Volt meter

[steriosm88]

I just hooked up my in dash volt meter on my 93 Tracker 17 footer deep V. It's working and showing about 12 volts with the motor off. What I'm wondering is this going to drain the battery on it's own? If I leave it sitting for a few weeks and it's registering the battery voltage will that alone drain the battery? There is no way to shut it off as it's wired right to the panel. Thanks

 

[tx1961whaler]

Re: Volt meter

I just hooked up my in dash volt meter on my 93 Tracker 17 footer deep V. It's working and showing about 12 volts with the motor off. What I'm wondering is this going to drain the battery on it's own? If I leave it sitting for a few weeks and it's registering the battery voltage will that alone drain the battery? There is no way to shut it off as it's wired right to the panel. Thanks

Most likely not. The voltmeter should have a pretty high internal resistance and will draw only a tiny amount of current.

 

[Mark42]

Re: Volt meter

I just hooked up my in dash volt meter on my 93 Tracker 17 footer deep V. It's working and showing about 12 volts with the motor off. What I'm wondering is this going to drain the battery on it's own? If I leave it sitting for a few weeks and it's registering the battery voltage will that alone drain the battery? There is no way to shut it off as it's wired right to the panel. Thanks

Can it be wired to the ignition switch so it only checks voltage when the ignition is on? That would be the normal way a volt meter is wired.

 

[BLDFW]

Re: Volt meter

A drain is a drain....

Funny you should mention this. I just today finished wiring a new and expanded set of replacement instruments on my '70 Evinrude Explorer and had the same issue.

The old OEM Ammeter had three connector posts, one marked Generator, one marked Battery, and the last marked Ground. The new voltmeter only had one battery line and one ground. Since there was only one "battery" post, I originally connected the two battery lines to the one post (somewhat replicating the wiring diagram however, the voltmeter stayed powered up. To me, that ain't right even with the key turned off. There's no point in it staying powered up and, like I said, a drain is a drain.

Sooooo.... I reread the instructions. Uh....it said to connect to the voltmeter directly to the ignition switch using that as it's power source and nothing about the battery lines being connected. So, I did what it said and ran a wire directly to the ignition switch and removed the battery cables from the unit entirely. I connected them to each other seperately. Now it powers up only when the switch is on and all other power activity is still functional. Just like a car, I can turn the switch on to check the drain when running accessories. At least now there is no chance of a draw on the battery.

 

[FlyinGuy1017]

Re: Volt meter

Don't hook it to the battery. It will drain your battery. Remember: if you leave your headlights on overnight, it might start in the morning; if you leave you dome light on for a weekend, it won't start at all. A lower amperage draw will drain the battery more completely than a higher one. Wire it thru the ignition and you will be fine.

I'm going to swap my voltage meter for an ammeter in my boat. Voltage output isn't as usefull to me as load on the system. When the sound quality from the speakers fluxuates, I know that the alternator isn't carrying the load and the battery has been drained considerably (usually while at idle for extended time). The voltage meter will still read 14V, but the the alternator can't carry the load and thus drains the battery.

Funny how at lower RPM's you usually run more things, i.e. radio, blower, blender, air pump for toys, nav lights, etc.

 

[Bondo]

Re: Volt meter

Can it be wired to the ignition switch so it only checks voltage when the ignition is on? That would be the normal way a volt meter is wired.

Ayuh,... Agreed...

It's only supposed to be On, when the key is On...

 

[Nandy]

Re: Volt meter

That volmeter will take loooong time to drain your battery. It does not represent a drain like a bulb would... However, it should be connected to the ignition switch so it is only on when the switch is on.....

 

[FlyinGuy1017]

Re: Volt meter

Sure it can drain it to nothing!!! Take your standard battery of 2-3 years old and...

e.i.: I plan on taking the boat out next weekend. Then a buddy ropes me into helping him move. Then I get put on yard duty b/c I was with a buddy last weekend and had the boat out the weekend before that. Then the in-laws come into town unexpectedly the weekend after (this is a true story). The draw on a simple voltmeter can kill a battery in that time. I'm sure 90% of us that don't pull to start their engines are using standard auto batteries, not a prefered marine deep cycle battery. How many put their battery on a 'keeper' while it's not being used?

I know the post is about wiring a guage, but to think that a voltmeter won't kill a battery under 'normal' circumstances if it is hooked to it, is crazy.

 

[BLDFW]

Re: Volt meter

A drain is a drain....

Funny you should mention this. I just today finished wiring a new and expanded set of replacement instruments on my '70 Evinrude Explorer and had the same issue.

The old OEM Ammeter had three connector posts, one marked Generator, one marked Battery, and the last marked Ground. The new voltmeter only had one battery line and one ground. Since there was only one "battery" post, I originally connected the two battery lines to the one post (somewhat replicating the wiring diagram however, the voltmeter stayed powered up. To me, that ain't right even with the key turned off. There's no point in it staying powered up and, like I said, a drain is a drain.

Sooooo.... I reread the instructions. Uh....it said to connect to the voltmeter directly to the ignition switch using that as it's power source and nothing about the battery lines being connected. So, I did what it said and ran a wire directly to the ignition switch and removed the battery cables from the unit entirely. I connected them to each other seperately. Now it powers up only when the switch is on and all other power activity is still functional. Just like a car, I can turn the switch on to check the drain when running accessories. At least now there is no chance of a draw on the battery.

 

[Nandy]

Re: Volt meter

Sure it can drain it to nothing!!! Take your standard battery of 2-3 years old and...

e.i.: I plan on taking the boat out next weekend. Then a buddy ropes me into helping him move. Then I get put on yard duty b/c I was with a buddy last weekend and had the boat out the weekend before that. Then the in-laws come into town unexpectedly the weekend after (this is a true story). The draw on a simple voltmeter can kill a battery in that time. I'm sure 90% of us that don't pull to start their engines are using standard auto batteries, not a prefered marine deep cycle battery. How many put their battery on a 'keeper' while it's not being used?

I know the post is about wiring a guage, but to think that a voltmeter won't kill a battery under 'normal' circumstances if it is hooked to it, is crazy.

That is total and utter nonsense. What are your numbers to back that up? I show you mine. A marine volt gauge rated at 1 ma/12v has a 12k ohm impedance. Using a 600 a/h cranking battery and using a battery load calculat0r it would take 108 years to drain the battery to 20%. This is giving the battery a 1.3 Peukert number which is about the worst... Any decent voltmeter would have an even higher impedance...

Anyway, that dont matter... just connect it to the switch...

 

[grego]

Re: Volt meter

Why worry? Disconnect battery. that way there is NO worry that there is a power drain and battery is fresh when you need it. very simple and i do it because it makes sence.

 

[steriosm88]

Re: Volt meter

Wow. Great replies. I'll rewire it to the ignition switch today. I only intalled it cause I now have a fish finder and gps wired to the main panel that is fed from the starter battery. I'm going to wire a second panel up front for the trolling motor and extra depth finder and a plug for a spot light to run off of a deep cycle battery. I just wanted the Volt meter to keep an eye on the starting battery as I'll only be using the big motor to get to the spot each time then use the kicker and trolling motor to put around. The gps and fish finder will be on all day. Thanks guys

 

[Mark42]

Re: Volt meter

Wow. Great replies. I'll rewire it to the ignition switch today. I only intalled it cause I now have a fish finder and gps wired to the main panel that is fed from the starter battery. I'm going to wire a second panel up front for the trolling motor and extra depth finder and a plug for a spot light to run off of a deep cycle battery. I just wanted the Volt meter to keep an eye on the starting battery as I'll only be using the big motor to get to the spot each time then use the kicker and trolling motor to put around. The gps and fish finder will be on all day. Thanks guys

Be sure to include all the gauges on the ignition circuit. Not so much to prevent battery drain, but to extend the life of the gauges.

 

[rebars1]

Re: Volt meter

Set up the starting battery so that it only serves the boat engine. Then you won't be able to drain it with the trolling motor. When the trolling motor dies, at least you'll be able to get home.

 

[steriosm88]

Re: Volt meter

I'm actually leaning towards getting a third battery. One for the main motor alone. The second for all the electronics. And a third deep cycle just for the trolling motor. Gonna need a bigger boat soon!

 

[Silvertip]

Re: Volt meter

Voltmeter, gas gauge, tach, temp gauge, etc are all electrical gauges. why on earth would you want any of them on when the key is off. Wire the voltmeter like any other gauge. You are intested how much fuel you have but having the fuel gauge active with key off is simply silly. Same for the voltmeter. If you want to check the voltmeter with the key off, install a momentary push button in addition to having it wired to the switch. If curiosity is the issue, push the button. At least the gauge is off the other 99.9999999% of the time when you are not looking at it or interested in it and there would be no reason to worry about it discharging the battery.

As for the discussion of installing an ammeter, be aware that the output of most older outboards is not very high so unless you had a fairly significant drain, the needle will never move. Besides, it shows current draw at that point in time. It does not represent how discharged or charged the battery is.

 

[steriosm88]

Re: Volt meter

Silvertip got it right. I ended up wiring in the volt meter with a push button switch. With the key off I can check the voltage of the starting battery with the push of a button. Next season i'll wire in a third battery and one of those big switches to use either battery. Thanks guys.

 

[gregg g]

Re: Volt meter

Oh, boy.....

Electrics and electronics are my line of work, I've done everything from TV and Stereo to industrial controls. I rewired a 53 Ford F-100 from front to back in 6 hrs (no choice- I needed to get home from work) I have installed some hi wattage car audio, and rewired most of my house and garage.

Now, here's what I'm getting at- I've redone a few boat wiring harnesses for friends, mostly stuff from the 70's, and for the most part even the factory original wiring ranges from embarrassing to downright hazardous. Considering that an electrical failure on a boat will leave you SERIOUSLY stranded, it makes me cringe reading posts like this. A voltmeter is a fairly simple device, and the concept is even simpler. Add to that "I reread the instructions" and you can have a potentially dangerous situation.
The pushbutton to read the voltmeter is handy, but what else is getting power when you hit the button? If the voltmeter is wired to the ignition terminal on the ignition switch it is also powering everything else, including the ignition. Congratulations! You just wired in a way to 'hot wire' your boat! All that's necessary then is to hold the button in while someone else jumps the starter terminals and you are up and running, a little duct tape and it's a one man job....


I spent a little time under the dash area of my boat, just checking things out- it hasn't been hacked into much other than the addition of a fish finder, but I plan to re-wire the boat because the stock harness is sloppy. A big tangle of wires and crimp connected ring tongues, with a few inline fuses. First up will be a watertight fusebox using modern blade fuses, watertight connectors (like these http://www.route66supply.com/store/page64.html )
and high quality UV resistant wire. I'll be adding an entire backup electrical system with a separate alternator and battery. The second system will power the accessories, leaving the original alternator and battery to power the engine alone. This way if I am running lights and the audio system it will not be draining anything from the starter battery.

This post may come off harsh, but if you saw some of the vehicles I've had to redo after someone's ham-handed 'sub install' you'd feel the same.

 

[Nandy]

Re: Volt meter

Gregg_g, I think you missunderstood. When they mention to use a momentary push button they mean it as an alternative to wired it constanly hot to the ignition switch. In other words, it will open up the circuit so you have to have the ignition switch on and the momentary button on... The other option is to have the volmeter wired to the battery with a momentary push button in series. Either will just power up the voltmeter...

 

[gregg g]

Re: Volt meter

Gregg_g, I think you missunderstood. When they mention to use a momentary push button they mean it as an alternative to wired it constanly hot to the ignition switch. In other words, it will open up the circuit so you have to have the ignition switch on and the momentary button on... The other option is to have the volmeter wired to the battery with a momentary push button in series. Either will just power up the voltmeter...

If that's how it's wired, then they are OK.

Worst I ever felt was watching a guy's $75,000 street rod burn to the ground because he didn't wire up his amplifier properly, he couldn't even open the door to put the fire out when it started because the electric door poppers wouldn't work. I'd hate to see anyone's investment destroyed because of improper wiring.