New Members with several questions

rainwolf

Had this posted on RV.net forums, & someone suggested this one, so here we are! :P Thought I'd share our story while I read through the great info here & learn a lil more.

Original post:

Long nightmare story short... purchased new 5er, had solar set-up installed, added panel & more batteries later. Thought all was well, unit in storage & good to go. Come to find out, the guy we had install the 2nd panel & extra batts hooked it up wrong, fried our controller & who knows what else. (No, it is not covered by dealer, as it was done aftermarket & one that installed it will not return calls now. We're stuck with the prob.)

Batteries totally dead & controller needs replaced for certain. There are NO solar experts in this area aparently (that we can find) & would like to attempt the repairs ourselves; but, we have limited knowledge on the subject, 'cept what this disaster has taught us. We have covered the panels & removed the over-heating controller. Plan to buy a reconditioning battery charger & try to salvage the bank.

What we have now: Carmanah 100W & Kyocera 130W solar panels, go power 1500 sine wave inverter & transfer switch station, & the 4 batteries (may or may not hold charge now... have yet to check).

My questions:

1) Can anyone recommend which brand/size charge controller would be best? And, why you say this/links to back it/etc. (Commence debates about MPPT, PWM, etc here. LOL (Current panels listed as 6 & 7something amps, may add another panel later, want something that could handle the upgrade as well.) Also, the best one for the money, as we are getting more limited by funds as the days pass.

2) What kind/size/gauge of wiring & adapters will we need & best way to run them to controller? (Currently spliced together & needs changed.)
Have read a cpl places to use smaller gauge wire to counter loss en route to batteries, & putting controller closer to batteries is better idea, but personally have no clue. Anyone here with experience on the matter that would like to advise?


Will appreciate all input & good supplier links (& prayers, of course )!
Would like to get this project finished up by Oct, along with some other mods, such as: trade out old heavy tv for lighter flat screen, more efficient lighting, remove mirrored closet doors, & a lot of other little things. Any & all help, advise or ideas might help ease the agonizingly grounded project & make the process go a lil smoother. Would really like to get it right this time. HehHeh

~M & P~

mike95490

Re: New Members with several questions

My condolences for your loss.

Your PV, how many of what panels ? What's the model # of each, or do you know the max power for each - that helps in looking up the panel specs

What's a "new 5 er"

What are your loads going to be? Lights, fridge, big screen TV, shop vac, table saw?

rainwolf

Re: New Members with several questions

Thank you!

Ahhh... apologies... forgot I was no longer on an RV forum. LOL This set-up is on an RV... 31' fifth wheel (5er).

Have 1 each:
Carmanah 110W (1st one installed at dealer - came in the Go Power! RV Solar Power Kit GP-RV110) (110 Watt 6.40 Amp 26"x62", but not certain this is the same for all their 110 panels)

Kyocera 130W (SPK130 - 130 Watt 7.39 Amp 26" x 57")

Load consists of A/C (when needed), fridge, microwave, heater, tv & stereo, laptop, lights, fans, water heater, etc.

Kamala

Re: New Members with several questions

Greetings!

I ordered my RV (much, much smaller than yours) without air conditioning because I hoped to make it electrically independent using solar power. IMHO the load that A/C represents is prohibitive for a small PV system. I would place all RV installations in this category.

The gurus, shoguns and experts on this forum will explain better than I what you can expect to achieve with your available dollars, space, equipment, knowledge, blood, sweat and tears.

Enjoy!

Craig

niel

Re: New Members with several questions

i don't want to sound rough with you, but it seems that you have more loads than what you can power with the pvs. like it was mentioned about the a/c being a huge consumer of electricity, you will find that a refirig will be along the same lines and need huge amounts to keep it going. then you're adding some major power consuming stuff like an electric heater and microwave too. i'm surprised you didn't say a coffee pot on top of it all. for solar to work you need more watthours being generated during the day than the loads will use in a day. you would need a remote mini solar farm for your proposed loads and the battery bank would probably need its own trailer to store the large number of batteries and the pvs as you move them to travel.
conservation before all and read to acquaint yourself better on the subject matter. by all means keep in mind to go solar, but get a better grip on what you can and can't do and costs are always high doing solar which makes us even more conscious of conservation. if you must do some high powered loads at times then get a generator to temporarilly handle the high surge, but it won't be constant i'm thinking for many reasons.

mike95490

Re: New Members with several questions

Well, you have pretty low recharge capacity, 110 + 130 = 240W max possible, and usually, when figureing on a battery based system, with all the losses, you are looking at 120W of actual harvest ( about 50% losses between bad sun angle, controller losses, battery recharge loss, inverter loss) About 5 hours of charging sun per day, you can harvest about 600Watt hours.

To spend that power, you can :
100w light for 6 hours
50w for 12 hrs
2ea, 12w CFL lights for 24 hours
(see how I'm going) Just figure out your appliance loads, and the times, and massage them around till you only spend 600WH.

You can spend more, if you run a generator that recharges your batteries.
In your case, I would find a pair of 6V golf cart batteries that are the same case size as your dead 12V batteries. Wire them in series and you have a big 12V battery. That solves the "batteries in parallel don't share loads equally" problem.

If you drain the batteries more than you recharge them the very next day, you will begin to sulphate them, and loose capacity that cannot be recovered. I doubt your old batteries are going to be worth the effort to salvage, they may work for a while, but will be waiting till you invite friends over and expire as you start the blender.

Recharging, I used the sizing tool at
http://www.xantrex.com/support/gtsizing/index.asp
to try to look up the details of your panels
Carmanah - not found, and I've never heard of them
Kyocera not found, so I randomly chose a KC130TM
the specs we need are
Max Power Voltage - Vmp 17.6 Vdc
Open Circuit Voltage - Voc 21.9 Vdc
Max Power Current - Imp 7.39 Adc

Assuming the other panel is a close match, and depending on your
budget, you could wire the panels in series, for 44V, and use a
fancy MPPT charge controller, to charge the batteries.
But series panels are more susceptible to problems if you have shade
on the panels, any shade anywhere, dramatically reduces the power output.

So if shade from roof rails, vents, skylights, antenna wires or masts are
present, you HAVE to use parallel wire, and use heavier gauge wire. In fact, I would use a "home run" wiring from each panel to the controller, not sharing wires at all.

An MPPT controller, I'd suggest the Morningstar "SunSaver MPPT"
If you go with parallel panels, I'd suggest the Xantrex C12 as controller.
Regardless of what you get, also order a battery temperature sensor
that will fit the brand/model you select.

What are your loads - do you really need 1500W inverter? If you are below 300W (600W surge for 10 minutes) you can use the new Morningstar SureSine inverter, which is very efficient. Mod sine inverters have both their internal losses, and any MOTOR you power with it, will run hotter, and draw about 20% more power. They can also unexpectedly "fry" appliances too, with their non-standard waveform.

Lots of questions.

rainwolf

Re: New Members with several questions

niel wrote: »

i don't want to sound rough with you, but it seems that you have more loads than what you can power with the pvs. like it was mentioned about the a/c being a huge consumer of electricity, you will find that a refirig will be along the same lines and need huge amounts to keep it going. then you're adding some major power consuming stuff like an electric heater and microwave too. i'm surprised you didn't say a coffee pot on top of it all. for solar to work you need more watthours being generated during the day than the loads will use in a day. you would need a remote mini solar farm for your proposed loads and the battery bank would probably need its own trailer to store the large number of batteries and the pvs as you move them to travel.
conservation before all and read to acquaint yourself better on the subject matter. by all means keep in mind to go solar, but get a better grip on what you can and can't do and costs are always high doing solar which makes us even more conscious of conservation. if you must do some high powered loads at times then get a generator to temporarilly handle the high surge, but it won't be constant i'm thinking for many reasons.

HehHeh... Yep... can add that coffee pot in there, too! :P I don't intend on attempting to run them all at once though. Will be staggering tasks depending on battery power & recharging with generator, as needed... frugal use of battery draining devices when boondocking, etc. (More than willing to find an alternative cooling device to keep the pet comfy while we're out exploring without having to run the generator the whole time.)

rainwolf

Re: New Members with several questions

Did find some specs for the Carmanah/Go Power panel...
GP-RV-110
Output power - 110W
Rated Current - 6.7A
Rated Voltage - 16.5V
(Their line of products is through GP Electric)
http://www.gpelectric.com/Default.aspx
The inverter we have is a pure sine wave, if it's not damaged. Did do enough research to know better than to buy a mod & why. lol Just should've researched installation & done it ourselves. Yeah, the 1500W is probably overkill (was part of RV dealer pkg) & if it needs replaced, I'm all for better efficiency & will keep the Morningstar line in mind.

600WH sounds about right for frugal use. May need another panel, but can survive with the two for now. We do plan to redo all the lights with more efficient ones, soon as I figure out how. Glad you reminded me.

LOL about the blender... good point! May be a wiser idea to invest in new ones again. Need 8 golf cart ones to replace the 4-12Vs we have now? All in series?? (This is where my inexperience shows... clueless on battery bank wiring, too. )

Yes, the 'home run' is how the panels were supposed to be wired to begin with (part of reason controller fried) & sounds like what we will stick with. What gauge wire exactly would you use? (So far I've been told to go with #14 flex)

Will look into the Xantrex C12... thanks... & for the great personalized assistance! VERY MUCH appreciated!!!

rainwolf

Re: New Members with several questions

Kamala wrote: »

Greetings!

I ordered my RV (much, much smaller than yours) without air conditioning because I hoped to make it electrically independent using solar power. IMHO the load that A/C represents is prohibitive for a small PV system. I would place all RV installations in this category.

The gurus, shoguns and experts on this forum will explain better than I what you can expect to achieve with your available dollars, space, equipment, knowledge, blood, sweat and tears.

Enjoy!

Craig

Thanks, Craig! Nice set-up you have! Always liked those type pop-ups.
Have been contemplating some type of alternative cooling, just haven't looked into it yet, other than seeing an ad for the new auto w/'solar ventilation' that sparked the idea prior to all these probs. lol Would like to be able to spend time in the desert boondocking in the summer, if we chose, & not suffocate.

BB.

Re: New Members with several questions

A blender (or microwave) are not the worst off-grid loads in the world--assuming they are not used much (like a few minutes per day).

Generally, you want to match the batteries to the available solar power. To little battery capacity--might overheat the batteries with too much current--or more likely--just a waste of solar panels (charge quickly during the morning, wasted charging power for rest of day). If the batteries are too large--then you cannot charge the batteries and equalize properly.

As a rough rule of thumb, ~5%-13% of the battery banks 20 Hour Rating...

110 watt + 130 watt = 240 watts maximum. First approximation (assuming 12 volt battery bank) would be:

240 Watts / (0.05 * 12 volts) = 400 Amp*Hour maximum battery @12vdc
240 Watts / (0.13 * 12 volts) = 154 Amp*Hour minimum battery @12vdc

As always, you can go outside the above ranges (like >400 Amp*Hours if you plan to bulk/equalize charge your bank with the genset/shore power once in a while)--but is a good start.

Usually, we recommend your daily load * 3 days (no sun) * 1/0.50 (50% maximum battery discharge).

Your heavy loads, should look for alternative power sources--such as (as Tony/Icarus recommends) a nice Coleman "Mr. Coffee" type stove top coffee maker, and such.

For very efficient A/C--there is a thread here about the Sanyo Mini-Split A/C system. Very off-grid friendly--but still takes ~240 watts to run on low speed (once your trailer is cool--perhaps it will run at less than 100% cycle time--a way to keep the pet cool and safe(r)).

Sanyo mini split AC (inverter/variable speed)

If you will be spending lots of time off-grid and need more power--then you should be looking at more extensive use of solar panels on your RV. Also, allowing them to point (roughly) at the sun can increase their output substantially (use the PV Watts Website to play with different mounting options (flat, tilt to sun, etc.) to see how much power you can generate from your array... As a first estimation, use a Derating Factor=0.52 for an off grid system).

Using a small inverter (like the very nice Morning Star 300 Watt 12VDC inverter) is a good way to save power when running your smaller loads (laptop computer, a few CFL lights, etc.).

Lastly, see if you can estimate how much fuel your genset uses vs how much power (kWatt*Hours) you generate... Most gensets are pretty efficient when operated at 50% load or greater. And most, when operated at less than 50% load, will consume about 50% fuel flow.

If you have a 6kW genset, then below 50% load, the kWhrs/gallon of fuel goes down (fuel flow remains high) and it gets "very expensive" to run the genset.

Try to size the genset + battery charger (plus any optional loads) to run at 50%+ load--or look at a smaller genset which can operate at a lower average power in a fuel efficient manner (the Honda eu2000i is rated at 1,600 watts max continuous and will run down to 400 watts or a bit less, at a very efficient kWhr/gallon=> approx. 5.5 kWhrs / gallon). May, or may not, be worth hauling yet another piece of equipment. :roll:

-Bill

rainwolf

Re: New Members with several questions

Thanks, Bill. Will check out that post. (& for another reminder of something else I need to find... that good ol' camp coffee pot! )

I imagine we'll have hookups approx. every other season, for 3 months/workamping... then in between, we'd be doing the boondocking. Never know what the future holds... not much is going as planned so far. HehHeh But, will bookmark that PV site.

We have something similar to the Honda gen you're talking about, but went with Yamaha (EF3000iSEB). Says on paperwork: Rated Output | kW(HP)/r/min | 3.5 (4.7)/3,800. 8 operation hrs at rated operation. Have yet to hit the road & put it to the test in conjunction with the solar set-up, but sure love the <60 dB factor! Time will tell if it comes along... 69 lbs leaves room for more toys!

BB.

Re: New Members with several questions

Forgot to add the other coffee accessory--A good thermos.

Regarding the genset--if you need ~3kW--a bigger one is fine (powering large tools/saws/etc.)... But if you can keep your loads down below 1.6 kW--the smaller one will probably be more fuel efficient.

With solar RE and off-grid power--conservation is job #1, #2, and #3.

-Bill

mike95490

Re: New Members with several questions

An MPPT controller, I'd suggest the Morningstar "SunSaver MPPT"
If you go with parallel panels, I'd suggest the Xantrex C12 as controller.
Regardless of what you get, also order a battery temperature sensor
that will fit the brand/model you select.

Just a note here, your panels will have both of these controllers about at their maximum limit. I'm sort of counting on the panels being flat on the roof and not aimed well, or else you will be AT the limit. If you plan on more PV later, you will need more controller, and maybe want to get the big fancy controller now, and have it "loaf" along.

And, with 2 batteries, you have more storage than PV, which is why I said you can only spend 600Wh. If you have a generator, you have more to play with, but you need to fully charge the batteries at least every other day, or risk sulphation.

rainwolf

Re: New Members with several questions

True enough, Bill.... went & got the thermos yesterday, along with the lil camp percolator. 8)

Yes, we could probably do with the 1.6kW... eventually. We are fairly new to being 'part of the solution, rather than part of the problem'.... & GenXrs (if that helps explain anything. LOL We were raised by TVs, pcs & video games. :roll:). So, we have to learn better conservation techniques & implement them on a daily basis... which has been a process already. Heh But, we're learning. (Thanks to a lot of great people like you!)

Mike... at the moment, we have 4 batteries & the 2 PVs are mounted flat to the roof of RV. Had planned to add at least one more 100-130W PV. Would be topping the bank off with the gen nightly, or as needed.

Yeah, I got to looking at the C12 & talked to another guy, who said the C35 would work better for us. Figured that, or the C40?

BB.

Re: New Members with several questions

Some handy tools for Conservation:

Kill-A-Watt AC Power Monitor Meter (less than $30)

Watts Up or Doc Wattson DC cumalitive Amp*Hour / Watt*Hour meters

Battery Monitor (permanently installed Off-Grid / Battery Based systems)

Hydrometer kit (for flooded cell batteries)

Note that the Kill-A-Watt, Watts UP/Wattson, and Battery Monitors measure cumaltive power usage (Amp*Hours, Watt*Hours)... For equipment that draw variable/cycling loads (like fridges, DVRs, Computers, Printers, etc.)--this is the only way to really know how much energy you use in an average day.

If you need to measure AC Watt*Hours / kWatt*Hours for a standard North American outlet--there is not better tool (for the price) to start with than the Kill-a-Watt meter. Highly useful for measuring/predicting your off-grid loads, or just to have around the home to work on conservation (and saving money).

-Bill

rainwolf

Re: New Members with several questions

Yes, I've been hearing that handy lil tool mentioned everywhere. The Kill-A-Watt is definitely on the list, along with the hydrometer. Battery monitor is a good idea, too, for us newbs. Just trying to keep costs as low as possible.

In regards to the controller... what does everyone think of this one?
http://www.amsolar.com/hpv22.html
Know it would handle what we have now & love the dry camp feature & 10 yr warranty... & it is favored among several RV solar users in the know; but, if we add the other 100-130W PV, would it still be ok, or too close to max? Any feedback on this brand?

---

on edit

---

This might help... Can view pix of the current problem set-up here:
http://s440.photobucket.com/albums/qq130/Mod3rn3nigma/Solar%20set-up/
(As previously stated, we've already removed the controller showing in the Inside Display Panel pic.) Doesn't show the PV mounted to roof, but will get them next time we're down there. The RV they're mounted on is in an album here:
http://s440.photobucket.com/albums/qq130/Mod3rn3nigma/Grey%20Ghost%20and%20Daemon%20Den/

mike95490

Re: New Members with several questions

rainwolf wrote: »

Had planned to add at least one more 100-130W PV. Would be topping the bank off with the gen nightly, or as needed.

Yeah, I got to looking at the C12 & talked to another guy, who said the C35 would work better for us. Figured that, or the C40?

Adding 1 more panel, you will be past the limit for the C-12 & sunsaver MPPT. C35 or C40 would work OK, whatever your price point is.

Does your Genset have 12V charger, or does it power your shore charger?

What is your 120V charger rating ? is it multi stage, or just an automotive charger?

Usually, end of the day the batteries should be full from the solar, and running the gen just for batteries is pointless, unless it was a cloudy day. Running for 30 minutes or more in the AM when you make coffee and run the blowdryer, gives them a good quick bulk charge, and the the slow solar will top them off.

rainwolf

Re: New Members with several questions

Here are the generator specs:
http://www.yamaha-motor.com/outdoor/products/modelspecs/444/0/specs.aspx

BB.

Re: New Members with several questions

Regarding the aux 12 volt output of the Yamaha--Typically (if like the Honda) the aux out is "unregulated" and not very much power (12v*12a=144watts). OK for random charging if needed--but not much power for charging a bank with more than a couple batteries (and probably not very fuel efficient). And when the Economy Control on (low RPM)--the aux 12volt output may not be usable to charge a 12 volt battery.

Just out of curiosity--I see that this model includes fuel use at 1/4 load (2,800 watts) for 20.5 hours on 3.4 gallons. Fuel usage at 700 watts (1/4 power):

700 watts * 20.5 hours / 3.4 gallons = 4,221 Watt*Hours per gallon @ 700 watt load.

Not to bad... But if your loads are less than 700 watts average, you should probably look at a smaller genset. The Honda eu2000i (1,600 watt--not electric start, only 50 lbs instead of 150 lbs) is rated for 15 hours at 400 watts on 1.1 gallons of fuel:

400 watts * 15 hours / 1.1 gallons = 5,454 Watt*Hours per gallon @ 400 watt load

-Bill