Took the Solar Plunge
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I know I've asked you this before Phil but I can't remember your reply. ::)
Since you have significant real world experience of this could you put some numbers on it. For example, given that the Alix box consumes ~5W (maybe less when idle?) what size panel and battery do you consider sufficient for continuous running? How many hours of sunlight does that require? Do you use a charge controller of some sort to keep the battery equalised?
These things vary substantially depending on where you are or course but some numbers would be very useful for anyone else considering this.Steve
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I was able to buys a Optima blue top marine battery. It can be use to store energy produced by solar panel. Can anyone confirm this.
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You can store energy in any battery, that's pretty much what defines a battery. ;)
But that looks like it's designed as a starting battery and would not be well suited to deep cycle work like a solar install.
Edit: But it looks like I can't read a website! See below.This thread is in general discussion but this is not the right forum to be asking about batteries in general.
Please keep discussion here to running pfSense hardware from a solar install (or related).
Steve
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Optima blue top marine battery
Lots of experience with those - Yes you can use those and they last forever if charged properly. Over-voltage murders them though.
And you can cycle them hard and they have a very fast charge rate.
Been using those for many years. I charge mine with morningstar sunsaver charge controllers attached to 12v 100w solar panels.
Pretty easy and very reliable. Relatively cheap for small systems.
As far as estimating how many PFsense boxes you can run on them, lets say you get 6 hours of direct sun in a day with 200 watt panel.
1200 watt/hours
if pfsense were using 5w continuous for 24 hours per day thats 120 watt hours… So, with ideal conditions you could run 10.
Conditions are never ideal and I like to leave a big cushion, so I would only really depend on it to run 5 - with a very good battery. Possible with a 100amp hour battery, but 200 would be better and last alot long since it wouldn't be discharging so deeply.
There is a pretty big loss when charging lead/acid batteries. Its generally thought that they are 85% efficient. I'd bank on 60%
Meaning you need to build your system at least 50% bigger in terms of both solar cells used and battery used than you will think by doing simple watt/hour and amp/hour math.
For a single pfsense box:
So, in a place with lots of light, like Hawaii, a single 40 or 50 watt panel and a single 20 amp hour battery should work fine.
If its a northern place and not as much sunlight and frequent clouding you probably want to go with a 100w panel and at least a 50 amp hour battery unless you like having dead batteries and pfsense offline. I would always plus-size solar.
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Optima brand has been sold many times over the years. For a while they came out of Mexico and reports are that 48% of the cells were bad. Now the label states Johnson Controls. They did Navy Base security here for a while.
Either way Ive had a number of Optima battery's go bad on me over the years prematurely and will never buy one again.
Look up Deka Battery's made by the East Pennsylvania Battery Company. I bet your battery bank lives much longer. I tend to use 4XD banks in some of my remote sites and they seem to never go bad.
C&D is another remote site battery company we use which do well in the longevity department.
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If your batteries are going bad you are probably floating them at too high a voltage or running a desulphure cycle thats too aggressive for that type a battery.
Wet cell batteries are far more tolerant of crap controllers and people who do crazy things. You can go that route if you have doubts but they do need maintaining.
That said, Deka is well known and reliable. I personally won't touch gel-cells and only recommend AGM.
If Optima has started making crap batteries I wouldn't know… Seeing as how all mine are a couple decades old at least and have never failed, thus no need to buy new ones lately.
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If your batteries are going bad you are probably floating them at too high a voltage or running a desulphure cycle thats too aggressive for that type a battery.
Wet cell batteries are far more tolerant of crap controllers and people who do crazy things. You can go that route if you have doubts but they do need maintaining.
That said, Deka is well known and reliable. I personally won't touch gel-cells and only recommend AGM.
If Optima has started making crap batteries I wouldn't know… Seeing as how all mine are a couple decades old at least and have never failed, thus no need to buy new ones lately.
Like I mentioned.. My Deka battery banks last forever under the same conditions. We are a site maintenance company and would never use a car battery on a site but have inherited a few already supplied with the optimas. But we did run them in vehicles with the same results. They just didn't last.. Maybe they are better now that Johnson Controls makes them but Im not willing to test that theory. ;) Optima bought out Optimus (another AGM battery supplier) which we did have good luck with. That's about the time they moved production down to Mexico about 15 years ago.
Our last business owner was a battery tech on submarines in the Navy. Our battery knowledge base here if pretty fair. 8)
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By the way guys I'm leaning of buying another Optima blue marine from http://4wheelonline.com as my back up battery would you think $204.35 is a fair price with free shipping?
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Whats the size of the battery? D31M?
It would have to be a massive pfsense to need two of those!
Also, morbid curiosity. Are you planning to run it in parallel with the one you already have?
I don't recommend running new batteries with ones that have age on them on the same charge controller.
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I don't recommend running new batteries with ones that have age on them on the same charge controller.
This is good advice. Batteries of differing ages will discharge at different rates. You'll always have one (or more) pulling the good ones down.
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I don't recommend running new batteries with ones that have age on them on the same charge controller.
This is good advice. Batteries of differing ages will discharge at different rates. You'll always have one (or more) pulling the good ones down.
He surely has a good point in this post.
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@kejianshi said in Took the Solar Plunge:
I didn't even look those batteries up - They came from walmart which is pretty much all I needed to know…
http://upsinverterinfo.com/exide-inva-tubular-battery-models-available-in-market.html
These also work well if you need something you can easily order from napa or auto zone:
http://www.carid.com/optima/optima-bluetop-marine-battery-4309821.html
http://www.marine.hr/webshop/eng/products/battery-exide-dual-agm-50ah-orbital-deep-cycle-18.html
But having an actual solar battery is even better:
http://www.wholesalesolar.com/products.folder/battery-folder/rolls-s550.html
Any of the batteries listed above and especially the last one will allow serious daily cycling for years. here's how a homemade solar panel works.. https://batteryforinverter.com/how-does-a-homemade-solar-panel-work/
Or... You can buy a new bank of batteries from walmart every 6 months.
I strongly agree with kejianshi! Solar is one of the most affordable and sustainable forms of energy today! #SaveEarth
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