Frozen battery bank

harry2012

i have 4 rolls 6V batteries s-530 400ah in a 12v bank at the cottage tempature in the area dropped below -26c the voltage dropped to 11.2V because of the high ammount of snow on my panels , when i took the caps off the batteries they were froze but when i tipped the batteries back and forth i could still hear acid splashing. I put them in the warm over night and once thawed i put them on charge with a charger after several hours the charger cut out at 14.8V saying the batteries were fully charged. i took the charger off but when i checked the cells with a hydrometer i was getting a consistant reading of 1.125 on all battery cells. After 24 hours the voltage was 13.26 with no load and no charging, and the hydrometer reading was 1.175. Im looking for some suggestions on what i should do, i drained the batteries again a little under load and charged the second time again batteries cut out at 14.8V but my hydrometer reading is still around 1.175-1.20 What can i do to bring my hydrometer reading up? Also batteries are only 8 months old.

Thanks in advance

Blackcherry04

Re: Frozen battery bank

Sounds like your already doing the right thing. I am not sure what type charger that your using, but it must not a multi stage. Once you can get them through a full charge cycle to float, then you might think about a EQ ( 15.5 volts ) if necessary. Happy for you.

harry2012

Re: Frozen battery bank

What charger would you reccomend because mine only has an automatic equalization i also have a tristar ts60 and a xantrex c60 but i am not using that one right now and i have 8x 100w solar panels.

westbranch

Re: Frozen battery bank

They could be stratified a bit, with the water on the top and concentrated electrolyte on the bottom. EQ'ing would help mix them.

Tell us a bit about the PV you have as well as other parts, CC, Inverter, 110V charger?, etc.

Something drained you batteries which allowed them to freeze. If they were topped up and had PV to maintain them they should have stayed full..

Blackcherry04

Re: Frozen battery bank

harry2012 wrote: »

What charger would you reccomend because mine only has an automatic equalization i also have a tristar ts60 and a xantrex c60 but i am not using that one right now and i have 8x 100w solar panels.

The cheapest would be a IOTA DSL-55 amp for those size batteries. I'd buy the plain model and the plug in IQ4, it gives you more options. It will run a 7 hour absorb, then you can see where your at with the SG level.

http://www.solar-electric.com/ioten55amp12.html

http://www.solar-electric.com/smarcharconi.html

It sounds like your Electrolyte was stratified and it just froze on the top.

harry2012

Re: Frozen battery bank

I have a 1000w Xantrex pure sine wave inverter, The reason for the drainage on the batteries is my inverter being left on with a load according to my wattmeter of approxemently 6-18 watts normally depending on if my security camera detects motion or not. This is at my cottage in a remote location and due to the high ammount of snow we had my panels were partly covered

harry2012

Re: Frozen battery bank

Also, i also use a Honda 3000w generator for backup, there is no electricity other than my solar or generator so i need a charger that i can manually set to equalization mode if needed im not sure if thats possible or not

westbranch

Re: Frozen battery bank

What is the measured load of the recorder for that security camera?
What is the standby and running load of the Inverter, measured?

Those 4 cells @ 400 Ah in 12 V congif would give you (Total) 800Ah @ 12 V or 400 Ah @ 24V ~ 9600 Whr.
So ~20 Watts would take a minimum of 240 Hrs (10 days @ 24hr/day) to 50% DoD and ~480 hrs to 100% DoD

I dont know what the SG you have now relates to for DoD...

I would look at raising the panels to vertical for the winter to ensure no snow buildup. Even just one panel would ensure a maintenance charge after a heavy snowfall.

Blackcherry04

Re: Frozen battery bank

harry2012 wrote: »

Also, i also use a Honda 3000w generator for backup, there is no electricity other than my solar or generator so i need a charger that i can manually set to equalization mode if needed im not sure if thats possible or not

It's a bit tricky with a IOTA, you have to open the case and there is a 10 turn potentiometer that you can crank the output up to 15.5 volts. If thats all your going to use it for then you can leave it, other wise you have to set it back.

You can actually take the Xantrex C60 cc and crank the IOTA up and run it's output through it and use it's settings and EQ from it. The only draw back there is a one hour absorb, but doesn't sound like you have to worry about that.

With a Honda EU 3000 you could use a 75 amp charger.

harry2012

Re: Frozen battery bank

Thanks for all of your help everyone, i will purchase the IOTA 55a charger, crank the voltage to 15.5v and connect it to my c60 charge controler to equalize manually if and when needed, and raise a couple of my panels during winter to avoid snow buildup .

Blackcherry04

Re: Frozen battery bank

harry2012 wrote: »

Thanks for all of your help everyone, i will purchase the IOTA 55a charger, crank the voltage to 15.5v and connect it to my c60 charge controler to equalize manually if and when needed, and raise a couple of my panels during winter to avoid snow buildup .

When you adjust put the plug in the jack for high output. The Potentiometer is easy to find, it's on the fan end , left side, blue in color, has a silver screw. It stands up from the board. Hook up your DVM and adjust output with a small flat blade screwdriver. I have 3 of them set up on Xantrex c 35 controllers for a few years.

westbranch

Re: Frozen battery bank

Also since your estimate of loads is so low you might want to look at a TSW inverter in the 100W to 300W range. this would minimize the total draw a bit more.

there are a couple here :

http://www.solar-electric.com/samlex-pst-series-pure-sine-wave-inverters.html

Where is the cabin?

http://www.solar-electric.com/mosu300wasiw.html

inetdog

Re: Frozen battery bank

The caps may have been frozen because of relatively pure water condensed around them from charging, while the acid electrolyte would have a much lower freezing point.
Mechanical damage from ice expansion is probably the biggest source of damage if a battery actually freezes.

Try to keep the batteries near full charge in the winter because the higher specific gravity electrolyte freezes at a much lower temperature.