BajaNomad

Dialing back the Charge controller worked!

Santiago - 3-28-2017 at 05:39 AM

Simple system: 2 190 watt panels going thru a Xantrex C 60 controller to 4 Sam's Club golf batteriers to a Xantrex 1500 watt converter.
I've always left the controller at 13.5 volts and 2 summers ago boiled off all the water. After being told by a few of you to dial back the controller to 12.5 volts when leaving, I did so last June. When I returned last week after some 9 months later I popped the caps of the batteries, worried that they would be empty but they were full. Sweet.

Russ - 3-28-2017 at 06:43 AM

Thanks for your update! I miss the posts saying to dial back the controller. That makes a lot of sense. I feel really ignorant! after more than 20 years on solar and never considered that.

woody with a view - 3-28-2017 at 11:21 AM

Should this be done for agm batteries as well? What if, on the morning of departure the bank hasnt started to float yet? Will it hurt the bank if float starts at 12.? for months at a time?

larryC - 3-28-2017 at 01:15 PM

Woody
No, don't do that with agm batteries. The only reason Jim did it was to try to avoid boiling away the water in his batteries. Your batteries are sealed and if you have your controller set properly your batteries will be fine. By setting the charge voltage at 12.5 Jim is risking his batteries and taking a chance that the plates will sulfate and will permanently damage them. FLA batteries are not the best choice for systems that will sit for long periods of time unmaintained. AGMs are a better choice for that type of service but you need a good/expensive controller that is temp compensated.

woody with a view - 3-28-2017 at 01:30 PM

Thanks Larry.

Russ - 3-28-2017 at 03:33 PM

Thanks Larry for the heads up. I had thought about that and thought maybe by equalizing for a few hours when you return it would clean the sulfate build up. I hope Santiago's batteries aren't damaged.

[Edited on 3-29-2017 by Russ]

woody with a view - 3-28-2017 at 08:44 PM

Larry will you be down end of May? Might need your assistance
For a couple of hours.

larryC - 3-29-2017 at 08:22 AM

Woody
Yes I'll be there.

woody with a view - 3-29-2017 at 10:31 AM

Ok, I'll ping you prior to leaving in case you need anything brought down again.

Santiago - 3-31-2017 at 05:40 AM

OK - given the batteries that I do have, where should I set the controller when I leave for months at a time? The controller does have temp compensation, I've never hooked it up.

Am I locked between either boiling off the water or sulfating the plates, pick my poison?
Set at 13.0 on leaving?
Is Russ's idea of running an equalization charge on returning a good idea?

As the batteries are only a year old and I got 4 years out of the last bunch, I suspect I have a least a few more seasons to go.

[Edited on 3-31-2017 by Santiago]

Bob and Susan - 3-31-2017 at 05:58 AM

just disconnect ALL the cables when you leave and connect them when you arrive...just make sure they are charged

leave them sit there like they do in the store before you buy them...no load

neighbors here do they and they last for years...I was amazed this works

chuckie - 3-31-2017 at 06:35 AM

Yeah! Why wouldn't that work? Thinking about it, I did that with boat batteries for years and years...Take em out of the boat, put em somewhere where they wouldn't be too hot and they seemed to last forever...

willardguy - 3-31-2017 at 09:16 AM

thats what we've always done. just DON"T EVER leave without bringing em up tp float, the set point the battery manufacturer dictates. we carry a group 27 deep cell, the day before we leave it replaces the fully charged bank then travels home and charged back up.

and get yourself at least a 50amp smartcharger ideally with adjustable set points to put on the generator in case you're met with a couple cloudy days at the end of your stay......nothing can ever be easy:no:

[Edited on 3-31-2017 by willardguy]

[Edited on 3-31-2017 by willardguy]

monoloco - 3-31-2017 at 02:14 PM

Quote: Originally posted by Bob and Susan  
just disconnect ALL the cables when you leave and connect them when you arrive...just make sure they are charged

leave them sit there like they do in the store before you buy them...no load

neighbors here do they and they last for years...I was amazed this works
That's what I would do. I disconnected the bank of golf cart batteries at the house in Alaska, and they were still at 6.2 volts after being left for 8 months.