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hipsters · 08-19-2011, 06:17 PM

My wife and I are complete newbies about to take our first lengthy trip in the AS and definitely want to spend some of that time off the grid. We are wondering how long we can expect to get by on battery power alone and whether we should bring a generator/inverter with us. We have a 2006 19' Bambi with all LED's. Since we aren't TV watchers and don't need to use 110 appliances, our only electrical draw should be lights, water pump and, most likely, some furnace use. (Montana mountains at night...) We are sailors, so we know how to conserve resources.

I'm considering buying a 1000W (I like the light weight) Honda to bring just to charge the batteries, if the advice I receive warrants it. If I do, how long would I need to run it to get a good charge back on the batteries?

Any help?

Airperson · 08-19-2011, 06:32 PM

Hipsters, I am sure glad you asked that question I would like to know as well...

Mexray · 08-19-2011, 06:41 PM

This is an age-old 'How far is up?' question...

It's similar to asking: I just picked up a clean used car - with a full tank of gas, how long will it last - how many miles can I go - what's my MPG going to be???

How big is the tank? How fast do you drive? Do you drive up hill very far? Do you tow anything, etc., etc...

The 12 volt battery is, simply put, an Amp Hour storage 'tank'...the larger the battery, the more Amp Hrs are available to use...

1 Amp Hr = the draw of 1 Amp, for one hour...what ever you draw out of the battery, has to be replaced in a timely manner for it to perform properly - but being boaters, you knew that, right?

The lights and water pump will use few Amp Hrs, but the furnace is an Amp HOG! The squirrel cage blower in the heater uses several amps while running - so the more you use it, the shorter your battery's useful charge will last...

We have (3) group 27 deep cycle batteries, rated at 100 Amp Hrs each, and if we watch some Sat TV and use the furnace on cold days, it's a MUST DO to fire up the Honda genny and recharge the batteries each day - they aren't completely discharged each day, but it's important to top them off for maximum performance...

Most battery guys will tell you to only use about 50% of your battery's capacity between recharges in order to get the maximum life out of them...

Even with all the calculating one does over these issues, it still comes down to your own individual situation, etc...It's a learning curve you'll have to experience...

I find our Honda (we have a 2K model) genny is one of our most important additions - we boon-dock a lot!...It has many uses, and firing it up and plugging the AS's shore power cord into it brings our battery system back up to snuff in fine shape...It's also great when we wish to fire up the microwave oven!

Have a great time on your trip...

RangerJay · 08-19-2011, 07:31 PM

We have a 2002 19' Bambi with a single group 31 battery. We also have a 1000W generator.

When we are in "energy conservation mode" the battery will last 3 days if the furnace is not used - (we also use LED lights in this mode). After 3 days the battery will usually be down to 12.2 or 12.1 volts - and then the generator gets turned on.

In that same mode - but using the furnace regularly - we will be charging every day. The routine then is to turn on the generator for an hour in the morning and an hour in the evening.

The 1000W generator is a great addition to all our trips (ours is a Yamaha) - it is light to carry - quiet - uses virtually no gas - and runs everything except the air conditioner. We don't have a microwave oven. My wife bought a hair blower specifically for the Bambi that has a 900W setting and a hand-held vacuum which is 1000W.

If boondocking is going to be a part your life - you will definately end up getting a generator - sooner or later.

Jay

kevin242 · 08-19-2011, 07:34 PM

Our 1977 Tradewind has a propane radiant heater as well as the forced air. The radiant has no moving parts and uses no battery power at all - a must if you don't want to drain batteries.

With very conservative light use, and pouring water rather than using the water pump, we can go 10-14 days on the two batteries.

Phoenix · 08-19-2011, 08:02 PM

We have a 2005, 19-foot Bambi, with two Optima Blue Tops (deep-cycle, marine battery, group 34). We use a couple of LED lights to conserve electricity and can go 5-7 days without recharging, if we do NOT use the furnace. Actually, we have never attempted to go longer, so I'm unsure how long the batteries could actually last.

If we do use the furnace (for a couple of hours in the evening and morning, but not at night; because we use sleeping bags and are OK down to around freezing), we can last 2-3 days. However, we run our generator daily for an hour or so in the morning, and again in the evening, usually to coincide with the use of the microwave oven for meals and TV viewing.

If you buy a generator, I'd suggest getting a 2000-watt model, since they are only a few hundred dollars more; and then you won't regret having bought a 1000-watt generator, if you decide to add a parallel unit to run the air conditioner. We bought two Honda 2000's, and carry the one with the RV plug with us all the time. We only bring the second one with us in the summer, and rarely use it. Please note that we live in Arizona, and this may not be as much of a concern in cooler locations.

While this was quite an expense, the generators give us a lot of flexibility and have extended time between KOA stops to recharge our batteries overnight on shore power. This allows us to stay more often in dispersed campsites (i.e., boondocking, free), and National and State Park campgrounds where the sites are spreadout and more scenic. In addition, National Park and Forest Service campgrounds are half-off with the $10 Lifetime Senior Pass (age 62+).

hipsters · 08-19-2011, 08:49 PM

Thanks for all the quick and helpful responses! I also found an older thread that covered some of the same information, so I think I'm pretty well set. We will be bringing a portable generator, so we can run the furnace and won't have to worry about cold tootsies in the morning!

See you on the road and off the grid...

Gary

Airperson · 08-20-2011, 05:21 AM

Awsome question and great responses. Thanks to all for a great read and useful information.

TouringDan · 08-28-2011, 10:12 PM

I finally got to go camping and try out my new LED lights. I was gone three full days. I barely used any electricity at all. My voltage when I got to the site was 12.83v. My voltage after 3 days camping was 12.71v. Now understand that I was by myself, and I was gone during the day for about 10 hours to a music festival. I only used power for the LED lights and the water pump for shower and sink. No fan or furnace power. Also I have 2 6v golf cart batteries in parallel. Voltage tables indicate that you can bring the starting voltage down about .7 volts to the 40% level before needing to recharge (12.83-.7= 12.13). Based on this I could go 17 days before needing to recharge (.7/.04= 17)(extrapolating). Now I had my little Honda genny just in case.

One useful tool is the Voltminder. I got this when I ordered my new converter from Best Converters. It only cost about $25 and you hard wire it to your 12 volt system and it is always connected and tells you the voltage. This allows you to keep track of how much power you are using when you operate the lights or the water pump or the fan. I highly recommend it.

Dan

ROBERT CROSS · 08-29-2011, 06:25 AM

Dock'n power management....

Two grp 27 Lifeline AGM 100ah....

One IOTA IQ4....

One Honda 2000i....

14 daze...four two leggers and two four leggers....

One hr per day on genset....

KISS....keep it stupid, simple.

Bob

TouringDan · 08-29-2011, 08:46 AM

Here is a photo of the Voltminder I use to manage the battery level for the two six volt golf cart batteries in my 66 Tradewind (see 2nd previous post).

Dan

Jammer · 08-29-2011, 10:20 AM

There are people who are good at conservation and who have various modifications made to make operation on batteries more practical. These threads draw many posts from people like that.

With a stock trailer though and typical usage you can't rely on camping more than 1-2 days on batteries. Running the furnace overnight is sure to limit you to one night as is running the fantastic fan all the time.

casarodante · 08-29-2011, 11:15 AM

In regards to heating, you may want to look into the Heater Buddy, a small catalytic heater. We use one in our 25' when dry camping and it keeps it sleeping temperature. No power usage either!

JamuJoe · 08-29-2011, 06:57 PM

Hipsters,
You might also consider the solar option. With a single 85 watt panel and MPPT controller, we have often camped off grid for three or four days, using the furnace, water pump, fridge fan, LED lighting, stereo and laptop (we're not TV users when camping). We recently spent two weeks in Olympic NP, (five different campgrounds) off-grid, often under thick canopy, and still had no power issues.

hipsters · 08-31-2011, 06:48 AM

Thanks, Jammer! That's exactly the kind of simple estimation I was looking for.

JamuJoe, solar is definitely on our list of future projects.

We are hitting the road on Monday, so my 'dockin education begins soon!

Gary

Bill M. · 08-31-2011, 06:54 AM

Very simple answer. If you are going to run the furnace, buy the generator. It will take about 2 to 3 hours for a decent recharge.

JamuJoe · 09-01-2011, 10:02 AM

Quote:

Originally Posted by Bill M.

Very simple answer. If you are going to run the furnace, buy the generator. It will take about 2 to 3 hours for a decent recharge.

Very simple answer, although not universal. We routinely run our furnace on battery power (two group 24's) along with the other utilities (LED lights make a big difference), and let the 85 watt solar recharge during the day while we're out and about. We've never dropped below 12v, and rarely does my MPPT controller not indicate a full charge before the sun sets. We've done this for many cold nights. I always pick a site with as little shade on the panel as possible. Actually, I had planned to add a second panel, in the place of the TV antenna, but have deferred because the single panel is doing the job.

Everyone has different needs and opinions, but I regret for newbies to think that they must have a generator. If one must use a microwave or A/C - then add the machine, and please be considerate of other campers who find the noise objectionable.

pod people · 09-08-2011, 08:56 PM

I have to agree with Bill - if you run the furnace - the generator is your friend.

We use a 2000 Honda - pretty darn quiet (makes it easier to be a good neighbor).

In the summer - we can stretch it to 3 days on one Group 24 battery. We found that switching to a Lifeline made a big difference.

Thinking of changing out the converter - maybe an Iota.

JamuJoe · 09-09-2011, 11:17 AM

Just returned from Rocky Mountain National Park. Beautiful trip, although we got completely rained out in the park - grey days, low cloud cover, continuous rain, night temps in the low 40's. Off-grid in Moraine Park CG (excellent CG - very large sites with great topography) for 3 days, furnace keeping the cabin at 70º, and the battery pack (2 gp 24's) never fell below 12.2v with marginal solar charging. (I was surprise to even see 0.2 amps of charging without a ray of sunshine). Headed toward home and spent a last night off-grid in the San Luis Valley, caught a few hours of sunshine, and four hours of trickle charging via tow vehicle, that brought the pack back to 13.6v before another cold night. The only issue with the furnace was the propane tank running empty at 0200 and having to dash out into the cold rain to switch over to the full tank. Our 2011 FC23FB tank monitoring system doesn't include a propane tank monitor. I'll be looking for an improved way to monitor propane levels. Has anyone added a propane level sensor/feed to the tank monitoring system?

vswingfield · 09-09-2011, 12:43 PM

Quote:

Originally Posted by JamuJoe

... Has anyone added a propane level sensor/feed to the tank monitoring system?

I added a Marshall Brass indicator that fits on top of the Marshall automatic switching regulators. It doesn't show the level, but a LED flashes inside when the regulator switches to the reserve tank and the indicator on the regulator itself changes from green to red.

My Excella has level lights on the Control Panel, but I don't have tanks with the senders, the wiring is gone outside too. I could deal with the wiring, but the cost of two new tanks with senders is prohibitive.

I know I could just check the regulator periodically to see if the indicator has turned red, but this reminds me. Painless to install, too.