Lazy Daze Owners' Group

Heliotrope RV30S Solar Controller Dip Switch Settings

August 22, 2016, 11:30:10 am

In doing research to decide how to best upgrade my incandescent lights to LEDs I came across discussion of the RV30S solar controller that came with the LD factory-installed two solar panel option on my 2003 LD.

I realize there is newer tech but this controller continues to work well for us so I'm not interested in upgrading at this point. But I did learn that there are dip switches on the back of the RV30S that allow one to change what I think is called the charge voltage or set point. And that LD set it up for 14.2 volts when it left the factory. Which is how it operates, with the LED indicators on the controller switching from Charging to Charged right about 14.2 volts.

Much of what I read suggests that may be too low. I use Trojan T-105 batteries and they recommend a "daily charge" voltage of 14.8. Plus there is a guy named HandyBob online who seems to know a lot about this and says most controllers are set too low, limiting the amount of charge that can be pushed into the batteries on a normal day out boondocking and thus relying on solar charging (we rarely plug in).

When things are working well, plenty of sun and fresh batteries, I usually start the evening with the battery voltage at 12.7. But HandyBob says that can be misleading, indicating a fully charged batteries when in fact they maybe still have significant "unfilled" capacity.

The Heliotrope allows setting this voltage in .4 volt increments. So I'm considering going up one step, to 14.6 volts. The next would be 15, which is above what Trojan recommends and seems a bit high to me. The two downsides I've read are possible increased need for battery watering and perhaps too high a voltage for some electrical equipment. But the engine is probably charging at about 14.4 volts when running and any charger with an equalization component is going to run somewhere above 15 volts for that, so it's hard to see how 14.6 volts would be a big problem.

But before I do this I thought I'd check the wisdom of this group to see if anyone has any information that would argue one way or the other, for or against this change. Thank you for any input you can provide.

Terry
2003 26.5' RB
Gardnerville, NV

Re: Heliotrope RV30S Solar Controller Dip Switch Settings

Reply #2 – August 22, 2016, 02:12:37 pm

Thanks, Art. We store the motorhome in the garage when not traveling. My understanding of the RV30S is that once the target voltage (14.2 or 14.6 in this case) it drops the voltage as you describe.

Terry

Re: Heliotrope RV30S Solar Controller Dip Switch Settings

Reply #4 – August 23, 2016, 04:00:46 am

Note that if upgrading to LED's many such bulbs will not tolerate as high a voltage as incandescents. Most such bulbs use series resistors to control the current, and increased voltage would cause premature failure.

Steve