which MPPT controller..? which battery type..?

[billmorrow]

Hello..

just starting with mono solar panels and trying to choose the best battery type..
GEL or AGM..? 8D or smaller..?

and best MPPT controller..
midnite solar 150 0r 200 0r (gasp!) 250..?
or itracer IT6415ND which is a new model and seems really capable..

both offer PC connectivity via Ethernet or serial or some sort of kludge -> USB with PC software..

seeking some thoughts from those who have some experience..

i'm not even sure I should overbuild as I usually do for future expansion..

also, any thoughts on EMP or CME hardiness for solar..?

thanks..
Bill

[Sunking]

just starting with mono solar panels and trying to choose the best battery type..
GEL or AGM..? 8D or smaller..?

Non of the above. Ideally you would use FLA, unless you could justify AGM. Gel should not ever be used.

and best MPPT controller..
midnite solar 150 0r 200 0r (gasp!) 250..?

No contest Midnite Solar smokes all the competition.

[SunEagle]

Hello..

just starting with mono solar panels and trying to choose the best battery type..
GEL or AGM..? 8D or smaller..?

and best MPPT controller..
midnite solar 150 0r 200 0r (gasp!) 250..?
or itracer IT6415ND which is a new model and seems really capable..

both offer PC connectivity via Ethernet or serial or some sort of kludge -> USB with PC software..

seeking some thoughts from those who have some experience..

i'm not even sure I should overbuild as I usually do for future expansion..

also, any thoughts on EMP or CME hardiness for solar..?

thanks..
Bill

Bill

Before we can recommend a battery type (although GEL is not worth it and AGM can be expensive so IMO FLA is best bang for your buck) and size we would need to know more about your watt hour power needs. Also you mention panels but not their wattage and type. If you haven't purchased any panels yet then don't until the battery system is properly designed. Then you determine your panel size and charge controller.

[Mike90250]

.....No contest Midnite Solar smokes all the competition.

Except in low light and self-consumption. My evergreen array on a Tristar MPPT outperforms the midnight with evergreen array, in low light and cloudy conditions.

[billmorrow]

Non of the above. Ideally you would use FLA, unless you could justify AGM. Gel should not ever be used.

I plan on housing the batteries (8D at this moment) in a generally unventilated mechanical area of my home, thus I can not have ANY outgassing..

I mentioned GEL since I had 6 sonnenschien prevailler gel 8D batteries on a boat for years with no trouble..

the AGM technology is new to me thus the question of which type would be best for a solar array..

i'm looking for longevity so I don't think flooded is a good idea for me..

so, please, why NOT GEL..? or AGM.. if the cost is less important than having a system that I can expand and enhance as time goes by..

No contest Midnite Solar smokes all the competition.

reading the specs this new Chinese unit is more efficient (they say) and at $525 more or less delivered is more cost effective..

though the midnite, while it looks like a vending machine waiting for a nickel seems to have a good reputation..

thus my battery type question..


Bill

[billmorrow]

Bill

Before we can recommend a battery type (although GEL is not worth it and AGM can be expensive so IMO FLA is best bang for your buck) and size we would need to know more about your watt hour power needs. Also you mention panels but not their wattage and type. If you haven't purchased any panels yet then don't until the battery system is properly designed. Then you determine your panel size and charge controller.

I have purchased 10 100 watt renogy mono panels and some cable, plugs and so forth..
about 22 VOC..
the ultimate plan is start with a minimal setup and expand it..

planning on starting with two 8D AGM (so far) in a 24 volt array and add another two every few months along with a pure sine wave inverter with the ability to feed some power back into the grid..

also trying to decide between some sort of parallel system for backup/redundancy..

Bill

[PNjunction]

Gels are typically abused with improper charging voltages, (usually limited to about 14.0 to 14.1v max) and limited to no more than C/20 current - hence they are slow to charge and prone to abuse.

Sonnenschein's gels are a different story, and can be charged at 14.4v with unlimited inrush current. However, many consumers don't take the time to read the battery manual or the specs from the distributor, or assume that gel's are "drop in". For instance, Sonnenschein also sells Deka Gel-Tech gel's which will burn up at 14.4v:

http://www.sonnenschein.org/Prevailer.htm

Still, unless you know your power needs over time, and where you are located to find out your "solar insolation hours", which are quite different than just sunrise-to-sunset, you could easily end up with a very expensive "deficit-charge" scenario where the batteries die early on. And you know that the cost of running off-grid from batteries is about 10x what the local poco charges you, right?

So the first thing to do is actually measure your power. Use a kill-a-watt meter, ammeters and such to do so and multiply that by the time you expect to run at least daily.

Unless you actually get some measurements on your power needs, you'll be winging it and that ends up being very costly as you rebuild the system over and over.

Stop buying things right now. Measure your power needs first. Then you move forward. Also note that attaching an inverter to the grid unless it is authorized/inspected and engineered to do so safely, can be illegal in many areas. You can easily take a lineman or somebody else's life with an illegal installation, or at a minimum burn your house down where there is no insurance recourse.

Slow down - you've bitten off more than you can chew at this point. Start with the basics of measuring your power needs.

EMP / CME hardness? Yeah, right. Forget it. This can mean that the question is not really serious, so we are watching responses carefully.

[billmorrow]

Except in low light and self-consumption. My evergreen array on a Tristar MPPT outperforms the midnight with evergreen array, in low light and cloudy conditions.

looked at the specs for the tristar..
a 60amp is about $500 and change..

question is can the firmware be updated..?
I see it can be connected via Ethernet.. good..! makes it a definite contender..
anything else I am missing in the spec sheet..?

thanks..

Bill

[SunEagle]

I have purchased 10 100 watt renogy mono panels and some cable, plugs and so forth..
about 22 VOC..
the ultimate plan is start with a minimal setup and expand it..

planning on starting with two 8D AGM (so far) in a 24 volt array and add another two every few months along with a pure sine wave inverter with the ability to feed some power back into the grid..

also trying to decide between some sort of parallel system for backup/redundancy..

Bill

Ok. You have 1000 watts of panels and want a 24 volt system. You can go with the AGM but they are expensive. Those 8D AGM's are around 250Ah and will require you to wire 4 pairs in parallel to get a 1000 Ah rating at 24volts which is not a good idea. If you only use 2 in series there is a possibility of having too much panel wattage which could over charge a small battery system if you do not get a really good MPPT charge controller.

Also once you have started using some batteries adding new ones to the old just cause the new ones to fail faster. Slowly expanding a battery system is not good practice.

Biggest mistake for most people wanting to build a solar battery system is that they feel they can do it in stages because the do not have enough money to build it all at the same time. Doing it in stages will not save them money and can actually kill their batteries much sooner.

Best solution is to design your battery system around the amount your daily watt hour load will be. Then get the right amount of panels and charge controller.

[Mike90250]

i'm looking for longevity so I don't think flooded is a good idea for me..

Good flooded will outlast premium AGM/GEL by several years.

Consider (don't BUY ANYTHING more) building a vented box in your basement for regular batteries, and have a good plan to move batteries in and out of the basement.

The Morningstar TS-MPPT is updateable - I've done updates to mine several times. But it does not come with the LCD meter panel. That's an extra item. The Classic is remotely controllable, the TS-MPPT is not easily remote controlled.

[billmorrow]

thank you for the food for thought..

just to clarify I was going to add 2 8D's in 2 months..
I was not planning to hook up all the panels at the same time..
I was planning on the best charge controller so overcharging would not occur..
initially was going to only power LED lights throughout the house.. 12 VDC or 3 VDC depending..

next item for consideration was pure sine wave inverter or two.. 1kw at minimum with 2kw or 3kw and appropriate surge but I need to do the math..

now with the help you all have given I should rethink a bit..

starting with flooded batteries and whether 8D or more smaller capacity (golf cart type) might be better..
I guess a vented closet might do.. but how much outgassing is present..?!

thanks again..

[inetdog]

initially was going to only power LED lights throughout the house.. 12 VDC or 3 VDC depending..

You really do not want to use 3V lights around the house unless you put them in series or use a buck converter to power them from 12V or higher. The voltage losses in long runs of copper wire will require you to use exceedingly expensive large diameter copper wire to handle the current.
For every reduction of a factor of two in load voltage for the same power, you have to quadruple the wire size to keep the same efficiency in the wiring.

Most people find that even wiring with 12V DC in anything larger than a single room cabin gets too expensive.

[SunEagle]

thank you for the food for thought..

just to clarify I was going to add 2 8D's in 2 months..
I was not planning to hook up all the panels at the same time..
I was planning on the best charge controller so overcharging would not occur..
initially was going to only power LED lights throughout the house.. 12 VDC or 3 VDC depending..

next item for consideration was pure sine wave inverter or two.. 1kw at minimum with 2kw or 3kw and appropriate surge but I need to do the math..

now with the help you all have given I should rethink a bit..

starting with flooded batteries and whether 8D or more smaller capacity (golf cart type) might be better..
I guess a vented closet might do.. but how much outgassing is present..?!

thanks again..

Before you look at what size inverter to get you do need to do the math of how many watt hours you will be using in a day including surge capacity.

Using an inverter that is much larger than the battery system can support will easily drain your batteries and may have a high "no load" loss due to inefficiency. A 3kw inverter may consume 150 watts just sitting there.

Adding those 2 additional 8D batteries in 2 months is ok as long as you do not use the first 2 at all. Then you will have a relatively "fresh" set of 4 that go into use at the same time.

I built a small battery system consisting of 4 - 50Ah 12v AGM batteries to get 12volt 200Ah capacity. I purchased them over a 4 month period and just kept an eye on their voltage to make sure they stayed above 12.4 volts. I then wired them up together at the same time. What I then found out was that the cost of those 4 AGM (~$400) could have gotten me 2 - 6volt FLA 232Ah batteries for about $250. Go figure I could have saved $150 and gotten more Ah out of my system as well as not having "paralleled" wired batteries which will shorten their life.

And after all that I also found out my 200Ah system can only safely produce about 600 watt hours a day. Then to find out I need about 1200 watt hours to run an oxygen machine a few hours during the night. I jumped into the purchase mode way before I knew what I needed and then spent way to much to get it.

Do the "math" first. Know your daily watt hour load and then size the battery system followed by the panel wattage and charger.

[billmorrow]

Before you look at what size inverter to get you do need to do the math of how many watt hours you will be using in a day including surge capacity.

**massive snippage here.....**

Do the "math" first. Know your daily watt hour load and then size the battery system followed by the panel wattage and charger.

you are correct..

but I tend to jump before looking in things like this..
I know just enough to get into trouble or wind up spending more when trying to manage costs..

daily watt hour load can vary quite a bit depending on weather..
I usually over build so as to have spare capacity..
(i'm the only boat captain I know who carried a sea anchor.. for so little expense, great safety item.. only has to save your life one time.. a small example of the way I tend to view things..)

it did not occur to me that a good inverter would suck power from its source when not doing anything..

maybe several smart inverters in parallel that are smart enough to shut down when not in use..
also, in my mind, is a grid tie inverter..
so as to mitigate the power bill a tiny bit..

You really do not want to use 3V lights around the house unless you put them in series or use a buck converter to power them from 12V or higher. The voltage losses in long runs of copper wire will require you to use exceedingly expensive large diameter copper wire to handle the current.
For every reduction of a factor of two in load voltage for the same power, you have to quadruple the wire size to keep the same efficiency in the wiring.

Most people find that even wiring with 12V DC in anything larger than a single room cabin gets too expensive.

about wire sizing..
and FWIW, in my colorful past wife and I did 10 years of liveaboard on an Irwin 65 sailboat (hull107 I think) and a kha-shing 65 motoryacht..
boats are an interesting way to live and travel..
they are wired usually with 12VDC and 220VAC split into two 120VAC..
now talking about the 12 volt stuff, none of the wiring I ever encountered was more than 14AWG or 16AWG except of course for the house batteries (the 6 prevailler 8D's)..
I had an interesting setup I did myself which included a trace 2KW (3.5KW surge) inverter that ran 24/7 and powered several circuits including the refrigerator on the motor yacht..
batteries lasted 10 years..
incandescent or fluorescent lighting, 12 volt search light (huge thing!) 12 volt bow thruster (always a headache), 12 volt dinghy davit and so on..
in this century and this year LED lighs come in lots of types from super costly whci nifty cooling fins to smd LED's on a flex PWB for, like $3 / yard..
so I have been experimenting with these in and outside the house.. the security phone now has some LED lights under its hood which I powered with a spare pair of cat5e cable about 50' to 60' long..
no problem, bright as they should be..
also power 2 strings of about 10 to 12 feet using a pair of wires stripped from a reel of old hard drive ribbon cable..
that stuff is really light.. really.. maybe 45AWG or so..

these LED lights will take a lot of voltage variation..
the 3VDC is for maybe single LED's.. the 12VDC is for those strings of lights..
ALL this is experimental..
not enough power to cause any problem..
in fact, I power a security camera (i'm testing the tolerance to cat 5e cable in 100' runs.. using video balun's and 12VDC for the speco intensifier cameras..

thanks for pointing out these BUCK things.. I already knew about solid state voltage regulators but never got into any kind of circuit assembly with all these new devices 'till now..
another FWIW my first transistor was a Raytheon CK722.. i'm sure google can say what year THAT was introduced.. try IKE was president..
Wikipedia is pretty forthcoming about BUCK and so forth..

I really am grateful for the time taken to reply and help me get up-to-speed on the newest in PV panels and all the new control stuff available..

one more comment: is EMP (HEMP), CME and lightening protection a part of the knowledgebase hereabouts..?

thank you guys..

[Mike90250]

one more comment: is EMP (HEMP), CME and lightening protection a part of the knowledgebase hereabouts..?

EMP & HEMP put electronic gear in a cardboard box (insulator) and place that in a metal trash can with a metal lid, inside a metal building. Your car won't start, and all other electronics will be fried.

CME, till you have more than a 1/4 mile of wiring above ground, not much to worry about.

Lightning protection, surge arresters at the PV array, input to the battery shed, output of the inverter. Use good low impedance grounding. That will help with nearby strikes, but a direct hit on stuff, will generally kill it all. Arresters can only do so much.