Any specific time to replace Batteries?

When they are no longer working as expected.

It really depends on how you maintain them. My two Sam's Club 6v GC batteries are 10 years old and I dry camp 95 percent of the time. I usually don't stay more than 3-4 days in anyone spot and have minimal 12v requirements so they may be at 70 or 80 percent SOC. Once maybe twice a year I stay for a week and they are at 50 percent SOC. I always charge to full within a week. Also equalize and desulfate several time a year. My Walmart starting battery was just replaced and was 10 years old also, I charged it along with my house batteries but it was a sealed battery so I could not equalize it. My first set were Trojan 105's which only lasted 4 years because I did not know at the time how to maintain them. I never got more than about 4 years out of my cars because the just get charged by the alternator. If you fulltime your 12v requirements will be much higher.

Gjac wrote:
It really depends on how you maintain them. My two Sam's Club 6v GC batteries are 10 years old and I dry camp 95 percent of the time. I usually don't stay more than 3-4 days in anyone spot and have minimal 12v requirements so they may be at 70 or 80 percent SOC. Once maybe twice a year I stay for a week and they are at 50 percent SOC. I always charge to full within a week. Also equalize and desulfate several time a year. My Walmart starting battery was just replaced and was 10 years old also, I charged it along with my house batteries but it was a sealed battery so I could not equalize it. My first set were Trojan 105's which only lasted 4 years because I did not know at the time how to maintain them. I never got more than about 4 years out of my cars because the just get charged by the alternator. If you fulltime your 12v requirements will be much higher.

good care as you mentioned equals long life. On a good GC, keep the water level above the plates, charge fully after use, equalize occasionally and you will get long life. Trojan GC are good for 500 + discharges to 25 percent SOC. Been there, done that and haven't hit the 500+ cycles, but came close and batteries lasted 14 years. and discharging to only 50 percent will give close to 1000 cycles. well beyond what most any camper will see.

The deeper the discharge the shorter the life.

The longer between full 100% recharges the shorter the life.

Add solar charging and life span may improve dramatically.

I replace on an As Needed basis.. I can't see replacing 'em till they need replacing . NOTE. Exception. on a trailer the battery is a safety device and Id' say 7 years tops but on a Motor home... Well for starters I have two sets of batteries.. No safety issues if one dies.

pianotuna wrote:
The deeper the discharge the shorter the life.

The longer between full 100% recharges the shorter the life.

Add solar charging and life span may improve dramatically.

good quick summary and excellent advice.

I'll add that most RV user's won't ever come close to being limited by the rated cycle life on a good 6V GC or real 12V deep discharge. Don't discharge GC below about 25 percent SOC, 12V below 50 percent.

True GC deep discharge are good for over 500 cycles to very deep discharge, 12V trojan deep discharge similar life but only to 50 percent. How many of us will ever discharge that many times to those levels?

But the key is to get them charged back up to a TRUE 100 percent full charge within a few days or week at the longest. watching water level, equalizing when needed.

Now if you have a marine battery, I believe cycle life is considerably less. they still have thinner plates for starting current and being a combo battery, likely lower cycle life.

ktmrfs,

For marine jars 20% is the figure to aim at. i.e. they should always be 80% or higher state of charge. I got around that by having 7 in two banks--which gave me 140 amp-hours of "safe" discharge and it ran large inverters with heavy loads as if they were no trouble at all.

I did get tired of laying in the snow to check electrolyte levels, so when they finally began to fail after 9 years I replaced them with used telecom jars.

Ok, it looks like I am thinking along the right line in changing out the batteries. They are about 5 or 6 years old and over the last year or so the chassis battery doesn't seem to be holding that good of a charge. We have been mostly hooked up at one spot for awhile (job) but now we are about to go cross country and more so I am right in thinking that we are needing to just replace them all before we leave at the end of the month.

EDIT:
Last year at this time we went to Vegas. Starting the coach to come home we realized that the alternator was not charging the battery. The only thing charging the chassis battery was the 20 yr old 100 watt solar panel. With nothing running (ie no lights or ac) we were able to keep the charge at about 12 or so just in order to make it home. We made it all the way back to Lancaster, CA just before the sun went down. About 25 miles away the sun started to go down and you could see the charge start to drop. My other half rebuilt the alternator and now it all works like it should but I had a feeling that the batteries got a little down from that and needed to be changed out.

Landscatter?

May through October daytime temps in the Antelope Valley, eats batteries chemically. Acid is thermally incredibly temperamental. Identical batteries, identical float a flooded high antimony battery at 50c day and night may last 3 years, while the other battery maintained at 10c will last 15 years.