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pianotuna
Hi All,

This is day 2 for my new solar system.

It consists of:

4 unisolar us 64 panels (total 256 watts)
1 blue sky 3024i charge controller
1 2500 watt cobra inverter

The RV was prewired for solar with a #10 wire (too small imho).

The panels are wired in two banks of two in series using #12 wire that is twinned (i.e. four wires for each panel--two for the negative and two for the positve) to the combiner box at the fridge hood.

The #10 goes from the fridge hood to the charge controller.

I used #8 wire from the charge controller to the battery

The wires are twinned to the inverter using #4 (because that was the maximum size the inverter terminals would accept)

The inverter output is sent via a #10 wire to a plug in the shore cord box. When I disconnect from shore power I simply plug the shore power cord into that outlet. Before I turn on the inverter I manually trip the breaker that operates the stock converter for the RV.

It was interesting to note that the stock converter only brings the batteries to 13.8 volts.

On day one I was trundling down the road and had my 1120 watt water heater on (by accident not design). I gathered about 84 amp hours (nominally 1000 watts) from the solar panels.

On day two I gathered in 84.9 amp hours (1032 watts) and ran a vacuum cleaner, the water heater, a small electric heater, some lights, ran the microwave (for one minute) drilled 68 holes and drove 68 screws.

Charging from the solar panels started at 6:15 am and was 0.2 amps. It rose to a peak of 17.2 amps. The morning was cloudy so at noon I was gathering only 6.5 amps. The afternoon turned sunny and I had solid readings of 13 amps from 1 p.m. to 4 p.m.

Battery voltage started out in the morning at "float" levels (14.8 volts) and at 8 p.m. the voltage was 12.3.

The batteries are what came with my RV. They consist of two 105 amp hour 12 volt batteries--and another one that doesn't' match and may be of lower capacity. I intend to change them in the future--but I want to see just how much energy I can draw from them first before getting replacements.

The only item I've not tried to run in the RV yet is the air conditioner. I may give that a shot later this week--particularly if I manage to figure out how to trigger an "equalization" charge.

I'm not at all sure the inverter will handle the load--and in any event I do not intend to run the AC from the inverter.

All in all, I'm extremely happy with the new system--it certainly will be of great use to me as I frequently boondock--and I try as much as possible to avoid propane use.



DXSMac
Wow! I don't understand all of it, but I'm sure it's high tech!

JJ
abbygolden
QUOTE(DXSMac @ May 3 2009, 12:02 AM) *

Wow! I don't understand all of it, but I'm sure it's high tech!

JJ



Me either! Solar is an interesting topic about which I know almost nothing. I do know that if I used it at my house, the payback period would be long after my death!
Lindsay Richards
Don't you need lunar for night time use???
Denali
Congratulations on your new technology. Your data on how much power you harvested from the sun is interesting.

When we boondock in the desert, we can get right around 100 amp hours a day from our panels. That satisfies about half of our energy-guzzling needs. We installed the solar system simply to cut down on the number of hours per day that we need to run the genset, and it has worked well for that. I don't know whether it will ever pay for itself in diesel savings, but the extra 2-3 hours a day of quiet is worth it to us.

You won't be able to run your air conditioner from your inverter/batteries. The compressor on your air conditioner draws something like 75-100 amps for an instant when it kicks on. This is called the "locked rotor" load in the manual for your air conditioner. Those are AC amps, so the load is 750-1,000 DC amps. If you try it, you may either smoke the inverter or trip an auto protection device (like a fuse) in the inverter. Or, the air conditioner start capacitor may take that load so your inverter never sees it. In any case, after an air conditioner starts, it will probably draw 10-13 amps AC, about like a large microwave. That's 100-130 amps DC.

With your 210 amp hours (plus the mystery battery) of house batteries, you would deplete them to the 50% level in about 15 minutes. I suspect that it isn't good for batteries to put that kind of sustained load on them, but I'm no expert.

Our coach, like most others its size, has a whole-house inverter wired into it. It's a 2,500 watt, like yours. The motor home manufacturers never wire the air conditioners into the inverter system on these things. The only one I know that does is a Prevost conversion, which has two 4,000 watt inverters and many more batteries than you and I have.

I use the equalization function built in to our inverter about twice a year. If you do that, remember that the equalization cycle raises the voltage going to the batteries to over 15.0 VDC. Purportedly, that can damage some DC equipment, like the circuit board in your fridge, fluorescent fixtures, thermostats, etc. When I run the equalization cycle, I disconnect DC power to the coach. You also need to remove the caps from the batteries while equalizing because it does boil them.

Keep us posted!
pianotuna
Hi Dave,

I agree on the Air conditioner--I have no plans to attempt to run it on the inverter. I suppose I could trip the breaker to it as well as the one to the converter--but I think that is needless. I do have a generator for that purpose, which is a "hand me down" from my previous RV.

I had a 14.9 volt reading with the temperature at 10C--so I know the temperature compensation is working! It is in an inverse relationship--as temperature rises voltage drops by 10 millivolts per 1 degree Celsius. The 3024i is preset to 14.4 at 20 C--but from what I'm observing it takes it to 14.8 (@20C) then allows voltage to sag back to 14.4. I'll likely know more later today.

I've already found that even trees bare of leaves have a large effect on the output.

Today (day 3) is a "non use" day other than a quick trip across town. Voltage started out at 12.3 this morning at 9:00 a.m. Charge rate was only 1.6 amps (bare trees). It is now 11:30, voltage has risen to 13.3 and amps are at 13.4 I'm expecting that I'll finally get all three batteries completely charged by late this afternoon--and if not today--then tomorrow it will happen. The short drive will likely not skew my results as the house batteries will most probably be above the set point for the alternator charging system.

I did read the manual and found out I can "force" an equalization--but it requires disconnecting the batteries from the 3024i. I'm too lazy to do so--so I guess I will let nature "take its course" and wait for the thirty day automatic equalization to take place. The 3024i limits equalization to 15.5 volts, but I may take your "tip" and use the coach disconnect switch when my unit is in storage.

The "old" batteries did have a desulphator added to the charging circuit. I'm not sure if that was done on the shore power side or the engine alternator side. I'm luck enough to have a solenoid type isolator--so I should get lots of "opportunistic" charging when I drive--letting the solar panels "top off" the system so that when I stop the batteries will be near or at 100% capacity.

If I'm standing still I think I'll have 1000 watts (100 amps) a day to charge and power the RV--with a reserve of 1500 watts (without dropping below 50% charge state) from the batteries.
Lindsay Richards
Lots of people boondocking in the desert use a swamp cooler instead of air conditioning and they can drop the ambient temp 10 to 15 degrees depending the humidity. They require extra water usage and a fan and small pump. We saw them a lot on houses in the West and I have read about them being used on RVís in the desert.
pianotuna
Hi Abbygolden,

Pay back depends on where you live. In Ontario, for example, the government legislation requires the electrical power grid to buy power from solar at 44 cents per kilowatt hour. My system may generate 1 kilowatt per day and cost for parts was $1900.00. Pay back in eleven years.

Today on the RV I broke my promise to not use power. I wanted to blow out the water lines in preparation for putting the unit back in storage. So rather than drag a cord from the house out to the RV, I decided to use the new 115 volt outlet I had installed in the waste water valve hatch. It worked like a charm! It saved me time, and aggravation. That, for me, is priceless.

On the other side of the coin, if I were boondocking and needed to run my generator I'd have about 1/2 hour "free" from the sun. Pay back would be about $1.50 per day, or three years. In actual fact, I think that with the system I have I'll but rarely start the generator at all, so pay back will be much faster than that.

The end result is that I skewed my results for today LOL! So the panels will not get the batteries up to full power (almost though--they got to 14.2 volts). I did get my 1000 watts again today.

A side bit of information is that I found out the charging voltage from my solenoid based isolator is 14.2 volts.

QUOTE(abbygolden @ May 3 2009, 08:03 AM) *

Me either! Solar is an interesting topic about which I know almost nothing. I do know that if I used it at my house, the payback period would be long after my death!

DXSMac
I think.... over on "another" RV forum, someone talked about swamp coolers, and said they are horrible in humid areas, as they create moldy conditions. I forgot where I read it, I think it was on "another" RV forum.

JJ

QUOTE(Lindsay Richards @ May 3 2009, 12:28 PM) *

Lots of people boondocking in the desert use a swamp cooler instead of air conditioning and they can drop the ambient temp 10 to 15 degrees depending the humidity. They require extra water usage and a fan and small pump. We saw them a lot on houses in the West and I have read about them being used on RVís in the desert.

pianotuna
Hi Lindsay,

Lunar you say? Is this a further development of the "Lindsay pole"? Solar from a flashlight? (get on the roof and wave it furiously over the panels?) *grin*

I've considered a swamp cooler--but they want huge prices for them. Zero-2-Cool made a portable unit for a while that used ice and/or water--I would have ordered one--but they discontinued them. I suppose I could hang a wet towel under the vent for my Fantastic Fan. and that might do a little cooling.

I'm happy as a pig in **** about how well the new system is working. I almost don't want to put it into storage so I could keep on monitoring the results. I finished today at 13.3 volts (and rising). The high point of the day was 14.2 and then I "ruined" things by using the air compressor--and later a vacuum cleaner. It is 7 p.m. and charge rate is 0.9 of one amp. (Thanks to the MPPT Blue Sky 3024i and my choice of series installation for the panels).

QUOTE(Lindsay Richards @ May 3 2009, 01:28 PM) *

Lots of people boondocking in the desert use a swamp cooler instead of air conditioning and they can drop the ambient temp 10 to 15 degrees depending the humidity. They require extra water usage and a fan and small pump. We saw them a lot on houses in the West and I have read about them being used on RVís in the desert.

pianotuna
Hi all,

This is just another brief report on my system.

It appears to be producing more than 1000 watts per day on sunny days. At high noon maximum output has been up to 17.1 amps. (or ~249 watts)

I've been waiting for an overcast day--which finally appeared May 8, 2009. At high noon output was 8 amps (or ~115 watts), and at 4 p.m. it was still 3 amps (or ~40 watts). I'm quite favorably impressed with those numbers. Perhaps 500 watts on a totally overcast day.

I'm happy as a pig in **** about these numbers. They are better than I had hoped.

As it is going to -8 C (17.6 F) tonight, and as I don't care about the tired old house batteries in the RV and as I did not fully re winterize this time (I only blew out the lines--never dreamt it could get this cold), I've put a thermostatically controlled heater in the waste valves hatch set at 5 C (40 F).

It will be a torture test for those 5 year old abused batteries--and it should protect the plumbing.
DXSMac
Lordy! The worst I have camped in was MINUS 2 Farenheit, but that was only ONE night.

JJ
pianotuna
Hi JJ,

-2 F = -18 C

It is the -8 C which fooled you I think. +17.6 F is not very cold at all compared to -2 F

QUOTE(DXSMac @ May 8 2009, 09:04 PM) *

Lordy! The worst I have camped in was MINUS 2 Farenheit, but that was only ONE night.

JJ
DXSMac
QUOTE(pianotuna @ May 8 2009, 08:57 PM) *

Hi JJ,

-2 F = -18 C

It is the -8 C which fooled you I think. +17.6 F is not very cold at all compared to -2 F


Yea.... after I posted that, I realized that -2 was colder than the temps you were quoting.

DUH!

JJ
Denali
QUOTE(pianotuna @ May 8 2009, 07:31 PM) *
As it is going to -8 C (17.6 F) tonight, and as I don't care about the tired old house batteries in the RV and as I did not fully re winterize this time (I only blew out the lines--never dreamt it could get this cold), I've put a thermostatically controlled heater in the waste valves hatch set at 5 C (40 F).

It will be a torture test for those 5 year old abused batteries--and it should protect the plumbing.
Let us know how that works out. A 1500 watt heater would draw 125 amps DC, which should drain your batteries down in an hour or so.
pianotuna
Hi Denali,

That's why I set the temperature on the heater for only 5 C. The heater is a car warmer type that draws 650 watts. It will be heating a tiny area. Too bad I didn't think to put a timer in the circuit so I could tell how long the heat will be on. I have 3 batteries--two 105 amp hour and one xxx amp hour, so I think safe run time would be about two hours in total. Of course if the batteries were allowed to be deep discharged run time would be closer to four hours. The inverter shuts down at 9.5 volts. That would be way below what I'd consider "prudent". But for these old "free" batteries that I intend to replace--this is a good experiment.

I'll be going over at noon hour to check on it--a much brighter day today and 4.6 C outside--so the heater will not be running when I arrive.

What I am seeing from solar on an overcast day would run the furnace for 4.6 hours per day without drawing from the batteries at all. If the forecast is correct for Tuesday night I may go to that option depending on what I find today--propane would be lots cheaper than replacing taps and plumbing lines.

My new RV is far less "cold tolerant" than my old one. I'm especially afraid of freezing the china toilet. I will be adding heater rods before the fall (finding them is the problem, I did take them from the old RV--but where in the heck did I put them).

The "overhead" for running the inverter is about 1 amp. It is a cobra 2500 modified sine wave--chosen because of space limitations. It "lives" behind the driver's seat which allows a cable run to the batteries of less than four feet.

When I went over today (May 9) to see what had happened overnight at 11:00 a.m. the solar panels had already gotten the batteries back to the "float" stage--they were still charging at 5.8 amps. I'm again, very pleased with how well the heater was powered.

I will be letting the batteries "recover" until Tuesday when our next cold front is due to arrive. I wish I could have access on Sunday to check out the results.

On Tuesday I'll probably put a 100 light bulb in the waste tank area, and move the heater with thermostat to the water closet. I may put a timer on the light bulb--and I may put a timer in parallel with the heater so I'll have data about consumption to share.

QUOTE(Denali @ May 9 2009, 09:31 AM) *

Let us know how that works out. A 1500 watt heater would draw 125 amps DC, which should drain your batteries down in an hour or so.
pianotuna
Hi all,

I changed some things today as it is supposed to go well below freezing tonight.

At 10 AM, I put a total of 34 watts of heat rods into the waste tank valve area--and did not put it on a thermostat.

I moved the thermostat and the 650 watt heater into the bathroom, plugged in my Kill-o-watt meter and plugged the thermostat into it--and set the kill-o-watt to record the total number of watts that are going to be drawn.

At 3:00 PM I went back and checked the system. The solar panels were putting out 5 amps (75 watts, from what I can infer) in a totally overcast situation and the batteries were at "float" charge level. So there was enough solar to run the 34 watts in the waste compartment, to do a 1 amp "overhead" from the inverter and keep the batteries essentially fully charged.

I deliberately triggered the heater by plugging it directly into the wall, and the output from the panels jumped up to 6.9 amps! This also caused the inverter fan to cycle *on* which surprised me a bit as the inside of the RV was only at 7 C.

It looks as if I get about 105 watts at 3 PM on an overcast day with an outside temperature of 2 C. That is pretty much in line with my guess of about 500 watts per day.

The Kill-o-watt meter also informed me that voltage was 114. My old "elcheapo" 800 watt inverter used to do 127 volts which I was a little uncomfortable about.

I'll be doing this three days in a row as the next two nights are forecast for below freezing too!

I'm deathly afraid of the China toilet bowl splitting.
pianotuna
Report after running for 24 hours!

At ten AM today for the last twenty four hours I drew 1678 watts from the system. Voltage was sitting at 12.2 and charging was at 5 amps under an overcast sky.

At 3 PM yesterday the batteries were float charging at 15 volts. The panels were providing enough energy to run the 34 watts of heat in the valves area--and provide the overhead on the inverter as well.

Running the valve area heaters 24 hours non stop used 816 watts, or 2775 BTU's

The heater in the bathroom used 550 watts overnight, or 1870 BTU's. It is set at 5 C.

The overhead for the inverter itself is at least 312 watts.

At noon today the batteries were at 12.7 volts and in darker skies than at ten AM were charging at 4 amps.

At 3 PM the batteries were at 13.1 volts and there was a bit more sun so they were charging at 7 amps. 7 amps represents a C42 charging rate for my system so the 13.1 would indicate 85% of full chargeówith another 3 hours for charging to continue, though probably only the next two hours will be significant.

Changes for today:

At ten AM, I unplugged one 9 watt heater bar and added a thermostat to the valves area. This unit is also set at 5 C. This should considerably reduce the number of watts used--but equally I will not have a way to measure that. I suppose I could put the kill-o-watt meter just after the inverter--but I did not have a cord to do that with me.
DXSMac
That's all Greek to me, but if I remember, you are in 30 degree F temperatures (less than 0 Celsius) right now? Hopefully those solar panels are keeping you toasty at night!

JJ
pianotuna
Hi JJ.

It would require some use of propane--but there would be enough energy to keep the furnace running for 4.7 hours per day--without "touching" the reserve energy in the batteries.

The RV is actually in storage at the moment so I've been driving over to "check it out".

As it has been overcast and is going below freezing each night this is a real "torture test" of the system.

QUOTE(DXSMac @ May 14 2009, 11:46 PM) *

That's all Greek to me, but if I remember, you are in 30 degree F temperatures (less than 0 Celsius) right now? Hopefully those solar panels are keeping you toasty at night!

JJ

Denali
Thanks for the great reports, Don.

One question, though: What are heart rods?
pianotuna
Hi Denali,

Todays report:

10:00 AM 13 volts and 6.2 amps charging.

It did not get cold enough for the heater in the bathroom to cycle on last night.

I've changed the heater in the bathroom to a lower wattage one that has no fan. Yes, JJ, it is a small oil filled unit--462 watts according to the Kill-o-watt meter.

I've moved the kill-o-watt meter to just after the inverter so it will track the 25 watts of heat in the waste storage *and* the heater in the bathroom.

3:00 PM voltage fluctuating with cloud cover from 14.1 (full sun and 14 amps) and 13.6 (full cloud and 4 amps).

The 14 amps @14.1 volts represents a C20 charging rate which suggests about 96% of full charge.

The 4 amps @ 13.6 represents a C75 charging rate which is not really on my chart--but the C40 rate which *is* suggests that is about 103%

The system has not reached "float charge" since Wednesday, but I suspect with the clearing of the clouds that today it will probably "get there" today.

The kill-o-watt meter reported I used 2 watts between 10:00 AM and 3:00 PM (I guess I'd better go out and get more panels!!! LOL)

This is the last night in the forecast for freezing temperatures--but just for insurance I think I'll leave the system running. After all, it doesn't cost a dime!

I'll be away on Monday--making a trip with my brother in his Citation (my old one).

I'll use that time away to monitor how many watts are used in a six day framework.

I don't know what heart rods are LOL!

Heater rods are used in humidity control systems for pianos. They come in various wattages from 9 to 50 watts and various lengths. I sometimes have extra rods that are not needed in the particular piano. I've used them in the past to help "winter proof" things such as my fresh water line.

QUOTE(Denali @ May 15 2009, 11:57 AM) *

Thanks for the great reports, Don.

One question, though: What are heart rods?

FosterImposters
I like the sound of these heater rods! Where could the non-piano-tuna-consumer purchase these devices? wink.gif
pianotuna
May 16 report:

10:00 AM voltage 13.1, charging at 10.1 amps. Sky was clear This represents a C 30 charge rate which suggests batteries are about 65% of capacity.

Kill-o-watt meter reading was 630 watts over a 24 hour period or 26.25 watts per hour

3:00 PM voltage 14.8 and 3024di (charge controller) indicating float charging at 7.0 amps. Sky was cloudy. This represents a c 42 charge rate which suggests batteries are at 115% of capacity

I'll not be doing another report for a week as I'm off in my old RV with my brother who is now the proud owner.
pianotuna
Hi FosterImposters,

There are two sources. The original DamppChaser humidity control system rods can be ordered by any piano technician for you.

9 watt rod is about 14"
15 watt rod can be 24" or 36"
25 watt rod can be 24", 36" or 48"
38 watt rod can be 36" or 48"
50 watt rod is 48"

All the 48" rods can be ordered with an "extender" so they can be made up to about 53" long.

There is a competitor as well whose rods come in shorter sizes and even lower wattage. Follow the link below.

http://www.kingmaker.net/mears.htm

The rods are distinctly *not* cheap. If you are the least bit "handy" you could wire some light bulbs sockets in series which will turn ordinary incandescent bulbs into fairly efficient heaters. Use Y connectors so there are four bulbs all together--two in parallel and two in series. That way if one bulb dies the heat output will be reduced by just that amount of wattage. Of course you can start at 7 watts and go up to about 300 watts for such a unit. It's cheap, and it works.

Another cheaper alternative may be heat tape which comes in various lengths and often has a thermostat built in. Wattage tends to be a lot higher. Make sure the heat tape is *not* overlapped. It may cause a fire if that is done.

QUOTE(FosterImposters @ May 16 2009, 10:42 AM) *

I like the sound of these heater rods! Where could the non-piano-tuna-consumer purchase these devices? wink.gif

pianotuna
Hi all,

May 23, 2009

My week "away" report has been "buffaloed" by the RV storage and repair facility--they brought the unit in for a replacement door lock--so no news on wattage for the week. Battery is showing at 12.5 volts at rest.

The RV was inside since 4:55 pm on Friday.
pianotuna
Hi All,

The batteries were full up today and I'm preparing for the trip in June, so I decided I'd "play" and see how things went with running the air conditioner from the inverter with the engine on the RV *not* running.

I started the fan first on low--and my kill-o-watt meter suggested a draw of 175 watts. Then I tried high fan and wattage jumped to 225.

I put the fan back to low, turned the thermostat up to 100 degrees, switched the thermostat setting to cool, and slowly slide the temperature indicator down to where the air conditioner compressor cut in.

The inverter didn't even burp and the draw according to the kill-o-watt meter was 960 watts. (I suppose about 80 amps).

I'm pleased as punch!

Are there any concerns I need to worry about if I'm trundling down the road and wish to use the roof air conditioner? The alternator is rated at 130 amps and I get about 12 to 14 amps from the solar panels.
Denali
QUOTE(pianotuna @ May 29 2009, 07:02 PM) *

Hi All,

The batteries were full up today and I'm preparing for the trip in June, so I decided I'd "play" and see how things went with running the air conditioner from the inverter with the engine on the RV *not* running.

I started the fan first on low--and my kill-o-watt meter suggested a draw of 175 watts. Then I tried high fan and wattage jumped to 225.

I put the fan back to low, turned the thermostat up to 100 degrees, switched the thermostat setting to cool, and slowly slide the temperature indicator down to where the air conditioner compressor cut in.

The inverter didn't even burp and the draw according to the kill-o-watt meter was 960 watts. (I suppose about 80 amps).

I'm pleased as punch!

Are there any concerns I need to worry about if I'm trundling down the road and wish to use the roof air conditioner? The alternator is rated at 130 amps and I get about 12 to 14 amps from the solar panels.
Thanks for the report, Don. I would never have tried that.

I don't have an informed opinion about using an inverter to run an AC while relying on the engine alternator to keep up with the electric load. We use our generator when we want to run the AC on the road.
pianotuna
Hi all,

Today's experiment was to see if I could bring the fridge down to where it would cycle using solar power only. It draws 305 watts from the inverter as measured by my kill-o-watt unit.

I'm pleased to say that the panels and batteries were "up to the task". It took about 5 hours for the fridge to cycle starting from scratch.

I had two freezer packs in the upper compartment, and about twenty can's of pop and juice in the Fridge.

I also measured the "draw" from the hot water heater and found it was a maximum of 1131 watts. It bounces around I think because of the wave form from the inverter.

The square wave from the inverter "fools" the kill-o-watt and makes it think the frequency of the power is about 15 hertz.

I guess I should start to watch for a cheap pure sine wave inverter if I intend to use the air conditioner--I really don't relish burning out the motors in it.

The only devices left to measure "draw" on are the microwave, and on the block heater. I do know the microwave will run, but I also know it doesn't much like the modified sine wave inverter power, either.

I'm hoping the block heater will be sufficiently low draw that I can, in mid winter, just go over, turn on the inverter and plug it in. It would be sooo nice to not have to haul my generator over at -30 C temperatures.
Denali
QUOTE(pianotuna @ May 30 2009, 06:45 PM) *
The square wave from the inverter "fools" the kill-o-watt and makes it think the frequency of the power is about 15 hertz.

I guess I should start to watch for a cheap pure sine wave inverter if I intend to use the air conditioner--I really don't relish burning out the motors in it.

The only devices left to measure "draw" on are the microwave, and on the block heater. I do know the microwave will run, but I also know it doesn't much like the modified sine wave inverter power, either.
I have read repeatedly that inductive motors, such as those in air conditioners, work just fine on modified sine wave power. That said, you are the only soul I know who has ever tried to run an AC from an MSW inverter. The $1,000,000+ Prevost conversions can run their ACs on inverters, but they have enormous battery banks and multiple true sine wave inverters. (I don't know any of those folks, smile.gif)

We have run our microwave ovens many times from MSW inverters. They run at about half power and make a loud humming noise, but they do work. Because they cause such a large battery drain, we always start the generator if we need to do more than warm a cup of coffee.

Keep up the research, Don. If makes fascinating reading.
pianotuna
Hi Denali,

Thanks for the encouragement.

I did the "draw" on the block heater and the results are making me smile from ear to ear.

It takes 584 watts--which means I can run it for over 3 hours without using more than 50% of my current house battery capacity! That is without the solar panels providing any energy at all as well!

That's enough time for the block heater to reach "steady state"--so no more dragging the generator over in very cold weather for this RV'er!

The generator will be relegated to those few times where I wish to take the RV somewhere and *not* move for a week or more.
pianotuna
Hi all,

Oh, the perils of shooting off your mouth without checking!

Turns out my solenoid is not set for 14.2 volts as I thought--in fact it is not working at all!!!!

Also my dash air is not working. This will impact my trip as I decided (foolishly it now seems) to leave my generator at home.

Getting Dash air fixed on the road may be nearly impossible. Ditto for the solenoid charging system.

Fortunately the solar system is working perfectly--so I do have full batteries--if I restrict how much power I draw.

I'll probably try to run the roof air on them for an hour this afternoon when the RV starts to become intolerable.
pianotuna
Hi all,

I have some more data on my solar system.

When I was not driving I'd from time to time watch how many amps were being presented to the batteries.

Because of the problem with the solenoid based charging system I managed to discharge them farther than I prefer to do so.

On that day, the maximum amps hit 19.5! That is higher than the rated output for my system!

I've also noted that even in a moderate rain the panels still kick out from 3 to 4 amps.
pianotuna
Hi all,

Well I'm back from a 9000 kilometer trip--lots of boondocking.

My panels put out 20.8 amps at one point--which is higher than their rated output. I'm very pleased to say the least.

I was able to run the Fridge on 110 volt from the inverter and the panels were able to handle the load. As a side light I also found out that when the Fridge thermostat cycles that the demand in watts drops way down.
RockinFX
QUOTE(pianotuna @ Jun 23 2009, 08:56 PM) *

My panels put out 20.8 amps at one point--which is higher than their rated output. I'm very pleased to say the least.


Did you head south to get those heady numbers on that looong trip? I'm in SE Arizona and don't expect to have much trouble with things like "cold" and "clouds", heh heh. I am dying to do a solar mod, though and really appreciate all of your great data and info - keep it coming!

FX
pianotuna
Hi RockinFX,

The 20.8 number for amps came up when I was driving in North Dakota.

Since you are planning a solar mod, you might be interested in the post I made here:

http://freecampsites.net/forum/technology/...-system/page-1/

and also

http://freecampsites.net/forum/technology/...troller/page-1/

In fact, solar panels work better (i.e. have a higher output) at cooler temperatures, so the "deep south" probably requires more panels for a given wattage than up north.

QUOTE(RockinFX @ Jun 24 2009, 01:14 PM) *

Did you head south to get those heady numbers on that looong trip? I'm in SE Arizona and don't expect to have much trouble with things like "cold" and "clouds", heh heh. I am dying to do a solar mod, though and really appreciate all of your great data and info - keep it coming!

FX

RockinFX
QUOTE(pianotuna @ Jun 24 2009, 08:51 PM) *

In fact, solar panels work better (i.e. have a higher output) at cooler temperatures, so the "deep south" probably requires more panels for a given wattage than up north.


Thanks so very much for the links, Don - *much* appreciated!

You are absolutely right about the PV output, of course. Generally the 325 days of unmitigated sunshine we get makes up somewhat for the reduced output per module. I was mostly referring to your travails with keeping things defrosted and heated. I have the exact opposite problem here, needless to say. Having ongoing real world experience like yours to refer to is priceless and I thank you again for sharing it.

FX
beemerchef
Solar is the way to go!
My fridge however runs on propane and so does my heater (catalytique). Buying propane does not bother me as I use external bottles, easily stored in the trailer behind us that tows the motorcycle and sidecar.
As I read you report I smile... you have the words of a new solar user! Many Friends, including myself, could not lift my eyes from the panel with all the info!!! I have not used a gen set in over a year now (no microwave and it is only Spirit and I) and I don't even look at the panel anymore! That's funny.
We have a Onan 5KW I am thinking about pulling out and a Honda 2KW that I do use for power tools and roasting my coffee...
Great show... Thanks!
Be well... Ara & Spirit

The Oasis of my Soul
pianotuna
Hi all,

I'm adding another four batteries to my system. Here is what I hope to accomplish.

Two banks of batteries. (A and B )

Each bank able to power the inverter

Each bank able to charge from the solar panels independent of the other bank

Each bank able to be charged from the engine.

Power able to be drawn from A or B, or from both

It seems to me one way to do this is to have the inverter, the solar charger, the engine charging circuit and the supply to the RV on one side of a three position switch that has an A, B, and both setting on the other side.

Can anyone think of better ways to accomplish this task?
Denali
Four more batteries? Wow! I'm jealous.

I don't know of a better way of accomplishing what you want, but I have a couple of questions.

Will your engine alternator be able to handle the charging load of four house batteries in addition to the chassis batteries? In bulk mode, our inverter/charger pumps 90-100 amps into our four six volt batteries. If I need to start the engine before getting the house batteries charged, the alternator charges the house batteries at a rate of 100-110 amps. I worry about our 130 amp alternator.

Do you have enough solar panels to take advantage of the extra batteries? I have considered adding more house batteries to our coach, but our 340 watts of solar panels wouldn't be able to keep them charged, even in the desert.

--
Dave Rudisill
2004 Beaver Monterey
pianotuna
Hi Denali,

I can charge and equalize up to 4 batteries per bank with just my solar system. That's one good reason to switch from A to B. For your solar system 6 batteries could be charged and equalized.

Alternators have a 30% duty cycle. That's another reason for the switch. I can charge up one bank--then switch over to the second bank without overloading the alternator.

For sitting still I plan on using the C setting and drawing from all seven batteries--that will ease the load from high draw appliances such as my electric water heater (highest draw item in the RV at 1360 watts).

I guess you might want to know how long the house batteries are charging at 110 amps! If your charging system is solenoid based there will also likely be a fuse to prevent burning out the alternator from excessive draws. It would be good to know where that fuse is!

I know that mine does--because the fuse was burned out! It happens to be a 60 amp fuse--I have no idea when it failed, only that it was definitely before my long trip to North Carolina.

I'm having the the stock solenoid replaced with an aircraft 100% duty cycle and will have it connected at the starter battery and fused.

My installer is my cousin--and he is very thoughtful and creative "farm boy" and licensed electrician. He may be making the charging system flexible enough that I can charge one bank on solar--and the other from the engine alternator. I'll know later this week what he has decided. I wish I were there being the "gopher", but that was not possible for me this time.
rangiebob
Don,

Wow, 7 batteries. I'm jealous! We currently have four for our solar system and want to change me to heavier duty and add two more but we can't figure out where to install the two extras. My husband was thinking that he'd probably have to build something to hold them.

Rachel
pianotuna
Hi Rachel,

You may want to look at my suggestions on "sizing" solar systems to batteries. Have a look here:

http://freecampsites.net/forum/technology/...-system/page-1/

Good luck on creating a space for your (extra) batteries!

QUOTE(rangiebob @ Aug 3 2009, 07:40 PM) *

Don,

Wow, 7 batteries. I'm jealous! We currently have four for our solar system and want to change me to heavier duty and add two more but we can't figure out where to install the two extras. My husband was thinking that he'd probably have to build something to hold them.

Rachel

rangiebob
Thanks, Don. I'll post what we figure out!

QUOTE(pianotuna @ Aug 3 2009, 09:44 PM) *

Hi Rachel,

You may want to look at my suggestions on "sizing" solar systems to batteries. Have a look here:

http://freecampsites.net/forum/technology/...-system/page-1/

Good luck on creating a space for your (extra) batteries!

rangiebob
QUOTE(rangiebob @ Aug 4 2009, 12:01 AM) *

Thanks, Don. I'll post what we figure out!


Don, we are going to be in Oregon in October for work and have made arrangements to drop our coach off at Oregon Motor Coach Center for the booth to be taken out and several other renovations, and we spoke to them yesterday and they'll also help us enhance our solar! So looking forward to these changes to our home. biggrin.gif biggrin.gif
pianotuna
Hi rangiebob,

What do you have planned to enhance the solar?

Just more batteries?

Thicker charging wire?

More panels?

Good luck with the mods!

QUOTE(rangiebob @ Aug 7 2009, 09:45 AM) *

Don, we are going to be in Oregon in October for work and have made arrangements to drop our coach off at Oregon Motor Coach Center for the booth to be taken out and several other renovations, and we spoke to them yesterday and they'll also help us enhance our solar! So looking forward to these changes to our home. biggrin.gif biggrin.gif
rangiebob
QUOTE(pianotuna @ Aug 7 2009, 01:58 PM) *

Hi rangiebob,

What do you have planned to enhance the solar?

Just more batteries?

Thicker charging wire?

More panels?

Good luck with the mods!


Not quite sure yet. I gave hubby all of your posts and he has them all in mind but we have to see what can be done with our Renegade. Hopefully, we'll be able to do it all! blink.gif One thing I know is that they will be building holders for 2 more batteries. We're doing whatever we can do to make our home more self-sufficient.
pianotuna
Hi all,

Hurrah! I have my four extra batteries installed.

I decided against welding a rack under my RV and gave up one storage compartment (there happened to be one of suitable size right beside the existing side out battery tray).

My cousin did the work. He welded a support brace under the compartment so that it would be much stronger than the original construction. He placed a piece of 3/4 inch plywood in the bottom of the compartment and secured the batteries with a wooden "frame" to keep them from shifting. He also added an "air hole" so that there can not be a build up of explosive gases.

The four batteries are tied together electrically by two copper bus bars. The positive one is covered in tape insulation.

The original solenoid had only blown a fuse--so that fuse was replaced with a 50 amp fuse. (all he happened to have)

A second solenoid was added--tied into the starter battery and fused at 60 amps.

This should give me a combined charging amperage of 120 amps--10 amps less than the maximum output of the alternator.

This also gives me "redundancy" if either solenoid or fuse decided to "pack it in".

The original solenoid was factory designed to connect once the engine was running. This has been changed to a manual switch with an led indicator light built in so I can control it. The new solenoid also has a similar switch. This has the side benefit that if I turn on the ignition key and flip the switches that power will flow from the house batteries to the starter battery. This means if the starter battery is low I can recharge it from the house batteries. It would take a few minutes for this to build up a sufficient charge in the starter battery, should it happen to be low. When starter is engaged the house batteries are disconnected. It's not a perfect system--but far better than the original design which did not allow any connection until the engine was running. The solenoid switches are disabled when the ignition key is in the Aux or Off positions.

Each battery bank can be charged from the alternator via the two switches--so I can avoid over loading the charging capacity.

Each battery bank has its own 100 amp disconnect switch to the inverter, so I can run 3 or 4 or 7, or if I really desire to do so 8 batteries (flipping the solenoid switches on with the ignition turned on {a poor idea, imho}). Running all 7 would give the best Peukert results, while protecting that all important starting battery.

The solar panels are able to charge either bank--again via a set of two switches. The switches are rated at 25 amps and are fused--and have lovely led lights in them to let me know whether they are "on" or "off".

One downside to that is that if the inverter is running on one bank--and the solar switches are both turned on the system can "back feed" through them and burn out a fuse. The way around that is, of course, to have both disconnect switches in the "on" position, and only one solar panel switch turned "on". That still allows the solar to add to the energy available without any back feed being possible. A diode could have been added--but that would have "cost" 3/4 of a volt, a sacrifice I was not willing to make.

All in all, I feel it is a brilliant piece of work and allows great flexibility.

Denali
Terrific! So when are you coming down to Quartzsite to join the rest of us sucking up the rays? smile.gif

--
Dave Rudisill
Coos Bay, OR
pianotuna
Hi Denali,

Would you believe I went to Quartsize three years ago--on July 31? It was too hot for me! I do hope to do a Florida trip starting Jan 15, 2010.

My next mod to the system should be straight forward and simple. I want to replace those old tired original 3 twelve volt batteries with 3 brand new ones from Walmart. Cost for 105 amp hour battery is $75.00 ($225 in total), and I've had wonderful service from the ones I bought for my previous RV six years ago.

I'll also replace the dinky toy sized starter battery that Village RV of Regina "gave" me when I purchased the Kustom Koach. I know that with the system I have that is perhaps money I don't need to spend--but a 650 cold cranking amps battery on a Ford Triton V-10 seems to me to be undersized.

QUOTE(Denali @ Aug 14 2009, 10:09 AM) *

Terrific! So when are you coming down to Quartzsite to join the rest of us sucking up the rays? smile.gif

--
Dave Rudisill
Coos Bay, OR

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