Looking for battery info

Got a lighter plug in the trailer?....Mine does. I keep a digital volt meter plugged in one of them.

 

10 bucks on amazon. Voltage meter. Wire to battery and viola! Energy consumption is very low but it does consume so make sure to have a set up to where it can be disconnected when your pup is in storage.

Here’s what I use search on amazon:
utipower Multifunctional 12V LCD Battery Capacity Monitor Gauge Meter for Lead-Acid Battery

 

Unfortunately, if you really want to know the true state of charge of your battery you'd want a Trimetric battery monitor - but they're hardly "simple" and certainly not inexpensive.

http://www.bogartengineering.com/products/trimetrics.html

If you use one of the "simple" voltage meters suggested you'll have a rough idea but that's about as good as it gets. Either that or measure the battery's SG (specific gravity), assuming of course it's a conventional flooded battery.

 

I went with this.
https://www.amazon.ca/dp/B07SJLZ3LZ/ref=cm_sw_em_r_mt_dp_U_nB3aDbQ92CFD6
It isn't 100% accurate but it gives you an idea. ( none of the wired in options like this are accurate) It has a switch to prevent passive draw and I can charge my phone!

 

Nice! I have a similar set for just 12v and usb.

 

I built up one of these DC VOLTAGE monitor panels out of PVC Electrical items... The two Dc volt meters and DC Current meter are glued to the back of three gang specialty wall plate.

My DC Switching is always two groups so each DC VOLTMETER is wired into each of the two groups. The DC CURRENT meter monitors the selected DC OUTPUT of the Bank 1 and Bank 2... If Both Battery Banks are selected then the DC VOLTAGE reads the same value... The DC Current meter also has and polarity symbol on it and this is useful when charging the battery Bank from my PD9260C Smart Mode Charger... No symbol showing is the Current being demands from the Charger. A NEGATIVE symbol show the DC Current being drawn from the Battery Bank when in use.


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I have this mounted on my cabinet wall just as you enter my OFF-ROAD POPUP. Real Handy here as I can view the meter panel from the outside as well to monitor what is on-going with battery setup...


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This meter panel is shown in one of my Battery Bank Switching diagrams...

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Monitoring the battery banks is one of most important things to do when camping off-grid. You certainly need to know what the status is at all times otherwise it may get dark on your at your most unexpected times... Constant monitoring also extends the life of your batteries... We never allow our batteries to get below the 50% charge state point which is around 12.0VDC in my case... When the VOLTMETRS are 12.0VDC we stop using the batteries until we get them recharged back up to at least their 90% charge state which takes around three hours charge time using my PD9260C smart charger being run by my generator each morning... Always do this when allowed during breakfast time...

Roy Ken

 

If you want the cheapest manual solution, get the free with purchase multimeter at Harbor freight when they have them on coupon. You will get a accurate measure of the battery voltage with that and you can monitor that status that way. Need to access the battery with that approach, but can't see doing it more than once or twice a trip.

 

We do off the grid camping a lot and just use cheap meters to do it. There all types from harbor fright to ones you need to hard wire. I would get the harbor fright one to start so you have one to use if you have electrical issues. But later on I would get a cheap one that you wire into the camper with a momatary switch. This way you can check the voltage when you are inside the camper.

 

OR

buy a cheap Renogy PV controller that takes their Bluetooth adapter (and buy the adapter) . Then monitor volts on your iPhone from nearby or inside the PUP. (yes, its using a sledgehammer to crack a walnut - but still pretty nifty)