Hawk solar upgrade

[Ronanmd1]

Ted - yep, that sounds like it will work fine. You may consider an extra portable panel to plug into the rear socket (if you have one). That way you can continue with charging if your camper is located under some trees or shaded while camping...

Cheers

Jason

 

[Trailbob]

"Trailbob,
Will your 160amp panel keep your batteries at 100% after a day's use?"

Terrapin,

I have a propane fridge (3 way), but I also have an ARB in the truck, plugged into the camper. I usually use the ARB as a freezer (for fish), so it may draw more power than your two way Dometic. With my 160W panel, I can keep the batteries in the 90's % range with decent sun.

Hope this helps- Bob

 

[Chadx]

Quote

Well drat! My 2013 Hawk is also wired with 12ga not the 10 I thought. I'm sure to loose a certain percentage of energy by letting it choke the incoming amperage but I'm still moving forward with new controller and panel upgrades.

Ted,
The voltage drop in the factory solar wiring is something many wring their hands over for no reason. For the two types of controllers, here is why:

Using an MPPT controller and panels wired in series, the higher voltage is impacted less by the wire size. Plus, the high "voltage/lower amps" are converted to your "lower charging voltage/higher amps". The loss from the voltage drop and from the conversion are both too little loss to worry about.

For a PWM controller, like the Bogart 2030, it is converting voltage that is inbound from the panels down to whatever you have your parameters set. PWM controllers do not convert amperage when they cut down the voltage. So when people worry about their panel sending 17v or 18v and then 15v or 16v reaches their controller, that voltage drop doesn't matter at all since your controller is cutting that voltage down to 14.# voltage anyway (whatever you have it set to). So as long as the voltage that makes it to the controller is more than your highest charging voltage parameter, there is absolutely no reason to fret about voltage drop. It doesn't matter. No matter what voltage gets to your controller, if you are getting 6 amps, for example, a PWM controller will drop the voltage to your charging voltage parameter and keep the same amperage (in this example, 6 amps) and push that to your battery.

Short version: Unless your wiring is causing the voltage, measured at the inbound wiring to your controller, to drop lower than your PWM Controllers highest charging voltage parameter, your wire size is fine.

Regarding the question about if a certain wattage is enough, it's different for everyone (amp usage, lat/long, panel orientation, weather, etc.) so no way anyone can answer that for another person. One needs to add up your average amp usage (easy with a Trimetric monitor), then calculate the apppropriate panel size for you geographical location. For that, I used the one gov website that most use and it seems accurate (you can set for your city, losses, efficiency, panel tilt and orientation, etc.) and it shows the amps you can expect for each month of the year for your location based on history (so cloud cover, for example, is taken into consideration). For example, Swouthwest Montana, with the panels flat, my 180w panel is predicted to create about 88amps on an average July day. It drops to around 20 amps on a November day (due to shorter day and lower sun angle). Then you can play with the numbers like increasing panel tilt to 40degrees and see the November number jump up quite a bit. Good stuff.

So worry more about those calculation than the wire size. As long as the voltage drop allows your voltage to remain higher than your highest charge voltage, you are good to go and it's a waste of effort and money to change out wiring.

 

[Vic Harder]

Ted,
The voltage drop in the factory solar wiring is something many wring their hands over for no reason. For the two types of controllers, here is why:

Using an MPPT controller and panels wired in series, the higher voltage is impacted less by the wire size. Plus, the high "voltage/lower amps" are converted to your "lower charging voltage/higher amps". The loss from the voltage drop and from the conversion are both too little loss to worry about.

For a PWM controller, like the Bogart 2030, it is converting voltage that is inbound from the panels down to whatever you have your parameters set. PWM controllers do not convert amperage when they cut down the voltage. So when people worry about their panel sending 17v or 18v and then 15v or 16v reaches their controller, that voltage drop doesn't matter at all since your controller is cutting that voltage down to 14.# voltage anyway (whatever you have it set to). So as long as the voltage that makes it to the controller is more than your highest charging voltage parameter, there is absolutely no reason to fret about voltage drop. It doesn't matter. No matter what voltage gets to your controller, if you are getting 6 amps, for example, a PWM controller will drop the voltage to your charging voltage parameter and keep the same amperage (in this example, 6 amps) and push that to your battery.

So worry more about those calculation than the wire size. As long as the voltage drop allows your voltage to remain higher than your highest charge voltage, you are good to go and it's a waste of effort and money to change out wiring.

Agreed! The bigger deal is the wiring from the truck alternator on back to the camper....

 

[Chadx]

Agreed! The bigger deal is the wiring from the truck alternator on back to the camper....

Yep, because alternators (after passing through our vehicles regulator) have pretty low voltage and then it travels through our wiring back to the camper. This is similar to using a remote solar panel with the controller right on the panel and then pushing the voltage directly over a long run of wire to a battery. Then one must be concerned with voltage drop. And is why it's best to have no controller directly on a solar panel but rather run the higher voltage directly off the panel over the run of wire to the controller located very close to the battery pack.

If one could run unregulated current directly from the vehicle alternator back to a voltage regulator located near your camper battery, then we could get by with smaller gauge wire exactly like we can, and for the same reasons we can, between the solar panels and the contoller. The higher voltage not only travels across the wires with less heat, but we really don't care about the voltage drop as long as it arrives as the controller or voltage regulator at a higher voltage than to what the device will cut it down to.

Summary: There are benefits to increasing wire gauge/size to decrease voltage drop when voltage has already been regulated. Examples: between vehicle battery and camper battery. Between solar controller and camper battery (doesn't matter if that is a remotely deployed panel WITH controller or the controller is near the battery, though with the controller close to the battery, the run is so short that there is very little voltage drop).
There is no benefit, or very little, from increasing wire gauge/size to decrease voltage drop when voltage has not yet been regulated. Examples: between a solar panel and a contoller. Between an alternator and a voltage regulator.

Regarding truck charging, the biggest issue I have is my truck's voltage regulator regulates voltage very low (mid to low 14s). The couple times I measured across the FWC installed 10 gauge run, the voltage drop was 0.2 volts, but I was only pushing around 5amps through at the time because the battery was pretty full. Voltage drop would likely be more with higher current. Not a big deal for bulk charging when your battery voltage is lower, but as battery voltage rises, then yes, any voltage drop is slowing your charge rate.

I actually have the truck to camper wiring disconnected at this point because the 180watt solar has us recharged to 100% by mid morning even with the Engel and fantastic fan are running and 30 minutes of off and on furnace use. Incredible how well solar keeps the battery pack charged to 100% (controller parameters are important there).

I'll reconnect it if I ever need it, but know that a truck alternator is best at bulk charging and that finishing charge would take unrealistically long since input voltage is so low, etc.

 

[dHART]

Splice at the junction box


Splice after the lift panel


I removed the bottom section of particle board filler and ripped about 3/8" off of the bottom to make room for the new 8awg
before

after


Drilled a hole in the paneling right behind the support for the bed slide and to the right of the cabinet


Cable running down the void between the cabinet and front camper wall


Used a Dremel to notch out a portion of the slide out support to fit over the cable


Slide out support re installed over cable


Cable path behind the storage area above the water tank and into the battery box

Hey there,

Not sure if you're still responding to this post. Im looking to install solar onto my roof as well. Im a little skeptical on drilling holes into my roof, but seems to be the only option. Did you remove the roof material to drill holes for the picture attached? Im really trying not to get too invasive with this project. Im curious if I can just drill straight through the roof all the way past the interior roof material.... Thanks!

 

[Vic Harder]

Hey there,

Not sure if you're still responding to this post. Im looking to install solar onto my roof as well. Im a little skeptical on drilling holes into my roof, but seems to be the only option. Did you remove the roof material to drill holes for the picture attached? Im really trying not to get too invasive with this project. Im curious if I can just drill straight through the roof all the way past the interior roof material.... Thanks!

Pretty sure that picture you linked to is what you would find if you took off the push panel as I suggested. So the hole was already there... round on top for the SAE connector, and square inside with wires inside if pre-wired for solar.

 

[Terrapin]

Hi Vic,
Thought this topic was long dead. I’m trying to recall the mess. I struggled with keeping the batteries charged for nearly two years before finally feeling comfortable. As for your question, I’m sure I did not drill through the roof. I replace the factory 90 watt panel with a Zamp 160w. I was able to attach to the existing aluminum channel and wiring. Very fortunate as I recall. As you may know the Hawk’s inner-roof support is a grid of aluminum box tubbing. I would not feel the solar panel was secure unless the channel was engaged for attachment.

My 160w panel is still inadequate for boon docking in the NW when it’s cloudy and I’ve often thought about adding a second portable panel for use during certain situations. I’d also recommend the Bogrart and Trimetic equipment that has been mentioned in earlier posts. You can dial in optimal charging rates for your particular batteries. Mine are 2-6V golf cart AGMs which seem to be superior to the smaller 12v factory batteries. With the Bogart they can be charged at high rates more quickly and efficiently. I also changed the truck-to-house wire with 4ga welding wire. Overkill? Maybe but it does seem to assist in charging with a little driving.

I was and am very disappointed with 4WC during this upgrade especially with the wiring and Dometic fridge installation. The charging circuit to the batteries was improperly wired to charge just one battery with the second simply jumped. Not in series. The condenser fridge had absolutely no venting which caused severe overheating and electrical surges that would quickly deplete the charge. Within a year the dual batteries were ruined. The factory was unable to correctly diagnose the problem even after a special trip from Oregon to solve the problem. Thanks to this forum and Handy Bob’s blog we have had several years of enjoyment from the rig. Oh, one other mod. We added two vents behind the condenser fridge. A CPU fan was attached to the upper vent and wired to the condenser fan. When the fridge fan runs the second one increases the air circulation. The additional draw is minimal and we have had no further problems with the fridge overheating.
More knowledgeable members will be able to help you achieve more with less.

Good Luck,

t

 

[dHART]

Pretty sure that picture you linked to is what you would find if you took off the push panel as I suggested. So the hole was already there... round on top for the SAE connector, and square inside with wires inside if pre-wired for solar.

Vic-

My terminology might be a little off. Is the push panel not the mechanism that helps pop the camper up?

 

[Vic Harder]

Ahh, no. I was thinking of the wooden strip about 4” x 36” that is mounted to the ceiling. There are two, one in front and another towards the rear.

And yes, the mechanism you push on to lift the roof is directly related and attached at the forward end with rivets.

I suppose it would be easy to get confused on the terminology!