter,I guess as it also shows that the alt. is charging.<br /><br />...confuseing yet...corm
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JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Volts vs. Amps gauge

Howdy, eireton. mbb's post under the topic "volts" seems to be an attempt to respond to your post. Check out my response there. Corm's experience underlines the value of having both, and his comments are spot on.<br /><br />Good luck.<br />JB
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Hi&Dri

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Joined
Apr 3, 2001
Messages
17
Re: Volts vs. Amps gauge

Hi - eireton, With an ammeter you see the current flow. Positive for charging, negative for discharging. A voltmeter shows you equivalent information in a different way, but in addition, shows your battery state of charge. All comments below assume good, clean battery circuit connections.<br /><br />If the engine is running and you see 13.5v on the voltmeter, the alternator is working.<br /><br />If the engine is off with a load on the battery, e.g., fishfinder, stereo, etc. on and the voltmeter reads around 12+ volts, you have a good charge. As it gets below 11.5 you will have a starting problem. The voltage under load shows you your battery status, not the amps drawn. The ammeter would show amps drawn which is interesting and useful but abstract infornation and not useable to determine the state of charge of your battery..<br /><br />In addition, with an ammeter, the ammeter has to be in the charging/discharging circuit meaning Large Long Wires to the meter from the battery to the meter. More opportunities for weather to corrode the circuit and degrade your charging circuit. A voltmeter draws virtually no current so a small wire can be used with no effect to the charging/discharging circuit.<br /><br />It's late and I welcome additions/modifications to this post.<br /><br />Regards, Mike
 

Hi&Dri

Cadet
Joined
Apr 3, 2001
Messages
17
Re: Volts vs. Amps gauge

Grumble, grumble. Can't edit on this forum!!!<br /><br />Check out JT Cornwell's post under "volts". Good knowledge. Also edit my 13.5 to his 14.5 volts under charge. He's correct. G'night, folks. Mike
 

eireton

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Joined
Apr 7, 2001
Messages
7
Re: Volts vs. Amps gauge

THANKS ALL...!<br /><br />Good point on the length and type of wires... I din't think of that.<br /><br />-Ed
 
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