Battery Monitors

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Rob&Deryl

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Mar 27, 2017
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On the road from mid NH
1) I am new to the RV world
2) I am going to do my first boondocking in January at Q
3) I just replaced my group 24 battery with 2 GC2 AGM 6v batteries

My wife worries about having battery enough to pull in the slides and run the landing gear when time to break camp.

So, it seems I need a battery monitor.

I do have an inverter generator. I don’t know how long to run it and how often.

I would like one that can have a remote display. Better is if I don’t need to run wires from battery to display. Best is remote display plus phone or tablet display.

Suggestions?

thank you
 
I do have an inverter generator. I don’t know how long to run it and how often.
A SmartShunt on your house battery will let you know when you're fully charged as well as anything else you will want to know about your house battery after once set up and calibrated correctly.

Or else you have to guess, as I used to.

You should be able to run your generator as you put in the slides. The converter should help with the battery being low.

73, -Don- AA6GA/7 Reno, NV
 
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The Victron 712 sounds like a perfect fit for what you're wanting to do. I would want to put a few outings under my belt with this setup so I got a bit more familiar with the monitor, and performance of the batteries under your intended use.

Separate from that, there's no rule that says you can't run your generator while putting in your slides and raising the jacks, if you have to. Mine run off the chassis battery and I run the engine when I actuate the slides and jacks, primarily because I can.

Mark B.
Albuquerque, NM
 
Yup, thanks. Last time, when the original battery died and I got a low voltage warning on the leveling system while on shore power, I connected the dual batteries of my truck to the dead battery and got it done (I have a big Andersen connector at each end of the truck with a jumper cable I can plug in).

I will check out the Victron 712.

At our current campsite I had to correct for a front to back 7 degree after putting 4” under the trailer wheels. It involved unhitching, failing to get the front low enough, re-hitching (getting it high enough), putting the adjustable part of the landing gear all the way up, unhitching again, then lowering the front all the ways, lowering the rear levelers lots, and getting to a half a degree level. Two hours. Happy about new batteries.
 
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Rob, I understand all your concerns about battery life and boondocking at Q. We had the exact same thoughts in 2019 when we started.
It's easy to say but don't panic, you will find a first class bunch of people on the rally that will sympathize with you, they've all had the same worries. Go, mix and enjoy Q. If things go to plan, we will be there again in January, just need to get things booked before we put our names on the list.
Hope to see you there.
 
I agree the first thing a boondocker needs is a battery monitor. We have a Victron with a Bluetooth connection we monitor on our phones. I can’t remember the model, and they have probably changed in the 3+ years since we got it anyway. Only if you understand your power needs can you really figure out how and when to recharge the batteries, and a battery monitor is the way. Remember you should only run lead acid batteries to about 50% of their capacity for long life.
 
A battery monitor only helps if you watch it and manage your consumption & charging to keep a sufficient reserve. It doesn't help move the slides! And that assumes you know how many amp-hours you need to do that (probably not all that many).

You need to plan ahead to save some power or to run a charger (aux generator?) just before moving out or while moving slides & landing gear. Or hook up your tow vehicle to assist with the electrical loads.
 
A battery monitor, especially when boondocking is a must, otherwise kind of like driving a car with a broken fuel gauge. The Victron 712 is an excellent unit. We have one and love the convenience of checking the state of our battery bank on our smart phones with the Victron app.
 
A battery monitor, especially when boondocking is a must, otherwise kind of like driving a car with a broken fuel gauge.
Yeah, but there is a human-oriented reason why car fuel gauges have Empty-1/2-Full kind of indicators rather than precision gallonage figures. And why distance-to-empty computers are popular with many buyers. The tech types (me included) always want to know the precise amount of fuel remaining, but many folks are satisfied simply to know it's "not empty yet". A battery voltmeter is good enough for them.
 
Yeah, but there is a human-oriented reason why car fuel gauges have Empty-1/2-Full kind of indicators rather than precision gallonage figures. And why distance-to-empty computers are popular with many buyers. The tech types (me included) always want to know the precise amount of fuel remaining, but many folks are satisfied simply to know it's "not empty yet". A battery voltmeter is good enough for them.
Yes I get that, which is why I said "kind of like". I too want to see the numbers especially when it comes to the state of our batteries. My comment was really a simple analogy, although if you drive a car with a "broken fuel gauge" you do not have the benefit of the empty, 1/2 full indicators and then like a boondocker without a battery monitor you run a risk of running out, or at best a more stressful situation.
 
Yeah, but there is a human-oriented reason why car fuel gauges have Empty-1/2-Full kind of indicators rather than precision gallonage figures. And why distance-to-empty computers are popular with many buyers. The tech types (me included) always want to know the precise amount of fuel remaining, but many folks are satisfied simply to know it's "not empty yet". A battery voltmeter is good enough for them.
I have trouble even imagining disagreeing with Gary, the guru of all RVing, but I do here. When we had a much earlier TT, we had a basic idiot light battery monitor that plugged into a 12v adapter. Three lights - green, yellow, red. It truly was inadequate to determine the battery status. Did we need to charge when the monitor first turned yellow? When it turned red? Going out with a voltmeter was a pain. We bought our first monitor, and it was soooooomuch easier to determine when to charge. We almost exclusively dry camped. We have put battery monitors in every rig we have had since, and our batteries were kept in good shape.
 
I have trouble even imagining disagreeing with Gary, the guru of all RVing, but I do here.
LOL! Are you disagreeing with my opinion on human nature? All I said is that some (many?) people will be satisfied with a sloppy approximation while others insist on precision. I feel pretty comfortable with that assessment. ;)
 
Whilst I don't think I have needed a battery monitor to date and managed with a digital voltmeter, I always think good information is better than none. My question is, if you have a bank of four batteries, how does the battery monitor know what amperage is available either as a total or individually? do you have to enter that when setting them up?
 
Depends on the sophistication of the monitor. The one I have the Ah is stored in the user's head. Some you preset, others will track usage history and empirically determine it.

Mark B.
Albuquerque, NM
 
I had two different battery monitors on my rigs. Both were programmable and displayed amps in, amps out, percent remaining, voltage, and several other parameters.

One was a Blue Sky that I got at Discount Solar. The owner assured me that it was comparable to the Trimetric Monitor. This one was for the eight batteries in the Country Coach DP. It was mounted on the wall in the bathroom and was viewable from the "Throne".

The other one was in The Stacker for the six batteries in the Trailer.

Both systems had about 800 watts of Solar Panel each.
each system also had several charge controllers wired in network configurations.

I had two inverters in the Stacker and a factory installed 3000 watt one in the DP.


Here are pictures.
 

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I don't know what brand my battery monitor is, but I recently started a thread asking how to understand what it is telling me.
It is a wired unit that I installed next to my bed,which is only a short distance from the batteries.
The folks here made a lot of good comments that may help you out as well.

The one time my battery was dead and I needed the tongue jack,I simply hooked up to my truck and used that power for the jack.
 
I've had one of the Victron BMVs with Bluetooth for a couple of years now, and absolutely love it! I wouldn't be without one now, especially as we do lots of boondocking.

Last trip, our friends were struggling with battery levels, and I showed them my setup. I'm going to their place tomorrow to install a Victron smart shunt. Took about 5 seconds to convince them. ;)
 
Whilst I don't think I have needed a battery monitor to date and managed with a digital voltmeter, I always think good information is better than none. My question is, if you have a bank of four batteries, how does the battery monitor know what amperage is available either as a total or individually? do you have to enter that when setting them up?
It looks at the batteries together, as a bank. In more advanced configurations I think it can check midpoint balance or something, but I don't need that function in my application and don't know much about it.

When you first commission it, you will need to tell it your Ah capacity in total for the bank. I Googled my two batteries (turns out they're Napa, branded something else), and found they are 75 Ah each for a total of 150 for both. (Looking forward to Lithium upgrade at some point.) Then, when you do a full charge, it will synchronize and the State of Charge percentage becomes dead on.
 
I decided on a Victron Smart Shunt As I didn’t want to run wires to a display. It seems to be working ok. The only downside is that with it mounted in the battery bay, the Bluetooth signal doesn’t reach very far. I can sit on the bed to use it though.

I charged up the batteries after installing, then turned off the converter and waited a while. I then had it sync.

i left the converter off for a few hours while we went shopping.
With the base loads (no lights), after several hours it said I had 4 days available. I have a pair of 6v gc2 agm 220 amp hour batteries. We then played with lights, & opened one awning.
I need to go back and check now,
 

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