Difficulty of adding a multimeter gauge?

[mlts22]

I'm wondering how difficult it is, in general, to add a set of digital LCD readouts to a rig's electrical system. I would like to get a column of displays for the amps across the house batteries, the battery voltage, and perhaps some additional ones (incoming amps/volts from charger), but the most important would be a digital voltage gauge for the 12V system, so I can tell how healthy things are at a glance.

Ideally, I wouldn't mind having a lot of readouts such as incoming generator voltage/frequency, shore power voltage/frequency, amps used, etc. However, just being able to keep a light on the 12 volt system would be a good start, so there are not any surprises once boondocking.

[markopolo]

It can be very easy or a bit difficult, cheap or expensive depending on how much data you want, how neat of an installation you want, ease of access to a suitable point to connect to the wiring and ease of routing wire to where you want the gauges.

If you are really into this and want to monitor amps in and out and more then consider getting a TriMetric Battery System monitor: http://www.bogartengineering.com/products/TriMetric

Or you could go low cost and not-so-neat like I did: http://www.classbforum.com/phpBB2/vi...hp?f=12&t=2257 I can monitor volts and amps in and out and more - I'd recommend buying a bit better stuff than I did if it is important to you. I rarely look at my monitors because they aren't mounted where I can easily see them. They are fun to have though when I am testing things or want to report what a my furnace fan draws for example. I have an inverter that displays volts (digital) so I turn it on to see the volts and that really is enough info to know the basics of what is going on. My solar controller also shows volts and has a light that indicates charging.

There is tons of stuff on eBay for display volts and amps if you don't want to go for the full featured TriMetric.

[mlts22]

Would I need to get a knife switch to bypass the shunt, or will it have enough amperage to handle whatever goes across the 12VDC lines?

Right now, I'm looking to start with a basic voltmeter and ammeter, just to see what electrical loads I have on the batteries, and to gauge load. I would like to go to a more exotic system eventually, but I might as well start small.

I eventually want to go with a Trimetric system, especially if I get a MPPT controller and a couple good panels on the roof, but I'm just starting out with the basics.

[markopolo]

You won't need a bypass switch if the shunt is adequately sized.

[arrveedogz]

Originally Posted by mlts22

Right now, I'm looking to start with a basic voltmeter and ammeter, just to see what electrical loads I have on the batteries, and to gauge load.

Recall that an ammeter is a series device (inline with one battery terminal) and a voltmeter is a parallel device (across both battery terminals). Most ammeters have built-in fuses; you'll need one fairly gutsy or you'll spend most of your time changing fuses.

And I recently re-learned that a battery voltage reading with no current flowing doesn't mean much.

Dan