Amp meter wired into micro monitor?

[cvin]

Wondering if i could wire in some kind of good battery monitor to wire that feeds the micro monitor for the battery level?

Would that work, or do i need to have a new separate wire run?

Would like to better monitor the batteries/solar stuff

[bobbecky]

Would something like this work for what info you are wanting to monitor?

https://www.ebay.com/p/DC-5-40v-0-200a-Volt-Amp-Combo-Meter-Battery-Charge-Discharge-No-Need-Power/1231750929?iid=181269197564

You would have to have a separate run of cable to your batteries from the display. You would also have to connect the shunt in line in the 12 volt hot leg. This would allow you to see voltage and current flow.

[cvin]

Yes something exactly like that

Just want a way to keep an eye on how much battery I am using/have left etc

Do you have one of these wired in your camper?

[JRTJH]

An ammeter needs to be installed (wired) into the positive terminal of the battery. It will only give you the amperage draw if wired into that connection. You can mount the "faceplate" most anywhere you want, but the shunt/pickup point must be on the positive terminal/wire of the battery.

Now, just a little "my take" on ammeters, voltmeters and "idiot lights" (status display).

An ammeter measures the amperage draw and nothing else. It won't tell you how much is left nor will it tell you how close to "empty" you are. Essentially, it's closer to a "instant MPG meter" than anything else. If you want to know how much you've got left (miles to empty) you'll need to do some calculations using a voltmeter. Someone posted a voltage/charge chart several pages back, I think in this thread. That will tell you "what's left till empty"... An ammeter will only tell you how fast you're "sucking power out of the battery" it won't tell you anything about how long it'll last or if you'll be "dark in the morning"....

That's why the RV manufacturers went to the voltage with 4 lights on the "idiot panel". 4 lights, Excellent; 3 lights, Good; 2 lights, Caution; and one light "OOPS" !!! It's easier for someone who doesn't have much electrical/battery expertise to comprehend. Adding an ammeter will only tell you how fast you're draining your batteries. It won't tell you anything about how long they'll last and there's really no correlation between how long they'll last and any specific amp draw. The only "relative figure" is bigger draws drain the battery faster than smaller draws, but we all knew that before we ever bought a travel trailer.

So, if you want to know the state of charge, use an accurate voltmeter with no draw on the battery. That will be the closest measurement of charge status you can get short of using a hydrometer to test every cell.

[cvin]

ok, wow, was under the impression it was opposite and i needed to monitor amps

i am getting good with the voltmeter and know how to do that

plus i just had a solar place make me some wires that plug in and out for the solar suitcase, they used nice grade 12 gauge wire and it has an andersen connector on it that i can easily get to, earlier today i checked the voltage on that ...

i am hoping to be able to check the voltage like that by unplugging the panel
actually the panel controller readout said the batteries were 100% and i think 13 volts- will see if that correlates with what i see on the batteries for the next few days

tomorrow will be first day with the solar panel out there so will see how it does

heat strip is disconnected in the frig so in theory my draw should not be too bad...

[BrentB]

There are indeed monitors that can measure amps in and amps out for your battery. They work just like a fuel gauge for your battery.
Check these out:

https://smile.amazon.com/Victron-BMV-700-Battery-Monitor/dp/B00MJ9TAN8/ref=sr_1_1?ie=UTF8&qid=1501764055&sr=8-1&keywords=bmv-700

http://www.bestconverter.com/Trimetric-2030RV-Battery-System-Monitor_p_557.html#.WaEmnyiGOUk

https://smile.amazon.com/gp/product/B01M5CWR2P/ref=s9u_simh_gw_i2?ie=UTF8&fpl=fresh&pd_rd_i=B01M5CWR2P&pd_rd_r=5807EM0FKDAKD9CSXW81&pd_rd_w=eCvE3&pd_rd_wg=rePIf&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=&pf_rd_r=8D8S7FCR4PMS1R65PKBH&pf_rd_t=36701&pf_rd_p=781f4767-b4d4-466b-8c26-2639359664eb&pf_rd_i=desktop

[cvin]

Looking at these do i really need one since the solar panel has a digital display and is showing me battery % and voltage all the time?

Hate doing a lot of mods to this trailer when i plan to trade into a 5th wheel in 2 years, but i also dont want to wake up to dead batteries...

[BrentB]

Does your current system include a shunt?

[cvin]

No, i just have a solar suitcase that comes with a controller on it

And it is wired to my 2 -6 volt batteries

[BrentB]

Without a shunt, the monitor will just show you the current voltage (as a number and as a percentage.) A monitor with a shunt can show you exactly how many amp hours have gone in, and how many have gone out.

[cvin]

Is this just something we wire next to the batteries? Then connect the controller wire to that? It looks simple enough just looking at pics of them

My controller is a RoHs solar charger controller 12/24 pwm with lcd display, do you think if we put the shunt between this cheap controller and the batteries it would be able to read amps? That would be handy

This whole suitcase was pretty cheap so not sure how nice this controller is

[bill-e]

About halfway down the page in the link below you'll see my post on installing an $18 meter from Amazon. I'm on my second season with it and I think it works great.

It will only monitor one way, either charge or discharge. I have it set to monitor discharge because I can use my solar controller to monitor charge. Or you can install two, one for each way. Use 4 conductor phone wire to install.

You can tell how full your battery is by the voltage though that wont tell you how much longer at your current discharge rate.

I think it works great.

I also just bought and returned the wireless meter shown in a post above. Three issues with it, significant parasitic draw, wireless is unreliable and very short range, the shunt/wireless module is not waterproof and too big for my battery compartment. Plus it wont connect directly to the post, had to make a short jumper so I think that adds a bit of inaccuracy.

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28952839/srt/pa/pging/1/page/3.cfm

[cvin]

awesome, thanks for that link

just added one of those to my cart for the next amazon order- that is definitely a company i should have bought stock in...


think with this and the display on the panel i should be pretty good for right now

going out to check the controller now, it is cloudy out the past hour

[BrentB]

significant parasitic draw,

How much is this draw?

[bill-e]

How much is this draw?Significant might have been overstating it, I saw about .2 or .3 amps on my meter. I might have overlooked that but I couldn't get the wireless to go 10' to where I wanted to mount the meter. I just don't think it's really suitable for External batteries.