Another house battery question..Help

hondo12 · 09-02-2010, 11:12 PM

Hello, I have a 08 gas adventurer 39' 2.5 yrs old with 2700 miles. Can anyone give me an estimate on how long my house batteries should hold a charge when maintaining minimal power draw such as a few lights, fridge and occasinal heat ? I have never used this coach without shore power before and when testing my batteries for a upcoming overnighter they went close to dead after less than an hour. I then checked them and had to add a bunch of water, then charged for about 18 hours with a 6 amp charger, genset said 13 volts, tested again for 2 hours and it was dead again! Think I need a couple new batteries? if so what do you all reccommend? also my solar charger is under cover most of time.
so I don't get any charging there. Thanks Craig

jperry29 · 09-03-2010, 08:29 AM

If your batteries have been in the coach for the past two years and just allowed to do whatever they do without monitoring and maintaining, then they have probably at the very least built up a layer of sulfates on the plates or more than likely, are completely shot.

Depending on your converter/charger, some of these can be pretty simple and charge too aggressively, cooking off fluids and causing heat that can shorten the life of a battery. Then, if left in storage for the winter, or heat of the summer, they can reach deep levels of discharge because of phantom loads. Even if you have a battery disconnect, discharge will occur over time. Deep discharges can significantly shorten the life of a battery.

You could get you a smart charger (I got mine from Sears, but they are available lots of places) and hook it up to the batteries to see if it will run a desulfating cycle. After it desulfates and charges you can test the specific gravity in each cell to see if they all came up to charge or if one or more of the cells are dead. If you have dead cells in just one battery you should replace all batteries. Do not mix old and new batteries.

And now that you have the smart charger, you can pull your batteries when the coach is in storage and keep them handy at home so you can put them on the smart charger about once per month. This will get you the maximum life out of a battery.

hamguy · 09-03-2010, 10:21 AM

Quote:

Originally Posted by hondo12

Hello, I have a 08 gas adventurer 39' 2.5 yrs old with 2700 miles. Can anyone give me an estimate on how long my house batteries should hold a charge when maintaining minimal power draw such as a few lights, fridge and occasinal heat ? I have never used this coach without shore power before and when testing my batteries for a upcoming overnighter they went close to dead after less than an hour. I then checked them and had to add a bunch of water, then charged for about 18 hours with a 6 amp charger, genset said 13 volts, tested again for 2 hours and it was dead again! Think I need a couple new batteries? if so what do you all reccommend? also my solar charger is under cover most of time.
so I don't get any charging there. Thanks Craig

Goto- The 12volt Side of Life (Part 1)

And read up on RV electrical systeems. And then get on E-BAY to find a good 3-stage Progressive Dynamics charger.

Problem solved.

Paul T · 09-03-2010, 11:05 AM

Keep your nose and eye’s on those batteries until they are replaced. I got myself into what I consider a dangerous situation with my coach after about two years when I thought the rotten egg smell we were getting was from propane or the holding tank. It was the the batteries boiling while attempting to charge while underway or plugged in. By the time stupid stupid opened the steps to check the battery fluid level they were half dry and nearly hot enough to melt themselves. Now I smile at the experience but then it was just new owner ignorance, (after two years of using it).

hondo12 · 09-03-2010, 02:13 PM

Thanks for the good information! I'm a hands on guy with
maintenance and small mechanical problems but I never even thought about maintaining the house batteries.
So if I understand it right replacing the (2) 12volt stock batteries with (2) 6 volt golf cart or t-105 batteries is the way to go? and then when not in use turn off the inverter and kill the coach switch and hook up a trickle charge specifically for RV use, along with monthly maintenance should be good??
If so can anyone chime in to share the best battery type at the most reasonable price and availability.
Thanks in advance, Craig

DAN L · 09-03-2010, 02:21 PM

Quote:

Originally Posted by hondo12

Thanks for the good information! I'm a hands on guy with
maintenance and small mechanical problems but I never even thought about maintaining the house batteries.
So if I understand it right replacing the (2) 12volt stock batteries with (2) 6 volt golf cart or t-105 batteries is the way to go? and then when not in use turn off the inverter and kill the coach switch and hook up a trickle charge specifically for RV use, along with monthly maintenance should be good??
If so can anyone chime in to share the best battery type at the most reasonable price and availability.
Thanks in advance, Craig

i like my 2 lifeline agm 6v batteries hooked up in series.

i mounted them on their sides for clearance. i now have 300 amp hours instead of the original 190 capacity. i never have to add water and there is no corrosion. there are pics of my installation in the archives on this forum.

Lifeline GPL-6CT Battery

Hikerdogs · 09-03-2010, 02:27 PM

I agree with those who feel you may have shortened the life of the batteries by not adding water regularly and possibly discharging them too deeply more than a few times. The original batteries in our Adventurer lasted less than 4 years because we ran them way too low more than we should have.

We replaced them with Sears Die Hard 12 volt batteries in 2004 and they're still going strong. We only use the altrernator and the original onboard charger (powered either by shore power or the generator). They will give about 8 hours of service with miinimal lighting and limited television. If we're boondocking and they get down to 12 volts we start the generator and let them charge for a few hours.We throw the disconnect whenever it goes into storage. They have gone through several winters with weeks of -20*F and a few summers with temps above 100*F.

Yellowboat · 09-04-2010, 12:12 AM

I replaced my two 12 volt batteries about every two years till I changed over to two 6 volt golf cart batteries.

hamguy · 09-05-2010, 11:55 AM

Quote:

Originally Posted by Yellowboat

I replaced my two 12 volt batteries about every two years till I changed over to two 6 volt golf cart batteries.

Since 2-6V batteries in series are the equivalent to 2 12V in parallel, you have some other problem to confront.

Each setup is equal to 6-2.1V cells in series.

stik · 09-05-2010, 12:04 PM

Quote:

Originally Posted by hamguy

Since 2-6V batteries in series are the equivalent to 2 12V in parallel, you have some other problem to confront.

Each setup is equal to 6-2.1V cells in series.

Hamguy is a wise man and should be listened to!

bachler · 09-05-2010, 01:20 PM

Over the years I have picked up some important information about batteries ;; I will share this. #1 A battery has an internal resistance, This is inpossable to measure, However it is believed near .07 amp. That means that a battery left standing or unused it will discharge,; #2 A Battery is only A storage Unit; But it is on a graph Comparison, it starts at 100% after uses it declines Down to 50% 25 % and down to 000% ; Also a battery must Be Charged right away after it has been discharged. Sulfaction starts imeditlay. # The most inportant thing is most motorhome converters DO NOT HAVE a sufficent Battery charger. I Install a good Merine Battery charger. it will charge 75 amps taper down to a trickel charge; Now for the rest of the story.. Our Winn. Ult' Adv; Is a 2000; It has a 1500 Watt inverter 75 amp. charger. I replaced the batterys in 2001. This year before the Winn. GNR i took the batteries out and took them down to DYNO, they build the batteries In Seattle .. any they checked the batteries , whooo, they were the same as brand new battries on the shelf; My friend That is 9 years old. our MH. is pluged in when at home, and We boondock Using the 1500 watt inverter To make toast, watch TV, make popcorn in the micro wave, The batteries like to be used,,;; Just the facts, Life is good.

hamguy · 09-05-2010, 01:37 PM

Quote:

Originally Posted by bachler

Over the years I have picked up some important information about batteries ;; I will share this. #1 A battery has an internal resistance, This is inpossable to measure, However it is believed near .07 amp.

Actually, you can measure the internal resistance (measured in OHMS) Doing so was part of my Physics Lab experiments.

That means that a battery left standing or unused it will discharge,; #2 A Battery is only A storage Unit; But it is on a graph Comparison, it starts at 100% after uses it declines Down to 50% 25 % and down to 000% ; Also a battery must Be Charged right away after it has been discharged. Sulfaction starts imeditlay. # The most inportant thing is most motorhome converters DO NOT HAVE a sufficent Battery charger. I Install a good Merine Battery charger. it will charge 75 amps taper down to a trickel charge; Now for the rest of the story.. Our Winn. Ult' Adv; Is a 2000; It has a 1500 Watt inverter 75 amp. charger. I replaced the batterys in 2001. This year before the Winn. GNR i took the batteries out and took them down to DYNO, they build the batteries In Seattle .. any they checked the batteries , whooo, they were the same as brand new battries on the shelf; My friend That is 9 years old. our MH. is pluged in when at home, and We boondock Using the 1500 watt inverter To make toast, watch TV, make popcorn in the micro wave, The batteries like to be used,,;; Just the facts, Life is good.

That is true!

bachler · 09-05-2010, 03:30 PM

I do not want to dissagree with anyone. it is bad policy; In my 4 years on electronic engineering we had newer found a way to measure The amp . draw. oms is but a measurement of load; How one would measure the load on each plate in a battery is quite a feat in itself. Yes a couple of my old professors would like to rap there minds around that formula..;; Lets not get out there were no one goes. Life is good most of the time;;

hondo12 · 09-06-2010, 12:17 PM

Thanks everyone for the great info, Due to a shortage of time to get this battery situation taken care of for the use of the MH the holiday weekend I went to sears and purchased (2) group 29 series deep cycle Die Hards. Let me tell you these worked great! After making a full charge and driving about 80 miles to our destination we used battery power all day Saturday, watched an entire movie Sat night and ran the heat a little through the night, Sunday morning the Genset read 12.1 .............. Very pleased! Craig