1998 Barth, it looks like original panels, about 2 x 4 feet (2). I get about 3-4 amps at 12.5 volts, so that is 50 ish watts. Never more than 3-4 Amps and the batteries not seeming to be fully charged. When is storage the batteries run down, and when in use don't even come close to keeping up with a vent fan or 2 for a day.

I assume the power/sq ft is much higher now than the 16 year old panels and would love to be able to rely on the sun to keep a charge when dry camping. Generator also...

Other option is to change the 4 12 volt batteries to 6 volt for more capacity.

I got rid of all the old electronic stuff, TV's, amps, some lights with LCD's and LED's....

And... the LCD TV's are 16.4 volt if I remember, but the are powered off a transformer to convert 110 to 16.4 volts....I use 110 to charge the batteries, then use the inverter to convert the 12 volt to 110, then plug the TV into the 110 and the transformer reduces it to 16.4...should I just get a 12 volt to 16.4 volt converter and always run the TV's off the 12 volt batteries?

Hi Tom, Are you sure that the TVs are 16.4 volt? A lot of LED/LCD TVs do run on 12 volts. However, there is a lot of spiking on the battery systems that can damage the TV by direct connection to the house or chassis system. 12 volt to 16.4 volt converters are not common. They are around but most are universal and may not have any surge protection built in.

Probably easiest to get a small inverter (12VDC-120VAC)dedicated to the TV. There would be reasonable isolation and surge protection thru the inverter. A 100-200 Watt inverter would power most LED/LCD TVs.

HTH

We run our TV directly off of 12vdc. I'll almost bet your 16.4 will run on 12vcd as the 16 might be the upper limit.

BTW my free opinion is that battery make great filters.

Yes Gary, you are right, batteries are great filters as long as they are fully charged and whatever you are running is connected dierectly to the battery with very short wires.

Unfortunately, any high pulse loads turning on or off will produce a surge that batteries are not good at reducing particularly if the pulse load is some distance from the battery. further complicating the situation would be if the load you are worried about is also some distance from the batteries.

Wires of any length will add inductance and reduces the batteries effect and will allow transient pulses to form due to load changes even if the batteries are fully charged and and at their lowest internal impedance.

I use 4/0 cable only 7 feet long from the coach batteries to the inverter the rest of the coach (+12VDC system) goes directly to the batteries) but even with that heavy cable and separation of loads, I still see the inverter pusles on the coach system when I am loading the inverter with a coffee maker going.

Any solid state device connected to the chassis batteries can be damaged by operating them while starting the coach.

HTH

Thanks for the comments. I looked at the output on the transformer and then inquired into step up transformer, was told it was flat and buffered. However 2 small 12/110 converters would be cheap and super easy to use. good idea.

Any comments about solar panels, I see sets now for 400 watts...... 1500$ ish

Solar is definitely on my wish list. I was talking to a couple who were full timers just the other day about it. They recommended portable systems rather than roof-top, like the ones at Go Power . Their reasoning was that it's lower cost and also that if you want to charge up, you don't have to park in the sun. You can park your rv in the shade and move the panels into the sun.

Anyone here have any thoughts/experiences on the subject?

I like them on the roof. You don't have to even think about them and they are working. In that temporary stop for lunch that ends up an overniter, In the early morning hours before you get up and you are in a parking lot somewhere, and many other unplanned times. Its one less thing you have to do in setting up camp somewhere. I look up at the guage on the wall and smile, as it is working and I am not.

Good morning, Tom Loughney and Jerry Jelsing;

Jerry, I see that you are also in the Puget Sound area. Then you are also aware of just how effective photovoltaic solar panels can be in a region known for its usual gray skies. Yes, solar power can be done here in Western Washington also. And it is easy in Eastern Washington.

Tom, you did ask about the two (2) solar panels that you have, but I am not able to do very much with just the physical size (2 ft by 4 ft) and that they put out "3 to 4 Amps" at about 12.5 volts. And it is helpful to describe how you measured the current and the voltage numbers you gave. A few things:

(1.) What "charge controller" (a solar industry name for a somewhat specialized voltage regulator) are you using with the solar panels? A brand and model designation would be nice.

(2.) For the solar panels themselves, can you get to the back of the panel to see if there is a label on it with information such as who made it, what is the model designation, what Wattage power rating does it have, what is the nominal voltage output (Vpmax), what is the normal output current rating (Ipmax), what is the open circuit voltage rating (Voc), and the short circuit current rating (Isc) for the panel from that label?

(3.) If you cannot get to the back to see if there is a label on it, can you count the number of individual solar cells under the protective glass cover? For most panels used with a "nominally 12 VDC" system, normally there will be about 36 individual solar cells wired in series to make up the solar panel, and its voltage output going to the charge controller will be in the 16.8 to 17.6 VDC range normally.

(4.) For the so-called "self regulating" type solar panels, they say that they do not need a charge controller, and usually they will be made with only 30 or 32 solar cells wired in series. They are intended for mainly just battery charging with a known fixed load. I actually do not recommend that type for most applications.

(5.) As far as the power output over time for a solar panel goes, that is not a problem, and it is really pretty good. And a 16 year old solar panel is not "old." Most of my portable system solar panels are the old Solarex MSX-60 polycrystaline (blue) panels that are 19 by 46 inch panels are all about 20 years old now, and they are still putting out their original rated power. Some of my fixed mount panels have been outside a long time and are showing some discoloration, but they still have over 85% of their rated power output. Many of the solar panel makers have been making a warranty statement of 85% power output for 25 years after purchase. They know that they never will have to honor that warranty under normal conditions.

The conversion efficiency rating for your solar panels are probably about 16%. It was just a couple of years ago when the newly developed Pereskovite solar panel technology broke the 20% conversion efficiency barrier. The maximum theoretical conversion efficiency for a silicon solar panel is only 27%. We have made some significant incremental improvements over the years, but the ones from 20 years ago are still quite acceptable.

Why do I say that? Because Solar Panel Serial Number 000002 is now well over 60 years old, but back when it was only 53 years old, they measured it again, and it was still putting out 85% of its original power from April of 1954. Silicon solar panels really are pretty good and reliable.

So why am I talking about solar panel 000002 instead of the first one? Well, unfortunately, solar panel 000001 suffered some unrepairable damage in an accident back in about 1956 when it was dropped. Bell Labs did not want to accept any warranty claims for that one. They were too embarrassed.

Anyway, Tom, without any additional specific information from you, I cannot really provide any definitive comments to you about your solar panels. I can only say that I have a feeling that they are probably about 60 Watt to 80 Watt panels, and they are worth keeping, but I do not yet know why the coach batteries in your Barth are not staying charged. There may be more questions for you as we see what you have, what they work with, and how they are wired.

Enjoy;

Ralph
Latte Land, Washington
who has a S. O. B. motor home

Well, . . .

It has been a week now, and there has been no response from Tom Loughney. A "PM" was also sent for him a couple of days ago, but there has been no response to that either.

Perhaps it is best to just leave this one laying fallow. If there is any responsive activity in the future, then we can pick it up again.

Enjoy;

Ralph, Latté Land, Washington

Not a snub - Tom splits time between the US and Thailand, and things there have been unsettled recently