What battery should I upgrade to?

Sharon_is_SAM

For those seeking battery wisdom, Northern Arizona Wind and Sun has the most thorough discussion/info on deep cycle batteries that I have seen.  Find Deep Cycle Batteries Frequently Asked Questions.  Gives all the pros and cons.  PXLated, how do I attach a link?

Sharon

AldebaranJill

Here are my favorite Trojan Links:

List of their RV Deep Cycle Batteries (12V and 6V)
http://www.trojanbattery.com/markets/marine-recreational-vehicle/

12V
http://www.trojanbattery.com/markets/mr/12v/

6V
http://www.trojanbattery.com/markets/mr/6v/

Battery Maintenance Guide:
http://www.trojanbattery.com/tech-support/battery-maintenance/

Videos of Trojan Tips 
http://www.trojanbattery.com/multimedia/#TrojanTips

User's Guides (These are awesome)
http://www.trojanbattery.com/literature/#usersguide

And on several occasions I have called them with questions, great superior customer service.

Love my Trojan!

Nomad

To post a link, copy and past into the popup box via this...

Sharon_is_SAM

https://www.solar-electric.com/deep-cycle-battery-faq.html#AGM,%20or%20Absorbed%20Glass%20Mat%20Batteries

Thanks PXLated!

ColoradoJon

Fixed: The link above is broken.  Missing the  : between https and the forward slashes.

Sharon_is_SAM

Thank you!  I am tech challenged.  There is hope- just got a smart phone!  Officially moved into the 21st century.

Nomad

SAM - The problem with that popup box is it already includes the first part of a url - best to delete that before pasting the copied one in :-(

Sharon_is_SAM

Got it.  Thanks!

BrianZ

Anybody ever tried this 12V golf cart battery?  Appears to be a group 27 size & 150AH..

https://www.batteriesplus.com/productdetails/SLIGC12VT

Was looking for something to purchase locally & fit inside the stock tub, with some modification.  Would like to be able to get through 5 days without hookups & add some solar at some point.

ericnliz

@BrianZ, I went to solar first. I'm still glad I made that decision as I have gone for 10 days without having to worry. Group 27 is a good alternative to the stock Group 24. @Homebodyatheart had one put in stock & just paid the difference for the upgrade. I still have the stock group 24, and am frugal with the amount of draw I put on the battery system. When the group 24 stock battery goes, I'll be looking at either 2 6 volt deep cycle, or a group 27.

rfuss928

I am on my seventh season with an Optima Blue Top AGM.  I found the D31M fit in the stock group 27 box that came in our T@B.  I later added a second one and solar.

Last summer both tested above original specifications.

I rarely even think about them until someone asks for a battery recommendation.

Jdcouple

I have a 2017 outback and am dieing to do the dual 6V mod. Way more life and not to expensive. The weight is the only draw back I can think of. I did this on an older travel trailer and it made a huge difference. This thing is so much more efficient I can only imagine how well it will work. 

Jdcouple

Also the the ones I used last time were Duracell golf cart batteries from Sam's. They were less than $100 a pice. 

MuttonChops

BrianZ said:

Anybody ever tried this 12V golf cart battery?  Appears to be a group 27 size & 150AH..

I'm also thinking about the best 'for me' next battery and the 12V Golf Cart are on the maybe list.  Several folks comment on the impact to trailer tongue weight.  My weight concern is more basic . . . will I be able to safely lift (remove/install) a battery weighting 100#, like your 12V model, by myself now as well as in a few years from now.

jgram2

I swear a TAG forum member has a winch on the front of his TV. With that available, you’d only need to consider the tongue weight. Or maybe a hydraulic arm for lifting the battery, the 6 gallon water jug to gravity fill the fresh water tank when boondocking,...

WilliamA

Perhaps I'm missing something but I have a difficult time working out how the charging line from a modern tow vehicle with (theoretically) up to 30 or (for short bursts) 40 amp capacity is having a difficult time keeping up with a refrigerator that draws a few amps.  As I've said over on the T@G forum over and over (until I'm starting to worry about being banned from talking about it) if you drive for a few hours and your tow vehicle isn't able to (mostly) charge your battery and run the fridge, something else is wrong.  I understand T@B's have larger fridges, but they're not walk-in's.  Suffice to say, if folks are having problems keeping a group 24 or 27 battery charged, putting in a bigger battery will actually make the problem worse as it will take a lot more time and energy to charge it.  

http://teardrop-trailers.vanillacommunity.com/discussion/382/food-for-thought-volts-is-volts#latest

I'll hang up now and take my answer off the air....
WilliamA

ScottG

No argument there, @WilliamA. Something may be wrong but if so it's common problem with many vehicles. I'm sure there's an explanation within the bounds of electrical physics, but thus far I haven't found the issue compelling enough to diagnose it and implement a remedy. Throwing a few jugs of ice in the fridge takes up space, but I need that ice anyway once I get to camp!  ;-)

Anecdotally, the fridge issue seems to involve the 3-way fridges installed in non-clamshell T@Bs. These do draw considerably more amps on DC than the 2-way models typically installed in clamshells (including T@Gs).

SweetlyHome

@scottg and @willA I have given this some thought as well.  IMHO it has to do with voltage drop in the TV charge line and the relative voltage of the battery as the battery and TV are parallel.  I applied the current squared times resistance calculation and got roughly a 1 volt drop in 15 feet of 10 gage wire at 10 amps.  The 13 volt alternator output is 12 volts at the battery and fridge at 10 amps draw. I stand corrected if I messed up the math.  The battery discharges trying to hold the voltage up, losing the ability to do so as it discharges.  Is there sense my thinking?

Ratkity

I was told that the phantom power, plus the lights, plus the brakes put a load on the alternator. The 10 gauge wire (or should be) that is hot all the time only puts out what I was told a "trickle charge" and not enough to handle 3+A. That's the 3-way. The two-way takes much less.

Even if you don't have the frig on and just hook up, the amount that is going to the phantom power that includes the converter-charger and then pushes power to the battery is still a trickle charge. You can get a slightly discharged battery to a higher state if you travel 8 hours or more, but it's a slow way to charge a battery. Heftier alternators are great, but the amount allowed to the circuit is still a trickle charge.

Just FYI, my "hot" wire does not turn on unless the truck senses there is no circuit interruption in the trailer's running lights. I have a 2018 F150. I wired a 7-pin male plug to my electric jack and didn't change the plug configuration because that worked for my other truck. Even running, the truck would not turn on that stupid hot wire. I got mad, wired it to the truck running lights and now the jack works if I have the truck lights turned on manually lol.

ScottG

@SweetlyHome, I think you are onto something there, though the technical details are a bit out of my pay grade. Compounding the voltage drop you describe is that modern vehicle generators ("alternators") feature circuitry that steps down the voltage under certain conditions. I've seen the output of mine (measured at the power plug in the cab) dip below 13V on several occasions. Some people have found a way to trick the generator into kicking up the output voltage, but so far nothing has worked on my particular vehicle.

@Ratkity's suggestion may also have merit. However, I've noted that even on relatively short trips my battery seems to charge up just fine so long as I am not running the fridge on DC. I'm thinking the LED trailer lights don't draw that much power. On the other hand, IIRC the fridge running on DC demands ~11A.

SweetlyHome

@ScottG and @Ratkity I believe the two concepts blend well.  Again the voltage drop in the charge line would result in the bulk of the available alternator current output going to the TV and its battery.  

jkjenn

WilliamA said:

Perhaps I'm missing something but I have a difficult time working out how the charging line from a modern tow vehicle with (theoretically) up to 30 or (for short bursts) 40 amp capacity is having a difficult time keeping up with a refrigerator that draws a few amps.  As I've said over on the T@G forum over and over (until I'm starting to worry about being banned from talking about it) if you drive for a few hours and your tow vehicle isn't able to (mostly) charge your battery and run the fridge, something else is wrong.  I understand T@B's have larger fridges, but they're not walk-in's.  Suffice to say, if folks are having problems keeping a group 24 or 27 battery charged, putting in a bigger battery will actually make the problem worse as it will take a lot more time and energy to charge it.  

http://teardrop-trailers.vanillacommunity.com/discussion/382/food-for-thought-volts-is-volts#latest

I'll hang up now and take my answer off the air....
WilliamA

I have been through 3 TVs with the T@b and no e, if I am driving for 6 hrs+ keep the T@b batteries charged if I run the fridge on DC. First if all, even with a factory tow package none of my alternators has exceeded a 180ah alternator. That is not an overly powerful alternator. Secondly, my most recent TVs are very electronics heavy and their "smart" system tends to vary how much juice it is sending to the TV based on the voltage of the TV battery. I can really tell if I am trying to run my ARB fridge, too.

In short, capacity does not translate to distribution.

BrianZ

Thanks for all the interesting perspectives on my question.  I'm still considering installing a group 27 sized box in our tub for a 150AH 12V golf cart battery, probably the Trojan T-1275 Plus.  Am I correct that the T@B's converter charger should not have any problem recharging the battery, as it has for our standard marine/RV battery?  I know that separate chargers are often recommended over the winter for garage storage, but I'm not planning on lifting that 90-lb battery in & out twice a year, just twice a lifetime. 😉
If a separate charger is necessary, some of them say for only up to 120AH batteries, while others don't say.  Also, if charging in a tub, how can this be done - are there waterproof chargers & do they plug into T@B A/C?  I'd prefer to do as I do now & just use the converter for charging.

We just want to be prepared for 4-5 days without hookups & not depend on solar plus standard battery.  We will likely still be using hookups mostly I expect, but still looking for more freedom occasionally.

TerryV6

Is there is there a considerable performance difference going to the bigger battery, time usage etc...?  Sounds like a dumb question - but hey, I’m asking it...  I’ve purused  lots of stuff by Jenn and others btw.  I know.... it depends....

Sharon_is_SAM

@BrianZ,

We have a 150 amp Lifeline AGM.  Regarding the converter charging, you need to identify your battery charging needs in terms of bulk, absorption and float and compare it to the converter specs.  If the converter voltage steps down prematurely relative to the battery requirements, it will not completely charge the battery.  Over time, this constant under charging will impact battery performance and effective life cycles.  I have a smart charger whose specs provide what my battery requires.  After a trip or during a period of battery cycling I use the charger overnight to optimize battery life.  I do not leave the Tab plugged in, rather it receives a good charge via the the smart charger.  We charge before storage and isolate the battery during storage.  I highly recommend an AGM.  More expensive than the flooded batteries, however I think they are superior.  After months in storage, they still read 98-100% charge.

BrianZ

Yes, @TerryV6, it's my understanding the typical marine/RV battery has about 75 Amp-Hours total capacity, so a 150 AH battery would last twice as long at the same usage rate.  By using Jenn Grover's handy chart for adding up various basic amp-hour T@B usages for an anticipated 4-night stay without hookups, I quickly realized that even using propane for both Alde and frig, we would not make it without depleting the battery well below the safe 50% discharge level (only 35AH available in a standard battery).  Since there are single 12V 150AH golf cart batteries that will fit in a Group 27 size box, which can be made to fit in a stock tub, that would give us enough to survive for 5 days of basic needs without recharging and using propane.

Thanks, @Sharon_is_SAM.  The AGM does sound like a nice option with its superior ability to hold a charge for a longer period with very little self-discharge.  I have yet to find one with that capacity though, that would fit in a group 27 box. Do you have the length spec of yours?  Trojan makes a 140AH AGM deep cycle battery, but it appears to be about a quarter inch too long to fit inside a group 27 box.  I really appreciate your feedback, though didn't want to start a debate about what's the ideal battery charger, and while I do understand there are some advantages for performing equalization on demand, etc, I still feel the built-in WFCO has done an adequate job for us so far just leaving it plugged in.  I've checked a number of times after leaving switch off overnight, and always found a fully charged battery.  Sometimes I will even find the monitor showing the 13.2V trickle charge (versus the usual 13.6V).  Will need to double-check the specs though, so thanks for that suggestion.

Sharon_is_SAM

Our battery will not fit in the footprint of a Group 27.  The factory made a custom box and created a custom battery frame.  The tub was moved forward to accommodate the battery.  You can check Lifeline for the dimensions.  Another option has been done in the past by other Tabbers.  They basically built a small, wood platform that rested and was secured on the current soldered battery framing.  In addition, you can create a lip to match the external dimensions of the battery footprint and place the battery inside the lip.  Look into the VMax Tank batteries on Amazon.

BrianZ

Yep, thanks, I've been reviewing Scott's battery installation, which is basically what I'm planning to do as of this moment.
Thanks again.

elbereth

@BrianZ, we did the 2, 6V golf cart battery setup in the standard tub with a wood platform, as @Sharon_is_SAM mentioned.  Ours are 225 Ah and so would easily do what you needed.  We have a CS-S and use the fridge on DC and it makes it through a weekend no problem, and have 100W of solar for extended trips.  I have been using the WFCO charger in between trips.  We have been very pleased with the setup.

BrianZ

Nice setup, @elbereth, that's great to hear (& see)!  What's hanging over the gas tank - is that a solar connector?  Did you relocate your gas regulator to the other side on the diamond plate?
I'm not sure this arrangement would work for us, because we have a sewer hose carrier tube mounted behind the tub, and it looks like your battery arrangement might make use of that space?
Thanks for sharing, and glad to hear the WFCO charger is working fine for you too.