To solar panel or not to solar panel

diver110 · 10-08-2010, 02:04 PM

A number of people say they use solar panels to keep the batteries topped off. I could see that being valuable when the SMB is parked for long periods and not in use, to keep the batteries from discharging, but I would think typically one would run the engine enough to charge up the batteries when using the SMB. Am I missing something? Do the batteries not charge well at idle? Thanks.

sdwindansea · 10-08-2010, 02:22 PM

If you never stay at a single spot for more than 24 - 36 hours, then you probably do not require a solar panel. However, if you do plan on staying put somewhere for longer than that or may be using a fair amount of electricity, a good solar panel will allow you to not worry about a generator, going for a drive, or leaving the van in idle. The fact that they are also noise-less and environmentally friendly isn't a bad thing either.

Jeffrey · 10-08-2010, 03:25 PM

And, you must consider your power consumption. Are you one of those guys with big screen TV's, DVD players, and all kinds of electronic stuff who like to heat 5 meals a day for a family of 6 in the microwave while charging numerous sets of batteries for laptops, cameras, and remote control cars?

Ford_6L_E350 · 10-08-2010, 04:20 PM

We use very little electricity. The biggest user of electricity is the 12V refrig. Our house batteries would get us through 3 days without charging. But, we found we like to stay in one campsite for a week or more, and I hate the noise of running the engine to charge the batteries, so we put in a solar panel.

Greatest thing we ever added to the SMB! We never have to start the van. And if it sits for a couple of months between trips the house batteries and the starting batteries are always fully charged.

Unless you only stay in one place for a day and then move on, solar is the way to go.

Mike

diver110 · 10-08-2010, 04:29 PM

Quote:

Originally Posted by Jeffrey

And, you must consider your power consumption. Are you one of those guys with big screen TV's, DVD players, and all kinds of electronic stuff who like to heat 5 meals a day for a family of 6 in the microwave while charging numerous sets of batteries for laptops, cameras, and remote control cars?

No, but I might want to make coffee or heat it in the microwave. Can the batteries (with an inverter) handle that out of curiosity?

Ford_6L_E350 · 10-08-2010, 05:21 PM

Quote:

Originally Posted by diver110

No, but I might want to make coffee or heat it in the microwave. Can the batteries (with an inverter) handle that out of curiosity?

Yes, within limits.

First, the inverter uses alot of power, even when you are not using the AC. 2nd, a microwave uses alot of power when you are using it.

Running the microwave for a couple of minutes and then turning off the inverter is not an issue. But, cooking a meal in the microwave, taking 15 minutes could be an issue.

Since we heat water with propane, someone should chime in with real world experience with a microwave.

Mike

sdwindansea · 10-08-2010, 05:33 PM

One other thing to consider about solar (this is where I am right now). As your batteries get older, they are not nearly as efficient as they were when new. So, the amount of time that they will last becomes less. Solar will help alleviate that problem as well. We did the solar prewire as part of our build. Theoretically it should be really easy for me to add a panel, hopefully in the very near future.

Scalf77 · 10-10-2010, 08:27 AM

Quote:

Originally Posted by diver110

No, but I might want to make coffee or heat it in the microwave. Can the batteries (with an inverter) handle that out of curiosity?

Yes you can use the microwave with the inverter. I thought I had a chart of doing popcorn in the microwave but I could not find it. I do have a chart of making coffee, it was running about 9 min. and dropped 10% off of the State of Charge for a 4D. If I get a chance I can capture data for the microwave. I have the trip-lite inverter installed and have used the microwave to heat up soup a couple of times, usually when I'm in transit, I don't think I would use it while boon docking.

TomH · 10-10-2010, 12:03 PM

Quote:

Originally Posted by diver110

A number of people say they use solar panels to keep the batteries topped off. I could see that being valuable when the SMB is parked for long periods and not in use, to keep the batteries from discharging, but I would think typically one would run the engine enough to charge up the batteries when using the SMB. Am I missing something? Do the batteries not charge well at idle? Thanks.

As far as using the engine at idle to recharge the batteries, it depends upon the engine. The Sprinter diesel uses a a filtering fluid which will gum up the engine badly if the engine is idled very much. See this thread:

http://sprinter-source.com/forum/showthread.php?t=11031

**BroncoHauler** · 10-10-2010, 01:24 PM

One other thing to consider. Yeah, a solar panel and solar controller aren't cheap, but replacing house batteries that have their life cut much shorter by over-discharging isn't cheap, or convenient, either.

I had some initial problems with the marine solar panels, or specifically the way they were mounted, but they were replaced with a single Kyocera panel, and I love my solar system (no pun intended).

Herb