240 watts of Solar Synergy panels ordered

[Mary B]

I have 2 solar synergy 120 watt panels ordered. Now to buy batteries. Nobody out here in the boonies seems to carry golf cart batteries and the local Sams or Costco is a 200 mile round trip. Any thoughts on boat deep cycle batteries from WalMart?

[ChrisOlson]

Marine deep cycle batteries work fine.  Walmart's deep cycle batteries are made by Johnson Controls and they are as good of quality as any out there.

I had some cheaper marine deep cycles on my original battery bank that went seven years.  And I actually abused those, many times drawing them down to 11.0-11.2 volts, and they still took it fine.  After seven years, out of 24 batteries, only one of them showed signs of starting to get weak on a load test, and it had one cell that wouldn't float the hydrometer float.  Those were Group 29/125 ah.

If they're all you got locally, and are readily available, I'd use them in an instant.  They don't have near the warranty on them that the real RE batteries got, but they don't have the price either.

--
Chris

[birdhouse]

i'd second was chris said.  if it's a first set, and you're not living off grid, i'd go for the cheap batteries.  they're fairly stout (from what i've heard) and the price is perfect. 

i went with trojan t-125's a "step up from t-105's" though i don't know if that's true, and every time i buy more it's $600+ dollars for four more.  i have a 24v system so 4 is the magic number. 

i've got eight of them now, and really need twelve, so i'm gritting my teeth for the next $$$  set

had i gone with the "johnson controls" batteries i'd probably have 16 of them by now with a way stouter system that would probably last close to as long as the trojans. 

adam

[DanG]

The folks at Wal-Mart can probably get different batteries, just as they can get different tires than what they have in stock...

[Mary B]

Thanks everyone, this is just backup for my ham station and maybe supply some computer or TV power in an outage. Not sure of my 1,000 watt inverter would have enough oomph to start the furnace blower. Want to go closer to off grid and I am working on cutting my electric bill as much as I possibly can.

[ChrisOlson]

The folks at Wal-Mart can probably get different batteries, just as they can get different tires than what they have in stock...

http://www.jsonline.com/business/83454852.html

They are as good of build quality as Trojan, Surrette, or any of the "RE batteries".  I have seen some cutaways of the Johnson Controls deep cycles and they have good sump area for "sludge" that falls off the plates eventually.  They also have extremely heavy duty separators between the plates, as they are designed to take the heavy pounding in marine applications on rough water that would kill a regular automotive battery in one season.
--
Chris

[Bruce S]

Not sure of my 1,000 watt inverter would have enough oomph to start the furnace blower.

Mine takes a 1500w inverter to start and run continuous. It is a Nat'l gas unit blower is 110Vac single speed unit.
As a test I ran two 6Vdc Golf cart fully charged batts and went with the closest wattage rating then went the next step higher.
I've run it a few times already this way and it has NO problems keeping up.

Hope this helps with the furnace part.
Bruce S

[DanG]

No matter what anecdotal stories are told, a 6-cell 12 volt battery is more complicated & limited by finer tolerances throughout over a 3-cell battery of equal weight.

This point-of-purchase decision will be with you for 3-5 years and may limit your future upgrade path - don't settle for convenience.

Again, ask if they can supply Group 3, 4 or 7D 3-cell batteries or any GC-Series even if they are NOT on display.

Johnson Controls makes decent six volt private label batteries whether or not Wally-World includes them in their slick in-store displays, If your local wally-world has an auto repair center (or store manager & customer service desk if not) will they have your 1st choice shipped from their warehouse on request would be the question to answer.

[ChrisOlson]

Again, ask if they can supply Group 3, 4 or 7D 3-cell batteries or any GC-Series even if they are NOT on display

If you want different configurations than the standard Group 29/125 ah you will find at Walmart it would be better to go to an Interstate Battery dealer.

Interstate batteries are also made by Johnson Controls and they have a wider selection of deep cycle batteries available than what you will find in the catalogs at the Walmart auto service center. Interstate carries the U2200's which are 6 volt 232 ah and weigh 62 lbs.  Or they have the SRM-4DM marine 12 volt batteries rated at 190 ah at 119 lbs.

A single SRM-4DM would more than likely easily power your ham station, TV and furnace blower.  I have an Interstate SRM-4DM in my 5th wheel camper and it will power the whole camper including lights, water pump, furnace, TV, and intermittent loads on a 3kW inverter running things like toaster (1,200 watts) or my wife's hair dryer (1,600 watts) for five days worth of fishing trip in the boonies in Canada.  I think I paid about $200 for that battery three or four years ago.
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Chris

[ghurd]

Formerly... I believed the wally-world class 12V boat battery was good.
They would last 2~3~4 years in my systems.

Now... I believe the 6V 220AH-class golf cart battery is much better (even if it is the "sam's" battery, which for a while was made on the Trojan T-105 production line, with the same parts).

'Sam's 6V 220-ish-AH golf cart batteries' I installed more than 10 years ago are still running fine (I expect their capacity is lower, but they are not 'drawing' the rest of the batteries down). 

I would rather have 2 series 220AH 6V golf cart batteries than 2 parallel 110AH 12V batteries.  That is what DanG implied, I think.

Myself, I'd make a day of it, drive the 200 miles, stop to see that stuff you never stop to see, eat at that place you always wanted to, etc.
G-

[Mary B]

I am on a very tight budget so the gas for the round trip is more than I care to spend. I checked the local interstate dealer, wayyyyyyy more than I care to pay.

[ChrisOlson]

That's unusual.  I think the last time I checked, the Walmart Group 29 deep cycles were $84.  My local Interstate dealer gets $88 for the same battery.

The stickler these days is the core charge.  If you don't have an old battery to trade in you'll end up paying a $25 core charge.

That being said, Interstate Battery dealers are independents and they will probably quote you list price over the phone.  I'm reasonably sure most of them will shoot you a better price in person if you push them in that direction a little bit.

Anyway, not that's it's a big deal - the Walmart battery is the same thing.  Just that if you wanted a big 4DM I don't think Walmart can order that.
--
Chris

[Mary B]

I talked to the Interstate dealer in person while they were putting some tires on for me.  Prices were to high. I can handle the smaller batteries easier with my bad back and shoulders so I think it makes more sense to go that route. Plus if one would die I can take it out of service and still have power. Place I got the first two panels from has a 140 watt for $1.60 a watt shipped, may buy it to boost my capacity to 380 watts...

[ChrisOlson]

So are you looking at the smaller Group 27 95 ah batteries carried by Walmart?  Or the bigger Group 29 125 ah?

There's not much you can get for less than $200.
--
Chris

[Mary B]

The group 29, 2 in parallel. Paired with 380 watts of solar should be about right, I ordered the other panel last night 

[Boss]

I bought a set of the Wallyworld 12v marine deep cycle batteries five or so years ago. Before the free replacement deal was up I returned them and bought two more, making my bank twice the size all the same age. I repeated this the next year. They didn't seem to mind, it was obvious what I was doing, well at least I didn't try and  hide my intentions, but I still felt guilty about what I was doing. I pushed it one more year, but had to go out of town for the next set as their stock was depleted. Anyway now I have six all the same year of production, They are all a couple years old now and I only use them periodically. My point other than displaying poor character on my part is that for ~`$150 per year I managed to build a decent matched battery bank for our 10 foot turbine.
 

[Mary B]

First panel is in, good build quality, decent packing, works above specs. Now I need to figure out mounting. Need to be ground mounted because my climbing days are over. Thinking wood rack that I can adjust the tilt and Unirac rails.

[ChrisOlson]

It's good to hear that your panels work nice.  I have had solar panels on the house roof for years (1,230 watts installed capacity).  It's ok and I can reach them to clean them off with a roof snow rake.  I put the other 1 kW installed capacity on my shop roof and I can also reach those with a snow rake.

I had ground mount panels several years back and they ended up getting buried under a 9 foot deep snow drift.  I attempted to dig them out with a skid steer loader and the rack collapsed from the weight on it and broke two panels.

I have never used ground mount since.
--
Chris

[birdhouse]

mary-
i know you don't seem to be able to accomplish it, but do you have any friends that could get your panel(s) on the roof?  higher elevations get sun much earlier, and later than on the ground, unless you live on a cornfield.  seems helpers might be kinda stoked to mount solar panels, as it's a fairly rare thing. 

adam

[ChrisOlson]

roof mounted panels are also much less likely to get full force wind under them, turning them into sails and ending up in a cornfield in the next county.

This is the remnants of what was a nice ground mounted array on a tracker after 65 mph winds from a thunderstorm


--
Chris

[Mary B]

I build to withstand 90+mph winds. Have to because they happen every year usually. No helpers locally, friend could come up from KS but that is a long drive.

[ChrisOlson]

At 90 mph the wind loading on your solar panels will be 24.9 Psf.
--
Chris

[Mary B]

4x4 treated framework set in concrete, 2x6 treated cross members should handle it  as I said I usually build to overkill.

[Rover]

I have 7 of the 100W Solar Cynergies (2 more arriving in March). 3 Mounted on my derrick rigged free standing turbine tower, 4 on the shed roof.

Been through at least 2 hurricanes, 1 of which squashed and twisted the shed. The panels on the shed survived even though they looked twisted.

The panels will actually take a fair amount of abuse, although mine are smaller.

Rover

[keithturtle]

On our last solar PV roof installation (March 2010), we closed the space at the bottom edge with aluminum trim to prevent wind from catching the array, and as a sight shield for the wires.  If the wind cain't grab it, it should stay put.

No problems yet

Turtle

[Mary B]

My roof angles are very wrong too, I have a barn style roof that is about a 15 degree pitch on the very top then the sides are about a 75 degree pitch and to steep.

[DamonHD]

Which direction are your roof surfaces facing?

That 15 degree bit will work reasonably in almost any orientation, even a due-north part wouldn't be too horrible.

The 75 degree parts will work much better more-or-less south facing than any other orientation.

So, maybe have another think about the top part?

Rgds

Damon

[Ungrounded Lightning Rod]

First panel is in, good build quality, decent packing, works above specs.

Works a bit above specs is to be expected (but not planned for):  The specs include some degradation with time and variation between panels.  So your typical panel will exceed them somewhat when first received.

At least it should.  B-)

You plan by the specs so you meet targets nearer end of panel life.

[Ungrounded Lightning Rod]

4x4 treated framework set in concrete, 2x6 treated cross members should handle it  as I said I usually build to overkill.

Sounds good to me.  Almost like my deck. 

[Mary B]

I live in MN and 15 degrees won't produce much power in the winter, my sun gets to low. The other angle is to steep for summer so neither is going to be usable. A tilting frame that lets me follow the seasons will be better.

[DamonHD]

But if you look at the actual track of the sun over the sky in summer you might get a shock to realise that you only lose maybe 10% by having panels at that sort of angle.

In the EU we have this lovely free tool:

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php#

where you put in your location, angle and direction of your panels, and get a pretty good estimation of energy out, which is what convinced me that me east- and west- facing roof surfaces at 23 degrees would be OK.

Rgds

Damon

[Mary B]

I would lose to much power in the winter when I need it the most.

[Mary B]

Up to 520 watts of panels. Searching for a 60 amp charge controller under $200. I know the Xantrex C60 works but looking for other options.