El Cheapo 45 Watt Solar Kit Kicks Me Off The Fence!

[White Tiger]

Just bought a 3 panel "kit" that includes a charge controller, a frame to link all of it together, and an assortment of plugs - all for $154 from Northern Tool (had a 30% off coupon)!!

I know it's a low-end model, I know it's inefficient, but it was so darn cheap...that it finally pushed me off the fence!

I haven't put it together yet - I wanted a power supply system before the start of the new hurricane season (which starts tomorrow). I have a funny feeling it's going to be an interesting season this year!

I'll update as soon as I put it together!

Here's a picture:

[Geek]

Looks interesting.  Please let us know how it performs.  I'd also like to know what you ue for batteries as this will be useless during an actual hurricane unless you have stored some power in advance.

[KC9TNH]

Concur, but a start nonetheless. At something under 4A though you can politely charge some decent-size batteries if the controller is reliable. Let us know how it works out.
:)

[Frosty]

Love Northern Tool, I can open their catalog to literally any page and find something I don't know how I've managed to live this long without owning. 

Nice kit WT.  Great price too.  A couple neighbors have the similar Harbor Freight model, Thunderbolt magnum I think.  One's had his for at least 5 years for his off-grid cottage, uses a single marine battery and it runs a few lights and a FM radio no problem - but only gets used 6-8 weekends a year.

45W of panels should provide something around 16 amp-hours (200 watt-hours) a day of power on average.   If you kept your daily usage at or below that, and assuming no other way to charge the batteries, then a battery bank with 160 AH total should keep the batts at 90% of charge or higher to get the max life out of them.   Just rough numbers.  Batts are always the weak link, and in a bank they're only as good as the worst one.  Deep cycles kept above 90% of charge should last for many years though.   Let us know how it goes, and how you plan to use it.

[KC9TNH]

I like Frosty's idea; rather than "oh, frack! I need to charge a battery" or "oh, frack! I need to run this toy" keeping a maintenance level on an existing bank would be a good use for this.

[WA4STO]

Just bought a 3 panel "kit" that includes a charge controller,

I just yesterday managed to get my four blue-top Optimas down in "the hole".

I've been looking at the el-cheapo solar charging kits for years now, but I never seem to find any that have a 'fully-charged, now use the power for something additional' circuitry.

I bought a PCB and all the parts, some years ago, to build such a beastie, but never got around to buying the relay needed to switch the incoming wattage to, say, a 12 volt water heater element.  I just gotta do all that one of these days.

So me, I'm still on the fence, although I do have one leg ready to set down.  Damned thing is a picket fence, though.  Ouch!

73

Luck, WA4STO

[White Tiger]

Looks interesting.  Please let us know how it performs.  I'd also like to know what you ue for batteries as this will be useless during an actual hurricane unless you have stored some power in advance.

Hah, yes! I have been trying to find the right type of battery for my main concerns (small refrigerator, recharging stations for flashlights/lamps, and of course - radio communication).

The ol' TenTec Omni D manual says she likes a 12v 18Ah type battery...so I spent most of the morning trying to run down a couple of those puppies...not so easy to find!? I can order some from Amazon/eBay - but I really wanted to get my hands on 'em today (while the Frau is out showing houses).

[White Tiger]

Love Northern Tool, I can open their catalog to literally any page and find something I don't know how I've managed to live this long without owning. 

Nice kit WT.  Great price too.  A couple neighbors have the similar Harbor Freight model, Thunderbolt magnum I think.  One's had his for at least 5 years for his off-grid cottage, uses a single marine battery and it runs a few lights and a FM radio no problem - but only gets used 6-8 weekends a year.

45W of panels should provide something around 16 amp-hours (200 watt-hours) a day of power on average.   If you kept your daily usage at or below that, and assuming no other way to charge the batteries, then a battery bank with 160 AH total should keep the batts at 90% of charge or higher to get the max life out of them.   Just rough numbers.  Batts are always the weak link, and in a bank they're only as good as the worst one.  Deep cycles kept above 90% of charge should last for many years though.   Let us know how it goes, and how you plan to use it.

Thanks Frosty, I have been pondering how many batteries would help me derive a minimal power bank...I was thinking about buying two at a time to run in series, and to not buy them too far apart...so as to match them properly...

The simple system will also allow me to buy/connect additional 45 watt kits - but Im not sure how many more I would need...and if I needed more than onemorekit it would probably behoove upgrading to more efficient panels & charge controller, etc.

This just started off to be an emergency power solution for the bare minimum requirements...

Then I remembered something about solar panels producing some loose RF "noise" ...and something about needing a "pure sine wave" device to overcome it...but Im not sure where that comes into play (remember, I'm the least technical guy any of you will ever know - for example: I typically just stare blankly at about half of what you say...then try to look up the key points, later...it could be that I've had a LOT of coffee already, and that's never good for my A.D.H.D. issues...could also be why the Frau is showing houses on a Saturday...), am I supposed to have an inverter that produces a pure sine wave, would that help my "el Cheapo Solar Systema" become a little "quieter"?

...or is that something I should'nt worry about if Im just running my radio, D, C, AA, AAA battery chargers, and some lights - off of battery power?

Other problems Im just now figuring out - where to install said panels, will there be a power loss associated with running the power lines across the house (panels on the roof in the backyard near the garage, shack in my office on the other side of the house, approx 40' away)?

See what I mean - new coupon iPhone app, time on my hands, wandering around Northern Tool...viola...instant karma...

....just not sure if I did something good or...baaad...!?

And Luck:

I've been looking at the el-cheapo solar charging kits for years now, but I never seem to find any that have a 'fully-charged, now use the power for something additional' circuitry.

Hmmm... Now Im concerned, the charge controller has button attached to an LED meter/display that is supposed to show the charged level (13.8v max) of the battery ...the LED meter drops as a source item is plugged into the battery. Perhaps I've misunderstood your meaning?

[White Tiger]

Here's the type of battery I was pondering:

[KC9TNH]

Here's the type of battery I was pondering:

Quality stuff; we use one of those throughout a season to run the scale at our weigh-ins.

Edited to ask: what does your Ten-Tec draw at less power?

[WA4STO]

Deep cycles kept above 90% of charge should last for many years though. 

Frosty's two magic words there are "Deep" and "cycle", Tim.  The one you show the picture of looks very much like a typical automotive, motorcycle or lawn mower battery, not the kind we're striving for here.

Deep cycle or deep discharge batteries are a completely different ilk. 

Just to bring more ants to the picnic, you'll quickly find that the true "Deep Discharge" batts are relatively  expensive.  Because of the intended use.  Consider  a single battery in a little fishing boat that has a little electric motor.  It might use a tiny amount of current  for a VERY long time, and by that time, it might have discharged the battery only a small amount.  Whereas the battery in your picture   is designed to start a motor for just a few seconds (hopefully) before it starts to again receive a massive jolt from the alternator. 

You can tell a great deal from the CCA (cold cranking amps).  Mine (I have four) are 900 CCA, but if the temp is up to 32 degs F, they are then rated at 1165 amps. 

More than the CCA, I can tell a lot from the weight of the fool things.  Mine are sixty lbs EACH.  The best ones I ever had (red Trojans) were something over a hundred pounds each.  Oof!

73

Luck, WA4STO

[WA4STO]

Hmmm... Now Im concerned, the charge controller has button attached to an LED meter/display that is supposed to show the charged level (13.8v max) of the battery ...the LED meter drops as a source item is plugged into the battery. Perhaps I've misunderstood your meaning?

Whoops!  Didn't mean to worry ya.

The thing that has always bugged me about the 'usual' method of solar charging is that, once the batteries are topped off, why waste all the rest of ole Sol's oomph?  The cleverest solution is to have circuitry that flips a relay and starts using that extra wattage for sump'n else.

Back in the days when I called my F650 and the RV "home", I enjoyed 'boondocking', meaning no commercial power, and no running water.  Oh, and yah, no hot water either.  But once the relay kicks in and the charging juice is diverted to a 12 volt heating element in the little water heater, well every bit helps.

The 'secondary' could also be another battery.  Or  anything to keep that power in use.

73 de Luck, WA4STO

[RadioRay]

This is reminiscent of living aboard the sailboat.  Back then, I had two 65 Watts Kyocera panels and the house battery was made of 2 'golf cart' type , marine batteries in series.  That gave us just under 400 Amp hour capacity in the house circuit.  I found that by replacing all the incandescent lights with  'Marine Beam' LED lights, I always ha plenty of juice for the HF set (radio e-mail), lights , navigation lights & equipment . . .  It was always easier to reduce power consumption than to find a clear space for more panels.

I mounted the panels over the helm station so that they also served as a type of hard awning.


>de RadioRay ..._ ._

[White Tiger]

Frosty's two magic words there are "Deep" and "cycle", Tim.  The one you show the picture of looks very much like a typical automotive, motorcycle or lawn mower battery, not the kind we're striving for here.

Deep cycle or deep discharge batteries are a completely different ilk. 

Just to bring more ants to the picnic, you'll quickly find that the true "Deep Discharge" batts are relatively  expensive.  Because of the intended use.  Consider  a single battery in a little fishing boat that has a little electric motor.  It might use a tiny amount of current  for a VERY long time, and by that time, it might have discharged the battery only a small amount.  Whereas the battery in your picture   is designed to start a motor for just a few seconds (hopefully) before it starts to again receive a massive jolt from the alternator. 

You can tell a great deal from the CCA (cold cranking amps).  Mine (I have four) are 900 CCA, but if the temp is up to 32 degs F, they are then rated at 1165 amps. 

More than the CCA, I can tell a lot from the weight of the fool things.  Mine are sixty lbs EACH.  The best ones I ever had (red Trojans) were something over a hundred pounds each.  Oof!

73

Luck, WA4STO

Ok, but the Ten Tec manual stated that the battery to use is a 12v 18Ah...it didnt occur to me that I could/should use something other than what was specified...?

The one pictured is an AGM, and it's a lead acid cell, and it is listed as being a "deep cycle" type...

See, now's about the time that that "least techy" rears it's head...I am a complete battery noob...

[Frosty]

am I supposed to have an inverter that produces a pure sine wave, would that help my "el Cheapo Solar Systema" become a little "quieter"?

I've only used modified sine wave inverters, the smaller (1000w or less) cheap truckstop ones were noisy - like a noticable hum from the speaker on some radios.  They also destroyed some cheap rechargable devices I tried to charge off them, some AC battery chargers do not like that modified sine wave.  Yeah I know, 12vdc -> AC inverter -> AC charger -> 9-12VDC device is hugely inefficient, but see below....  The Xantrex modifed sine wave I'm using now doesn't have these problems. 

...or is that something I should'nt worry about if Im just running my radio, D, C, AA, AAA battery chargers, and some lights - off of battery power?

If you can live with only <= 12v devices and can keep them within a few feet of the batteries that's the most efficient, but for longer distances you almost have to go with an inverter.  The voltage drop on long 12v wire runs is the problem, unless you have some really big wire. 

Other problems Im just now figuring out - where to install said panels, will there be a power loss associated with running the power lines across the house (panels on the roof in the backyard near the garage, shack in my office on the other side of the house, approx 40' away)?

40' is a fairly long way for 12v.  Using 10 AWG wire it'd be about .5v voltage drop across the wires in EACH direction - so 1v total drop (en.wikipedia.org/wiki/American_wire_gauge).  That's not good.  It might work as the panels usually put out 14-15v, but getting into the "iffy" territory I think.  You'll probably want larger wire.   To save some money, might get 80' of 4 wire (3+gnd) Romex type wire at the local hardware store, and use 40' each for the pos/neg runs.  Just twist all 4 wires together, at both ends, of each 40' run of Romex.  Four #12 AWG wires running in parallel this way is the equiv of about a single #6 wire, and would only be a .4v drop total over the 40' - and should be a lot cheaper than 80' of #6 wire.

The battery question is the tough one.  A 18AH battery isn't very big.  To keep it above 80% capacity for longer life, you'd only be able to draw 3.6 AH from it after the sun goes down - that's only 46 watt hours (12.8v X 3.6A).   Or said differently, a 15w CFL light bulb for 3 hours.   Since your panels should provide about 16AH a day, I'd say 80AH of batteries would be the minimum.   Then you can draw off the 16AH of juice your panels put in each day, and not drain the batt(s) below 80% charge.   

See what I mean - new coupon iPhone app, time on my hands, wandering around Northern Tool...viola...instant karma...
....just not sure if I did something good or...baaad...!?

Yep, you can go broke trying to capture and store 'free' energy :)   Sure is nice when the power goes out though.