Solar charging?

[radin2son]

If only I could convert the brain power I've expended on whether or not to invest in solar, I might have just enough for a brief trickle charge. At best, NV alternators will only charge "house" batteries 90% of capacity. So driving around all day will only give you a mostly charged battery. This is important if you are off the grid for a while. Solar should do it. Right? No!

 

On our recent trip to the NW, days were short and we had plenty of cloudy/rainy days. On sunny days we sought shady sites to avoid global warming inside. (Even though our NV would get warm, the water in the 20 gallon tank didn't. This made for some quick outdoor showers when we didn't start up our NV to get the flat plate to warm the water. It felt so good...) The penthouse (ph) as SMB calls it, driver/passenger and slider screens make for great ventilation, but it still gets warm.

 

Someone on the SMB forum did some fuel calculations on charging while idling vs using a generator. Very little gas was used to convince him to ditch the generator. The main argument was that many places have no idling rules in addition to quiet hours. When we were able and needed to, we idled. Not that big an impact on mpg.

Edited October 21, 2015 by radin2son

[wollip]

There are ways to do solar in an rv correctly. The first thing to do is discard practically everything you think you know about the subject and start reading handybobsolar.wordpress.com or just do a search for Handy Bob's Blog.

This guy has enough information to make your head explode.

I think I understand where you are coming from. It is extremely difficult to make even the best system work when you are on the move daily.

Not so much of a problem for those that park for extended days in the same spot (unless you need the shade more).

 

You can fully and correctly charge your house batteries with a dual alternator system. A good explanation is at sprinter-source.com. Here is the best I could do getting the path to the discussion:

Sprinter-Forum >

Sprinter-Based RVs & Conversions >

Sprinter-Based RV Brands >

Great West Vans >

2014 Great West Vans Legend SE >

Page 10 >

 

The discussion starts at post #100.

 

Nation's Starter and Alternator makes the same kit for the NV and it is equally pricey. Roughly $1500 plus a mechanic unless you also have those skills.

 

I haven't justified the price yet. Would love to hear from anyone that has done this or the equivalent.

 

Until I learn more about the pros and cons, this dual alternator system looks like a better choice than solar for anyone with a smaller battery bank

and daily driving.

[radin2son]

In 2013, we were in Grande Prairie, Alberta getting service. The Commercial Manager recommended a second alternator. Later, I asked the owner of SMB West about this and his response was "Why?" The NV alternator was sufficient.

 

The $1500 plus labor price tag puts the Zamp 80 Watt portable solar unit ($800) in perspective. With a second alternator, you start with a full charge; however, to maintain battery charge, one (idle) is faster than the other slower (trickle).

 

A larger battery bank brings up other issues. Where to put them and weight. The power draw for a cup of coffee would be the same, but you would have more power in reserve, which would be a benefit.

 

We can manage our power reserves to keep the lights, water pump and refrigerator running, but we need our camp stove for that cup of coffee.

 

Like you we haven't justified the price and would like to see what other NVers are doing. Mahu, if I remember correctly, you are going with a propane stove top/oven and refrigerator. Since you will have a propane tank, are you considering a propane generator.

Edited October 21, 2015 by radin2son

[KMG]

I have the C-TEC 250S Dual with the C-TEC Smartpass system.  I like how it takes the charge from the vehicle plus the solar panel charge and combines them to max the charge input.  Only used it for about 3 months but I use a C_TEC battery charger with my business and it has worked great for 6 plus years charging batteries every week.  www.ctek.com

[radin2son]

KMG, I didn't realize or forgot you have a solar system, plus I knew nothing about C-TEC. I just assumed that permanent solar panels did this whether or not in motion.

 

With a fully charged battery at the end of the drive and with the charge maintained by the panels, what can you do with the power you have? This reads like a stupid question, but can your solar system recover quickly (in ideal conditions) from repeated heavy power draws?

 

I keep ending up at cost, will there be more power available and how often will conditions be ideal.

[RICK]

My sprinter has a factory 220 amp alternator with the contractor package and second accessory/ inverter battery.

 

Why a second alternator and not just a larger primary alternater? Unless you mess with the voltage regulator to up the voltage and elimate the trickle down charge.

 

Rick.

[radin2son]

I may be simplifying this way too much but... Isn't substituting a larger primary alternator but not altering the voltage regulator and trickle charge the same as leaving things as is and not worrying about the 10% deficit? In context of a camper van, particularly the way we use our's, then owner of SMB West was correct. (?) No reason to "mess" with this.

 

But if you do, Nations starter and alternator (nationsstarteralternator.com) has received good reviews on the SMB forum. Their XP high amp alternator will set you back $640 to $750 for either the V6 or V8. (More efficient idle may be the reason to make this modification.) The dual alternator kit is $1100.

 

That still leaves solar battery maintenance.,.

 

This last trip is the first time we have had anything stolen, a "city" water hose (leaked like a sprinkler) that I left connected to the spigot while we were away. I can't imagine leaving a portable solar unit hooked up unattended.

Edited October 21, 2015 by radin2son

[wollip]

Rad -

I'm still fuzzy on this - do you have the stock alternator? Also, what are the details on your battery bank?

 

I think KMG is onto something here. We just need him to detail how he is using this charger - stuff like DIY or factory build, details on his solar equipment, stock or up sized alternator, details on his battery bank, etc. And what he is powering up with his setup.

And if he is not retired he should consider it in order to have more time for answering our questions.

[radin2son]

I'm rambling, which contributes to it being fuzzy.

 

Stock alternator with 2 UPG (upgi.com) AGM sealed lead-acid batteries (UB12900) bolted on under the sliding door step.

 

There may be room to add another, but they weigh 58 lbs. Life expectancy is 3 to 7 years. I know this means calander years, but adding up all the time spent in our camper, it comes to over a year. That is a lot of discharge, recharge...

 

When and if the stock alternator needs to be replaced, the higher amp alternator may be the way to go. Again, probably over simplified, it seems to make charging more efficient at idle when charging the house batteries or using a high draw appliance.

 

I couldn't pull up info on KMG's system. I wonder where he put the solar panels since he didn't want anything on his roof, as well as what he is powering.

 

Time to make "meet up" plans in Missouri...

Edited October 21, 2015 by radin2son

[wollip]

The SEARCH function on this site is horrible. Not specific enough. For example, if I were to ask it for all of your posts - I am instead given a list of all topics which you contributed to - then I have to scroll thru them one by one until I find the post(s).

Not even a retired person has that kind of time - and for sure not the patience.

[wollip]

When I started my NV/RV conversion I knew even less than the dismal amount I think I know today.

Not much in the way of innovation on my part, I'm afraid. I used our 2003 Coachhouse as a guide - along with reading a lot of posts on the Sprinter forum.

I installed a Progressive Dynamics PD 4000 (Mighty Mini - 45 amp) and a small 70 amp/hr AGM battery. I went small with the battery while I am learning - not wanting to destroy a greater investment up front.

My goal is to be able to power two 12v fridge/freezers and the ceiling vent fan during the day whether going down the road or parked in some tourist trap parking lot. We use shore power at night.

Only have one of the two fridges installed right now but will add the second one very soon.

The Mighty Mini, despite being billed as a multi-stage charger, just doesn't seem to live up to that claim. So I am very interested in hearing more about KMGs setup. Not certain yet that I want a solar panel but haven't ruled it out.

[radin2son]

I have two 90 amp/hr batteries that need to be replaced in 3 to 5 years. 2 years less than l read somewhere else.

 

They power lights, a water pump, small fridge and an always on carbon monoxide detector. The van came with a microwave, which we use with shore power or infrequently with the engine idling. SMB says this is ok, but Roadtrek says not to, according to an owner.

Edited October 21, 2015 by radin2son

[KMG]

I'm out on a job site.  I'll go into details on my system soon.  Try www.smartcharger.com for information on the C-TEC 250S Dual and Smartpass combination.  I'm not very knowledgeable, so other input would be great.

Edited October 22, 2015 by KMG

[wollip]

I found a short but informative review of the CTEK D250S at www.themotorreport.com.au

Search under reviews for CTEK D250S Dual DC - DC 12V 20 AMP 5-step Charger Review

[KMG]

Sorry it took me a while to reply with information about my secondary power system.

I ran short of time prior to departing for a recent trip and didn't get the solar panels installed.  I did temporarily installed the CTEC D250S and 3 100 Ah batteries.  I supplied power to the CTEC through my dash accessory receptacle.  I powered 3 accessory plugs, 2 LED lights, an 800W inverter, and a vent fan.  I chose to purchase a 95 quart Pelican cooler and not power a refrigerator.

My logic was the cooler is more versatile, a fourth the cost (not including the additional expense to increase the power system to accommodate the draw), and I'm never away from an ice source for more than the 7-10 days the cooler holds ice plus I like ice in my drink at night.

My plan was to use the van without the upper wall and roof panels uninstalled so I could learn where best to install accessory plugs and lighting. Now I am going to install the electrical system, accessory plugs, lighting, the wall and ceiling panels, as well as the roof top solar panels.

I'm building a solar panel rack that will locate the two 135W panels toward the rear and create two "rub rails" from front to rear mounted to our factory mounts.  Hopefully this will to aid in keeping branches off the panels.  Like rock crawling sliders for my roof.

I have a CTEC slideshow that does a better job of describing how the system works.  I tried but wasn't allowed to download the file.  PM me your email and and I'll mail it to you.

Thanks and I really enjoy having other NV owners to share with and learn from.

Edited November 4, 2015 by KMG

[radin2son]

Wild Oats in Tucson, before they became Whole Foods, had a reputation for hiring staff based on their "smile." At the deli, I asked if they had any roasted veggies. No response. Like peppers... "I don't like peppers" was the response. So KMG, I don't like ice in my drinks. Good thing, because our fridge doesn't do ice very well. If you set it much above 3, it will freeze whatever is near the tiny freezer.

 

I looked at Yeti coolers, hoping they made a 12 volt model. Still may go with one, Yeti or Pelican, when the Coleman stops working. I think I was put off by all the referrences to iced drinks.

 

3 100 AH batteries should keep you and your ice off the grid for a long time with what you are running. Are you going to use any high draw appliances, a coffee maker? You know, I expect you to say "I don't like coffee."

 

I will PM my email address. We should have done this earlier when we were both in the NW.

[wollip]

KMG-

Thanks for the detailed post on your setup. I found the Ctek slide show online and it really helped fill in the blanks about this system - especially the ones explaining the Smartpass module. There are a few YouTube videos that are good but that slideshow really explains how the Dual and Smartpass work together.

I can't thank you enough for bringing this to our attention. It is the solution I have been searching for.

The rub rails for your solar system rack is an excellent idea - please post a pic when you get it done.

[KMG]

Wollip, No thank you's are necessary but you're welcome.  The Dual and smartpass combination fit my requirements and budget.

I'll post images of my roof rack when complete.  May be a few weeks.

 

Radin2son, My system has room for up to 6 100Ah batteries.  My goal is to keep my lighting and accessory items's power consumption to a minimum to allow for electric heat at night.  Heating with electric requires a larger battery bank and the ability to replace the consumed power before the next night.

I think if I insulate the walls and ceiling well and add insulated curtains to my windows and windshield I will be warm enough.

When I camp in cold weather I'll install 6 batteries and when it's warm weather I'll probably install only 2.

 

Remember my van is odd in that everything I add for RVing has to be easily removed to return to a cargo van.  So my plans/ideas might not work well for others.

[radin2son]

I agree with Wollip. The slide show is excellent and answered most if not all the ?s I posed.

 

I like versatility in vans, plus you may do more RVing and less cargo than you think. I like the ability to add or delete batteries.

 

Not counting your labor etc., what do you expect your CTek project to cost? Estimated retail figures are fine. Given my current setup, my frame of reference is the Zamp 80 watt portable unit ($800) as it only requires a quick attachment to the house batteries for a trickle charge.

[KMG]

My rough numbers are:

C-TEC D250s and Smartpass  $550

C-TEC Multi US 25000 Battery charger $300

Kyocera 135W Solar Panel $275 ea.  FYI:  80W  $175

100Ah AGM Battery $100 ea.

Material for solar panel rack and battery hold down frame  $150

Wiring, Terminals, Fuses, Plugs, Receptacles, Misc.  $150

 

If I was going to build a portable single source system, I'd buy the Kyocera 80W and a Morningstar Prostar-15 Solar Controller.  They are designed to charge and maintain a battery bank from a solar panel.  Very reliable and affordable.  All one would need supply is wiring between the panel and Prostar and from the Prostar to the battery bank.  Plus a simple panel rack.

 

My system gets a little more expensive because I want to charge the batteries from 3 sources.  The van's alternator, a solar panel, and with land power via a C-TEC Multi US 25000 battery charger. 

[Great White]

KMG, I have been looking for a way to charge my battery bank while on the road. I am going with an AGM set up and portable solar panel because I live in Oregon and most spots are too shady to rely on all day sun so chasing sun spots are as good as it gets at times. Since I am mixing batteries, AGM and wet cell, I have heard that trying to charge both off an alternator will shorten the AGM's life. I'm not sure about that but the C-TEC system sounds like a good way to keep the charge tailored to the AGM bank. How is it working for you? Have you tried powering it from the inverter? I park in sites with electric hook ups a lot so I can charge it on 110 on the rainy days here. Is the charger you using set up for 12 volt or an adapter, or are you using two separate chargers? The rig sounds just like what I need up here. Thanks.

[KMG]

Sorry Great White I'm not sure what you mean by powering it from the inverter.  My inverter takes the house battery bank's 12VDC and inverts into 120VAC so I can supply power to AC accessories.  

I've attached a diagram of my setup except I'm using a different C-TEC charger, and my 12VDC to 120VAC 800W inverter is connected at location E.  When I plug into land power it supplies power to the battery charger which charges the house batteries and the van if need be.  Also, if the van sits for a few month, heaven forbid, I can plug in and charge both battery systems prior to departing.  Downside to my setup is while plugged into land power, I'm still powering all AC accessories through my house battery via the inverter.  Not the most efficient but simple.  While traveling, I don't plug into land power very often.

 

attachment.tiff

 

I hope this helps. KMG

Edited October 30, 2015 by KMG

[Great White]

Sorry about the confusion. I had rushed through the post and didn't have time to research the website before contacting you. I have just got off the C-TEC website and think the D250S Dual and Smartpass should be a good solution to my issues. I need something I can charge with while driving and supplement spotty solar panel charging especially in cloudy and rainy days we have here. I will insulate my battery bank for fans, lights, a radio and maybe a cooler or go with a Pelican cooler.  Thanks for getting back to me.

[wollip]

KMG-

 

"100Ah AGM Battery $100 ea."

 

Really?

[KMG]

Wollip you are right.  The Panasonic UB121000 battery I use is about $175 ea.  I recently sold a business that purchased around 200 annually and the 6 I have somehow were left off the inventory list.  I mistakenly listed what I had in them.  Sorry for the confusion.