just a few que. about sun & wind

tutenkp

Hello (yes I am new to this forum, old to other forums ...... thats life) ,

I've been reading a lot lately, and learned new stuff ,, and I always appreciate those "wise guys" who have the answers you 're looking for.

with that being said, i'll get to my question(s):
is blue sky sb2000e a good investment for a MPPT charger? or there are better MPPT controllers out there in the $200 price range?

I currently have 4 solar panels of 63W and a small windmill (it gets windy at night)
I guess my question is, do i need 2 diff. charge controllers for solar & wind? .... as far as I know, sb2000e doesnt support windmills, right?

thanks

BB.

Re: just a few que. about sun & wind

tutenkp,

The "Blue Sky" controllers are an older design. They work and people are happy with them--but they have some known limitations (cannot support higher voltage solar panels/strings--helpful for long wiring runs and such).

The current, small best MPPT controller out there at this time is probably the MorningStar Sunsaver MPPT 15 amp 12/24 volt controller. Not cheap:

Morningstar SunSaver MPPT Solar Charge Controller

If you don't need MPPT, the standard PWM controllers can work well too (for less money).


Regarding wind turbines, generally they dump 100% of their energy into the battery bank -- this is to prevent a horizontal axis wind turbine from over-speeding in high winds with no load.

The typical connection is a "dump controller"... The controller is connected directly to the battery bank, and when the bank voltage gets above XX.X volts, the controller turns on its output and dump the excess energy into a load (typically just a resistance heater).

Many controllers include a "Dump Mode"--Use whatever controller gets you interest--MPPT or PWM does not matter for Dump Mode (having a pair of controllers can be nice--only one type of controller to learn and maintain).

Some new, larger, mid-range MPPT controllers should be out sometime in the "near" future (can be many months if issues arise).

-Bill

nigtomdaw

Re: just a few que. about sun & wind

You will still need 2 separate controllers though, if your wind turbine is not equipped with its own internal charge regulator unit like the AirX

As Bill said some of the popular controllers Xantrex C series and Morningstar TriStar series are mulitfuction charge controllers / load/dump, but if i remember right the can only do one of these functions at any one time .

tutenkp

Re: just a few que. about sun & wind

wow, you guys r fast ....

the thing is, I am building my own solar panels (i buy the cells off ebay) ... so my system is growing slowly ,,, with my 4 panels, i should be getting over 12A .... so I don't want to get a 15A and not be able to use it in couple of months ............ thats why I thought that the sb2000e will give me some room until 25A.

I am using A sunforce charger http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100658291

but sine I tried to use both the panels and the windmill together, the charger won't charge at stady current .... it will show 0.3A and then go up couple Amp for few seconds, and then drop back to 0.3A ... so I think the windmill blew it, somehow (even thou I used diodes to protect both the panels and the windmill)

I measured the output on the windmill, and it even got to 30V ( my system is 12V ) so thats why I was looking to controll the charger from the windmill as well.


Thanks guys for all the input.

BB.

Re: just a few que. about sun & wind

You have to be careful about how you wire stuff together and understand all of the pieces so that things work together...

Generally, you don't want or need a diode between the battery a solar charge controller. The charge controller should have its own internal diode type protection and adding a diode between the controller and the battery will confuse the charge controller (it will think the battery is ~0.2-1.0 volts higher charged than it really is--depending on diode type and charging current).

Many wind turbines use a diode to prevent the battery feeding the turbine's electronics--but not all wind turbines need a blocking diode (see installation manual and follow directions).

If you have an appropriate sized battery (its 20 Hour Rating ~10x or larger than the charging current) and everything was connected directly to the battery bus (and the battery was not disconnected while the turbine and solar charger were still connected together--which can cause electronics damaging high voltage)--then you probably did not over voltage your charge controller (properly working batteries are very good at keeping the voltage to a reasonable value).

Another place to check is your solar panel themselves. Take your DVM/amp Meter (set to 10 amp full scale), disconnect each solar panel, and place the A,mp Meter across the leads (solar panels are the only place it is safe to do a dead short--never dead short a lead acid battery) and see how much short circuit current you get when the panel(s) are in full sun... You may find you have a connection problem somewhere.

If the battery is fully charged and/or you have a series diode between the battery and the charge controller--you will see reduced current from your solar panels and charge controller.

What is the battery voltage at the time you see reduced current (~14.2 volts or so?).

-Bill

tutenkp

Re: just a few que. about sun & wind

I just checked the batteries and the charge controller was showing fully charged at 13.3V (i have 2 deep cycling marine batteries (125Amh)

I placed the diodes between the panels and the charger because I was using the same wire for the windmill ( its a 12/3 to be exact, and i used 2 wires for + and - together) (solar + windmill

---

>charger

---

> batteries) ..... this is why I think the volts from the windmill screw the controller ....

right now the panels are going through the controller, and the winmill is separated directly to the battery (no controller) ... I did however installed a diode and a 12V car light bulb to discharged whatever is over.

THe thing is, I am seeing lower results than before I added the windmill ...... the solar panels are ok, they output the same current as before ... the only thing left to blame would be the controller.

BB.

Re: just a few que. about sun & wind

Yes, connecting the wind turbine to the Solar Panel input of the charge controller could have cooked the controller.

I am not understanding the 12 volt light and the diode connection with the Wind Turbine... I don't think this is helping you (other than possibly wasting wind turbine power if before the diode, or wasting batter power if after the diode (lamp directly connected to the battery).

-Bill

tutenkp

Re: just a few que. about sun & wind

I am trying to decide if I should go with the sb2000e and get a separate charge controller for the wind, (like the xantrex Trace C Series 35A) .... or if I get the C35 would it work with the solar & wind connected at the same time? ...


thank you

mike95490

Re: just a few que. about sun & wind

tutenkp wrote: »

I am trying to decide if I should go with the sb2000e and get a separate charge controller for the wind, (like the xantrex Trace C Series 35A) .... or if I get the C35 would it work with the solar & wind connected at the same time? ...

thank you

No controller will handle both wind & solar You will need 2 controllers.

C35, C40 have provision for dump load, as if any wind gen works well enough to need it. ( I think they both do, check specs)

How much PV are you going to make? And how are you planning to have them last (weatherproofing) ?
You may see power gains with the MPPT solar controllers, but I think you will be better off spending less money on a PWM controller like the C35/40
and set one up for solar, and one up for wind. You have redundancy, and only one instruction manual.

tutenkp

Re: just a few que. about sun & wind

mike90045 wrote: »

No controller will handle both wind & solar You will need 2 controllers.

C35, C40 have provision for dump load, as if any wind gen works well enough to need it. ( I think they both do, check specs)

How much PV are you going to make? And how are you planning to have them last (weatherproofing) ?
You may see power gains with the MPPT solar controllers, but I think you will be better off spending less money on a PWM controller like the C35/40
and set one up for solar, and one up for wind. You have redundancy, and only one instruction manual.

I am actually running the whole thing as an experiment, and trying to determine if it is worth it or not (my dad and I used to be electricians). So yeah we're running home-made panels.
WIth the sunforce PWM controller I was getting 7A input, and only around 4A output (charging the batteries) .... thats why I figured I should be able to see an improvement with MPPT.

the sb2000e is about $236 and C35 is about 100$

right now I have about 150W, but I might double it .... will see

niel

Re: just a few que. about sun & wind

7a in and 4a out? it may be a defective controller as the controller is sinking 3a. i could be wrong though as some controllers are shunt types and they may do that. i'm just not sure if yours is a shunt type or not.

tutenkp

Re: just a few que. about sun & wind

i got the sb2000e ..... measured the Am of the solar panels (which is about 6A) but the sb2000e only displays 3.5A input, and 3.4A charging current ... I don't quite get it ..... is the charging current limited by the battery voltage? (i have 2 115Amh 12V batteries)

BB.

Re: just a few que. about sun & wind

The batteries have to be somewhere about 90%-80%, or less, State of Charge (i.e., somewhat discharged) for the charger to output full current (and use MPPT mode).

What is the battery bank voltage when charging? Less than 13.5 or over 14.2?

Assuming the controller is set correctly (right voltage, right type of battery), wiring is good (and wire not to thin), full sun (between ~10am-2pm), etc... Does the controller show what "charging mode" it is in (MPPT, or not).

-Bill

tutenkp

Re: just a few que. about sun & wind

BB. wrote: »

The batteries have to be somewhere about 90%-80%, or less, State of Charge (i.e., somewhat discharged) for the charger to output full current (and use MPPT mode).

What is the battery bank voltage when charging? Less than 13.5 or over 14.2?

Assuming the controller is set correctly (right voltage, right type of battery), wiring is good (and wire not to thin), full sun (between ~10am-2pm), etc... Does the controller show what "charging mode" it is in (MPPT, or not).

-Bill

the batteries volatage is over 13.5V close to 14V.
the sb2000e has a red LED that shows when its in MPPT mode, and yes, it is on.

the wires are thick (8/0), and the batteries are deep cycle ...

the thing is, when I turn on the inverter and start to draw power, the battery voltage drops to around 12.9V, but the charging current doesn't go up to the available 6Am, it stays about the same as before.

It has been a while since I adjusted my panels, therefore instead of 10.5A I should be getting, it only shows around 6-7A .......... but it doesn't matter, because the charging current doesn't go up more than 3.5A.

A single panel should output 3.5A, 18V .. 63W ... I am aware of the current dropping etc ... but still it looks like i am using only 1 panel even thou there are 3......

BB.

Re: just a few que. about sun & wind

I believe I read elsewhere here that the SB family can get confused trying to run MPPT mode when there is an AC Inverter connected and operating. The 120 Hz ripple from a properly operating inverter can cause the issue.

Ideally, the inverter and the charge controller should be directly/solidly connected to the battery... Do not share the charge controller to battery wiring with the Inverter wiring.

What is the current when the AC inverter is off (perhaps you have some 12 volt loads you can draw the battery down with a bit)?

-Bill

icarus

Re: just a few que. about sun & wind

A simple test for Pv out put is to take a blanket or moving quilt up on the roof (if you can) use a walkie talkie or phone to call down to a partner. Cover all the panels put one,, read the current with only one panel,, then cover that one and move to the next,, and on and on until you have determined that each panel is working well. It is hard to tell if all the panels are working right if your batteries are (near) full and mppt is working.

I had a problem with a solder joint in a Siemens panel about a month ago. I was getting what seemed to be lower than I thought it ought to be. I checked all the panels this way, and found one that had tiny current, even though it had full voltage. I found a weak solder joint between the ribbon connector from the cells and the diode.

Good luck.

Icarus

dwh

Re: just a few que. about sun & wind

tutenkp wrote: »

the wires are thick (8/0)

I believe that should be #8, not 8/0?

tutenkp

Re: just a few que. about sun & wind

dwh wrote: »

I believe that should be #8, not 8/0?

yeah u're right ... got carried on by the excitement of having new parts :P

I did test each pv, and they all output about the same current. I am getting over 10Am when I measure all, but when I connect them to the charger controller, it only shows 4.5 ... no more than that ..... no matter if the battery voltage is 12 or 13 V .

I don't get where the rest of it goes

and yes, the inverter is directly connected to the batteries,
same with the charger controller (diff wires from the inverter)

niel

Re: just a few que. about sun & wind

put a good load on the batteries to ensure the controller should open up to allow more current to flow. if it continues to be low then recheck all you can before you contact bluesky. i think there is an adjustment inside for the mppt charging and this may not be right.

tutenkp

Re: just a few que. about sun & wind

ok, i'll try to put a bigger load .... I usually use it for couple of fluores. light bulbs over the night, and it does drain the batteries to about 11v

I switched the controller, and put the pv on the xantrex one, and it shows about the same Am (just a few miniAm bellow the sb2000e, since its not mppt)

does the battery voltage & Am has anything to do with the current output by the charge controller? ... I mean is the charge current regulated by the batteries?

niel

Re: just a few que. about sun & wind

at 11v that is drained far enough that the full bulk current (and then some due to mppt) of the pv should be being delivered to the battery. unless the battery is a very low ah battery i'd think something is amiss with the controller. what is the ah capacity of the battery?

tutenkp

Re: just a few que. about sun & wind

i have 2 115Am/h deep cycle marine batteries ........
I'll be off camping for couple of days ... but when i'll be back, i'll post some pictures with my setup.

thanks for all the info so far!

niel

Re: just a few que. about sun & wind

ok, i can suggest to you to get a good charge into the batteries as soon as possible even if you have to go to the degree of bypassing the controller and watching that the bulk voltage does not get exceeded. if you bypass the controller keep in mind that not all pvs have a built-in blocking diode so it's not advisable to leave the pvs connected during the night as the batteries could discharge through the pvs.