I just dropped off the two group 24 deep cycle
RV batteries from my TT at Camping world where
I purchased them about 15 months ago.

They are the green topped Interstate brand.

One will not take or hold a charge and the other
one after being charged will be dead within a
about 10-15 hrs.

The sale people keep touting going to two of
the 6 volt deep cycle batteries (golf cart
batteries?).

Opinions/comments welcome

Most of the time you are better off with two 6 volt batteries than two 12 volt ones since they tend to stay in balance better and provide better service.

You might look into why your batteries died so early, it might kill your new ones too.

Are they being charged properly and at the correct voltages?

Are you limiting the discharge level to something (25-50 %) safe?

Are you topping them off regularly with distilled water?

Stan, thanks for repling.

I've kept them topped off with distilled
water, I keep them disconnected while at
home to eliminate battery draw and have
used battery tenders on both.

At first I thought maybe it was just the
brand (Interstate), but is it possible
using the battery tenders is bad???

I have to agree with Stan -- I think something caused them to go bad early. And your original batteries lasted around 33 months?? (2004 rig, 48 mo old). My OEM Interstates Group 29 (total of 3) lasted a little over 5 years, the first three in somewhat erratic use and the last two in fulltime use. I did equalize them a couple of times a year after the first 2 yrs.

Paul,

It's really a little hard to tell, I bought
the TT when it was about 1 yr old and then
lived in it for about 2 years in a park pluged
into electricity. It then went into storage
when I moved in with my now wife. But this
set of batteries was bought 4/2007 before we
went on a trip to Seattle, but not a lot of
use since exept a few dry camping trips since.

This last week of dry camping at the beach
seemed to kill it all off. Even running the
generator for hours at a time did not bring
them up enough to last overnight.

Another problem, that I think is caused by the
battery problem is the monitoring panel inside
has been reading waaayyy off, but I think it is
because of the batteries going bad.

Phil - you mentioned in an earlier post that maybe it is the "Interstate" brand that is the problem. I have a lot of experience with the manufacture of wet cell batteries because my engineering specialty was in the field of dust and fume control systems design. I have worked in several of the largest battery manufacturing companies around the world.

Johnson Service Company (yup, the ones that do the building automation systems and thermostats) are one of the largest battery manufacturers in the world. They make around 70 different brand names in the same factories. On the same assembly line. With mostly the same components. There are some differences in some of the internal components. But these differences are very minor.

Some of the top name labels that come out of Johnson Control are Die Hard, Interstate, Champion, Everlast, and I'm sure I missed a dozen or more. I've slept since then.

Larry,

Over the years I've just had better luck
with batteries sold at CostCo more so than
Sears or other places.

Over the years I had just heard stories about
the low quality of Interstate brand batteries,
but that is what Camping World sells and at
the time that is what I could get when I needed
a set before the trip to Seattle 4/2007.

brand name, voltage, and so on should not be factors of significant concern in your battery decisions.

There are only a few OEM's and each provides a line that reflect trade-offs between longevity, capacity, and cost.

Early battery death is most often due to poor use and maintenance practice.

Don't run your batteries down more than 50% SoC, recharge promptly with a good 3 stage charger, use a proper battery maintainer when the batteries are not in use for more than a couple of weeks.

If your batteries aren't providing 4 - 7 years of service life, it's likely something you are doing. Figure out what and forget quick fixes.

You mentioned running the generator to charge the batteries, how did you charge? Converter (brand and number) external charger (type) or inverter-charger (brand and type) would be helpful here.

The battery panel is a sure way to kill your batteries, it is nice for a quick look once you know what it is really showing but until you have it calibrated be wary of its readings. A decent multimeter that will display 1/100 (12.99) of a volt is your best bet. You can get one for around $25 that will do the job, a bit more for a fancier meter.

This is a rough chart:

>SG Volt SOC
1.265 12.66 100%
1.225 12.45 75%
1.190 12.24 50%
1.155 12.06 25%
1.120 11.89 0%

SG is Specific Gravity
SOC is State Of Charge

If you go below 50% often you'll kill your batteries early, go to 25% and you'll kill them quickly.

Stan,

Only once on the next to last day we were
camping did I use the direct battery changer
on my Honda 2000i generators to try to recharge the battery. Other than that it was charging through the main power cable into the trariler
so I would think that is a invertor?

I keep the trailer at home so I do have the
ablitity to just keep it plugged into house
current all the time if that would be better
than the battery tenders.

I put in 1100 cubic yards of concrete at the
house so we have a 16 x 60 slab on the side of
the garage for both of my trailers (TT & car)
plus more parking out front too.

So until 2/2008 the trailer sat in a storage
lot and I probably did not always disconnect
the power wires to the batteries running them
down too far.

Would it also help to install a cut off switch
in the wiring to the batteries to kill power
to the trailer??

quote:

the monitoring panel inside
has been reading waaayyy off, but I think it is
because of the batteries going bad.

Monitor panels in RVs nearly all are just very cheap volt meters that read whatever voltage is reaching the monitor panel and equate that to battery charge condition, which is poor indication. I'm not just sure what way off means, but I would not put any significant faith in those indications.

A battery isolation device is generally a good thing for stored batteries, as it does prevent any phantom load from discharging the battery.

Does your charger also make AC power when you are not connected to power or the generator? Then it would be an inverter-charger.

If it just charges the batteries and provides 12 volts for lights and such it is a converter. converters range from several levels of awful to a few that are fair and a few that are good. That is why we need the brand and model to give you a decent response.

One of the awful ones will kill your batteries all on its own by overcharging them or by letting them sit at a less than full charge and sulphate the plates. Another issue is that many converters charge the battery at 3 amps or so, you'll need to run the generator for many hours to see any usable charging.

Getting a good charge is vital to useful power production and lifetime of the batteries. they need to bulk charge to over 14 volts (exact value varies by battery) then taper off the voltage to around 13.8 until the battery is full then drop back to 13.2-13.4 for maintaining the battery.

A disconnect switch is good, we used one when we had a house and an RV. Get a good heavy duty one and if you have a big inverter don't run it through the switch.

Take a look here: 12 volt side of life

Final results, Camping World checked my group 24 batteries and found both to be bad after 15 months. The credit was enough to get two new for the price of one.

Now should I add a cut off switch to the #8 wire
that goes to the batteries?