Battery Ratings

[Sagorsch]

Greetings!

I am buying new chassis and coach batteries. I would like to augment my research with experience from fellow forum members.

I have a 2002 Winnebago Adventurer 35U. The batteries are housed in the stairwell and are well ventilated under the carriage.I bought my rig, Addie, with 2-12V group batteries. I do not know if they are 24 or 27/31.

I plan to do a lot of dry camping this year. I will likely be running the AC/Furnace/Heat Pump, and the TV/DVD/Radio/CD, as well as charging phones, tablets, and lap tops, and using lights and sometimes vacuuming when "at home". 

So, here are my curiosities:

• What is your experience with 24 and 27/31 group variety batteries? 
• What kind of CCA/CA, AH and RC ratings should I be looking for?

• Considering the price of a liquid cell maintenance battery plus watering system cost, what is the difference in price between the AGM or GEL variety. I recognize among the varieties there are differing considerations depending on my RV lifestyle, so, if you have any perspective +/- among the 3 varieties I would greatly appreciate hearing them.

Sharon

 

 

[wolfe10]

Sharon,

Excellent question and thought process.

Couple of points:

What is access to batteries and how likely are you to check the water monthly.  If difficult or too much hassle, AGM's are a good "upgrade".

As far as what batteries (6 volt in series vs 12 volt) and number, since you are interested in dry camping where maximum amp-hrs is a plus, measure all three dimension of your battery box (length, width and height). Then go to any battery manufacturer's website and see what is the largest amp-hr @ 12 VDC what will fit.  Make sure you only look at deep cycle wet cell, AGM and/or gel. Marine or dual purpose batteries are not as well suited for your needs.

Also be aware that if you will be running your generator to recharge them, AGM's will take a charge faster due to less internal resistance. This is particularly important if you have a high-amp charger or inverter/charger.

[jleamont]

Here's one for the Q&A while on the subject of chassis batteries. Coach came with 1, 8D for the chassis, someone over the years switched it to 2, 31 group batteries 980 CCA each. Considering replacing these and taking it one step father to 3, 31 group 1000 CCA batteries.

I have plenty of room as the tray was designed to house 2, 8D's

Thoughts?

[wolfe10]

Yup, more CCA are better/less voltage drop when cranking.

[blakeloke]

Joe,

Our coach came with (2) group 31's for the chassis.  They didn't last long - probably because I didn't have a maintainer and went dead too frequently - but anyway, I installed (2) 8D's.  I believe they've been in there since 2013 and still running strong.  Installed the Battery Tender at the same time.

Hope I didn't just jinx myself!

Blake

[jleamont]

Thanks, the more I thought about it....I bought three 31 group batteries, I will make up the cables needed to add a battery this weekend, the extra couldn't hurt. They are 1000 CCA each, I figured I would change them as a PM measure, the chassis batteries look good but are not dated and I have no idea how old they actually are.

Blake,

[hermanmullins]

Blake & Joe,

I found out about a good way to add a battery tender to your coach.

Most all diesel coaches have a Block Heater to be used in cold weather. There is a 110 Volt receptacle in your engine compartment for the heater. When the coach is connected to shore power or the generator is running the receptacle is hot. When the Gen is off and or the coach isn't connected to shore power it is not hot. If you connect your Battery tender to the Battery and plug it into the receptacle it will come on then you and connected but will be off when you are traveling.

A very simple solutions to an on going problem on coaches that do not charge the Chassis Batteries through the Inverter while on shore power or running the generator. 

Herman

[jleamont]

Thanks Herman! My coach came from the factory equipped, I got lucky!

I also have the block heater 120V receptacle in the engine bay, I use it for my drop light while working back there , serves many purposes I guess.

[smitty777]

For the ISL, our coach came with one 8D chassis battery. When i replaced it 6 years ago, a fellow Country Coach owner suggested I look at the CAT 8D Maintenance Free battery. He said at the time he researched it, it was the largest CCA at 1500 that he could find. I spent about two hours surfing, again this was a little over 6 years ago now, and could find nothing with higher CCA. 

So our Cummins has been started by CAT these last 6 years:)!. Maintenance Free has meant very little upkeep on my part. I looked every 6 months the first 1 1/2, and then realized I was just dribbling water in to each cell for the sake of saying I had done so. Now I just check them yearly, same time a clean the posts, and still only seem to be semi dribbling a bit more water in each year. Doubt I use over 1 1/2 OZ between all cells:)! 

Different sophistication so charging will result in differences in outgassing, in our case, very little. 

You can find less expensive batteries for sure, but I can testify that the CAT 8D Starter MF battery is really a solid value. 

Best to all,

Smitty

Note: On IRV2 Cummins section. I once posted a question asking: How Many? and What Size? and How Old? were they when needing replacement, or how old and still running. Very interesting the way different manufactures and chassis builders approach starter batteries in general... We've never had a problem with a single 8D, and alway shave the house bank to fall back on via Boost and or direct Jumper Cabling if ever needed. 

[smitty777]

OP - Yes to measuring and installing the largest combo of AH you can in that stairwell space. Look specifically for 20 AH ratings when making comparisons. And no question wet cell batteries will be least expensive, and also no question that AGM would be the easiest to live with. And as Brett mentioned, AGM will accept a faster charge. So if really planning to do some heavy boon docking, going AGM and budgeting to upgrade your charger (IF NEEDED) can yield many less hours of generator run time... Even adding a solar panel or two could be cost justifiable to you. (Say get up and do your AM stuff with generator running doing some heavy bulk charging, I call it the heavy lifting of battery charging. Then if the SOC levels are getting to the right levels, and good sunshine exits, let the solar do the final absorb/float top off. AGM's are OK say going to 90-95% SOC for two-three days in a roll. Just be sure whatever method you do for charging, you get those batteries back to 100% SOC at least every third to fourth day - longer generator runs if needed. This will keep the investment in say AGM's living a longer life:)!)

A well liked not quite as expensive AGM are Fullrivers. A more expensive, and probably a bit longer living AGM are the Lifeline's... (And of course, other brands exists too:)!)

Best to you,

Smitty

[jleamont]

Update; now three chassis batteries are installed. Wow what a difference!! It cranks nice and fast to the point it fires faster. Interesting, I removed two Interstate Workaholic 31 group batteries, what I found odd was they had little weight to them. The replacement Deka product was noticeably heavier. 

[alflorida]

On 3/28/2017 at 0:38 PM, sagorsch said:

Greetings!

I am buying new chassis and coach batteries. I would like to augment my research with experience from fellow forum members.

I have a 2002 Winnebago Adventurer 35U. The batteries are housed in the stairwell and are well ventilated under the carriage.I bought my rig, Addie, with 2-12V group batteries. I do not know if they are 24 or 27/31.

I plan to do a lot of dry camping this year. I will likely be running the AC/Furnace/Heat Pump, and the TV/DVD/Radio/CD, as well as charging phones, tablets, and lap tops, and using lights and sometimes vacuuming when "at home". 

So, here are my curiosities:

• What is your experience with 24 and 27/31 group variety batteries? 
• What kind of CCA/CA, AH and RC ratings should I be looking for?

• Considering the price of a liquid cell maintenance battery plus watering system cost, what is the difference in price between the AGM or GEL variety. I recognize among the varieties there are differing considerations depending on my RV lifestyle, so, if you have any perspective +/- among the 3 varieties I would greatly appreciate hearing them.

Sharon

 

 

Smitty777 gave some good advice/suggestions.  I would like to add some additional info and considerations for you to think about.

--  For larger batteries I would upgrade to 6V golf cart batteries that you can buy at Costco or Sam's Club for about $80-$100 each.  They should fit in the space under your stairs.  They fit just fine in my 2006 Sightseer.   The dimensions of this type of battery are 10.5L x 7.2W x 11.5H.  You will have to do some minor rewiring of the batteries to wire the batteries in series.

--  VERY IMPORTANT:  You need to have some way to quickly recharge your batteries.  The standard converter your RV came with, works fine to charge your batteries when connected to shore power, because of the 12 to 24 hours it takes to fully charge the batteries with the converter.  You don't want to be running your generator that long to recharge the batteries.  You either need to replace the converter with a newer 3 stage converter, or have a 1000-2000 watt inverter/charger installed.  The 3 stage charging system will usually get your battery to 85-95% charged in about 1.5 to 2 hours versus the 12-24 for the standard converter

--  Quote: "What kind of CCA/CA, AH and RC ratings should I be looking for?"  You want a true deep cycle battery.  Any battery labeled with CCA or RA is NOT a true deep cycle battery.  It is a combination starting and deep cycle battery.  Not nearly as robust as a true deep cycle battery. 

-- What kind of inverter do you have?  If the Adventurer is like my 2006 Sightseer there is a small 300 watt inverter to run the TV and entertainment center.  However you won't be able to run a vacuum cleaner off of it.

--  You will not be able to run your air conditioner or heat pump from your batteries.  You will be able to run the propane furnace unless the temps drop down to near freezing and you want to keep the inside temp up around 65-68 degrees.  The furnace blower will run much to long overnight and use to much power from the battery. 

--  If you plan to do more than 2-3 days of dry camping before hooking up to shore power you must install a battery monitor like a Trimetric.  Without the monitor you don't know how much capacity you have taken out of the battery, nor do you know how close to 100% charged your battery is.  Both are extremely important to get long life out of any battery.  For long battery life you don't want to discharge the battery to more than 75% FULL (that is use 25% of capacity).  If you use 50% or more of the capacity of the batteries you will reduce the number of discharge/recharge cycles from around 2000 to around 500 cycles.

--  There has been mention of AGM & Gel batteries.  While they are very good batteries and have some advantages, they are 2-3 times as expensive as the golf cart batteries.  If you are going to spend that type of money, you want to be sure to totally educate yourself on how to properly monitor the discharge and recharge the batteries.  For that type of money you want to be extra sure you get the longest life possible out of the batteries. 

[alflorida]

WOW!  It looks like we have two separate and distinct threads going here. 

One about a diesel pusher with more sophisticated battery system and the one started by the OP with a gas powered motorhome.  

As you read through the posts keep in mind which topic and thread the posts are addressing. 

[Sagorsch]

Because I had a trip coming up and did not have more time to do an upgrade, I replaced the house with 2 12v group 31 batteries 800 CCA (Deka). Oh, and when I measured I only have room for the 2 house batteries and 1 chassis battery. I am not at the point where I want to build out the existing shelf and re-position the chassis battery. 

Thanks everyone! I have a lot to consider and more to learn before upgrading.

A hopeful thought...Lithium batteries will be safest and most convenient solution in the near future

Happy travels!