Opinions needed (volt or amp meter)

[Beck]

Now setting up a new to me Tim's 16x54 custom flat. Mounted CMC ptt, transfered outboard, mounted tach, compass, dash switches, wired trolling motor, etc. But there's a aprox. 2 1/4" hole in the dash. I have a volt meter and an amp meter (they came out of a disposed bat. charger for a generator) that would fit perfectly. My question is which one would be the most practical and how should it be wired? <br />Thanks,<br />Beck

 

[Silvertip]

Re: Opinions needed (volt or amp meter)

By all means the voltmeter is most practical because of wiring issues. A voltmeter is simply wired POS terminal to a 12V line that is active with the key on. It will then measure electical system voltage and tell you whether the engine charging system is working (anything above 12.6 - generally 13.5 - 14.5 volts at 2000 RPM or more is good). On the other hand, and amp meter is wired in series with the main 12V charging lead connected to the battery. This means that the entire electrical load must pass through the meter and it also means the much heavier wire must run from the back of the boat, to the dash and back again. And depending on the scale on the amp meter 30-0-30, 10-0-10, etc, you may not see enough needle deflection to even tell if the system is charging or not. My preference therefore is voltmeter and that's whats normally fitted on most boats these days.

 

[18rabbit]

Re: Opinions needed (volt or amp meter)

Ammeters become useful when it is critical to manage battery resources, like with a house bank of batteries supporting a DC/AC inverter. Even then, we are at a point where the ‘managing’ is best done by a microcomputer with status displays, alarms, and predictive resource limits, etc., so you would benefit more from the display of a system controller and not necessarily the ammeter itself.<br /><br />Ditto UpInSmoke. Opt for the voltmeter. Personally, I think every boat with a battery, regardless of size, should have a voltmeter onboard.

 

[Beck]

Re: Opinions needed (volt or amp meter)

Thanks Up.. and 18...<br /><br />I will install the volt meter. One other ? off hand which wire should be Pos. with the key on? I was thinking on just wiring it to a switch like the lights etc. That is a dedicated switch for the meter not tied in to the same switch as the lights. Key would be more professional. I do have the service manual for the engine I can look in there but if someone already knows I would appreciate it. <br /><br />One other ? how often should one open the control box? The very last time I opened it (quite some time ago, prob. 8 yrs.) from the looks of it I never wanted to open it again. Too many parts etc.<br />I felt lucky to get it back together.<br /><br />Should I just try to splice the control wire going to the engine? How would you more professional wrenches do it?<br /><br />Thanks again,<br />Beck

 

[Dunaruna]

Re: Opinions needed (volt or amp meter)

Jump off the back of the tach, should be purple (ignition 12v).<br /><br />BTW, what size troller have you got for a 54fter

 

[swist]

Re: Opinions needed (volt or amp meter)

Or just hook it to the distribution bus. The meter doesn't draw any current to speak of and there is no reason it can't be on whenever the battery switch is on. As a matter of fact that will give you even more info (state of battery after long period of not running engine).<br /><br />Just make sure the lights, if any, are hooked to the other instrument panel light circuit. You don't want them on all the time.

 

[Beck]

Re: Opinions needed (volt or amp meter)

Thanks Dun... and Swist,<br /><br />I tied it to the tach, had the ground (-) and ignition (+) within inches. Will this give me the status of the battery same as wiring to the distribution bus you speak of Swist? Seems like it would being the pos. and neg. comming from the battery but just going thru the key switch via the control box.<br /><br />Thanks again,<br />Beck

 

[swist]

Re: Opinions needed (volt or amp meter)

Your meter won't read with the ignition off, which is probably more normal than the hookup I suggested (although I don't know why, voltmeters in cars don't read with the ignition off either).<br /><br />It's no big deal, if you want to see the battery state when the engine is not running just turn the ignition to the on position and take a look. If it reads 9 volts you know you were anchored out in the lake with your 1000 watt stereo running too long and you better have another battery you can switch to!

 

[Beck]

Re: Opinions needed (volt or amp meter)

Thanks for the info.<br /><br />Have it all wired up now. I'm not crazy where I mounted the light switches, may move them later. I need to mount the batteries but they seem a little tall for the area they were stored. I also want to mount the gas tank in the rear compartment.<br /><br />Are there any regulations preventing having the battery and gas tank in the same compartment? I noticed there is a vent for the compartment sticking out the port side of the boat.<br /><br />Beck