Solar trickle charger

I don't believe it makes much difference what model Magnetek (Parallax) converter you may have. The company is no longer in business.

Open the panel door to the converter & the model number should be right there.

Call Best Converter, as indicated above. :W

Thanks for all the great information--I will be studying/reading up for sure. I'm glad to know that the unit I found on Amazon is overpriced and won't suit my needs ... :-)

I also realized that my original post is unclear--I haven't allowed my battery to LOSE 70-80% of it's charge, it was STILL at 70-80% (so only 20-30% discharged). My battery is pretty easily accessible, and I've been using my handy voltmeter to check (waiting until at least 18-24 hours after any charging). Since I'm not really using the camper over the winter (I'm driving it for day trips only) I thought that this was the time to learn how the electrical system behaves.

I'm not sure which model MagnaTek converter I have--the manual is for "900 Series Converter/Battery Charger" and covers several actual model numbers. In the specifications, all of the listed model numbers give DC Output (volts) 12.0 min @ full load, 14.1 max. @ no load.

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT. What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.

One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!

Solar Spread Sheet N8GS

For a nice explanation of solar, try this link:

Golden rules of solar

In addition tot he above suggestions, get an accurate voltmeter mounted in the RV to monitor the battery state and learn what it is telling you.

crcr wrote:
That 16 watt panel is insanely overpriced.

Indeed.

You have two options.
Solar & or a new converter.

I just posted a similar question concerning Solar a few days ago concerning my needs & it was recommended to me, 100 watt solar as bare minimum with controller.

As far as the converter, I would replace it no matter what. I also have a Magnetek in my 2000 TT & it is absolutely useless for charging.
I recommend a 9200 series Progressive Dynamics converter with a built in Wizard smart charger.

On another note, never let your coach batteries get below 50% discharge. Get & install a meter of some type that monitors the batteries & tells you the SOC. Do not rely upon the coach monitor panel for the batteries. It is VERY inaccurate.

If you run the generator 3-4 hours per day,whenever boondocking & after installing a new converter you should be good to go. When connected to shore power, you won't even need to run the Genny.

Call these people & tell them what you have & they will recommend a replacement converter.

BEST CONVERTER

Since this boondocking trip sounds like a one time deal. Make sure you have a three stage converter (as mentioned) and then just use your generator each day to charge up the batteries. That's what it's for...

Find your charger model number and post it. You may be better off replacing the charger with a modern three stage unit. I had a MH that only charged at 3 amps. That was an 89 model and yours is later but it is worth looking at.

I tried to find the converter/charger model for your unit and only came up with MagnaTek 6332 . This may not be it but is a good indication to me that your charger may be very wimpy.

These chargers share their outputs. For example if your charger puts out 40 amps and your heater is running and you have lights on you may be charging the batteries at a very low rate. Getting a better charger will supply plenty of power for the systems and battery charging,.

Another note - you shouldn't allow your battery to discharge 70 - 80%. That will shorten it's life very quickly.

No, that 16W one is worthless for your needs, especially at that price.

You could do okay with 100 watts, if you get sun every day, and if you are very conservative with your electricity usage. With our Class C, 100 watts on the ground in full sun would let us go forever, but again with being conservative. I have a 100w (2x50) folding kit that I made from scratch.

Here are some much better choices for you. I'd recommend the 100 (2x50) kit. Notice they have a discount code at the top of the page (today anyway). That kit will require about 2'x2'x4" of storage room.

http://www.eco-worthy.com/catalog/folding-solar-panel-c-71_61.html