Daily Electric Usage When Boondocking - RV-Dreams Community Forum

Adam and Karen · RV-Dreams Community Member

Daily Electric Usage When Boondocking

Sushidog · RV-Dreams Family Member

Well, I only have a small Aliner, but do boondock frequently. I use about 20-30ah/day. I run my fridge on propane, so there's little 12v power draw. I typically run my water pump about 10 minutes every other day to shower and maybe 390 seconds/day to wash dishes. I don't use LED lights but do use a small fluorescent light. I don't use a furnace blower as these draw lots of power. I do have a 19" TV/DVD player that I power about 2hrs/day off of a small inverter. I disconnect my inverter from the battery when not in use to avoid any parasitic draw. Other than that I have a couple fridge fans (120mm computer muffin fans)that cycle frequently and a couple roof vent fans that I run occasionally. I run my generator about an hour every other day to recharge my single group 27 battery.

Here's a solar planning worksheet that may come in handy, because it doesn't matter how much power I consume, but how much you consume. www.rvsolarelectric.com/index.php

That said, here's an interesting quote from the article: "But, based on the thousands of systems we've been involved with, the average Rver, one without unusual needs, generally finds that one 80 watt panel and one 105 AH battery (or equivalent) per person provides an adequate system for long term outings. An extra panel and battery provides insurance during bad weather and enough power to handle the unexpected."

Chip

Adam and Karen · RV-Dreams Community Member

Thanks for the info, Chip. I would think you're probably on the low end of the usage scale, but I see references to some big users using over 200 ah/day, I expect you are at the low end of the spectrum and they are at the high end. I figure Karen and I will be somewhere about average, or a touch above, depending on how much time I spend on the ham radio.

In figuring the power coming from the panels, I typically take the rating and half it; ie I figure a 100 watt panel will produce about 2.75 amps on average, or about 13 ah/day. That said, I'm hoping for about 52 ah/day, on average, from 400 watts of panels (I know, there's many different factors involved and each day will be different, I'm just looking for longer term averages.). So, I guess a corrolary question would be, in the real world, how close am I?

Adam

Jack Mayer · RV-Dreams Family Member

Sushidog wrote:
Well, I only have a small Aliner, but do boondock frequently. I use about 20-30ah/day. I run my fridge on propane, so there's little 12v power draw. I typically run my water pump about 10 minutes every other day to shower and maybe 390 seconds/day to wash dishes. I don't use LED lights but do use a small fluorescent light. I don't use a furnace blower as these draw lots of power. I do have a 19" TV/DVD player that I power about 2hrs/day off of a small inverter. I disconnect my inverter from the battery when not in use to avoid any parasitic draw. Other than that I have a couple fridge fans (120mm computer muffin fans)that cycle frequently and a couple roof vent fans that I run occasionally. I run my generator about an hour every other day to recharge my single group 27 battery.

Here's a solar planning worksheet that may come in handy, because it doesn't matter how much power I consume, but how much you consume. www.rvsolarelectric.com/index.php

That said, here's an interesting quote from the article: "But, based on the thousands of systems we've been involved with, the average Rver, one without unusual needs, generally finds that one 80 watt panel and one 105 AH battery (or equivalent) per person provides an adequate system for long term outings. An extra panel and battery provides insurance during bad weather and enough power to handle the unexpected."

Chip

That is an extraordinarily low usage. I rarely encounter a person that can document such a low usage for long term boondocking. An overnight maybe, but most people boondocking for extended periods use far more than that. I also totally disagree that an 80 watt panel and ONE 105 Ah battery per person is typical. That may have been true in the 90's but a typical coach these days used for extended boondocking is going to need far more than that.

Given that everyones needs are different an energy audit is the only way to really find out what you need. That said, "most" people use around 125Ah overnight, more or less. But you can argue (validly) that is too much, and it is for some people.

Do your energy audit, then plan a system that can be expanded.

Adam and Karen · RV-Dreams Community Member

Thanks for your answer, Jack. As I said, I agree that 20-30 ah would be very low on the usage chart. I also imagine that 200+ is pretty high. The 125 ah figure kind of confirms what I expect to hear from most people who tract their engery usage. My goal with this question is to get some real world experiences of what people are actually using.

Even energy audits are a guess. For instance, my Icom 746Pro ham radio pulls approx 1 amp when receiving and 23 amps when transmitting at 100 watts output, less if I am able to run less transmit power. During the course of an hour of talking on the radio, how much I am transmitting vs receiving is a guess at best. And that ration has a big bearing on my energy usage.

Sounds like the best solution is a battery monitor and monitor my usage for a few days once I hit the road.

I agree with building the system that has the ability to expand. At present, my plan is to have 400 watts of solar. When I add the incidentals; ie controller, wiring, etc, I will use components adequate to handle 600 watts. Thus, to expand, I only have to add panels, not replace parts I've already paid for. I'm not sure I can place more than 600 watts of panels on the roof of our Dutchmen 30RL travel trailer.

I will still appreciate hearing how much electricity others are using.

Sushidog · RV-Dreams Family Member

No doubt, 20-30 ah is on the low side as I only have a 112 sq ft camper! If you have a 350 sq ft camper multiply that by 3. I can go for up to 3 days before recharging my 105 ah battery, but it is down to around 11.6 volts by then (about 20% charge left) - bad for longevity, so I charge it at least every other day - sometimes 45 min. to an hour daily if I watch a couple DVDs at night and I won't be towing, thus charging off my vehicle's alternator. I agree that 80 watts/person sounds insufficient, but that's what RV Solar Electric reported. Personally plan on adding 4 - 250 watt high voltage panels and an MPPT controller as panels are so cheap these days, around 80 cents/watt. sunelec.com/solar-panels/sonali-pv-module-250w-polycrystalline-etl-to-ul1703.html
www.solarblvd.com/Solar-Panels-&-Systems-24-Volt-Solar-Panels/c1_270/p2949/Vikram-250-Watt-24-Volt-Eldora-Ultima-Series-Solar-Panel/product_info.html

Chip

Bill and Linda · RV-Dreams Family Member

In our previous rig we had exactly your setup. 300AH battery bank (Lifeline AGM’s) and 400 watts of solar.

Without a residential fridge we were good including running the satellite receiver most of the day to keep the guide and recordings current. We had converted all lamps to LED and I had a Tri-metric battery monitor to keep close tabs on usage and a good three stage charger.

I found we used, including making coffee in the morning (the largest power hog) about 150 AH’s / day and were fine. That included running the vent fans a lot. Naturally we needed a little generator time to get a good bulk charge in the morning and then the solar did the rest. We use an electric mattress pad at night to keep toasty. Very low 120 volt amp use and a lot less than running the furnace which is likewise a 12 volt power hog including LP.

From our experience with an RV fridge 300AH is about the minimum without constantly turning everything off and using the rig as we wanted to. With an RV fridge 600AH and 600AH solar is the minimum for comfort. Naturally, it depends and your mileage may vary. With 600AH in our rig now and an RV fridge I think we are in very good shape for our lifestyle of use.

jimindenver · RV-Dreams Family Member

At one time when we had no generator or solar I knew and it was low. Even when it was below freezing at night and we were using the furnace set at 50F, it took 3 days to bring a 95 ah grp 27 down to 12.3v. We got a bit less conservative once we had a generator and LEDs but even then we knew the instant that generator shut off we were on the battery and it had to last 22 hrs including the nightly furnace run.

Last year we took 230w of solar up and any concept of conserving power went out the window. We didn't have a big inverter and big loads but we could set the stat at 74F and leave it there. Most of our loads are in the day time and we found we could turn on every light, fan, the furnace plus whatever else we had and the battery wouldn't drop any voltage at all. The panel produced enough to cover and kept the battery in float. The only time the battery discharged was over night and that was the LEDs, maybe a movie and the furnace. The daily drop in voltage was only to 12.57v and float came early the next day.

This year we took two 245w systems up, added a cheap 3000w PSW inverter and a 150w inverter to run a TV/Sat system. Those are powered by a old 8-D starting battery and together they run our 1375w microwave, a auto drip coffee maker, hair dryer and vacuum, just not all at once. The panels are good for 34a while tracking and that provides a good chunk of what the inverter uses keeping the battery from being pulled down as fast. it also replaces what was taken out quickly. After use the big inverter is shut off.

The little inverter/TV/Tailgater Sat. is hooked up at the start of the trip and left on to keep from having to reset it. Even when it is cloudy, the only time the battery knows it is there is at night.

So how much power do we use? i have no idea. The best I could do is see how many WH the solar controllers recorded, between the two maybe 15000 wh in two weeks.

After checking the controllers the WH's are 16788 which converts to 1399 AH, so around 100 ah a day on average.

-- Edited by jimindenver on Monday 22nd of September 2014 01:30:12 PM

-- Edited by jimindenver on Monday 22nd of September 2014 01:48:09 PM