best practices for long battery life

[mrad]

I cannot get more than 3 years out of my battery on my TT. Original battery was an interstate. It was replaced under warranty going into its third year. The replacement lasted two years. I then tried the walmart brand. This was it's third year. When putting it away for winter storage this year, it would not raise the tongue jack when not hooked up to shore power. When I checked the battery indicator in the TT, it showed it had no power 15 minutes after being disconnected from shore power.

I leave the TT plugged in all year once we start using it. Usually May- October. After that it goes in my basement and gets a charge every 2-4 week until ice fishing season. Then I take it to the fish house every weekend (Mid December through the end of February). I use it with a 750 watt inverter to run the tv and lights/ ceiling fan when I tune the generator off. I can usually get 6-7 hours on the battery before it needs to be charged. I then start the generator and charge it with my vector smart charger until it is full.

Should I be turning the disconnect switch off in the summer when it is plugged in at home, or is 2-3 years the average life span for a deep cycle battery?

[mrad]

red31 wrote:

mrad wrote:
I usually check water in spring and fall and have not had to add so tht should not be the issue.

a death of repeated undercharging.

What do you mean by undercharging????
From reading the posts, I it looks like I ran the battery too low before charging, but the battery always received a full charge before being used.

[midnightsadie]

X2 ,my boat batteries get plugged in after every trip. from the posters words he,s killing his own battery.

[red31]

mrad wrote:
I usually check water in spring and fall and have not had to add so tht should not be the issue.

a death of repeated undercharging.

[DutchmenSport]

Mine have all varied over the years. Our first pop-up, battery lasted less than 1 year. Next one lasted 5 years and sold it with the pop-up.

First TT, lasted almost 3 years, original from the dealer, never replaced it.

Next TT, 5 years, original from dealer. Second one 3 more years, sold with trailer.

Next TT, 5 years original battery.

New 5er? well ... how about 6 weeks now and going strong!

And by the way, I leave all my campers plugged in 24x7x365. I've NEVER had to add any water to any of my batteries. Never. Unbelievable yes. Never. It's always good, and I check 2 or 3 times a year.

[mrad]

I think i'm finding some of my issues. I usually check water in spring and fall and have not had to add so tht should not be the issue.

In the winter, I have been running the battery down to full discharge occasionally. I am also running a ceiling fan with the battery. I have a size 24. I am thinking of changing to group 27 or 29 and in the winter running them parallel to get more time before they discharge.

Thanks for the good info/suggestions

[theoldwizard1]

First, are you using a TRUE deep cycle battery. "Marine"/dual purpose batteries are really not "deep cycle". The only readily available true deep cycle batteries are 6V golf cart batteries. 12V true deep cycle do exist, they are expensive (as much or more than 2 gold cart batteries) and probably only available at a golf cart store.

The rest is standard. 1) Keep it clean, 2) keep it watered, 3) keep it charged at all times.

[jkwilson]

The best way to make a battery last is to not use it. Unfortunately, discharging a battery is what shortens its life, and the more often and more deeply you discharge it the faster you use up its life.

Running the battery down with the fan is really hard on it.

A rule of thumb is to choose your batteries so you never get below 70% state of charge. This isn’t a hard threshold beyond which things get worse, it’s just an economic balance point between low battery cost and long battery life.

A larger battery or multiple batteries in parallel will last longer than the same number of batteries used one at a time or a smaller battery.

I’d suggest you invest in a multimeter so you keep an eye on the battery state of charge. It will tell you how your battery matches up to your use.

[midnightsadie]

my boat batteries are wal mart 6years old and still going, on my rv, I unhook the battery and put a battery tender on.I don,t remove the battery from the rv I don,t rely on the rv converter charger. theres always some small power draw on a battery when in service.

[dclark1946]

A few questions:

1. How often do you have to add water to the battery?
2. Do you have a digital volt meter and what is the trailer's converter voltage when it is plugged in and not being used?
3. What does the battery unloaded voltage drop to before you start charging it during winter use?

[mike-s]

You don't mention ever checking the water levels. Are you depending on the converter to keep it charged in the camper, what brand/model? Have you ever checked the specific gravity when you think it's fully charged? Do you ever give it an equalization charge?

[valhalla360]

Check for loads when you disconnect shore power: 15 minutes to dead after disconnecting means you either have a heavy load or the battery was already toast.

You don't say what size battery it is but your winter use is likely drawing too much before recharging. TV/Lights/Ceiling fan could easily be pulling 20amps. At 6hrs, that would add up to 120amp-hr. For a single dual purpose battery, that's likely leaves it completely dead before you recharge.

Going below 50% charge on a lead acid battery typically does damage.

It's possible you have something on in the RV that is damaging the battery but my bet is the winter use.