Help Designing 200 Watt System

[B and C]

Since it's finally starting to cool off (hi 80's) here west of Houston, it is time to get on with the modifications.

So now that I am ready to add solar, Renogy is out of stock on their 100W flexible panels :dodgy:   I was hoping to place an order for my system soon.  Maybe they will be back in stock by the time I get the controller installed.  I know it has to be installed before the panels are installed anyway.

Everyone is going to ask how much power do I use.  I want to build with the assumption that my usage may increase, but not buy anything I don't need if my consumption does not increase.  All I can say is this is what we have used.  We were running off battery power for a week and used just 40% of the battery before firing up the generator, so my needs are not great.  I have 375 ah of AGM batteries (3x125A).  These are connected in parallel and I have the ground connected on one battery and the positive connected to the battery at the other end of the string.  I consider this my learner set as they were used for 3 years on a telephone system battery backup (UPS) and did not cost me anything.  They are wired with 6 Ga. cable.  I have a Bogart Engineering TM-2025-RV Trimetric battery monitor with a 500 amp shunt installed about 4 cable feet away wired with 6 Ga. cable.  I would really like to not deep cycle the batteries and it will give me a great deal of reserve, just pull a little and replenish the next day.  Hopefully running this way I will not be tickling the batteries to death.  I installed a Progressive Dynamics PD 3945 so I can recharge from generator and is how the batteries are maintained while on shore power.  I installed this before reading the threads and am pleased with myself for picking one that is recommended here (pats self on back).  They also recharge from the alternator.

I do have a few questions as I am not sure of what I am looking at as far as panel outputs and charge controllers.  Lots of threads and I do not recall a shopping list for a 200 watt setup like I want to start with.  I know I need a programmable charge controller since I have AGM batteries and probably a mppt one at that.  I am not looking for ideal as the batteries work for me and I will replace them every few years as dictated.  Just the cost of power in the boonies!  That is what reserve funds are for anyway.

I want to start with 200 watts of solar and see if this will cover my daily usage and if it does not, going to go to 300-400 watts which sounds like a lot to me.  From what I have been able to glean is if I want the panel's remote from the vehicle, a 10 gauge 50 ft. extension cord should work if I wire the panels in series and have a couple of extra feet at both ends for a quick disconnects (100v male/female wired to endpoints?) and it would still allow the extension cord to be used for its originally designed purpose and I already have the cord.  I don't want to cut the ends off as this is an expensive cord.  This is how it will always be connected (through the extension cord) whether it is lying on the ground or hung from (or on top of) my awning.

So now to my questions:

1.  Do the MC4 connectors come apart easily (no tools) or am I going to have to cut them off and connect the 110v adapter plugs directly to the wires?  I can use these on both ends to make my little adapters if they come apart easily or at least the panel end if they don't.  I would guess that I would make the connections in the 110v plugs to the ground and neutral wires in case someone were to plug 110v into it.


2.  What charge controller to get?  I am sure to get a LOT of different opinions on this one.  I have been eyeballing the Bluesky Solar Boost 3000i. Link takes you to the pdf manual 

http://www.blueskyenergyinc.com/uploads/pdf/Manual_BSE_SB3000i.pdf 

If I have to add the other 100 or 200 watts of panels (max 400 w) will this controller work?  

If you can suggest a better controller for my application, it would be great.  I do not really have a budget for this but I am not made of money either.

2.  I would like to tie the controller to the batteries with 6 Ga. cable (I have a lot of this and the crimp ends), but what fuse to use?  All I see are 10Ga. wire fuse's.  Do I just use 10 Ga. wire for the controller to battery?  This run will be about 6 ft.

3.  If I use smaller wire (or 6 Ga.) to the battery from the charge controller, can I just adjust the charge controller to where the batteries see the correct charging voltage?

4.  How do I end up wiring the panels?  Can they all be put in series (2,3 and 4 in series) so I can get the panels farther away or do I have to parallel/series or series/parallel them?  Can I run 3 in series with the recommended controller or do I need to skip straight to 4 and use one of the parallel methods?

I guess I need a shopping list.

1.  2 100 watt solar panels (waiting for availability)
2.  1 charge controller make/model with battery temp sensor
3.  1 ea male/female 110v plugs
4.  1 fuse - size/Ga.
5.  MC4 10 Ga. extension cable for the two ends to connect to the 110v plugs.  (parallel plugs later if I add more panels)
6.  6 Ft. 6 Ga. cable to positive (double the 6 Ga.?)
7.  3 Ft. 6 Ga. cable to Shunt (double the 6 Ga.?)
8. Misc. mounting screws, tie wraps, etc.

Forgetting????

I do not want to stop the installation in the middle while I have to wait for a part to arrive.  I should be able to get the controller installed in a day or less.  I am old and work slow with plenty of breaks  I also have a bad case of CRS (can't remember sh*% err stuff!) and is why I am asking for help  

Thanks for helping.

Brian

 

[akrvbob]

I really appreciate it when people do their homework and just come here for clarification. You've got it all done really well!!! Everything you said up to here is just great!

So now to my questions:

1.  Do the MC4 connectors come apart easily (no tools) or am I going to have to cut them off and connect the 110v adapter plugs directly to the wires?  I can use these on both ends to make my little adapters if they come apart easily or at least the panel end if they don't.  I would guess that I would make the connections in the 110v plugs to the ground and neutral wires in case someone were to plug 110v into it. No they don't come apart easy,  but you'e already got it figured out, never cut the MC4 from the panel, get an extension and cut the ends off and put the 110 ends on. The critical point is to chose a color from the 110 cord and use it for Pos and neg (red and black through out the system. Really very simple!

2.  What charge controller to get?  I am sure to get a LOT of different opinions on this one.  I have been eyeballing the Bluesky Solar Boost 3000i. Link takes you to the pdf manual I'm a big fan of Blue Sky! I have two of their controllers and they are great! I had a friend who had a problem with his, so he called the company and they did a truly superior job of customer service, even though it wasn't their fault. 

http://www.blueskyenergyinc.com/uploads/pdf/Manual_BSE_SB3000i.pdf 

If I have to add the other 100 or 200 watts of panels (max 400 w) will this controller work?  Just be sure it can handle all the voltage you want to give it. In series your at 38 volt and if you add a third panel you're at 57. I'm a big believer in redundancy, I'd give serious thought to just adding another 100 watt kit in the future so you have two complete systems. If one every fails, you still have power.

If you can suggest a better controller for my application, it would be great.  I do not really have a budget for this but I am not made of money either. I don't have any direct experience but the Midnight Sun Kid is very highly spoken of. I probably know a dozen people with the Morningstar Tristar and I've never heard a bad word about them.

2.  I would like to tie the controller to the batteries with 6 Ga. cable (I have a lot of this and the crimp ends), but what fuse to use?  All I see are 10Ga. wire fuse's.  Do I just use 10 Ga. wire for the controller to battery?  This run will be about 6 ft. The fuse has to handle high voltages, not just 12 volt so you might want to go with circuit breakers in a box. Get them from most solar places. No, you want a bigger physical size, fatter diameter wire going from the controller to the batteries because the MPPT is going to step down the volts and step up the amps. 6 gauge will be fine.  

If I use smaller wire (or 6 Ga.) to the battery from the charge controller, can I just adjust the charge controller to where the batteries see the correct charging voltage? I have no idea what this means but I'm pretty sure the answer is no. You want the charge controller to do everything after you give it the parameters. It uses very technical algorithms to set the voltage. It's much smarter than you are.

4.  How do I end up wiring the panels?  Can they all be put in series (2,3 and 4 in series) so I can get the panels farther away or do I have to parallel/series or series/parallel them?  Can I run 3 in series with the recommended controller or do I need to skip straight to 4 and use one of the parallel methods? If the controller can handle the voltage you can do it either way. If the manual and spec sheet doesn't make it clear, call Blue Sky and ask them.

I guess I need a shopping list.

1.  2 100 watt solar panels (waiting for availability)
2.  1 charge controller make/model with battery temp sensor
3.  1 ea male/female 110v plugs
4.  1 fuse - size/Ga.
5.  MC4 10 Ga. extension cable for the two ends to connect to the 110v plugs.  (parallel plugs later if I add more panels)
6.  6 Ft. 6 Ga. cable to positive (double the 6 Ga.?)
7.  3 Ft. 6 Ga. cable to Shunt (double the 6 Ga.?)
8. Misc. mounting screws, tie wraps, etc.

Forgetting????

I do not want to stop the installation in the middle while I have to wait for a part to arrive.  I should be able to get the controller installed in a day or less.  I am old and work slow with plenty of breaks   I also have a bad case of CRS (can't remember sh*% err stuff!) and is why I am asking for help  

Thanks for helping.

Brian

 

[wayne49]

I suggest buying the inexpensive MC4 "wrenches" from Renogy (from Renogy or Amazon) to "break" the MC4 connectors easily.

-Wayne

 

[B and C]

Great idea on the MC4 wrench set Wayne49. 

Bob, as always you break it down to where even I can understand it.  I am in a class B and don't have a lot of vertical space (where I want to mount it) to mount the charge controller.  I really like that Tristar but the dimensions are huge compared to the Blue Sky.

I will call Blue Sky for confirmation.

Thanks, Brian

 

[highdesertranger]

what's the reason for the 110v plugs? why not just leave the MC4's? highdesertranger

 

[B and C]

what's the reason for the 110v plugs?  why not just leave the MC4's?  highdesertranger

The plugs are so I don't have to cut the ends off my 50 Ft. 10 Ga. extension cord.  Quick connect and disconnect.

Brian

 

[highdesertranger]

so now I am even more confused, why do you need a 50ft extension cord? remote panels? highdesertranger

 

[B and C]

I want to park in the shade and put the panels on the ground (in the sun).  Barring that, I will either hang them from the awning or lay them on top of the awning.  The cord allows me to put them where they will be the most use to me.

Brian

 

[highdesertranger]

I do that to, but I just use MC4 cable. highdesertranger

 

[B and C]

Sorry HDR.  The tone of my last post sounds a little curt.  Dinner was ready right as I started the reply so I rushed through it.

I plan on using two of Renogy's flexible 100 watt panels because they take up very little room at 0.2 inches thick each and are very light.  I will be able to stow them easily out of the way in my lower outside storage compartment.  The charge controller will be going in the lower storage compartment on the other side where it is closer to the house batteries.  The charge controller will have one 110v plug on the solar panel input side of the charger so I can use my extension cord to connect to the panels.  I will be making an adapter cable from the panels MC4 connectors to a 110v plug.  That is why the MC4 extension cable is on my list, to use for parts.  I don't want to cut the MC4 connectors off the panels.  I hope this clarifies it.

I do not want to fasten panels to the roof as I will always have to park in the sun.  If I am going for a walk or drive into town, they will be easily stowed away.

Brian

 

[highdesertranger]

hey don't worry about sounding curt, I didn't take it that way at all. some say I sound that way all the time. highdesertranger

 

[B and C]

Unfortunately, I am in that boat with you.  Sometimes I can be a crotchety old fart too

 

[akrvbob]

I'm a big fan of the 110 volt extension cord. You already have it so it's free, it's weatherproof and nearly indestructible, and it can be used for more than one thing. Being 50 feet it will get the panels far away form the rig then it's easily wound up and stored..

Perfect choice!!
Bob

 

[jimindenver]

50 feet is a good leash for a portable. I started with 25 feet and then added a second portable with a 50 foot run and the difference was night and day. I could keep the shorter portable in the sun but was moving it more often.

 

[B and C]

I am going to continue this thread to maybe help someone down the road get an idea of the trials and tribulations they may have to go through because I am going through them now only because I have very narrow specifications.  I am trying to do my research before talking to a salesman and get talked into something that may not be the best fit for me and I don't think that fast on my feet anymore :s

Well, the Blue sky Solar Boost 3000i was a bust  It will not do series panels.  I think the cut-off voltage was somthing like 24 volts.  The Renogy panels only produce a max. of 17.7 volts (X2=35.4V which is over voltage) and would have to be connected in parallel.  This defeats the purpose of the series configuration in that I will have my panels out in the sun while I stay in the shade using a 50t. 10Ga. extension cord + adaper cable length.  The Blue Sky salesman ran a voltage drop and said it would only be 4%? (if I remember correctly).  He may have only done a calculation on 200W though.  When I do an online voltage drop calculator, I get 15.59% and voltage drop of 2.76V @ 60Ft of 10Ga. wire with the panels putting out a max of 17.7V and a current of 22.8 amps (4x5.7A).  Way too much voltage drop for the Renogy panels to be a viable option running in parallel especially if the day was overcast or hazy. I could be figuring this wrong too.  It seems the Solor Boost 3000i was designed for 36 or 60 cell panels which would be at a higer input voltage than the Renogy 30 cell panel.  They suggested a Solar Boost 3024 as this would handle the panels the way I want to configure them, but this thing is large and requres more space that I have to mount it.  The Morning star Tri-star is also huge.

I am installing this in our Roadtrek in the understorage area where it will be close to the batteries but out of the way and have ventillation.  The vertical wall space to mount it on is only 12 inches tall.  I could move it to the closet inside but would be giving up a huge amount of space on the inside and it would place it electrically farther from the batteries and panels.

This leaves me with the Midnite Solar Kid as it seems to be the last programmable one that is worth anything (there may be others but I am not aware of them).  I like this one because it is small and doesn't seem to require all the vertical ventillation space which they do not even mention and is only 9.5"Wide x 6.6" tall x 3.4" deep.  It will do series panels, but I lose the chassis battery charging option.  Dang, it is more expensive too!  I could not find any info on minimum mounting clearances either which leads me to believe this will be my best fit.  I guess it just goes to show if you want a MPPT controller, it is going to cost (one way or the other).  I am going to call Midnite Solar on Monday to make sure the calculations that I put in on their website about the Renogy panels holds firm and it will work for me.  They ask for a lot more info on the panels than Renogy supplies on their site :huh:

So it is waiting game again

Brian

Renogy rep want to answer 2 of these questions that the calculators ask for?

These are for your 100W bendable panels:


 
Temperature C°   F°  

PV Module Data (STC)
(Found on back of module or spec sheet)

Power (Watts) 100
VOC (Open Circuit Voltage) 21.7
VMP (Maximum Power Point Voltage) 17.7
ISC (Short Circuit Amperage) 6.1
IMP (Maximum Power Point Amperage) 5.7
VOC Temperature Coefficient C° ? -0.33% Default
VMP Temperature Coefficient C° ? -0.45% Default

Environmental Data

Coldest Ambient Temp F° 22
Hottest Ambient Temp F° 104
Nominal Battery Voltage (Volts) 12

PV Array

Number Of Modules In Series 4
Number Of Parallel Strings 1

Total Modules 4
 Submit Parameters Reset

 

[SternWake]

I have not kept up with solar controller offerings.


Since October 2007, I've been  using the Bluesky SB2512i and the IPN pro remote which is a battery monitor and also allows me to change the voltage setpoints and durations.  It is MPPT, but can only handle 12v nominal panels, upto 25 amps.

My only regret is not getting the ix model instead as it allows for a battery temp sensor.

Bluesky does offer a 2512HV than can accept higher voltage panels.  The charge controller is a nice compact unit, fitting inside a standard 4" electrical box.  The IPN pro remote might not be as good a battery monitor as the victron or tri metrics, but I've found it to be a very enlightening tool, a great learning tool. My biggest complaint with it is when another charging source is charging and brings the voltage above the controller setpoints, the controller Instantly goes to 100%  and 0AH from full.  As my Alternator can go upto 14.9v, this happens often when I drive.  Not a huge deal if the solar can actually hold Absorption voltage for long enough afterwards, but if it cannot then the % figure, which I never use anyway, and the AH from full screens are not accurate, and will not be until I reset it, at night.

If I had to Start a solar project over from scratch, I think I would get Kyocera's 325 watt panel and an appropriate MPPT controller.  Right now I have a 130 watt framed Kyocera and a Unisolar stick on pvl-68 watt panel in parallel, and will get upto 13.5 amps on June21 with them flat on my roof.  I could certainly make use of another 127 watts.  Perhaps not every day, but it is hard to have too much solar and all too easy to have too little.

Hope you find a system which meets your expectations.

 

[B and C]

Thanks SW. Wish I had a place to carry a large panel or three. The rigid panels are a LOT cheaper.

The Blue Sky guy did not even mention the 2512ix-hv. Great size and has the chassis battery charging option still. That looks like it gets real pricey (~$500) if you have to add the IPN Pro remote to program it and the temp sensor. I will have to call back and ask about the 2512ix-hv. I will check on the Midnite Solar Kid too. At least there is another option to look at.

I already have a Trimetric, so none of the monitoring features are needed.

Brian

 

[SternWake]

If you already have the trimetric, then i'd not bother with the BS2512HV, as to get the full features of this charge controller requires the IPN pro-remote and one does not need to have 2 battery monitors.


I think the Absorption voltage presets on the BS2512 series are only 14.2v, and most batteries require higher voltages and how long this higher ABSV is to be held is a moving target to achieve a true 100% recharge with many variables affecting the precise time required.

So any controller which allows you to set the ABSV and its duration it is to be held, as well as float voltage, will allow you to fine tune the settings and keep the battery happier significantly longer.

I would not recommend the BS2512 series without the IPN pro remote to accommodate these absorption voltage/duration adjustments.

It is these adjustments which allow one to indeed fully charge a battery, and a battery returned to 100% charge will last significantly longer than one only returned to 94% via a preset unadjustable algorithm.

Blinking green lights that supposedly indicate a fully charged battery, in reality mean only that the charge controller held absorption voltage as long as it was told/programmed to do so.  14.2v achieved and held for 90 minutes is not the same as 14.8v  achieved and held for 3 hours, or 4 hours, and this might be required for a 50% depleted battery to maximize the Specific gravity and return to a true 100%.

Often on this forum, a poster will state that their solar has their batteries full by XX:XX o'clock daily, but all it really means is the controller has dropped to float voltage.  A Hydrometer will prove otherwise, or, with an AGM battery, when amps taper to 0.5% of the AH capacity, then the battery can be considered fully charged.  Anyone who employs either method for determining  whether their battery is indeed full, will find their blinking green light/full charge indicator is an insane liar more often than not, especially those that cycle their batteries deeper.
  But for most it does not matter and works 'just fine', which is fine, for them.  But if maximizing battery lifespan is a concern/goal/desire, it is anything but.   'Just fine' can mean, just has not failed yet, or mean 'I have no idea, the green light fills me with warm and fuzzies and that is all I need to know.'

Also, if the battery is not cycled the night before, then the solar controller holding 14.7v for 3 hours is simply abusive to the battery, so changing the voltage or the thresholds that force float voltage instead can also greatly increase battery longevity.

The IPN pro remote allows me to pick 30 minutes to 4.5 hours holding ABSV before dropping to an adjustable float voltage, but it can also force float voltage when the amps required to hold ABSV fall to a certain level.

Currently on my 90AH AGM battery, I have this set at 14.4v 3.5 hours and 0.4 amps, so it reverts to 13.6v once it is held for 3.5 hours or when the amps taper down to 0.4.

I so wish plug in automatic  chargers allowed these variables to be set but it seems they all employ similar algorithms that will safely undercharge most every deeply cycled battery.  I use an adjustable voltage 40 amp power supply, as a manual charger, and I determine how long it holds absorption voltage, manually, with the help of an Ammeter.

My next flooded battery I will set the controller to 14.8 ABSv, 13.2v float and the duration/ threshold will be figured out by using a hydrometer and some trial and error.  I will seek 1.280 specific gravity and set the ABSV and its duration accordingly to achieve this daily, at my levels of battery depletion, in my climate.  The goal is a 100% recharge daily via solar combined with other charging sources, but to not hold Absorption voltage any longer than needed.  Overcharging causes more water usage and deteriorates the positive plates faster.

 

[akrvbob]

That's a shame because i have a friend who just bought the 3000i and we are both very impressed with it. With just the face plate he could set the absorption voltage to 14.8 and extend the time it held it. He got an AGM battery that likes big voltages.

But he has two Kyocera 140 panels so they are low voltage, we didn't even check the voltage limit on the 3000i because of that.

They probably didn't suggest the 2512 series because they won't handle the 400 watts which may be your ultimate goal. Blue Sky appears to just be staying out of the big amperage market and focusing on smaller controllers.
Bob

 

[Sabatical]

This is our current setup in the camper. Two Kids for 840 watts via two panels. Working well for us and we use the Whiz Bang Jr. for monitoring.