dumb question about volt meter

[VicCT]

Hi all,
New to trailer ownership and trying like mad to figure out the whole 12v thing, among many other things. I did a search but could not find the info I need. I have been to 6 or 7 different auto parts stores, and Sears, looking for a portable digital volt meter for my battery. They have things that plug into cigarette lighters, and things that plug into wall sockets, but isn't there something that I can just clamp onto the battery to test the voltage (without permanently installing it)? If so, none of them had it. I want to be able to monitor the voltage so I know when to charge it when it isn't being used.

I realize there is probably a simple answer to this question, but I can't find it.

[David B.]

Try Harbor Freight
Search results for: 'volt meter'
Dave & Paula

[Bob Miller]

The VoltMinder was a great solution, but I believe that they may not longer be available. But there is a sorta smart battery box available that has an LED monitor for battery condition and some other useful features.. Fairly inexpensive as well. Here's a link:

And you can leave a plug-in digital meter in one of it's outlets.

Marine Smart Box Battery Case


There may be others like in in the Marine catalogs, but expect to pay $$$

[blodn1]

This might be of use:

Amazon.com: Save A Battery 3751-S 12 Volt 6' SMART Alligator Clip-On Cable with LED Voltage Meter: Automotive

[Dudley]

a cheap multimeter would work well or a simple panel mount voltmeter from ebay
ebay voltmeter

Mount it in the trailer and run wires to battery or tie it in to the power in the inside of the trailer so you can easily monitor it

[Carol H]

Originally Posted by VicCT

They have things that plug into cigarette lighters, and things that plug into wall sockets, but isn't there something that I can just clamp onto the battery to test the voltage (without permanently installing it)? If so, none of them had it.

I personally really like the simple LED ones that plug into the 12 volt socket (looks like the cigarette lighter) in the trailer. The one I has also has an alarm on it that will sound if the battery gets down to 60%. I like it as I can plug it in only when needed and don't have to take the top of the battery cover off as I do when I use the full sized Mastercraft voltage meter I have. I tend to only use the large one when trouble shooting 12v issues.

[Raz]

A digital multimeter that has it's own power source.( 9 volt battery ). Avoid anything with an analog meter ( needle) or anything that draws it's power from the circuit being tested. All you really need is DC volts scales 2v, 20v 200v, AC volts scales 200v, 600v., and resistance which will include a continuity tester. Don't pay extra for transistor testers, frequency, capacitance etc. Less than $20 anywhere. I wanted one for my tool box in the trailer so I just bought this one.

http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

Raz

[VicCT]

Thanks all! This is where I ask, there is a 12 volt socket in the trailer? I haven't seen one . . . but that doesn't mean it isn't there! If it is there, then there is something to plug it into, which solves my problem, at least when the battery is on the trailer.

[padlin00]

I've not seen one that clamps on to the battery, those that have clips on the leads are too small for battery terminals. With the one that Raz shows, you hold the leads on the battery terminals after setting the switch to the right setting. You get a multipurpose tool with these that you can use for troubleshooting, if you figure out how.

The ones that plug in to the lighter sockets can stay there giving you continuous readings till you need the socket for something else. They are quick and simple.

If you are not aware, you do not have to check battery voltage at the battery, you can check it anywhere the 12 volts is present. As in a light if you have access to the contacts, or a lighter socket.

You could also install a 12 volt meter permanently, as in this article.
SOLAR FOR EMERGENCIES: 12 Volt Meter a must for RV's and Small Solar

Depends how easy you want things. I use a DMV like Raz bought but can get a rough idea from the trailers status panel that shows full, 3/4, 1/2, etc. If I didn't have that I'd add either the permanent meter of the lighter one.

[Bob Miller]

Originally Posted by VicCT

Thanks all! This is where I ask, there is a 12 volt socket in the trailer? I haven't seen one . . . but that doesn't mean it isn't there! If it is there, then there is something to plug it into, which solves my problem, at least when the battery is on the trailer.

As it seems that everything was optional in the Scamps you may well not have a 12 volt power outlet. But, if not, it is something you will want to add I am sure. They aren't that difficult to install, but I suggest that you have at least two installed as there are more and more uses & needs for them. Everything from small inverters for 120 VAC to cell phone chargers need 12 volts to keep going.

In 13' Scamps, the easiest place to install them is in the front of the left dinette seat and/or the side or front of the sink cabinet, as both are near the power chassis/DC fuses.

[Steve L.]

I agree that having 12v outlets is pretty handy. There are any number of cigarette lighter USB devices that expand their usefullness. They're cheap enough but they do tend to be low amp devices so larger items like tablets can take a long time to recharge. But that's not the point of the original post so this is an extra-credit answer.

[rabbit]

It seems cigarette lighters have been replaced with 2 dollar Chinese voltmeters. I guess that's progress; perhaps not quite on the scale one might hope. Get the probe type multimeter which Raz recommends. They pay for themselves the first time you need to check voltage on small AA or AAA or 9V household batteries. Save the instructions so you can learn new applications AC and DC as they arise.

jack

[Timber Wolf]

I just this morning saw a clip out coupon in a magazine for a "free" multi-meter from Harbor Frieght. I have a bunch of them already ($3-$4 on sale) or I would go get another.

[Bob Miller]

Originally Posted by Steve L.

I agree that having 12v outlets is pretty handy. There are any number of cigarette lighter USB devices that expand their usefullness. They're cheap enough but they do tend to be low amp devices so larger items like tablets can take a long time to recharge. But that's not the point of the original post so this is an extra-credit answer.

That's a good point, most 12 volt to USB adapters are limited to about 2 amps

The work-around for devices like tablets is to plug in a small inverter and use the original tablet charger for charging. At 10 amps x 12 volts, you should have well over 100 watts to work with.

As I have mentioned earlier, some inverters can interfere with computer and/or tablet operation, but they will usually still charge batteries with the device turned off.

[Carol H]

Originally Posted by VicCT

Thanks all! This is where I ask, there is a 12 volt socket in the trailer? I haven't seen one . . . but that doesn't mean it isn't there! If it is there, then there is something to plug it into, which solves my problem, at least when the battery is on the trailer.

If there is one Scamp normally puts them up on the end of the top kitchen cabinet facing the rear table. If the trailer also is TV ready it may be a combo receptacle with the cable connection and 12V plug. If you don't have one they are pretty easy to add.

[VicCT]

I will head over tonight to check, but I think I would have noticed if it was there. Couldn't I add a regular outlet to run on 12v, instead of the socket? Forgive me if that is a newbie question! This is all a bit overwhelming.

[Steve L.]

Originally Posted by VicCT

...Couldn't I add a regular outlet to run on 12v, instead of the socket? ?..

You could but I think that's a bad idea. 120v outlets should look different from 12v outlets and you shouldn't be able to connect a 12v device accidently to a 120v one. And there are many 12v devices configured for cigarette lighter sockets and none, I expect, with 120v plugs.

[David Tilston]

A lighter socket has become the de facto 12 VDC outlet.

[Bob Miller]

"Lighter Sockets" and "12 Volt Accessory Sockets" should be two different birds to the point that many vehicles with both, label the accessory sockets "Not for cigarette lighter use". I think that the accessory sockets are designed to hold the plugs better as well as be designed for constant use.

That said, I have no idea how to tell them apart, but if it sez "Lighter Socket" on the package I keep looking.

[Rick Mooyman]

I use a automotive volt meter and a momentary on switch to check the battery voltage

Originally Posted by VicCT

Hi all,
New to trailer ownership and trying like mad to figure out the whole 12v thing, among many other things. I did a search but could not find the info I need. I have been to 6 or 7 different auto parts stores, and Sears, looking for a portable digital volt meter for my battery. They have things that plug into cigarette lighters, and things that plug into wall sockets, but isn't there something that I can just clamp onto the battery to test the voltage (without permanently installing it)? If so, none of them had it. I want to be able to monitor the voltage so I know when to charge it when it isn't being used.

I realize there is probably a simple answer to this question, but I can't find it.