charging batteries

[solar blue]

vic panels are csp 220 canadan batteries werent frozen just bout a 1/8in or just a little better

[Vic]

solar blue,  thanks for the added info.

Those PVs  --  CS6P 220,  have a Rated voltage (Vmp) of about 29.3 V,  and a current  (Imp) of about 7.5 A.   SO,  two of these PVs in series for each string would be fine,  connected to the input of the Classic,   strings of three in series would probably be OK.   But,  one would need to know the lowest temperature recorded for your area,  in order to run these numbers to make certain.

The batteries will freeze from the outside,  in.   So,  even a layer on top,  and around the outside,  probably on the upper part of the sides of the case could still damage the plates,  but  go for it in getting these batteries recharged,  assuming that there has been no real damage to the batteries.

Questions;

Are there ANY loads on the batteries?

Are these batteries new,  or previously used?

Have the batteries been sitting,  without being charged for a while?

Were the batteries fully-charged,  when you got them   ... when did you get them?

Do you have Grid power,  or are you using a generator to run the AC chargers?   If you had a way to heat the batteries,  it would help,  as the early charge stages  will not create much battery heating.

Later,   Vic

[solar blue]

   hi vic   ive moved battery in took awhile   the batteries arent under load    yes bought in mid nov   they were new at battery place and dont knw if it had been a great while sense charge   ask seller if they fully charged said yes   i do have grid power   building where batteries is being heated as we speak  so out of 16 panels 24 can i paraell to 48 and run safely with out damage to 150

[Westbranch]

solar blue you should use the Classic sizing tool at 

http://www.midnitesolar.com/sizingTool/displaySizing.php

I just ran your PV's numbers and you can safely use 3 panels ( in series ) and 4 strings giving 2640W....  using a - 40*C as the lowest temp expected. 

Please do the calculation  again for your own edification and to see the maximum # of panels you can use.

I hope you got as many panels as you need , it appears that they are now discontinued.

[solar blue]

   hi westbranch      yea  they are off line trying to recover batteries      why 48v or 72 will that make batteries charge faster be easy to wire the panels either way     would i have to go to 48 or 72 battery or can i still run 24v battery with it      im willing to try anythang

[Vic]

solar blue,

The wiring of the PVs into strings of three will have no benefit verses PVs in strings of two.  The Classic will convert the PV input voltage into a voltage that the battery needs,  regardless.

Strings of three of our PVs will be slightly less efficient verses strings of two,  but this is a small difference.

Having MORE PVs weird will help,  by increasing charge current,  within the limits of the Classic output current limits for a 24 V battery.

Do you have that Battery Temp Sensor (BTS)??

If not,  with a cold battery,  once that most of the charge for the battery is done  --  when the  Bulk stage is done,  you may want to manually increase the Absorb voltage.  This is what the BTS would be doing automatically,  if is were connected to your system.

The Bulk stage does about 80 - 85% of the battery charge,  and Absorb does the final charge.

Vic

[Westbranch]

Solar  Blue I was not trying to tell you to use strings of 3, and 4 strings.  I just used that as a maximum that appears to be safe... IFF you are going to use a 48Volt battery...

Sorry I left the voltage out in the previous post...

You said

so out of 16 panels 24 can i paraell to 48 and run safely with out damage to 150

I had a hard time trying to decipher what it was that you were really saying..  but you were clear that you did NOT want to damage your classic..  that I tried to answer and gave the link to the Classic Sizing tool..

Please clarify the above quote for us all...

thanks. 

[solar blue]

  yea westbranch i know   im going to parell to 48with 5 strings going into charger do i have to go to  a 48v battery an inverter i would like to keep 24v battery   im going to parell em gota do something ill listen  and be happy i did im just learning and am so grateful for all the help all yal give guess im brain dead lol  down here in kentucky guess we sometimes are hard to understand we type like we talk im the only one in the south according to insureance man that is doing this thanks again for your help

[Vic]

solar blue,

The Classic is an MPPT Charge Controller.  It has the ability to convert a higher panel voltage into the voltage that the battery requires.

So a 60 volt string voltage from two PVs in series will be converted to proper voltage for your 24 V battery.  All that you will need to do is to set voltages into the Classic that match what your battery needs,  based on what the battery manufacturer says are the proper voltages for your battery.

Other types of Charge Controllers  --  PWMs  --  need a PV string voltage  that is much closer to the battery voltage.

CCs like the Classic work magic.   Does this make sense?

Vic

[solar blue]

   vic yes that makes good sense  thats what i want a do is make 5 or 6 strings at 48v  now if i can do that and still run 24v battey do i have to put the controler back to  factory settings and  let it quick set or just leave as is hook everythang to it and just put in battery settings 

[Vic]

solar blue,

NO,   if you have set the Classic for your 24 V battery,  you will not need to make any change in the settings for any change in string voltage.

AND,  if you were running single PVs previously,    you should find that running two in series will do a better job of charging the batteries.

Again,  if you are not able to use the BTS to adjust the Absorb,  Float and EQ voltages,  then you should do this manually.,   assuming that the batteries are still cool,  or cold.

The Temperature Compensation value for your batteries should be --5 mV,  per 2v Cell,  for every degree C change from about 25 C.    So,  for cool/cold batteries,  the Absorb  (and Float/EQ)  voltages will need to be increased  by 0.06 volts for every degree C that the BATTERY is below 25 degrees C.  The compensation can be a large value for cold batteries.

Later,   Vic

[solar blue]

   hi vic     first i thank you and westbranch for your patient  and all the help it took long enough to drill it in my head. let me see if i got  it  take ten panels 24v. series them   to make five strings 48v  to controler. then that should be enough to charge batteries.  i think i spoke with you about frozen battiers. well have warmed them and charging for 24hrs  are now at 1.275  a couple are at 1.300. i am both lucky to say the least and beside myself happy with the out come again many many thanks for helping

[Vic]

Hi solar blue,  thanks for the new info.

Very good that you have warmed the batteries,  and that it appears that the SGs have risen to nearly a full-charge.

Do you have the BTS for the Classic ??

Yes,  10 of your 220 PVs arranged as five strings of two PVs should do fine with your 24 V battery,  and the total power from those ten PVs should not exceed about 1600 - 1750 watts ( depending on the outdoor temperature and available sun).   This would yield,  about 50 - 65 amps of charge current into the batteries,   which is a good place for a Classic 150 to be running.

As dgd mentioned previously,   you really should use a Combiner,  with a circuit breaker for each string of PVs,  primarily as a fire safety measure.

If you do not have a MidNite BTS,  you really should try to get one soon,   as this will help your batteries receive a full-charge,  without overcharging them.

What type of Hydrometer are you using?   It is important to have a good quality Hydro,  as you will be basing many decisions,   based upon the readings that the Hydro gives you.

It is a good idea to have a battery Logbook,  where you can log  SG readings,  settings in the Classic for Absorb,  Float and EQ voltages,  absorb time,   EQ duration,   and date,  as well as amount of Distilled Water that was added to the battery bank,  and the date of this topping-up,  etc.

Hope that you will let us know how you are doing.   Good Luck,
Vic

[solar blue]

     vic going to order the bts monday   will get the combiner the hyd was given me by battery dealer guess its cheap send type later  we will begin  a log  and yes will give update when done again many thanks to all

[Vic]

Hi solar blue,

Looks like you have done quite well in recovering from the situation,  by making some good decisions.

It is nice that the battery dealer gave you the Hydrometer,  many battery dealers do not do this.

The BTS should help your general battery health.

Good Luck,   and please do let us all know how things are going. Thanks,   Vic