Boondockifying A Winnebago

[MattTaylor]

We are true amateurs. We've had our Sightseer 35N for about two years and have taken two long trips, about 6000 miles so far. On both trips we found ourselves staying at KOA or other commercial camp grounds. This is not what we had in mind when we bought the RV. So, we are amateurs on a quest to boondockify our Winnebago.

Step 1 - I've added a Go Power 600 watt solar power system that feeds 4 Trojan T-105's giving us 450 amp hours of storage, and 225 amp hours of power. I think I'm going to add 2 more t-105's to bring the usable amp hours up to 337ah, and am not opposed to adding 4 t-105's to give us 450ah of usable power if need be.

Step 2 - Today I'm going to order and will install an auto generator start system for the Sightseer. I understand that this will kick on the generator to charge the batteries if they get to low at night or when there is no sun or we are just being power hogs. My other concern is that we sometimes leave the dogs behind, like when we go shop or whatever, so temp control is important.

Step 3 - We have been told by many that running even one of the air conditioners is flat out not possible well, that's not true. The 3000 watt inverter runs one AC unit just fine, just not for very long at a time, thus more batteries. This is my primary reason for wanting to double the battery bank to 450 amp hours of useable power. Beyond that we have a Bonaire portable swamp cooler that we set in front of a bedroom window, a high air volume fan, and the non-temp controlled Fantastic fan that came with the coach. My main concern here is keeping the bedroom cooled off at night.

Step 4 - Here's where I need some help and some suggestions / recommendations from my betters, the more experienced, you perhaps? Being rank amateurs at boondocking we don't know what else we need or what else might be important for that purpose. Is there anything else I need to add or should add soon? Whether it's a true need, or just a nice to have, we would like to know what YOU think is important.

Thanks so much for any insights you can provide. This coming weekend we are boondocking for the first time at Oloogah Lake which is local and close to home for us. We want to test and evaluate the RV and ourselves, so if I'm not around come Monday, someone send help

[DAN L]

matt t,
is your inverter pure sine wave or modified sine wave?
do a forum search on the problems some have experienced with MSW inverters.

[MattTaylor]

Hi Dan,

The inverter is the Go Power PSW 3000 watt unit. I'm still amazed at this point how it well it runs everything. I did come up with another idea, lights. We don't have a single LED light in the RV. I did an ebay search and found some that appear to be a direct replacement, but they sure look strange, not like a bulb at all. So I'm kinda stuck there, not sure it I'm looking at the right thing or not. Thanks for the reply Dan.

[MattTaylor]

Can anyone tell me if these are the correct LEDs to use inside the motorhome?

20 x 5050 7000K White 1156 BA15S RV Trailer Interior 12V LED Lights Bulbs 27 SMD | eBay

Thanks,

[mriderLeon]

Originally Posted by MattTaylor

Can anyone tell me if these are the correct LEDs to use inside the motorhome?

20 x 5050 7000K White 1156 BA15S RV Trailer Interior 12V LED Lights Bulbs 27 SMD | eBay

Thanks,

Those have the 1156 base. If your existing lights have that round base with a single positive pole, then these LEDs will work.

[JFNM]

Hi Matt,

It appears you are in Oklahoma so should have pretty good sun for your solar system (that is good).

My summer/hot weather boondocking is usually a compromise - park in the shade to keep temps down or park in the sun to maximize solar output. Typically, in the warm/summer months, I go for the shade. The solar seems to keep up just fine (for my system and my usage, which is fairly light). One solution to this is remote/movable panels (park in the shade and set the panels in the shade). That's never been necessary for me but it sounds like some find it useful.

My roof vent fan usually runs a good bit of the night (until temps drop) and I also have a fan-tastic 12V fan in the bedroom that blows on me all night (unless I wake up cold and turn it off - a ceiling fan would be better but I haven't made that enhancement yet). Neither of these fans are big power draws. I have no doubt that some would much prefer AC to keep things cool (I would too) but that comes at a price (that I am unwilling to pay - either running the genny or a HUGE battery bank/solar system).

Window sun covers (mine are here) usually make a HUGE difference in internal temps. I even have one for the sun roof thing over the shower (it is tinted but can still be a real heat generator). Another option is placing Reflectix material on the inside of the windows.

[pcurt23]

If your lights are in a fixture, I used these. 10x BA15S 1156 1141 Dome Bulb 36 1210 SMD LED Warm White | eBay boondocking using propane for water heater and fridge I pull 6amps.

Also, Depending on which AGS you select you may have to have an additional control panel with AGS function button. I installed mine 3 years ago and have yet to use it. Boondocked at the balloon festival last weekend and had the ags turned on. Never needed it because by the time we started the genny to use the microwave the batteries never depleted enough to auto start. Some AGS systems will also automatically top off your batteries prior to quiet time at 10pm.

Using air on inverter power is very hard on your batteries.

[OLYLEN]

Two comments, well maybe three. One with the system you have now you should be fine. Two while you can run the AC on the inverter, it is a terrible drain on the batteries, so can and should comes onto play. And three, it sounds as if your not adverse to running the Gen, So in the high use AC Times use the Gen. This will help keep the batteries on the full end and power everything you want need during this period of time. We had a similar setup with less solar and our constraining factor was Gray water rather that power. And last conservation of power, while the Gen is running do all your power duties.

LEN

[Reed Cundiff]

A couple of minor things for first time boondocking

1. Install a number of 12 V receptacles (aka cigarette lighters from olden days). You can use these to charge camera, Iphone etc batteries and set up 12 V fans (1 amp = 12 W) which make a great change in comfort when sleeping.

2. Do got with LEDs both inside and out.

A problem with your Step 2 of having automatic starting of generator when battery status of charge drops is that you wind up cycling the batteries several times a day and the battery suite degrades rapidly. This is not a problem if your travels are only a month a year. There would be a problem if boondocking 365 days a year.

Most a/c require about 1750 W (145 amps at 12 V) so that even with 337 Amp-hours of usuable power (50% SOC), you will only have two hours maximum of air conditioning. We have an effective 8.6 kW-hours (at 48 V nominal) of LFP or over 7 kW-hrs usuable (20% SOC) and have run a/c for 3.5 hours. Could have run for 5 hours but would have been down to 30% SOC at dark. LFP only makes sense if you are full-time boondocking
Reed and Elaine

[SkiSmuggs]

Originally Posted by Reed Cundiff

A couple of minor things for first time boondocking

1. Install a number of 12 V receptacles (aka cigarette lighters from olden days). You can use these to charge camera, Iphone etc batteries and set up 12 V fans (1 amp = 12 W) which make a great change in comfort when sleeping.

2. Do got with LEDs both inside and out.
Reed and Elaine

This is excellent advice from a guru! My DW was not happy with me installing extra 12v receptacles (it's her fiver) and buying 12v fans until we dry camped in warm weather, then she was all over it.

[MattTaylor]

Thanks for all the info everyone!

I find that I'm running head first into a learning curve
The electric system in the RV is a 30 amp system. It would seem logical to expect, for example, a 300 amp energy source to last 10 hours if it was drawing the full 30 amps, but somehow that notion is flawed and I don't understand why.

30 amp at 110 volts = 3300 watts

Since my inverter is a 3000 watt with a 6000 watt surge capacity, it seems to me that as long as the 110v appliances in the RV are pulling 27 amps or less the entire system should run just fine. 27amp x 110v = 2970 watts. If I have 270 amp hours of usable power I should be able to run for 10 hours, and the battery bank would be at 50% SOC. But somehow that too is flawed.

I just ran a test. I had an electrician put a 30 amp plug on my house a few days ago so that I could plug in the RV if I wanted. If I plug it in and run 1 AC unit the RV's AMP draw meter says that the RV is drawing 12 amps total. Now I unplug the RV and turn on the inverter, it's running the exact same equipment so should be pulling the same load. With this scenario, in my mind, with 225 amp hours of battery I should be able to run just like this for almost 19 hours, but that is evidently not the case.

This is frustrating, and I know that I must be irritating those who already know and understand this stuff, I'm sorry for that everyone. The electrician/solar guys that know and understand all of this stuff earn every penny they make, and those of you who put up with newbies such as myself are near sainthood so to speak.

[JFNM]

Matt,

It appears that you are missing the 12V portion of the equation. If your load is 3000 watts and you are pulling this from your 12V batteries, you are consuming something around 240 amps (at 12.5 volts). That ignores the approximate 15% loss of the inverter.

Edit: That was much too quick of a response - apologies. The 30 amp "capactity" of your rig doesn't mean much in this case. You need to know the actual 110/120 volt draw of your AC unit. It is probably close to 20 amps at 115 volts (splitting the difference). That equates to 2300 watts. Pulling that from you 12 V batteries would be 2300 (watts) divided by 12.5 volts = 184 amps (plus the losses). That is a BIG draw.

Edit #2: That 190 amps (rounded for losses) for an hour would draw your 270 amp-hour capacity down to below half in less than an hour. So, in theory, if you inverter and wiring could handle this load, you could run it for about 20 minutes (before going under the 50% point on your battery bank).

[MattTaylor]

Eureka!! I get it, maybe...

So if I had 5 x 100 watt light bulbs the inverter would supply 500 watts to run them from the 450 amp hour battery bank at 12 volts.

500 watts / 12 volts = 42 amps per hour. So I would reach about 50% SOC running these 5 light bulbs in about 5.4 hours. (225 / 42 = 5.35)

Is this the right way to calculate how long the batteries will last? Is wattage draw the way to go here?

I think one of the meters that tell you how long the batteries will last at the current load might be a GREAT idea for me. Anyone using one of those that can make a recommendation?

[JFNM]

Yes, correct. Keep in mind that there are some losses involved - particularly when inverting from DC to AC (very rough rule of thumb = 15%).

I have a Trimetric that I love (here). I'm not sure if it does 'time at current load' but it provides a ton of information and percent of 'full' based on the amps that have been removed since full.