Best way to monitor battery-Centurian 3000 30amp converter

[jefflarsen]

I am, as they say, electrically challenged. Plan to install a new AGM battery in the Scamp this weekend and would like a simple way to monitor it from inside the trailer. Looked at the Bayite but the wiring is not in my playbook. Plan to get a good deep cycle "Battery minder/charger" for the off season, but would like a way, at a glance to see how the battery is performing during my upcoming travels to the southwest. To ease charging concern is there a way to add a "charge wizard" of some sort to the mighty Centurian to control how the battery is charged, or would that mean a converter change? If so which converter would be best for the pretty standard array of electrical equipment on the Scamp (no ac)? Progressive Dynamics 45amp with power wizard? Thanks as usual.

[Carol H]

If you are looking for something fast and simple to keep a eye on where your at in regards to battery level then for under $10 you can get something like this that just plugs into the socket in the trailer.

[Donna D.]

Originally Posted by Carol H

If you are looking for something fast and simple to keep a eye on where your at in regards to battery level then for under $10 you can get something like this that just plugs into the socket in the trailer.

I bought one, going boondocking at a National Park in a couple of weeks. Need to monitor the batteries.

It's waiting for me now at an Amazon Locker

[jefflarsen]

Originally Posted by Carol H

If you are looking for something fast and simple to keep a eye on where your at in regards to battery level then for under $10 you can get something like this that just plugs into the socket in the trailer.

Thanks. Our 2002 Scamp Deluxe is like it was new from the Scamp farm in MN but unfortunately in 2002 it was ordered without a 12V socket indoors or out. Plan to install at least one soon. A battery charging safeguard associated with the converter instead of a steady stream of 13.6 to the helpless battery when plugged in would be ideal. For boondocking portable solar is in its future as well.

[redbarron55]

I have had good results with this


https://www.amazon.com/dp/B013PKYILS...472764879&sr=1

[The Minimalist]

You might want to print and laminate a copy of this chart, so that your battery voltage has more meaning.


This chart is courtesy of The 12volt Side of Life (Part 1)

There is a great deal of information here to bring you up to speed. There is also information on this site which will help you calculate your projected daily amp hour usage, which is key to projecting how much usable power you have remaining.

While I have a plug in meter such as Carol suggested and use it from time to time, over the long haul you will want a decent digital Volt-Ohm meter. I would normally suggest a battery hygrometer, but since you are going with AGM, that wouldn't do you much good.

Do what you can up front to reduce usage, such as switching your fixtures to LED lighting.

And remember, you don't want to run your battery down below 50%. Sometimes that might be unavoidable, but don't do it often. You will get more life out of your battery.

[jefflarsen]

Originally Posted by redbarron55

I have had good results with this


https://www.amazon.com/dp/B013PKYILS...472764879&sr=1

Yes, that is the Bayite I mentioned. Did you wire it yourself?

[jefflarsen]

Originally Posted by The Minimalist

You might want to print and laminate a copy of this chart, to that your battery voltage has more meaning.


This chart is courtesy of The 12 Volt Side of Life at The 12volt Side of Life (Part 1)

There is a great deal of information here to bring you up to speed. There is also information on this site which will help you calculate your projected daily amp hour usage, which is key to projecting how much usable power you have remaining.

While I have a plug in meter such as Carol suggested and use it from time to time, over the long haul you will want a decent digital Volt-Ohm meter. I would normally suggest a battery hygrometer, but since you are going with AGM, that wouldn't do you much good.

Do what you can up front to reduce usage, such as switching your fixtures to LED lighting.

Thanks for the info Clif, After a couple of years with an Airstream Sprinter 3500 Interstate with dual group 27 Lifelines and 100W solar, I learned a lot about distribution charts and how to read the gauges. Kind of like learning foreign language basics but never learning how to speak it. All of that was installed on the Sprinter by pros. Now I would like to learn enough to either install a different converter with more control over the charge or, more simply, how to install a monitor like the Bayite. LEDs are forthcoming, along with solar. Changing bulbs I'm good at and I know a little bit about solar from 7 weeks house sitting off the grid in Panama and the AS Interstate.

[redbarron55]

If this guy can do it so can you.

https://www.youtube.com/watch?v=eXF_bR4QUkM

[redbarron55]

https://www.youtube.com/watch?v=7pTKgc5l3Z0

[Carol H]

For me unless I am trouble shooting something the simple meter gives me what I need to know. I have the chart above laminated and stuck on the wall by the meter socket.

If I am getting into the low 12's its time to put my solar panel out or bring out the generator if the sun is not shining.

[redbarron55]

I thought it was worthwhile to know the current and power used.
My setup is attached all the time and I can look at it and the companion AC unit when I walk into the Scamp.
If you are happy with your setup then so am I. The meter will show you the voltage, but the current and power are a little more involved.
I have the shunt in the negative led of the battery an it shows the current if on the battery or the converter.

[Carol H]

Originally Posted by redbarron55

I thought it was worthwhile to know the current and power used.
.

Oh it is worthwhile to know such things! Particularly if you are someone who has never camped off the grid with your trailer before.

Just feel that once I have a handle on what eats up power & how much in my trailers and how much power I can expect or not expect from my solar under various conditions to provide, my main concern is watching the battery level. As at the end of the day that is the number you really need to most concerned with.

[redbarron55]

Carol,

I think that you are correct, but it takes some time and measurements to figure it out.
The power meter as instrumental in figuring out exactly how much the Reefer used.
If you know how much power is in the battery you can know exactly how much you have removed as well.
I find I am not as concerned with the readings, but if I want to know the voltage it is there all the time.
It is interesting that the current and power is easily measured when you turn it on and off.
Since you are happy with your setup then that is what you should use.

[Carol H]

Originally Posted by redbarron55

Since you are happy with your setup then that is what you should use.

LOL I actually do have a system that tells me all! Not the same one as yours but it does the same

I was simply suggesting for someone staring out who does not want to do any wiring & even for those who have been camping for awhile the One thing you really do need to know is your battery level. The rest is good stuff to know but not a serious requirement.

A hand held multi meter will go a long ways in helping figure it all out if there is a problem. Every trailer owner should probable own one of those regardless of whether they have a monitoring system that tells them all or only their battery level or have no monitors.

[John A]

I like this one from MidNite Solar for a battery meter, though I don't own it yet- I still just use a good multimeter. The percentage LEDs light in green/yellow/red which would be nice and simple. Some people want much more data but I don't need anything more.

MidNite Solar MNBCM:

https://www.solar-electric.com/mnbcm.html

[sokhapkin]

Originally Posted by Carol H

I have the chart above laminated and stuck on the wall by the meter socket.

Unfortunately the chart is for no load voltage. Are there similar charts which provide battery voltage depending on the battery charge level, battery capacity and battery load (in amperes)?

For example, fully charged battery voltage in my trailer quickly falls to 12.1-12.3V level when powering up a netbook computer (I expect this corresponds to about 1-2A load).

[jefflarsen]

Originally Posted by redbarron55

If this guy can do it so can you.

Thanks I'll check it out in the morning..the pencil is sharpest then.

[Glenn Baglo]

I simply let the battery rest for an hour and turn everything off except the propane detector before using my simple, cheap voltmeter. It plugs in to a 12VDC outlet and has a sticker on it telling you what the voltage means as per cent charge.

[gordon2]

If you battery is in use or has been recently (charging, discharging, etc) then the voltage reading alone will be of limited help in knowing the state of charge of the battery. In fact, if you go by voltage reading while the battery is under even a fairly moderate load, then the voltage reading is about useless.

Yes, you can let it sit for some time while fully disconnected and then get a fairly good idea of the state of charge from the voltage reading, and an even better idea of the state of charge by using a hydrometer (in the later case, even the state of charge of the individual cells which can be important information). But who wants to wait around with no battery power, or mess with sulfuric acid in a fragile glass tube? There are few shortcuts in life (or in proper battery use).

So, the next step up in accuracy, cost, and convenience (convenience of use, not of installation) is a real time recording monitor using a shunt. The shunt allows you to know how much energy is going into, and out of the battery. Using the battery capacity figure (typically around 100 amp hours at the 20 hour discharge rate), the meter can give you a pretty good estimate of the state of charge all the time, load or no load, under charge or not.

My choice is the TriMetric meter which also has a optional solar charger available. The TriMetric comes in at about $200 for parts including all needed wiring. There are other (cheaper) meters but I like the quality and tech support for the TriMetric. The TriMetric is also smart enough to include the charging parameters for different types of batteries - something that cheaper monitors might not do and especially something to consider if you are using AGM batteries.

These systems can be installed by many people but keep in mind that ALL the power to and from the battery goes through the shunt so be sure to have one the proper size (rating) as well as proper wiring and fuses.

Do you need a battery monitor? Of course not

Do you want a battery monitor? Very likely yes (depending on your camping style and needs)


Here is a good write-up on the topic:
How to Monitor Batteries - RV, Sailboat & Tiny Houses too