Community Forums

CapnMorgan · 01-14-2012, 12:01 PM

I have a Trace RV2012 inverter/Charger. RV2012, 2000 Watt, 12 Volt RV Inverter

This is an expensive 3 stage charger, why couldn't I just plug my solar from the roof into this?

It is probably a dumb question, but it's been bothering me.

John

Wanderman · 01-14-2012, 12:10 PM

Simple answer...it's designed to take 120v AC power and turn it into usable 12V charging for your batteries. When you do not have shore power (120V AC) it takes power FROM your batteries and makes 120V AC for you to use.

There is no capability to take what your Panels develop from the sun and route it to the batteries.

I do not know what the voltage/amperage specs of your panels are, but you should purchase a charge controller to take that and charge your batteries from the sun.

Rich "The Wanderman"

CapnMorgan · 01-14-2012, 06:00 PM

Does the generator generate 110v and then the inverter/charger converts that to 12v in order to charge the batteries?

CA Traveler · 01-16-2012, 09:30 AM

Yes the gen provides 120V and the converter converts that to 12V for charging, lights, etc.

If you were to install a small solar panel of about 18V (often referred to as a low voltage or 12V panel) then you could connect it directly to the batteries for maintaining the batteries.

Solar and inverter/converters are somewhat independent of each other.

However for larger panels you need a solar controller that converts the solar panel power to match the batteries. ie A 240 watt panel (which is likely 25 volts+) would be converted to 240/12=20 amps (maximum) to the batteries with the converter.

It would be helpful to know what you're trying to accomplish.

RickO · 01-16-2012, 10:30 AM

Quote:

Originally Posted by CapnMorgan

This is an expensive 3 stage charger, why couldn't I just plug my solar from the roof into this?

.

John

Quote:

Originally Posted by Wanderman

There is no capability to take what your Panels develop from the sun and route it to the batteries.

Rich "The Wanderman"

I'm a little confused. If you already have a solar panel installed isn't it already connected directly to your batteries to help keep a maintenance charge on them? While your inverter/charger doesn't have the capability to route solar to the batteries I think they're usually already connected directly.

Rick

CapnMorgan · 01-16-2012, 11:13 AM

Quote:

Originally Posted by RickO

I'm a little confused. If you already have a solar panel installed isn't it already connected directly to your batteries to help keep a maintenance charge on them? While your inverter/charger doesn't have the capability to route solar to the batteries I think they're usually already connected directly.

Rick

I do already have a 90 watt solar, I'm guessing that it is wired directly to the house battery for a trickle charge, without a controller. I am looking to go from 90w to 400+watts, so now I need a charger. I'm new to this MH and to motor homes in general, so I am trying to learn how all the parts fit, before I go and start tinkering.

John

Ed-Sommers · 01-16-2012, 11:31 AM

They are separate systems, period!

The only thing they have in common (generally speaking) is they are attached to the battery's but for completely different reasons.

Ed

lonestarace · 01-16-2012, 12:09 PM

Quote:

Originally Posted by CapnMorgan

I do already have a 90 watt solar, I'm guessing that it is wired directly to the house battery for a trickle charge, without a controller. I am looking to go from 90w to 400+watts, so now I need a charger. I'm new to this MH and to motor homes in general, so I am trying to learn how all the parts fit, before I go and start tinkering.

John

For anything over about 15watts, there should be a solar controller. Here is what an original factory installed Heliotrope RV-30 solar controller looks like mounted above the frig/freezer for a single 90watt panel in a 2000 Monaco Signature. There are 4 ways to charge your batteries: 1) solar, 2) alternator, 3) shore 120v thru inverter/charger, 4) generator 120v thru inverter/charger.

CA Traveler · 01-16-2012, 02:27 PM

What you are asking about is a solar controller (not a charger). The pieces are the panels, wiring to the controller and a possible combiner box inbetween, the controller, the wiring to the batteries and fuses or disconnects.

Check the Morningstar PWM controller for lower voltage panels and the MPPT controllers for higher voltage panels. $150-450.

You're asking about a complicated system that starts with a energy audit to confirm that 400W is what you need. Installation of panels that have no or very minimum shadows, UR resistant wiring of the correct size. Adequate controller or larger for future panels, correct wire size which will be larger for the controller to battery portion and many other details.

You will likely be well served to start searching the internet to get the basics of what is required and then size your needs along with helpful input from various forumns including this one.

jimbo16720 · 01-17-2012, 12:11 AM

Quote:

Originally Posted by CapnMorgan

I do already have a 90 watt solar, I'm guessing that it is wired directly to the house battery for a trickle charge, without a controller. I am looking to go from 90w to 400+watts, so now I need a charger. I'm new to this MH and to motor homes in general, so I am trying to learn how all the parts fit, before I go and start tinkering.

John

If you don't have a controller between the panels and battery it could over charge your batteries and boil them dry. The controller prevents to much juice from being sent to your batteries.

CA Traveler · 01-17-2012, 08:39 AM

CapnMorgan,

I'm considering solar on my new to me rig of about 400W like you. Larger panels are the most cost efficient today and I can mount 2 of the larger 200W panels with minimum shadows if I remove a satellite dish. Wiring would go to a combiner box in the closet, larger wire to the controller, disconnect and fuses and even larger wire to the batteries. For me visible wiring is NOT allowed but I've worked it out with minimum length wires.

Cost: About $500 for 2 panels that I'll pick up so no expensive shipping. With low voltage panels I could use a PWM controller for about $160 or use higher voltage panels and MTTP contorller for $325-$450 with optional remote. Add say $200 for miscellaneous, etc. Wiring cost are significant. 4 ga welding cable (very flexible) to the batteries.

For RV's parallel panel connection is generally best because rig or tree shadows on one panel still allow the other panels to create power.

But first things first: The energy audit. I have DVM's and clamp on ammeters that can be helpful but I want more than they can offer. By next week I will have a Trimetric 2025 RV battery monitor installed (communication cable already installed) that will monitor and record battery usage 24x7. $188 with shunt. The monitor will tell me the amp drain of every device and record the total battery drain/charge. So I will have the accumulated day(s) drain and recharge amount. $188 with shunt.

Panels will be flat mounted (5 degrees for water drain) as I will not be climbing on the roof to tilt and hence will lose efficiency especially in the winter months. I'm reasonably sure that the panels with this setup will have to be suplemented with the gen for sustained dry camping.

Hope this gives you some ideas.

Bobs911 · 01-25-2012, 08:33 PM

Some info
The RV Battery Charging Puzzle « HandyBob's Blog

RV Solar Part I – The Discovery Process | Wheeling It

A couple of hours of reading.

I just put 430 watts on the roof today... A bit of an overkill, but I want the option of not tilting, so the 30% loss for flat panels won't hurt me.

Gilleshps · 02-23-2013, 01:35 PM

I just put up 2-130 watt panels 17.2v 7.7 amp each in parallel ($179 each, mounted nearly flat, 1/8" off level to allow the rain to wash the dirt off Morningstar TS45 PWM,. Trimetric 2025 RV, 4 interstate 6v batteries 450 AH ($50 each new blems) otherwise I would have bought the Trojan T-105's. Combiner box on roof, 18' #4 to the disconnect then to the controller. 2/0 to disconnect then battery about 9'. Wish it was closer, but its an 1984 so space was limited.

Already had a 1500w inverter which was factory installed years ago. I can draw out 100 amps day dry camping and never turn on the gen. I may add one more 130w panel for a total of 390 watts. I oversized all the wire to allow for additional panels. Works like a champ, the trimetric 2025 is a must have. Well worth the minimal investment.