adding solar

[jimb]

I want to add 2-140 watt solar panels to my 2003 26' RB.
I would like to put the battery monitor and the solar controller as close to the battery compartment as possible. Which means on the drivers side wall, between the stove and the kitchen sink.
What is in that wall ? How thick is it? Is there enough space to run the needed wires?
I though that I could run the wires down the inside of the wall and underneath the coach to the battery compartment. The total run looks like only6'.
Any help is appreciated.

Jim in San Diego

[al1florida]

I think the wall is thick enough. I believe it is hollow and filled with fiberglass batting. However there probably is a cross piece of 2"x2" wood framing which could keep you from just pushing the wire down.

Since the really heavy wiring only needs to be right at the battery, you could run #8 wire down the fridge vent and then under the coach to the batteries. You could then put the controller on the entry wall by the fridge.

Here are two websites which can help you plan the install:

http://www.jackdanmayer.com/rv_electrical_and_solar.htm
http://www.rv-dreams.com/rv-electrical.html

[Jim Hofmann]

Jim, when I traded in my 23'RB on a new 26' RB I had BornFree remove my 2 solar panals and install them on the 26'. I don't know the route they took with the wiring, but the controler is located on the front side of the sink cabinet just below the protruding overhang and above the doors to the cabinet.
I would have posted a picture, but I am not that computer literate. If you would like a picture I could send one in a private e-mail to you.

Jim H.

[jimb]

I think the wall is thick enough. I believe it is hollow and filled with fiberglass batting. However there probably is a cross piece of 2"x2" wood framing which could keep you from just pushing the wire down.

Since the really heavy wiring only needs to be right at the battery, you could run #8 wire down the fridge vent and then under the coach to the batteries. You could then put the controller on the entry wall by the fridge.

Here are two websites which can help you plan the install:

http://www.jackdanmayer.com/rv_electrical_and_solar.htm
http://www.rv-dreams.com/rv-electrical.html

[stevek]

I am also interested in adding solar.
The 2 links had some great info. Thanks.
Any and all input appreciated.

[hrgermany]

I have been using solar panels for over 20 years.Very important is to use a good solar charge control panel.The panel I am using is a Solar Boost 2000E
that I got from Blue Sky Energy.They might have a newer model now.

Hans Rueckert
1995 BF RSB

[oliverpsmile]

Why are you all reluctant to run you generators to charge the batteries? Savings, environment concerns or what? So much expenses for so little gain. I would understand if you are forced to be off the grid for long period of time but camping for week or two, to me is totally unjustified.

Two years a go, in Arizona, I met a lady (former scientist) living in BF full time. She was the most knowledgeable person regarding energy management I have ever met. Her monitoring sytems were equal to none. She was combining - generator, solar panel and campground hookups for energy sources. Giving the fact that she was full time resident in her BF and apparently her $$ were not unlimited her approach was very well rational.

[al1florida]

Why are you all reluctant to run you generators to charge the batteries? Savings, environment concerns or what? So much expenses for so little gain. I would understand if you are forced to be off the grid for long period of time but camping for week or two, to me is totally unjustified.

Two years a go, in Arizona, I met a lady (former scientist) living in BF full time. She was the most knowledgeable person regarding energy management I have ever met. Her monitoring sytems were equal to none. She was combining - generator, solar panel and campground hookups for energy sources. Giving the fact that she was full time resident in her BF and apparently her $$ were not unlimited her approach was very well rational.

Several reasons why running generator to charge the house batteries doesn't work as well one might think.

First though, if you don't use an inverter to run a TV, computers, and any other electronics, don't park/camp w/o electric hookups for more than one night, and do drive for a few hours every day, you don't really need solar. It is expensive. Driving for 3-5 hours will do a good job of charging the house batteries. Born Free did a good job of installing heavy enough wire so the engine will be able to do a pretty good job of recharging the battery. So unless you need to run the a/c or microwave you probably don't even need to run the generator.

Second, the down side of using the generator:
-- If you don't have a good 3 stage charger, trying to charge the house batteries using the converter, factory installed in the BF, will take many hours of running the generator to get a good charge. We are talking about 4-6 hours of generator run time (or more) to charge the 2 house batteries from the 75% full level to the 90% level.
-- A few of us primarily dry camp or boondock, seldom staying at a place with electric hookups. Being retired we frequently travel for weeks or months at a time. We have an inverter which powers computers, TV and a satellite dish receiver. The satellite receiver is a real power hog! We seldom use the microwave/oven when we don't have elect hookups. If we must, we do start the generator. The inverter I installed is not powerful enough to run the microwave.
-- Most all inverters have a good 3 stage inverter built in which will recharge our batteries from the 75% level to a little over 90% in about an hour and half of generator run time.
-- However consistently recharging the batteries to 90% is not good for the batteries if you plan to keep them in good condition for 5-7 years.
-- Solar panels will really help in getting the batteries to the 100% full level.

Lastly, but most important to those of us who camp away from population centers, is the NOISE of the generator running! While the generator is no louder than a person talking in a somewhat loud conversational voice, having a constant noise level of someone talking beside you while you are wanting to enjoy the piece and quiet of the outdoors in very irritating. Even if I didn't mind the noise, my next door neighbor 75-100 feet away will have to listen to constant background noise of my generator.

[bcope01]

Not yet mentioned..... Any thoughts on why it is or is not a good idea to just start the chassis motor and idle to charge the house batteries? Seems like that would work better and faster than the generator since the chassis alternator puts out many more amps. Wouldn't this be the same as plain driving, which is what Born Free recommends for charging the house batteries? Also would be more quiet than running the generator.

Bill

[Mike Jean Bandfield]

Even if I didn't mind the noise, my next door neighbor 75-100 feet away will have to listen to constant background noise of my generator.

Yup, I've cussed quite a few inconsiderate neighbors running their generators for hours on end and through the night winter and summer. Good solar power systems, like good fences, makes for good campground neighbors. It's clean and quiet and has low operating costs and will allow you to stay in the boonies longer if you manage your resources efficiently.

Mike

[al1florida]

Not yet mentioned..... Any thoughts on why it is or is not a good idea to just start the chassis motor and idle to charge the house batteries? Seems like that would work better and faster than the generator since the chassis alternator puts out many more amps. Wouldn't this be the same as plain driving, which is what Born Free recommends for charging the house batteries? Also would be more quiet than running the generator.

Bill

Idling your engine for 3-5 hours uses a lot of fuel. Trying to charge your house battery with the chassis battery charging system doesn't work as well when charging the house batteries. I think this is because the alternator regulator doesn't "see" the house battery as well as the chassis battery.
Here is a link to a persons website, who I consider to be very knowledgeable, where he talks about the shortcomings of trying to charge house batteries with the engine alternator:
http://www.jackdanmayer.com/truck_proje ... use%20Bank

However my experience shows my house batteries get pretty well charged after 3-5 hours of driving. Of course that assumes I have not discharged my batteries very far.

The following info is fairly technical and is based on our 5 month trip in 2012. Much of the time we dry camped or boondocked.

Here are my experiences with charging my BF house batteries:

Some back ground info:
-- my BF has two 12V house batteries with a total amp hour (AH) capacity of about 200AH. I think all BF's come this way.
-- for long life of your house batteries, it is best to not discharge more than 25% or about 50AH and try to never discharge more than 50% or about 100AH. You must have a battery monitor to know how far down you have discharged your battery.
-- since we dry camp or boondock a lot I installed a TriMetric battery monitor http://www.bogartengineering.com/.
-- I have not installed solar panels yet. I am planning on adding about 250-300 watts of solar this spring.
-- one of the key things the monitor does is to keep track the number of AH taken out of or put into the battery bank
-- an Amp Hour (AH) is one amp being put into or taken out of a battery for one hour. This means when I see 15 amps or even 40 amps going into(charging) a battery at any one moment it means nothing unless that charging rate continues for a long period, one hour or more.
-- I seldom take more than about 40AH out of the battery bank before recharging.

Typical charging numbers I have see in my BF with my batteries being discharged 35AH to 45AH(this is coming from memory, not numbers I have written down):
-- Converter charging .... Right after starting the generator or plugging into shore power, I would see the amps going into the battery jump to about 25 to 30 amps. This would be great if the amps stayed that high. However after about 2-3 minutes the amps would drop to 15amps and after 5 minutes I would see less than 10amps. In 15 minutes or so, I would see 3-6 amps going in. Taking 5amps going in, it would take 6 hours of generator run time to put 30AH back into the battery. I no longer have a converter in my BF. When I installed my 1000 watt inverter I removed the converter. The inverter has a 3 stage charger built in. Running the generator for about 1.5 hours puts about 30AH to 40AH back in.
-- Alternator charging...after starting the engine I would see the amps going into the battery jump to about 30 amps and drop to around 20 amps in about 10 minutes and stabilize at around 7 -8 amps after 20 minutes or so. Much better than the converter. Taking 8 amps going in and driving for 3-5 hours my typical driving day, would put 24AH to 40AH back. A reasonably good charge, but not if the battery had been discharged to 50% to 60% full, that would be 80AH to 100AH of the battery bank used.

So the bottom line would be, if when you dry camp or boondock, you only use the battery for lights at night, running the water pump, keeping a laptop charged and occasionally runing the furnace you could get by with idling the engine for an hour or so each day. Also you could dry camp for 2-3 days and then drive for 5 hours or more. If you run the furnace a lot you will need to idle the engine longer. The furnace is a real electric hog. Not to mention a propane hog, but that is a topic for another time.

However charging the battery bank with the converter is best done when connected to shore power. That way the converter would be charging the batteries for 10-24 hours or more.

[bigdipper]

Al,
I have 440AH AGM battery bank and while I cannot measure amps into batteries, it appears that idling engine puts considerably more AH in than you are reporting. When the sun doesn't shine I (no generator) seem to move from 12.2 or so to 12.7 or so with one hour idling. Battery input voltage rather quickly climbs to about 14.4. While I may never see a real resting voltage, I do load batteries to attempt to get rid of surface charge. Do you suppose the low AGM internal resistance and ability to accept high charge rate is an explanation?
Ralph

[al1florida]

Al,
I have 440AH AGM battery bank and while I cannot measure amps into batteries, it appears that idling engine puts considerably more AH in than you are reporting. When the sun doesn't shine I (no generator) seem to move from 12.2 or so to 12.7 or so with one hour idling. Battery input voltage rather quickly climbs to about 14.4. While I may never see a real resting voltage, I do load batteries to attempt to get rid of surface charge. Do you suppose the low AGM internal resistance and ability to accept high charge rate is an explanation?
Ralph

Without measuring the AH out and in the battery, it is pretty much guess work on what is going on.

Using voltage to determine the true state of battery charge can give misleading results.

Anyone wanting get long life out of their house batteries and also will be doing a lot of dry camping really needs to have a battery monitor system like TriMetric. That is the only way to KNOW what is going on.

I'm not sure if you feel, with one hour of idling, you are bringing your batteries back to even 90% charge or not. One battery voltage chart I just looked at shows a AGM battery bank discharged to 12.2V is a little over 50% discharged. Your 440AH battery bank being at 12.2V, assuming that is 50% discharged, it would take 210AH to go back to 100% full. To put 210AH back into the battery in one hour would require 210 amps being sent continuously for 1 full hour. The batteries are not capable of taking that fast a charge nor is #2 wire going from the alternator and engine battery capable of that much current.

You might consider investing about $150, plus install costs, in a battery monitor. I'm guessing you have 4 AGM batteries which I'm guessing cost between $700 and $1000 total. If you use your batteries a lot, you need to monitor your usage to get your longest battery life. You will also know just how well your solar system is preforming.

Are you the person who doesn't have a generator but had batteries installed in the generator compartment? That is a nice setup. However we live in the south and even traveling to the north it is really nice to be able to have air conditioning with the generator running.

[jimb]

AL,
I have ordered a Trimetric 2025 and wondered where you mounted the battery monitor in your 26' BF.
Jim in San Diego
2003 26'RB

[al1florida]

I mounted it above the entrance door. I routed the cable from the battery under the rig, and drilled a hole in the floor just in front of the passenger side rear tires. That brings the cable up into the empty space under the closet just behind the propane detector and 12V cutoff switch. From there it was easy to run the cable up the inside corner of closet and out above the door. With a little work I was able to fish the cable between the plywood panel which is the side of the closet, and the wall. I didn't need to drill a hole in the side of the closet.

See pictures below. I looks like the pics were uploaded in reverse order than I added them, first uploaded on the bottom.