Battery life while boondocking

Gilm2113 · 09-07-2016, 03:23 PM

My wife and I both enjoy getting out into the mountains of Idaho in our Forester 3051S. We have found that the batteries do not seem to last quite as long as we expected. Our 3051 does have the larger, 12 cu.ft. fridge and most of the time we have very little running (lights/radio, etc.). I can go to bed in the evening with what the idiot lights say is a full battery and wake up with what I believe is barely 2/3's. I say barely 2/3's because as soon as I run the furnace it drops to 1/3 very quickly. Is this normal? I typically have been running the generator for an hour or two during the day to top the batteries off and have a repeat the next morning.

In our earlier travel trailers we could go 4 days with two batteries without needing a generator and in our Forester 2651 we could go 2-3 days with no issues. Does the larger fridge which is usually quite empty have that big an impact?

Any advice or comments would be appreciated.

JimOneil43 · 09-07-2016, 03:40 PM

Quote:

Originally Posted by Gilm2113

My wife and I both enjoy getting out into the mountains of Idaho in our Forester 3051S. We have found that the batteries do not seem to last quite as long as we expected. Our 3051 does have the larger, 12 cu.ft. fridge and most of the time we have very little running (lights/radio, etc.). I can go to bed in the evening with what the idiot lights say is a full battery and wake up with what I believe is barely 2/3's. I say barely 2/3's because as soon as I run the furnace it drops to 1/3 very quickly. Is this normal? I typically have been running the generator for an hour or two during the day to top the batteries off and have a repeat the next morning.

In our earlier travel trailers we could go 4 days with two batteries without needing a generator and in our Forester 2651 we could go 2-3 days with no issues. Does the larger fridge which is usually quite empty have that big an impact?

Any advice or comments would be appreciated.

If you are not plugged into shore power and the generator is not running, your fridge should be set to "auto" so it will run on propane rather than on your battery power.

Gilm2113 · 09-07-2016, 03:57 PM

Jim, I believe we have had it set on Auto but I will check for sure this weekend. From what I recall, it does say LP when we are out and about. Thanks for the advice.

Still Kickin · 09-07-2016, 04:18 PM

Assuming your fridge worked, then you were on propane. I say that because, the heating required in an absorption fridge comes from an element that is 120v, while the fridge electronics are 12v. while not plugged into shore power. As for your expierenced fast battery discharge, you need to first establish what cond. your batteries are in, before you try and determine why they seem to not last as long as you assumed they should.

stevejahr · 09-07-2016, 04:38 PM

For boondocking and managing battery power you really really need a good monitor. The silly LED panel that comes standard on most RVs is worthless here.

Lots of folks swear by the Trimetric monitor. But you can get the critical functions for a lot less using the Bayite monitor. Either of these will give you a real current draw number which you can use to measure what different electrical loads you run. If you are running too much then a low battery is to be expected. If you are not then the battery may be weak. But without a monitor you are just guessing.

Note that the fan in a furnace is 12v and a fairly big draw. The monitor will tell you how much draw.

ScottBrownstein · 09-07-2016, 05:13 PM

If you are boondocking I really recommend a good battery monitor. While the BayLite will give you a good instantaneous voltage and current reading, it lacks the state of charge capability of the Trimetric or Vectron. These two units continue to add the instantaneous current supplied and give you a real time indication of the "state of charge" of your batteries, in the same way a bank teller keeps track of your deposits and withdrawals. SOC can really only be measured by continuous integration of current supplied and replaced or by using a hydrometer and measuring the specific gravity of the electrolyte in each and every cell of your bank. Voltage is a really bad measure of SOC and only works if the battery has been sitting disconnected for at least 24 hours.

What this means is your LED panel or the Baylite only measure instantaneous voltage and give you no good way to asses the state of charge of your batteries when they are being charged or discharged...which is pretty much all of the time.

Personally I recommend the Trimetric and would never be without one, especially with a big battery bank, solar, inverters, etc.

Gilm2113 · 09-07-2016, 05:54 PM

Still Kickin -- I had the batteries tested at Camping World the last time it was in the shop for another issue and they told me that the condition of the batteries was fine that they were still like new. I don't have a lot of faith in Camping World's 'expertise' but that is stated on the work order.

Gilm2113 · 09-07-2016, 05:58 PM

stevejahr, Scott --

Thank you for the information. I will look into both systems and see what I can do. It is all great information to have while out in the woods with no cell service!

Thank you both again.

stevejahr · 09-07-2016, 07:41 PM

Quote:

Originally Posted by ScottBrownstein

... While the BayLite will give you a good instantaneous voltage and current reading, it lacks the state of charge capability of the Trimetric or Vectron. ...

True that the Baylite has some limitations...

The Baylite will tell you voltage and current on an instantaneous basis. It will also track power used over time based on the measured current. So it will actually do a good job of telling what you have pulled out of the battery.

The big limitation is the Baylite only measures current in one direction not two directions as does the Trimetric. So as Scott is pointing out it will not tell you what goes back into your battery (unless you wire it up wrong...).

But for the price... I could install two Baylite's and track both the goes outta and the goes inna and still have a lot of beer money left over

Not to mention that the Trimetric is not going to win any aesthetic awards.

Knowing goes inna and goes outta does not quite tell you charge state, unless your battery is 100% efficient at taking a charge but it does get you closer.

ScottBrownstein · 09-07-2016, 08:01 PM

While the Trimetric isn't a design award winner, it does do a lot of calculating beyond just out vs in and does allow for efficiency in recharge cycles and does a lot of calculating in order to develop it's SOC display. Don't know why people insist on installing it in a big surface mount box, mine is recessed flush into the bulkhead by the entrance steps. It will display a lot of other data but SOC for the uninitiated is where most leave it.

It really comes into its own when used with their companion solar controller do function as the main display for all charging and loads.

If I were going to add anything it would be a relative of the Baylite for my shore power so that I can be sure of the power quality coming in on my 110 volt systems. Would have already bought one but I am concerned with the bad reviews. Don't mind spending $20.00, but I hate to have a hole where it went when it ceases working and there is no replacement

Bluepill · 09-07-2016, 08:18 PM

Keep in mind also that your converter/charger may not be fully charging your batteries, especially with 1 or 2 hour generator runs. If you have a WFCO converter, you are probably being under charged, since they often run short or skip all together on the important "Bulk Charging" mode.

An easy way to confirm is to monitor the battery voltage when you start a charging cycle (either with shore power or generator power) After a night's discharge, you should see about 14.4 volts at the begining of the charge cycle, and for at least 20 minutes thereafter. If it starts out at 13.6 volts, or drops to that level within a few minutes, you are not getting a proper and full charge.

More info here:

http://www.doityourselfrv.com/rv-bat...olar-inverter/

Gilm2113 · 09-07-2016, 09:43 PM

Thanks Bluepill, I will take a look.

NMWildcat · 09-07-2016, 11:41 PM

We boondock most of the time with only 2 batteries and no solar. We also have never had any battery monitoring system. We have 2 Honda EU2000i that we run in the morning for a few hours so the wife can have coffee. microwave, and watch the morning news, and then a few hours in the evening to watch TV, top off the batteries.

When we go to bed for the night the idiot lights are always 4 of 4.They are always at 3/4 in the morning, heater or not. If the heater comes on it always drops to 1/2 while it is on. A few minutes after it turns off, it is back at 3/4. And I agree, the idiot lights are just a general indicator but it suffices. I don't really care what the exact voltage is.

I keep looking at solar and inverters, but so far the expense and PITA is not worth it to me as the generators work so well.

Every RV we have had is different as far as power draw. The newer ones have many more parasitic energy devices. We used to be able to go a few days without having to run the generator if we were so inclined. Those days are gone with all the 'advances' in RV life

Yep, we are now spoiled and loving it. And we really don't mind running the generators a little longer if necessary

ScottBrownstein · 09-08-2016, 07:12 AM

I think that NMWildcat is completely right. When we had our old RV with two house batteries and a propane reefer that is exactly the way we ran. Genny for a couple of hours in the morning or at night. Go a couple of days without running anything...even wit a small inverter to power a small TV.

Our new coach changed all that. Now we have 4 batteries and a residential refrigerator. We love the reefer and would never want to go back, but now need to be more serious about things electrical. No more stovetop coffee maker since we need to run the genny in the mornings anyway...and again at night.

The monitor is essential and frankly I don't understand how an RV company could put 4 batteries and a 2000 watt inverter in a coach and still have a 4 LED battery condition panel!

papakilo · 09-08-2016, 01:48 PM

Quote:

Originally Posted by Gilm2113

My wife and I both enjoy getting out into the mountains of Idaho in our Forester 3051S. We have found that the batteries do not seem to last quite as long as we expected. Our 3051 does have the larger, 12 cu.ft. fridge and most of the time we have very little running (lights/radio, etc.). I can go to bed in the evening with what the idiot lights say is a full battery and wake up with what I believe is barely 2/3's. I say barely 2/3's because as soon as I run the furnace it drops to 1/3 very quickly. Is this normal? I typically have been running the generator for an hour or two during the day to top the batteries off and have a repeat the next morning.

In our earlier travel trailers we could go 4 days with two batteries without needing a generator and in our Forester 2651 we could go 2-3 days with no issues. Does the larger fridge which is usually quite empty have that big an impact?

Any advice or comments would be appreciated.

One way we have saved on battery power is to change all of the lights to leds.

awellis3 · 09-08-2016, 01:57 PM

Quote:

Originally Posted by Gilm2113

Does the larger fridge which is usually quite empty have that big an impact? Any advice or comments would be appreciated.

OK - back to the original question. It isn't the size of the fridge, it's the model year of the trailer. Back in the day, reefers equipped with heating elements to prevent frost build up around the doors also had an off-on switch so you could turn off the element. (My 1995 Sunline did.) Not so anymore. They're always "on." Your reefer may have such an element.
Also, some slides, the Schwintek being one, require voltage to the slide motors all the time. This acts as a slide brake. When I boondock, I remove the 30A fuse to the slide control to kill this sizable draw.
Now to all that add the parasitic sound system, reefer brain, propane detector, water heater brain and it's no wonder our battery charges don't last as long as the ones did on our old trailers.
Remember the old canned hams that didn't have a 12V system at all? Propane lights, radiant heater and a water system you pressurized at the gas station tire filler (with foot/hand pump backup). They were boondockers, by gum!

Gilm2113 · 09-08-2016, 04:00 PM

Thanks NMWildcat and Scott, I agree that is the tack I will take - just need to get used to running the generator more than I have had to before! I appreciate both your input.

Gilm2113 · 09-08-2016, 04:01 PM

Papakilo -- Unit is already full LED inside and out.

pmsherman · 09-08-2016, 04:06 PM

You can remove the cover on the fridge control panel and disconnect the "light/heater" wire which will eliminate the ~25A/day draw for the fridge door heater. A better long term solution is to install a switch for the heater at the interior light where the heater is connected to the wire from the control panel.

DO NOT REMOVE THE WIRE IF THE RIG IS PLUGGED INTO AC POWER. The connector is near the 120V heater fuse and the fuse's bare contacts can give you quite a jolt if you touch them

Phil

Gilm2113 · 09-08-2016, 04:06 PM

Awellis3 -- Tank you, this is all great information. I wasn't aware of the slide requiring power! All of the other bells and whistles add up, they are nice to have but do consume a lot of power. I appreciate you taking the time to respond to my post, it was very helpful.

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