House batteries useful life

[C.Martin]

Yeah...Depending on your converter’s AMP rating, and how many batteries you have...when the plates decay..there is an increased likelihood of material shorting out a cell. The converter will see something close to 10v instead of 12v. It will go into BULK mode and deliver it’s full amperage. The battery won’t likely achieve absorb voltage...meanwhile the cells will boil, and battery acid will come foaming out the top. Folks usually figure this out if their battery box has a Drain/Vent...and they see the driveway bubbling as the acid eats away at the concrete.

[Mark_K5LXP]

Originally Posted by Old-Biscuit

But weak batteries are causing converter to over work.....pumping out charging amps AND DC System Amp needs

Not really, likely even less hard because old batteries have fewer Ah's to restore. During bulk phase the amount of available power to house loads for a given converter won't be any different if the batteries were 7 years old or 7 days old.

To the OP, the operating range of a flooded lead acid battery is between 10.5V and 12.75V, so being somewhere south of 12V only indicates it's being discharged. As batteries degrade their slide down the voltage scale happens more quickly with a given load. The end of their service life is when that time to dead is shorter than you want or need it to be. 7 years is a decent run for a lead acid battery so a preemptive replacement is easily justified. But if you really wanted to know the merits of this set a simple capacity test will quantitatively tell you how good they actually are. Might be a useful data point to know, then re-running the same test on the next set during it's service life will give you an idea where they're at along the performance curve.

Mark B.
Albuquerque, NM

[BCam]

Originally Posted by Arch Hoagland

Might I suggest replacing with AGM batteries...$179 at Sam's Club.

Pricey but you never have to check water levels again. It was worth it to me when I replaced my 7 year old batteries.

Sam's Club AGM batteries are dual purpose, deep cycle/starting, "RV/Marine" batteries. Golf cart batteries are "true deep cycle" batteries and are much more robust.

Go to a professional, old school battery shop (not something like Batteries Plus). They can test your batteries and possibly re-condition (de-sulphate) them for a reasonable cost. I once bought a boat with golf cart batteries that wouldn't hold a charge. I took them to an old school shop who de-sulphated them (it took a couple of days) and they lasted for several more years.

In addition, a battery watering system like this will help keep your batteries topped off with minimal effort, thereby extending their life:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

If you want to go the AGM route, look for true deep cycle 12V AGM batteries like this. You'll need two to match the capacity of your golf cart batteries:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

AGM golf cart batteries are also available but they can be expensive:

https://www.amazon.com/VMAXTANKS-Vol...8387195&sr=8-5

The cheapest solution, if you need to replace your batteries, is to replace them with two, flooded golf cart batteries from Costco or Sam's Club.

[153stars]

The Sams AMG GC2 are not available in half the country somebody had inside scoop I don't remember the division line. My Sams had them for short time then never again. I have had real deep cell 12v and GC2 over last 25yrs ,the GC2 will out last 12v by up to double in my experience. But there's situations where not practical to convert and not huge cost difference either way in overall picture for RV use..What works best for user . I had few 12v for TT and charged and swapped them out also small John boat at that time 12v were practical . Then I tried Sams GC2 wet cell platinum that they used to carry 10yrs of abuse and were still usable.

[noserider]

I have 2 golf carts. I have run Trojans in them for many years. They have served me well and I use the crap out of them. I never let them discharge below 50% and keep them on the charger all the time. Also never let the plates get exposed. There is a place near me that sells them for around $130. On the RV I have a battery watering system since they are more difficult to get to than my golf carts. But I do like the idea of maintenance free.

[Gary RVRoamer]

Originally Posted by Mark_K5LXP

Not really, likely even less hard because old batteries have fewer Ah's to restore. During bulk phase the amount of available power to house loads for a given converter won't be any different if the batteries were 7 years old or 7 days old.

Mark B.
Albuquerque, NM

I have to agree with Old Biscuit - one or more weak cells drags the voltage down and the charger works at or near full capability trying to bring the voltage up. Yeah, it's whatever the chargers max rate is, but it's non-stop. The most recent chargers will either detect that or simply time-limit how long it stays in that mode, but older models may simply pump out high-rate amps for hours or days on end. Continuous max load is hard on any device.

[twinboat]

Your mixing amps with volts.

Only a shorted cell is going to over work the charger. Heat, smoke, high amp draw.

A weak cell charges right up to the rest and the charger sits in float mode.

I had 2 batteries in parallel, one good one, one bad. Both would charge up to 13.6 volts and the charger amp input would drop.
If I seperated the batteries, one would read 12.6 + volts. The other would drop to 8 volts in a few minutes.
It was basicly taking up space but it wasn't sucking any energy from the other.

[Winemaker2]

BCam
"Sam's Club AGM batteries are dual purpose, deep cycle/starting, "RV/Marine" batteries. Golf cart batteries are "true deep cycle" batteries and are much more robust."

That is not what East Penn, the manufacturer of Sams Club Duracells told me when I emailed their tech help folks. Trojan had a similar response.
They said that in the AGM line a GC had the same hi amp / start performance asca GP31 and the GP31 had the same deep cycle performance as the GC. (acknowledging minor differences in the specs for AH and CCA)
I interpret that to mean the often discussed plate thickness differences in FLA idoes not apply to AGM and is the reason mfg provide both AH and CCA/MCA for their AGMs.

[David 70]

The first thing I would do is get them tested. If the don't show really bad I would keep using them. It doesn't sound like you are staying in the boondocks so you are close to help when the time comes. Some people on here are real fast to spend someone else's money. I do some dry camping but close to help. When I do dry camp I generally run the generator in the morning for my coffee.
My batteries don't last for days it does not concern me that much.

[Mark_K5LXP]

A shorted cell would definitely put a converter into current limit and by extension there would be less power available to other loads. But the energy would be going somewhere, specifically heating up the remaining good cells and dissolving water. Let that go on long enough and you end up with a hot fizzing mess. Those weren't among the symptoms originally described, so I wouldn't suspect shorted cells. Dead or weak cells (one or more) having less capacity discharge more quickly and also recharge more quickly which is more in line with the symptoms described.


Mark B.
Albuquerque, NM

[Crasher]

At five years old, if they do not perform as they should or used to, just go ahead and replace them. Most brands of AGM would be a good choice. Five years ago, I replaced six 3 year old wet cells with 300 amp Lifelines for 900 amps of battery bank. I check them once a year and blow the dust off of them. I expect them to go another 4-5 years before replacement. The solar panels keep them @ 100% charge while in storage. I call that low maintenance.

[Domo]

5 to 7 years.
Always check for bulging on sides/top when checking water level. If it has bulges start budgeting for new batteries - no matter what the age.

My 4 - 6 volt Interstate batteries lasted 5.5 years - the original set also lasted 5.5 years under a different owner.