House Battery Life

red31 wrote:
I thought the whole ideas of 2 GC was to have enough capacity so ya don't heavily discharge a single 12v. Note the OP does not ALWAYS stayed plugged in. I assume full timers use plenty of power when they happen to be off grid.

Anyone care to suggest how much capacity the OP needs for one day with 2hr gen run time limit? how 'bout 2 or 3 days?

Doing 50-90's daily,

...it would take about 2 hrs at 14.8v and a C/4 rate.

So, figure out daily usage, times it by 2 for bank size, then divide by 4 for charger size.

Doing 70-97's daily, at the same rate would take about 2 1/2 hours

Hi,

I don't have a source for this idea but in my many readings about batteries I've noticed that cycling at least 5% seems to be recommended for golf cart and similar jars.

Perhaps that is the key to the short life span? A work around would be a timer on the converter so that the batteries would actually have to cycle.

red31 wrote:
I thought the whole ideas of 2 GC was to have enough capacity so ya don't heavily discharge a single 12v. Note the OP does not ALWAYS stayed plugged in. I assume full timers use plenty of power when they happen to be off grid.

Anyone care to suggest how much capacity the OP needs for one day with 2hr gen run time limit? how 'bout 2 or 3 days?

Most full timers are better equipped to handle their power needs when off-grid. Solar is very popular, along with the on-board Genny. You would be surprised how much 12 volt power is consumed when the appliances, CPAP's, furnace, lights, frig etc are in use. I use two six volts (210 amps) but try not to let my system get below 12.2 & that doesn't take all that much before starting the generator. I dry camp only & am very frugal with power usage. At 12.2, it takes about 3-4 hours to get my batts back up to near capacity & that's with a portable charger, connected to my generator with NO load on the batteries. My converter is useless for charging (Magyjunk).

Assumptions lead to gross miscalculations...

But a realistic scenario would have a rig traveling a day or so to reach an alternative RV park with power post.

Enter the value of charging the battery while traveling

Enter the value of how much discharge the battery can suffer without damage

Enter the value of hotel loads for an adventurous overnight at a Wal Mart

I cannot foresee where a single group 29-31 AGM could not handle the duty and laugh about it.

I thought the whole ideas of 2 GC was to have enough capacity so ya don't heavily discharge a single 12v. Note the OP does not ALWAYS stayed plugged in. I assume full timers use plenty of power when they happen to be off grid.

Anyone care to suggest how much capacity the OP needs for one day with 2hr gen run time limit? how 'bout 2 or 3 days?

Dakota98 wrote

"The converter charging system typically gets the lead acid batteries to approx. 90% only."

My apology, I should have qualified this statement further.

The Coach being in use.

If the coach is connected to shore power or generator & the converter charging system is charging the batteries & putting more amps into the battery than are being drawn from it at the same time, then it will reach 100%. If while charging & more amps are being drawn than the charger is replenishing, then you won't see a 100% reading.

I remember reading a particular review about an inverter, once. I forget the exact model, but I do remember it was a decent quality 1000w unit. In fact, those with actual experience with 12v systems gave it good reviews.

But one reviewer gave it a rating of only one star, and insisted it was a piece of junk. But as it turned out, the guy had it connected to a small car starter battery, and was trying to power a 900w microwave with it! So, clearly, this guy had no clue what he was doing. No concept of battery capacity. No clue as to how many VA's a 900w microwave needs to operate. And apparently, no idea that inverters don't magically pull power out of thin air!

So, when I hear about folks giving a particular battery poor reviews, based on short lived lives, I can't help but wonder if these people even have a clue as to how to maintain their batteries in the first place?

Now, perhaps the OP's batteries were junk to begin with, but poor maintenance will condemn even the best of batteries to a premature demise. So how much more so with a sub-standard battery?

Clearly they were never fully charged, if being floated by a converter at 13.2-13.6v, from 80-??%, for 3 years, with never so much as a single top charge, let alone a proper equalization / de-stratification during their short lived lives. Never was an SG reading taken. Never was a pre-service top charge done. And never was a capacity test done to compare with future readings. Just one day they seemed fine, but now they're dead! ... From all this, I cannot even begin to think these batteries were properly cared for.

But hey, let's all just ignore all this, and blame the batteries. AND, let's continue to insist converters do a good job at maintaining batteries, even though dozens of folks come to this forum complaining their batteries went dead... even after 12-16 hours of "charging"! And then, let's blame everything BUT the converter! "It's your furnace, it's your fridge, it's your cpap machine". Solution? Turn everything off, sleep in the cold, use a cooler with ice, and just stop breathing at night!!! :(

If only there were a simple solution to all this. If only it were possible to install a proper battery charger that charges at the battery manufacturers' recommended rates. And if only there was a simple device for checking SG levels occasionally, and maybe even a device for taking voltage readings. Maybe, hopefully, someday perhaps, there will be a way for rv'ers to maintain their batteries. I guess, for now, we can only hope and pray.

Compromise A) Regular RV 24, 27,& 29-30-31 battery

Compromise B) Golf Car, Scrubber, L-16 and other 5% antimony battery

Compromise C) VRB such as absorbed glass mat

Weigh positive and negative attributes in each class, then decide which battery best fits the purpose. There is no alternative sane way to choose a battery.

I suggest the OP uses the Search function and start reading, before asking any more questions.

Regular group 24, 27 and 29/31, while hooked up to a pedestal full time, are a much better bet for their type of usage.

Industrial type batteries are what the small minority, off the grid, with generators, charge controller and solar panel crowd prefer, only because they actually USE the deep cycle function on a daily or pretty regular or majority of the time situation.

For the OP GC-2's were the wrong battery being used in the wrong application.

BFL13 wrote:

IMO the T-105s would not act like that 31 or the T-1275s, but would act like normal 6s which need

http://pdf.wholesalesolar.com/battery-folder/charging_instruction_2011_2.pdf

The basics are in that thread though which is more than what most people do.

BFL13 wrote:

"Most" are on shore power with 12v batts AFAIK.

The overwhelming majority of RV's are on one or two 12V batts with a WFCO converter.