GC2 batteries: help me pick power supply for maintenance

hammick, fixed Abs time is a feature peculiar to some CC, not all of them. My CC ends the Abs when the current tapers to set value (user adjusatable) OR when the timer expires, whichever comes first. Morningstar TS also regulates its Abs time, if memory doesn't fail me. Bogart CC also adjusts the Abs time, but only when paired with their battery monitor - their CC has very limited functionality on its own.

You are right, CC will go into Abs every morning. But it shouldn't stay there long when battery is full. After few days in storage my CC ends the Abs almost immediately, and this is how it should be. You are correct, the alternative in your case is setting a very short Abs time on your CC while in storage.

Almot has exactly what the battery wishes. The imtelligence level of a manual power supply matches exquisitely well with the intelligence level of the person utilizing it in battery maintenance.

I am beginning to favor encouraging the use of an 8 to 12 position rotary snap action switch connected to an array of precision 1% resistors to decade the voltage control of the MegaMean's.

12-steps affords great resolution in voltage selection and voltage steps are pre-definable.

"Click! Bumperup a couple of tenths". The upper step being reserved for equalization. The 2nd step down for top charging. Would work with AGM conditioning.

Affix a 3-1/2 digit LED panel meter next to the panel mounted rotary switch......

Almot I'm intrigued by your idea to pair a Meanwell PS to a charge controller. If this is possible why would the Meanwell be needed? Couldn't the CC just be hooked to the 13.6v (or 13.2v float) output of a regular converter. Anyway, doesn't apply to me since I don't have shore power at my storage place. If I get a Meanwell it will be for battery maintenance in the driveway before storage.

Let me elaborate on a few things about the Blue Sky SC30 Controller. I have attached the manual. Also in my previous post I did mean schedule an equalization as often as five days.

The SC30 has a charge status indicator that clearly shows whether it's in bulk, abs, float or eq. The manual seems to indicate that it will go into absorption every morning (assuming sun is out) and hold abs for the set time. I called Blue Sky and they confirmed that it will run a daily abs cycle whether needed or not. We agreed that I should set the abs time to probably 1/2 hour when in storage.

Now I won't know for sure if it runs a daily abs cycle until I test it. With a fully charged battery I will cover the solar panel overnight. I'll go to the trailer the next morning and remove the cover. It will either run the abs cycle or quickly go to float.

Now my limited understanding of these adjustable charge controllers having a set abs time is so you can adjust to figure out what keeps your specific batteries fully charged. No CC can figure it out based upon tapering current.

Now the Bogart CC paired with the Trimetric is supposed to be super smart to prevent potential overcharging buy measuring amps in and amps out so it doesn't run a daily abs cycle if not needed.

My Go Power CC that I just replaced worked the same as the Blue Sky but it wasn't adjustable. It would run what it called a boost cycle for 1/2 hour every morning at 14.4v whether the battery needed it or not.

Interstate does have an abs time spec for their GC2 batteries. It is between 2-4 hours. Their eq spec time is also two hours.

So my plan is to set the SC30 to interstate abs specs (15.3v for two hours) when I am using the trailer and lower abs voltage and time when it is in storage (currently set to 15v for 1 hour).

Am I missing something about how these charge controllers work? You either choose one that determines when the battery is charged in which case it will always undercharge the batteries or you get a fully adjustable one and figure out the best settings to allow full charge and minimize fluid loss, right?

Or you get the Bogart with Trimetric which should stay in float until the Trimetric senses amps out.

So what is better for GC2 batteries during storage. Constant float or a daily abs to stir the electrolyte?

Blue sky manuals: http://www.blueskyenergyinc.com/manuals/

The reason I asked was that this is a viable solution: 12V supply like Meanwell, paired with a "good" CC that would add some brains to stupid always-on Minny. Kind of 120V maintainer, only with proper 3-stage adjustable charging.

hammick wrote:

I believe my controller goes into absorb mode each day as soon as there are amps available from the panels. It doesn't just default into float.

No, it doesn't (shouldn't) just default to Float. Believing is good, this is what pastors ideally would like to see in their flock :). Without a log in your CC you only have indirect evidence that batts have gotten over the hump of Abs.

So it will run the set absorb time at the selected voltage even if the battery is fully charged.

If it runs Abs every time for one hour no matter how full the batts are, this isn't good. I thought Bluesky had units with better algorithm.

If I have the voltage set high enough and the absorb time long enough they should never get stratified, right?

V Abs should not be higher than battery specs suggest. Same with time - no need to boil them longer than necessary, but you won't find Abs time in battery specs.

I can also set an absorption schedule as often as every five days.

I "think" you are confusing Abs with EQ. Let other folds comment, with my AGM all this wealth of education in EQ, watering, measuring SG etc etc has been passing me by ;)

So batteries will be fully charged and SG proper before storage. It is stored outside and panels are never shaded

Then you do have a functional solar "maintainer" for when in storage.

Even if my rig and house were not set under a rain forest triple canopy June to October has the skies partly cloudy after 11AM then full clouds from 2-6PM.

Course I always could reverse the polarity and have the panels work at night...

Almot wrote:
Are you powering controller from some 12V supply? Because if you are not, the issue with "power supply for maintenance" remains unresolved.
160W panel will work as such maintainer, but not always. Depends on location, time of the year and how badly you've depleted the batteries before putting it into "maintenance mode" between the trips. You can't rely on being always able to equalize on solar whenever you feel like. Not with this ratio of solar W to bank AH.

No just Solar. I believe my controller goes into absorb mode each day as soon as there are amps available from the panels. It doesn't just default into float. So it will run the set absorb time at the selected voltage even if the battery is fully charged. If I have the voltage set high enough and the absorb time long enough they should never get stratified, right? I can also set an equalization schedule as often as every five days.

I never plan to run the batteries lower than 50% and likely never lower than 70% SOC. Also the trailer always comes home first for cleaning before storage. So batteries will be fully charged and SG proper before storage. It is stored outside and panels are never shaded (unless it's cloudy of course).

Are you powering controller from some 12V supply? Because if you are not, the issue with "power supply for maintenance" remains unresolved.
160W panel will work as such maintainer, but not always. Depends on location, time of the year and how badly you've depleted the batteries before putting it into "maintenance mode" between the trips. You can't rely on being always able to equalize on solar whenever you feel like. Not with this ratio of solar W to bank AH.

Looks good!

Good luck with the batteries, solar is just seamless once you have everything set up.

I think I will skip a power supply for now. Yesterday I installed a fully adjustable Blue Sky PWM controller. Set it to 15v with a one hour absorption and my GC2 batteries quickly had a nice slow bubbling in the cells. Exactly what I wanted. 15.1 - 15.2v at the terminals (I'm assuming the temp comp increased the voltage slightly).

My non-adjustable CC was never able to bubble the cells. The new CC is easily adjustable. I'll experiment with settings. Probably use more conservative setting when in storage to minimize fluid loss and put them to exact battery specs when boondocking.

What does hermit have to do with energy use, I find the Neanderthal grades stay outside socializing and not using power.