Another battery question

[uintafly]

Over the course of the next few months I really want to figure out how much juice I have in my batteries and what draws them down. We do a fair amount of boondocking so I would like to know timelines of how long I can go without briging a gen. I have a multimeter and can measure how full my batteries are, but how do I measure what is drawing what, and how many amp hours I have left? A couple times last year we would park our trailer and use it in consecutive weekends, but the parasitic draws would really run the batteries down over the course of the week, to the point I didn't really trust it to leave any perishables in the fridge for fear it would kick off. Any advice woud be greatly appreciated.
Thanks,
Chris

[jmckelvy]

Bill.Satellite wrote:
What I believe you are looking for can be searched out with the use of a Kill-A-Watt meter. You plug each device into this meter and it reads exactly how much power the device uses. It may take a few days to plug, run, read and add up all the devices using all the power, but when you are done you can accurately measure how much power you are using so you can determine how much power you need.

The Kill-A-Watt (at least the model I have) only does AC. It plugs into a standard outlet and the device under test plugs into the K-W. Its a cool device though.

I have a Xantrex XBM system for keeping tabs on my two 12 volt AGMs.

[Bill_Satellite]

What I believe you are looking for can be searched out with the use of a Kill-A-Watt meter. You plug each device into this meter and it reads exactly how much power the device uses. It may take a few days to plug, run, read and add up all the devices using all the power, but when you are done you can accurately measure how much power you are using so you can determine how much power you need.

[MEXICOWANDERER]

"I can't be overdrawn! I still have checks left!"

This is what ampHOUR meters are made for. They analyze and TOTALIZE all the power that goes in and out of a battery whether it's one amp or 500. Over a period of time.

That's the modern, and fast way to keep fairly accurate track of "Where Your Battery Is At" when camping. Charging or discharging. The old fashioned way is with a hydrometer. Each method has a specific advantage over the other. Campers need both to manage a standard RV battery.

AMP

HOUR

METER

[BFL13]

pianotuna wrote:
Hi,

I went for 14 years with only solar, as far as camping goes. I mostly boondock. I did have a genny--but it was to run the block heater in winter time. I left it behind when camping. It failed and the replacement was no good. (mea culpa)

Then I switched to full time and I thought a genny was needed. Turns out I would have been better to do more solar. The new genny has run less than fifty hours in 10 months. Over 1/4 the run time is exercising it. (I.E. running it for no good reason).

Since I started full timing in Oct, I've not run the generator *once* except to exercise it.

But PT you also said you have been on shore power most of the winter. You are not making any sense, while being seized by this solar/no-gen Religion mania.

We use the gen for weekend camping off-grid in winter and the solar for off grid in summer. Sometimes in cloudy weather we also need the gen in summer. So what? Is God going to "get us" for that?

You have a nice gen, so use it (instead of shore power, or when solar can't keep up off grid.) You don't need to duplicate the gen with a bunch more solar and then never use the gen you just paid for. (Unless it is all part of some illogical Religion thing)

Balance, toujour the Balance! 🙂

[wa8yxm]

I fully agree with VP9KL. (But then I should).

However I might suggest that if you have the room.. A pair of GC-2 is easier to lift and carry than a single 4D and holds a few (insigniicant amount) more amp hours.

[Veebyes]

We are 'in the trees' kind of people too so solar is not even a thought.

Those 2 group 24s don't have much power. Pack as much amps in as space permits. We swapped out 2 group 24s for a single 4D AGM. That was 4 years ago. Another 4 years is expected out of it. We have a 2kw multi stage inverter/charger. Got rid of the converter. For charging & when 120AC is needed the Honda 2000 is enough.

[mena661]

The clamp-on DC voltmeter will tell you how many amps are being used at any given time. What I did before decided on my current setup was go in the rig and turn things on one by one and measure their draw with the clamp-on. Made notes on that. Went camping at a full hookups CG and made notes on how long we used stuff. Then went from there.

[Peg_Leg]

I do like Roy. I picked up a DC and a AC volt meter on Ebay for about $6 each including shipping. I installed them on a counter end just inside the entry door with a on/off switch for each. The blue lit meter draws next to nothing and makes for a nice night light. I leave mine on all the time except when not camping.

I have the chart Roy shows, laminated and taped inside a cabinet door and another one near the batteries. Recharge at 12.0, my 3 stage Power Dynamics 9260 does a great job of caring for the batteries.

[pianotuna]

Hi,

I went for 14 years with only solar, as far as camping goes. I mostly boondock. I did have a genny--but it was to run the block heater in winter time. I left it behind when camping. It failed and the replacement was no good. (mea culpa)

Then I switched to full time and I thought a genny was needed. Turns out I would have been better to do more solar. The new genny has run less than fifty hours in 10 months. Over 1/4 the run time is exercising it. (I.E. running it for no good reason).

Since I started full timing in Oct, I've not run the generator *once* except to exercise it.

RJsfishin wrote:
Can't believe you solar guys ! Like solar is the answer to everyone's problem.
Seems ya all forget that solar needs sun ! Buy a small quiet generator first, then you don't have to worry what each little thing in your rig is using.
Go camping, then you will find out how much your daily AH requirements are.

Here's a poor many battery monitor,.......
If you have the sat tv playing, and a couple lites on, and the water pump comes on, and you don't notice any noticeable lite dimming, or the sat tv skippin a beat, you are well over 50% yet, and good till morning.
I couldn't care less what each dc item is drawing, I just care how often I need to recharge !
And I dint just start dry campin yesterday.
But yep, I got ammeters and voltmeters all over the place, but I know how often I need to recharge, and that doesn't change by much.
And yep, my solar works fine, when the sun is shining, but that hasn't happened in a week now.

[korbe]

I was curious just like you. My volt meter also has the ability to test amperage. so DW would turn on each 12 volt switch and then off again while I read the meter display. I wrote down each amp user and I now know how long I can camp to keep the batteries at or above 50%. I use the voltage indicator on the meter to determine draw down on the battery. In conserve mode, we use about 24AH per day.

[uintafly]

Thanks for all of the replies. I like the idea of having a DC voltmeter in the trailer that I can monitor. How difficult are those to install?

I currently have 2 group 24 batteries. Not a ton of AH I know, but I want to make due with them for at least a season since they are new with the trailer this year. As for solar, for the most part we are forest folk and try to get the shadiest place we can find, which would negate a lot of the solar benefit for us. We do usually take a trip or two to the desert but have no problems with a generator iin these areas.

Thanks again,
Chris

[RJsfishin]

Can't believe you solar guys ! Like solar is the answer to everyone's problem.
Seems ya all forget that solar needs sun ! Buy a small quiet generator first, then you don't have to worry what each little thing in your rig is using.
Go camping, then you will find out how much your daily AH requirements are.

Here's a poor many battery monitor,.......
If you have the sat tv playing, and a couple lites on, and the water pump comes on, and you don't notice any noticeable lite dimming, or the sat tv skippin a beat, you are well over 50% yet, and good till morning.
I couldn't care less what each dc item is drawing, I just care how often I need to recharge !
And I dint just start dry campin yesterday.
But yep, I got ammeters and voltmeters all over the place, but I know how often I need to recharge, and that doesn't change by much.
And yep, my solar works fine, when the sun is shining, but that hasn't happened in a week now.

[pugslyyy]

uintafly wrote:
Over the course of the next few months I really want to figure out how much juice I have in my batteries and what draws them down. We do a fair amount of boondocking so I would like to know timelines of how long I can go without briging a gen. I have a multimeter and can measure how full my batteries are, but how do I measure what is drawing what, and how many amp hours I have left? A couple times last year we would park our trailer and use it in consecutive weekends, but the parasitic draws would really run the batteries down over the course of the week, to the point I didn't really trust it to leave any perishables in the fridge for fear it would kick off. Any advice woud be greatly appreciated.
Thanks,
Chris

How much battery capacity do you have in the TT?

As others have said, if you are going to boondock you need to get solar going.

I can run happily off of batteries/solar for everything except AC and the microwave.

[RoyB]

I use a standard DC VOLTMETER setup for my battery monitor panel that I can watch from the inside of my trailer.


This is not absolute but is close enough without getting into all the inner workings of things...

I use this simple CHART to determine the % of charge for my battery bank when camping off the power grid.



When I read around 12.0VDC I know my battery bank is somewhere around 50% charge state. This is where I either quit using the batteries or start re-charging using my smart mode on-board converter/charger unit direct connected to my 2KW Honda generator using a RV30A to 15A Adapter.

I plan out what is being used when camping off the power grid so that my batteries make it through the one day/night run off the batteries and end up with around the 12.0VDC reading at 8Am the next morning.

Here on the east side of the USA this usually fits in with most of the campgrounds that have generator run time restrictions in place and I can re-charge my batteries back up to their 90% charge state in as quick as three hours so we can do all of this all over again for the next day/night run off the batteries.

Works pretty successful for us when camping off the power grid...

Roy Ken