Solar Storage Protocol?

Thanks to all. I think that I will disconnect the panels during the four month storage period. I am not going to purchase another controller. Apparently, a fully charged flooded cell battery will lose some charge and life after sitting for four months unattended. I suspect there will also be a small reduction if they are connected to a charger for that length of time. As long as I get the performance that I want, I don't care if I have to replace batteries every 4 years instead of 6, or 3 instead of 5.

Fwiw
I leave my 80W solar panel conected and charging my AGM batt..
(while TC sits parked in the yard),,continuously summer and winter even when not using power for anything,,the solar controler keeps maintaining proper charge year round..
Has been couple years now and the battery is stil A OK..

TomG2 wrote:
I replaced the battery in my 2008 Sentra after six years as a precaution, not out of need. It never saw a charger and sat for six months out of the year for six years. South Texas seldom sees 32F.

you aren't camping in a Sentra, so don't confuse a momentary high current draw battery with low current, long term draw deep cycle batteries. Your term "reliable" also needs to include life span. Isn't that the point of the post?
At the end of the day if you have the right float charger, eliminate the discharge death of the battery and leave it on. It's only 100w of solar total, correct? If this is S. Texas storage (don't remember if you stipulated where), factor in winter angle losses (that I'm sure someone here has figured out), and you have nothing more than a trickle maintenance charger feeding 232ah batteries.

I have 520ah with 500W feeding them in the California sun 24/7/365. And my water losses over the course of a year are minimal, never coming close to exposing the plates.

I prefer cheapskate maintenance. Acid eats things for a living and the difference between cold acid and very warm acid is staggering. Nothing on the face of the earth beats temperature corrected constant voltage maintenance for lead acid batteries. It is foolish for someone in Vancouver BC or Miami Florida to insist "his way" of battery storage is "The Right Way". Unless it incorporates temperature corrected constant voltage. The object is to find a happiest medium between sulfation and plate erosion.
Down here high temps with no temp compensation plus washboard terreceria off pavement driving makes for removing a battery from an oven then strapping it to a hardware store paint shaker.

I didn't figure that it meant anything, but had to ask. Stupid me.

It means ya can't get a precise answer, note the 4 or so decimal places :B

under charging and 'storage' cause irreversible damage, so does overcharging. I pick overcharge vs stagnation.

red31 wrote:
disconnected you will loose 4.3720 ah due to irreversible sulfate and stratification.

Connected you will gain 1.3753 ah from previous sulfation etc.

What does this mean? If I start out with 200 ah of storage, that I will be down to 196 after four months? Isn't there some deterioration whether in use or in storage for four months? Batteries do wear out. Even those that live their whole life connected to a charger.

disconnected you will loose 4.3720 ah due to irreversible sulfate and stratification.

Connected you will gain 1.3753 ah from previous sulfation etc.

I replaced the battery in my 2008 Sentra after six years as a precaution, not out of need. It never saw a charger and sat for six months out of the year for six years. South Texas seldom sees 32F.

MEXICOWANDERER wrote:
If they're wearing shades, and are slathered in coconut oil, you got too much self discharge to store 4-months without a maintenance charger connected.

Seems to be the case. He said "when going up North for summer". Snowbirds or Mex expats.

Gringos in Baja leave their disposable "baja trucks" for summer with 3W panel sitting on the hood.
Without charging it will survive 6 months @90F, when new. Next year it won't start as easily, and in two more years you'll be afraid to shut the engine down when going grocery shopping. 4 years of life instead of 6-7.

With cheap controller and wrong setpoints I would be tempted to let it self-discharge rather than leaving current flowing. 2*6V cost more than starter battery, but running trailer lights is an easy task, they will be able to do this until the last few minute before they die.