Batteries not full with xantrex XW-MPPT

System

Hello,

Sorry for my english, I live in Costa Rica and I speak spanish...
I have 6 Evergreen 190W panels(3x2 strings), 1 solar charge controller Xantrex XW MPPT60, 1 inverter Xantrex DR2412 and 2 batteries Surette S-530 (530A 100hrs, 400A 20hrs) 6v in serie. Off-grid system.
The installation has 3 months.

My problem :

I come to realize that the batteries wasn't full, with an hydrometer all cells indicate 1180SP.GR., approximately 45% charged, with voltmeter 6.1 v each battery, but the charge controller show float stage and no warning message.
The sun is here but he don't wants to charge more the batteries. In full sun he can rise at 1000w in input .
I set the following parameters in: 12v batteries, flooded, 400A capacity, 60A limit, 12.5 recharge, 180min absorb time, force state Bulk, 3 stage charge cycle. The sensor is placed on the batteries. I made an equalize cycle 2 months ago.

Thanks for your help.

niel

Re: Batteries not full with xantrex XW-MPPT

i am sorry, but somewhere along the line you got it wrong as you are severely undercharging your batteries. they should be about 2.33-2.36v per cell if i read it correctly. please read it for yourself and get the proper charge parameters for your batteries. your sg reading also says your batteries are nearly dead so you need to get them charged asap.
http://www.surrette.com/content/renewable-energy-bulletins-solar-wind?q=node/43&phpMyAdmin=2eda4dec0bd69647b9e3cf0f71e01d23&phpMyAdmin=9dec4a269d70t7a63be7c

Solar Guppy

Re: Batteries not full with xantrex XW-MPPT

I'd suggest you change to 2-state charge, there is no point in going into float mode if your using all the energy some where. Float is Ok for systems that are left for weeks at a time with no use.

What can happen, and this is in general, not xantrex specific, if a charger goes into absorb, but doesn't hit the re-bulk value, in 3 hours you will go into float mode, regardless if the battery's are charged. changing to 2-State, will leave the unit in Absorb the remainder of the day.

System2

Re: Batteries not full with xantrex XW-MPPT

Thank you for the answers.

Tomorrow I change to 2-states charge.

I forgot to say that I had a trimetric, it tells me the charge/discharge of batteries.
I could compare the charge data and they match with the Xantrex XW.
I made a mistake because after a few weeks trimetric told me that the batteries were not full (about 95%) and I thought it was not set up correctly and did a reset of the Amp hours from full. A few weeks later same problem, reset again ... the 3rd time I had a doubt and I used my hydrometer. He tells me that the batteries are far from full ,1180SP.SG, I checked the hydrometer with other batteries with a neighbor and it works well.
I think there is no problems with the panels and wiring but i'm beginner...
I use about 1 kW per day. 3 Lights, 1 computer, 1 DC fridge sundanzer , no more.
the Xantrex XWCC get to the bulk/absorb setpoint and stay there about 3 hours.
I do not understand why the Xantrex XW decides that the batteries are full and go to the float stage.
I checked the data of bulk and absorption stage, default values.
Today I tried to make an EQ but little sun, tomorrow I retry.

Sapitofeo

BB.

Re: Batteries not full with xantrex XW-MPPT

When the sun is up, what is the XW 60 controller's output voltage right at its BATT Terminals? Does the DVM read the same voltage as the XW's display? Is the voltage at the XW's terminals nearly the same as the battery bank voltage? (XW in calibraion, no poor connections to battery bank)

-Bill

Windsun

Re: Batteries not full with xantrex XW-MPPT

Sometimes batteries for hotter climates are supplied with a lower specific gravity acid. Might want to check with the mfg or supplier.

System2

Re: Batteries not full with xantrex XW-MPPT

Hi,
No sun today, I hope tomorrow to see the output voltage and make an EQ.
The DVM read the same voltage as the XW's display and the voltage at the XW's terminals is the same as the battery bank voltage.
I bought the batteries in sunelec in Miami. (sunelec.com).
I remember the hydrometer measure when I've received and they were in 1265 SP.SG.
Some data from last week:

Day PK,KWH,KAH.
591,0.86,64
239,0.35,24
286,0.68,50
397,0.82,61
514,0.93,68
752,1.15,85
833,0.88,64

Thanks for your help.
Sapitofeo

Solar Guppy

Re: Batteries not full with xantrex XW-MPPT

I would suggest you set the absorb timer to its maximum value ( 480 minutes ).

Do you realize you have maximum of 60 amps on the battery side? .. at 14.4 volts that 864 watts , your going to be limiting probably 70-80% of the available power from the panels ( 1140 watts peak ) and in your climate which I am assuming is tropical, you probably have lots of partly cloudy weather so peaks would be even higher if you had more amp capacity on the output side.

halfcrazy

Re: Batteries not full with xantrex XW-MPPT

you need to make sure the charge voltage is set right then you also need to make sure the actual voltage at the battery agrees with the XW i have had 2 that where off by 5 volts and oddly enough in different directions.

Also tell us what the charge voltages are set at?

hillbilly

Re: Batteries not full with xantrex XW-MPPT

"Day PK,KWH,KAH.
591,0.86,64
239,0.35,24
286,0.68,50
397,0.82,61
514,0.93,68
752,1.15,85
833,0.88,64 "

If those are your numbers, then one problem that you clearly have is that you're not putting enough energy back into your batteries, if you're using 1KWH a day thats more than you are generating. Perhaps the charging parameters are off (too low a voltage?). You should be charging them up to at least 14.4V or even as high as 14.8V, depending. Do you have a generator as well to charge them up with? If so, you may want to EQ them right away, as it sounds like they are really low...
Also, while those trimetric meters are really nice for a lot of things, they are not always an accurate reflection of the actual state of charge on the batteries. Basically when everything is in proper working order, the Trimetric should be "close enough" to give you an idea on how "full" or how "empty" the batteries are; the only way to consistently tell for sure how charged your batteries are is with a hydrometer. What type of Hydrometer are you using, and are you compensating for temperature when taking the readings?
Donde vive en Costa Rica? Hace unos años, pero he pasado mucho tiempo cerca de Turrialba... mucha lluvia...
Suerte con los baterias

creakndale

Re: Batteries not full with xantrex XW-MPPT

Take the charge controller out of Tracking: Auto (which is MPPT mode) and configure it for Tracking: Manual. Set a Reference" of ~75% of the array's Open Circuit Voltage (~68V). It's worth a try to prove that the MPPT mode of the Xantrex is somewhat functional and harvesting near the array's Vmp/Imp.

Also, be aware that there was a Technical Bulletin issued for the XW-MPPT60-150 (976-0177-01-01 Rev A) for units manufactured from June to September 2007 dealing with a defect. See:
http://www.xantrex.com/web/id/2331/docserve.aspx

creakndale

niel

Re: Batteries not full with xantrex XW-MPPT

hmmm. this sounds vaguely familiar as in possibly outback's problem with the flexmax series. maybe they are experiencing counterfeit components as well.