My super simple, single battery solution... or... good thing I have AAA

[con kso]

Four days, -20 C and why I need to learn a lot about batteries.

Well, in short, it worked.

We did four straight days of camping, flogged that ARB like a mule- ran it at -20c the whole time while deploying the 120watt portable solar whenever I got around to it.

Did I deplete my battery below 50%, I have no idea.

Did I do some type of harm by not charging it completely? Again I have no idea. But here's what I do know:

1. I ran the ARB directly from the battery, no solar, from Monday 3pm to Tuesday 9am. The reason for that was that I got to camp and found that with all the big trees around us, at that hour, we were mostly in the shade. So I figured, we just ran the truck for 6 hours of driving, the battery should be able to handle it. I proceeded to drink lots of beautiful cold beer. It was glorious. The next morning I hooked up the Zamp Solar Portable, pointed it at the early morning in sun and let it run all day. The 'fridge ran that way until Wednesday noon- when we packed up. I was wondering if the truck would start- BAM, no problem. She fired right up... with vigor. Summary: Two complete days at -20c with only battery and solar? Yes.

2. The Zamp portable is pretty much made for idiots like me- just unfold, deploy legs, pick your battery type (it defaults to AGM- so no adjustment for me), and connect to battery- bam it goes to work (you can see the little battery-filling-up icon doing it's thing).

3. The next day, Wednesday, we fired up the truck and drove to another beach about two hours away. Lots more sun exposure at this place, no trees.... free energy? ITS ON. So I ran the thing all day, tried to figure out what the different screens (you toggle through them on the controller) were trying to tell me (I've got photos- lemme know if you want to see them) and wondered if the wire was too thin to be effective. Then I went for a surf, drank a rum drink and didn't worry about it.

4. Thursday afternoon, redeployed solar (had to put it away overnight- the wind came up to about 20 knots and would've blown it right off the Aloha deck on top of CON KSO), ate breakfast, drank a cup of coffee, packed everything up and BAM once again she fired right up. Summary: Monday to Thursday, combination camping with a couple hours driving in between, do-able? Yep.

5. Is this a good set up for my needs? Maybe. I'd probably feel better with that second battery hooked up to my alternator, etc., etc.. But I'm just wondering if I can get away with this stupidly simple system. For four days with a little driving in between it seemed to work. How will it function for my upcoming three-week southern Baja trip? Well, that's going to be the ultimate field test. I'm going to go with this set up for that trip and I will report back.

6. The Zamp Portable is pretty sweet- but the legs are a little rickety feeling. They do fold out and in nicely, but they are pretty weak when you move them sideways. I'm not saying they're going to break or fall apart (it will be put to the test over that 3 week trip) but I would have liked them to feel a little more solid side-to-side.

7. Wiring: I do wonder if the length of wire I deployed to reach from the panel to the battery was detrimental to the juice that was actually reaching the battery. And, was the gauge of wiring too thin. I purchased the 15' extension for the Zamp panel and it's wiring (not the wiring that comes with the panel) seems pretty wimpy... so another unknown for me. BTW: the little battery full icon on the Zamp never did reach the full indication- I was always three-quarters full.

Anyways, it worked. I had a fully functioning 'fridge, cold freshies and a truck that started.

I now realize that there's a lot I need to learn about, I'd really like to know more about what's happening with my battery. For example, am I even charging it (I started reading that solar RV guys blog with tons of info about charging and how I HAVE to be at 14.-something volts etc and got all confused)- so yeah, I need to educate myself in that regard.

We leave in a couple months for the big trip- I'll report back on how it works out.

 

[BigSwede]

My "plan" is to run the single battery system for now. If I feel the need for dual batteries, in a couple of years the LiFePO4 batteries will probably be affordable, and they offer many advantages over lead-acid including smaller/lighter and more cycles at deeper discharge.
http://store.starkpower.com/12V-100...ttery-LiFePO-Energy-Storage-Battery_p_24.html

 

[con kso]

Lithium batteries- "chargeable" from solar?

Hey Big Swede- sounds like you and I have the same system. Cool! I read through your post and it seems like you put even more of a load on the Diehard than I did- and your system was fine- that's encouraging.

I'm wondering how long the battery will last being used the way it is. It's got a three year warranty so if it goes dead before that time, I don't see why I shouldn't just bring it in for a new one.

I like the idea behind those lithium batteries too- I was looking at the aspect solar set up but I think it only was viable for 20 amp hours, not enough for me AND it seemed that they offered it with a pretty low wattage solar panel that took a long time to top it off.

My panel has setting that you choose on the controller for different battery types- I noticed that it does not have a lithium setting so I'm wondering if I could safely use my panel to charge a lithium battery. Not that I have the 800 to go pick one up but, dang, I really like the weight savings and long life of those things.

Keep me posted on what you work out- sounds like you and I are kind of on the same track as far as power goes.

 

[schulz11]

Well, in short, it worked.

We did four straight days of camping, flogged that ARB like a mule- ran it at -20c the whole time while deploying the 120watt portable solar whenever I got around to it.

Did I deplete my battery below 50%, I have no idea.

Did I do some type of harm by not charging it completely? Again I have no idea. But here's what I do know:

1. I ran the ARB directly from the battery, no solar, from Monday 3pm to Tuesday 9am. The reason for that was that I got to camp and found that with all the big trees around us, at that hour, we were mostly in the shade. So I figured, we just ran the truck for 6 hours of driving, the battery should be able to handle it. I proceeded to drink lots of beautiful cold beer. It was glorious. The next morning I hooked up the Zamp Solar Portable, pointed it at the early morning in sun and let it run all day. The 'fridge ran that way until Wednesday noon- when we packed up. I was wondering if the truck would start- BAM, no problem. She fired right up... with vigor. Summary: Two complete days at -20c with only battery and solar? Yes.

2. The Zamp portable is pretty much made for idiots like me- just unfold, deploy legs, pick your battery type (it defaults to AGM- so no adjustment for me), and connect to battery- bam it goes to work (you can see the little battery-filling-up icon doing it's thing).

3. The next day, Wednesday, we fired up the truck and drove to another beach about two hours away. Lots more sun exposure at this place, no trees.... free energy? ITS ON. So I ran the thing all day, tried to figure out what the different screens (you toggle through them on the controller) were trying to tell me (I've got photos- lemme know if you want to see them) and wondered if the wire was too thin to be effective. Then I went for a surf, drank a rum drink and didn't worry about it.

4. Thursday afternoon, redeployed solar (had to put it away overnight- the wind came up to about 20 knots and would've blown it right off the Aloha deck on top of CON KSO), ate breakfast, drank a cup of coffee, packed everything up and BAM once again she fired right up. Summary: Monday to Thursday, combination camping with a couple hours driving in between, do-able? Yep.

5. Is this a good set up for my needs? Maybe. I'd probably feel better with that second battery hooked up to my alternator, etc., etc.. But I'm just wondering if I can get away with this stupidly simple system. For four days with a little driving in between it seemed to work. How will it function for my upcoming three-week southern Baja trip? Well, that's going to be the ultimate field test. I'm going to go with this set up for that trip and I will report back.

6. The Zamp Portable is pretty sweet- but the legs are a little rickety feeling. They do fold out and in nicely, but they are pretty weak when you move them sideways. I'm not saying they're going to break or fall apart (it will be put to the test over that 3 week trip) but I would have liked them to feel a little more solid side-to-side.

7. Wiring: I do wonder if the length of wire I deployed to reach from the panel to the battery was detrimental to the juice that was actually reaching the battery. And, was the gauge of wiring too thin. I purchased the 15' extension for the Zamp panel and it's wiring (not the wiring that comes with the panel) seems pretty wimpy... so another unknown for me. BTW: the little battery full icon on the Zamp never did reach the full indication- I was always three-quarters full.

Anyways, it worked. I had a fully functioning 'fridge, cold freshies and a truck that started.

I now realize that there's a lot I need to learn about, I'd really like to know more about what's happening with my battery. For example, am I even charging it (I started reading that solar RV guys blog with tons of info about charging and how I HAVE to be at 14.-something volts etc and got all confused)- so yeah, I need to educate myself in that regard.

We leave in a couple months for the big trip- I'll report back on how it works out.

Great Report!

Did you move the panel with the sun to make sure you were getting a direct angle the entire day? This will give you 25-30% more amps for more hours.
Also, all of you with the standard charge controller that comes with it, if you step up to a MPPT charge controller ($139 for 20 Amps) you will get about 40% more juice out of your panel than with the PWM (http://www.solarpaneltalk.com/showthread.php?13845-Charge-Controllers-PWM-or-MPPT).

I currently have the Dometic CF50, a trojan 31AGM, 45 watt 4 amp panel, and the Renogy MPPT 20AMP charge controller ( https://www.renogy-store.com/MPPT-Charge-Controller-p/ctrl-mppt20.htm ). With the PWM in direct full sun I would get max 3 AMPs (36 watts) out of my panel in perfect condition but more realistically 2.5amps or 30 watts. With the MPPT I get full 3.75-4 amps of current to my battery. I know it doesn't sound like much but when you think of % it is big.

On your 120Watt panels, you are probably only getting about 6-7 amps (72watts) with the included charger. With the PWM, you will get about 9 to 9.5 (about 110 watts). When you think about it. We pull about 2.5-3.5 amps with our fridges, the difference you get with the MPPT gives you an extra hour of run time each hour it is up and running. Could save you from having to run dual batteries. Just my $.02. All in all, if all you are going to run is the fridge, the 120watt system will take care of all your needs as long as it is sunny every day.

 

[CaliMobber]

Schulz11 I Think you are over estimating the advantages of your mppt controller.Where are you getting these numbers from? Just because the website says 30% more efficient than pwn doesnt mean it true.

The only real benefit of the mppt is the ability to use a higher volatage solar panel on a 12v battery bank. the higher voltage allows you to use thinner wires, thats it. its not magically pulling power from no where.


Im looking into that brand now, never even heard of them before. reviews look good on amazon.

 

[con kso]

I have to say- the solar panel was my new favorite toy of the trip. Whenever I put it out I tried to point it into the sun. A big problem were the shadows created by trees around our campsite at one of the spots we hit. And, on the coast sometimes it's overcast. I have to say though, whenever I saw good clean sun, I was excited to plug in (I ran an SAE plug from my battery down to a plug in a recess on the front of my truck- so I didn't have to pop the hood to plug in, I just plugged into the hidden SAE port) and see what numbers I could get.

The major lesson I learned though is that solar won't produce the dream numbers you think it will unless you put the system together just right or have more panel than you think you need.

Here's an example from about 8am in the morning:



I think this was the amp hour readout: 2.31 amp hours... which I take to mean that's the rate of amps being added per hour to the battery. Am I correct?



Hard to see the unit on this screen but I checked it and it's the amp readout, so at this moment the screen said 2.6 amps. Is that what the panel is producing? Why doesn't it match the amp hour readout? Help.



And this screen is the volts readout, 14.3volts which I think is pretty good for that early in the morning. Volts is a measurement of "pressure" right?



And this is the general set up. Like I said before, this thing was my favorite new toy. It seems to be effective for my needs. Any additional tips, or comments regarding the photos I posted are welcomed.

 

[CaliMobber]

Yea voltage is pressure. so if your batteries are 14.0v you need more than 14v to push more power into the batteries. Thats why the proper charge controller is so important since alot of them dont let the volts get high enough to fully charge most batteries.

Wow thats a long run to those batteries, you are def getting some loss in that line. So far the biggest problem I see is the charge controller is at the panel and for the size of those wires its way to far away.

You want the charge controller as close to the batteries as possible, maybe 1 or 2ft away max.

The reason for this is that the line has a huge voltage drop from one end to the other. the charge controller is using the voltage to try and decide how much power the batteries need.

So imagine if there is a 1v drop in that line, the batteries are 13.5v but the controller see's 12.5v. It might only provide 13v and add more amps to charge more power but 13v cant even charge the batteries because the voltage is to low. I know this can throw a wrench in your gear but just something to think about.

If you have or know a friend who has volt meter with a amp meter and clamp I would set that up and read the amp at the meter then walk over and read the amp/volts at the batteries. See how far off they are.

If this was my setup, for starters I would try and remove the charger controller and mount it in the hood next to the batteries, and just hook the wires up to the controller when im using it or maybe modify the wiring so the meter is on the other end of the wireing.



When you have time read handybob blog, at first it seems like alot of reading but I got hooked and read ever page he has. All that info applies to us since he deals with small RV charging setups

http://handybobsolar.wordpress.com/ Good luck my friend, I love the setup and enthusiasm

 

[con kso]

Thanks Mr. Mob, that's some good and useful information.

I'll go pick up a volt meter and try that out- compare voltage at the battery to the voltage at the panel (use monitor's numbers, right?).

I found this electrical site (can't remember the name right now) that will make up some heavy gauge (low number) cables with crimped ends for any type of terminal you have or want. I'm thinking I may have some more robust cables made up.

I've looked at charge controllers- not that expensive, I may purchase one and play around with mounting it in near the battery. Morningstar sounds like the reader's choice around here.

Tried wading through that blog- I'll take a deep breath and give it another shot.

Appreciate the advice!

 

[CaliMobber]

Yea i would imagine the meter would be fine, but if you access the wire itself to check the meters accuracy also.

Yea my vote it morning star, I have the basic unit since I only have 60watts but it only handles 4.5amps.

If i was you I would just get this unit, it can handle 10amps which your panels are rated for max but they will never see 10amps. Its a little basic So it does not have a read out but you will need to spend well over $100 to get that. just pull out the volt meter when you want to see what going on.

The formula is volts x amps= watts. So your 120w/12v=10amps. I would only expect to see 7-8amp under ideal conditions with perfect sun.

http://www.amazon.com/Morningstar-S...&qid=1411923308&sr=1-17&keywords=morning+star



haha yea its a long and drawn out blog but with it in the end. Ill keep up on this thread so ask any questions you like and ill try and get you the right info.

 

[BigSwede]

Here is my thread from earlier in the year when I was mulling over the issues - possibly it will be of help to you. As you can see I went from 'not doing a dual battery system', to 'yeah I should do dual batteries, why not'...then later I came back to single battery - for now at least. In the end the improving battery technology I linked earlier tipped the scale; I didn't want to put a lot of money into a system that might not be needed in a few years, or might not be the right system with the new battery technology.
http://www.expeditionportal.com/forum/threads/120685-Fridges-CPAPs-and-Batteries-oh-my!

Hey Big Swede- sounds like you and I have the same system. Cool! I read through your post and it seems like you put even more of a load on the Diehard than I did- and your system was fine- that's encouraging.

I'm wondering how long the battery will last being used the way it is. It's got a three year warranty so if it goes dead before that time, I don't see why I shouldn't just bring it in for a new one.

I like the idea behind those lithium batteries too- I was looking at the aspect solar set up but I think it only was viable for 20 amp hours, not enough for me AND it seemed that they offered it with a pretty low wattage solar panel that took a long time to top it off.

My panel has setting that you choose on the controller for different battery types- I noticed that it does not have a lithium setting so I'm wondering if I could safely use my panel to charge a lithium battery. Not that I have the 800 to go pick one up but, dang, I really like the weight savings and long life of those things.

Keep me posted on what you work out- sounds like you and I are kind of on the same track as far as power goes.

There is considerable information regarding LiFePO4 charging on the Starkpower website, although it doesn't answer all of my questions for our type of application.

 

[uscg2008]

SO I mounted my National Luna single battery monitor to keep an eye on my group 31. Mounted it in my sunglasses holder and the best part is I can still fit a pair of shades in there

Truck off

Truck on and charging

 

[perkj]

For your question regarding your amp hour calculation. Keep in mind the fridge will only be pulling 2 amps when the compressor is cycling and thus won't be pulling 2 amps for 24 hours straight. A quick look at the ARB Australia website shows the following for the 60L fridge:

CURRENT DRAW: 0.89 amps/hour*
*Average power consumption tested at 3°C (37.4 F)
cabinet temperature, 26°C (78.8 F)-31°C (87.8 F) ambient
temperature range, test duration of 66 hours
and supply voltage of 12V DC

based on this you should be consuming more like 21 amp hours in a 24 hour period

 

[con kso]

USCG- that National Luna meter is cool! I checked it out- only 30 bucks. Hmmmm, my PayPal is getting itchy. Clean install too.

Big Swede- read through your thread, funny- you posed all the same questions as me, and came to the same conclusions. Let's compare notes and see how it all pans out.

 

[con kso]

Perkj: That's good news- I knew the draw was less than 2 amps/hour but I wanted to go conservative. I'm going to have to do more reading up on how people use their ARBs. I ran mine at -20 with LO cut off to see how it would all work out when maxed out. I will use the SEARCH function and try to answer my own questions about ARB useage before I post them here (even though it's more fun to just post it up).

 

[uscg2008]

Thanks ya good price for a piece of mind when I have my roof rack lights running or th light in my trailer on. I can check the battery real quick. Plus it has an alarm on it that will sound when you are close to getting to the last chance to start your vehicle