T@B Battery

chuckshaver

If I plug my T@B into shore power, then after overnight I unplug and test my battery and it reads 12.6 +. Then I leave it unplugged and pull the fuse at the battery and by 3:00 I test the battery again and I get 10.6 or so, Is my battery bad?

Ramrod

Probably

ScottG

Sounds like it, unfortunately. That's how mine behaved in its last days. The inability to hold a charge even when completely disconnected usually means lights out.

You might check the water level in the cells, and top off if needed. I doubt that will make a difference, but why not give it a try.

Don't feel bad, many of us have been there, done that!

chuckshaver

The issue is that when we bought it new, the dealer never told us about the draw on the battery and that we should pull the fuse. We put it away for the winter in our garage and I would plug it in to power for a day and then unplug it so the battery would not freeze. Problem is that the battery kept draining down and recharging and draining down again to very low. I believe that killed it.

ScottG

Yup. Classic case. If you drain 'em too low, too often, they don't survive. I knew this was true of automobile batteries; I learned pretty quickly that while deep-cycle batteries are more rugged, the same general idea applies.

Nomad

Just replaced mine after two years of continuous use - Had the same symptoms, would show fully charged and 6-8 hours later it'd be 9 or 10 something. Can't complain though, I live off it 24/7/365.

ericnliz

PXL, What did you replace it with?

Nomad

I didn't have a whole lot of choices since I wasn't near a good, knowledgable battery outlet. The rv place I stopped at had two 24s in stock - one with the same Interstate model numbers as mine and one with higher numbers. They were clueless to the difference, didn't know anything about Amp hours, etc so went with the higher numbered one on the blind theory that it had to be better since it was slightly more expensive. In my haste to get it installed, forgot to write down what the model number was - Need to get back into the battery box at some point so will look then.

ericnliz

PXL, Please let me know what you find out, as I have an Interstate battery outlet close by, and would like some comparison when I get to the point of replacing it, thanks!

Ratkity

I replaced my no-name group 24 battery (still good) with an Interstate group 27. Very happy so far and have almost 30 Ah more juice to waste!!

Nomad

Didn't have the luxory of modding the battery frame so the 24 had to do.

leenscottfl

Replaced my Group 24 today with a 27 Barracuda AGM. No mod necessary just cut a piece of plywood to put in the frame, screwed the new 27 case down and ploped in the new 27 AGM. Now I just hope I don't newbie fry this one.

Nomad

Am aware of all the various mod methods but no wood, no saw, etc - If I was off the road or in a different location I'd have had some options.

Estancio

chuck shaver, just curious how many years you got out of your first battery? I am on year 5 and still going strong.

chuckshaver

Really, not even a year. But not the battery's fault. It's mine. I wasn't aware of the parasitic draw and never pulled the fuse at the battery. Bought our T@B 2016 in the fall, camped once and stored it in our garage. I left the battery in because it's fairly warm and I plugged into shore power every few weeks to keep the battery topped off. Never knew it was drawing down to nothing. So, I ruined it.

lapowers57

How long should a deep cycle battery last?  That is an interesting question and obviously there are many variables.  I know for me a car battery lasts about 5 years the way I use it.  I have no idea what to expect from the battery in my T@B since I don't have the same history with it.  I found an article at  https://www.solar-electric.com/deep-cycle-battery-faq.html that discussed this.  For us T@B owners here is the average life for various deep cell batteries.

• Starting: 3-12 months
• Marine: 1-6 years
• Golf cart: 2-7 years
• AGM deep cycle: 4-8 years
• Gelled deep cycle: 2-5 years
• Deep cycle (L-16 type etc): 4-8 years

One of the interesting things it talked about was over charging AGM batteries.  I had forgotten that my boat charger had a lower voltage setting for AGM.  Does the charger in the T@B have different setting for gel vs wet batteries?  If not you will be over charging and shortening the life of a gel battery if you install one.

Nomad

Remember, I'm full-time so it's in constant use.
The Zamp solar controller allows you to pick what type of battery you have so it can adjust.

lapowers57

Yes, if you rely solely on the Zamp and choose the correct battery type you are good to go.  It is the charger built into the trailer that I am wondering about.

Verna

lapowers57 said:

Yes, if you rely solely on the Zamp and choose the correct battery type you are good to go.  It is the charger built into the trailer that I am wondering about.

There are some informative answers about the T@B converter here:
 
http://wfcoelectronics.com/faq/#tab-57c1077b6e3b2

"Can I use AGM or Gel batteries? 

AGM batteries are ok. We do not recommend the use of GEL batteries unless you contact the battery manufacturer to see if the battery is capable of being charged with a converter putting out 14.4 Vdc."

Ratkity

I'm not sure what model of converters they are putting in the T@Bs now, but I've never metered above 13.7 (via shunt, so direct battery metering on shore power with parasitic load only). Only my solar set up allows selection of battery type and I can set max charging (bulk) to 14.4V. It never goes about 13.7 with the parasitic load when metered.

Like V said, Gel batteries are not recommended. The link she gave is the best I've seen so far!! (thanks V) Lead acid bulk charges at 14.4V and many (not all - Trojan brand is exception) AGM bulk charges at 13.8V. Most stand-alone consumer battery chargers err on the low side and have a max setting of 13.8V (most, not the expensive ones). It's a "consumer protection" issue (aka liability CYA company thing). *All* battery types charge at a relatively low voltage. There is no fast and dirty way to fully charge a battery faster than it can take a charge (think chemical explosion).

The thing to remember is that to fully charge any battery, one has to charge it overnight. To correctly meter a battery's charge, it must sit another 24 hours without any load so the chemicals equalize or you can get a false reading. This is a pita for most cuz all we wanna do is CAMP!! No one wants to lift 48# of a group 24 battery out of that bin to do do proper metering (except maybe PXL during his T@B Yoga exercise regime). 

For people who depend on battery power and live full-time in their campers, a 95-99% charge is just fine. The other percentage isn't a big deal because they are using their batteries to their fullest. For us weekend warriors, extra care needs to be taken because the battery is sitting unused for long periods of time.

Verna

I have seen 14.6V on my battery meter before. It doesn't stay long. I had to check the website to make sure it was OK. 

Ratkity, it says to check with the GEL manufacturer to see if they can take the current, but that AGM batteries are OK.

Now, I'll have to research because I thought AGM were GEL batteries. Whew, answer one question and get 2 others

Ratkity

AGM has a mat matrix between the plates. It does have a similar chemical composition of gel consistency, but it's not the exact formulation of a full "gel" battery. The matrix is great for deep cycle because it doesn't allow as much layering of chemicals as a lead acid or full gel when sitting around, thus it can sit 3 months unused without barely losing a charge (not true of flooded lead acid - never bothered to research the full gel ones). 

The lower threshold for charging an AGM is because no matter the battery, hydrogen is off-gassed. With a flooded battery, one would just loosen the caps and it can be charged at a higher rate. Since an AGM is sealed, it has to be charged at a lower rate or you'll get bulging of the battery (not a good thing). This could lead to a dangerous situation where the battery casing splits. As most know (and perhaps can recall the Hindenburg), hydrogen gas is very explosive. 

ScottG

Ratkity said:

I'm not sure what model of converters they are putting in the T@Bs now, but I've never metered above 13.7 (via shunt, so direct battery metering on shore power with parasitic load only). Only my solar set up allows selection of battery type and I can set max charging (bulk) to 14.4V. It never goes about 13.7 with the parasitic load when metered.
...

According to the paper manual that came with my converter (WFCO model WF-8735P) There is a 14.4V "bulk mode" that activates for "up to four hours" when the battery voltage drops to below 12.2V (NOTE: the manual actually says 13.2V, but I'm pretty sure that's a typo!)

I've never seen it go into bulk mode, but I've never had my battery below 12.2 since I've been monitoring it.

Ratkity

Ditto Scott, I've never let my battery go below 12.2v as per instructions here and other places where increasing battery life has been discussed.

Verna

That's strange because when mine went up to 14.6V, I had been plugged up for days in my driveway when I got back from Arizona. (20A circuit with nothing else on it.)

I took it as the converter wasn't used to a steady 110V after using solar most of the winter

ScottG

I agree that doesn't sound right under those circumstances. Maybe your converter (or your battery) was having some sort of momentary hissy fit. That's the best explanation I can conjure!

Verna said:

That's strange because when mine went up to 14.6V, I had been plugged up for days in my driveway when I got back from Arizona. (20A circuit with nothing else on it.)

I took it as the converter wasn't used to a steady 110V after using solar most of the winter

Verna

I just looked it up, stored it in the gray matter data base and ignored it, @ScottG. 

ScottG

Verna said:

...

There are some informative answers about the T@B converter here:
 
http://wfcoelectronics.com/faq/#tab-57c1077b6e3b2
...

I just checked out this link. Very helpful--thanks, Verna.

For those who care about such things, I noticed that--like my paper manual--the FAQ states that bulk mode kicks in when the battery is below "13.2V." This makes no sense, but with the same apparent typo appearing in two places (and with time on my hands) I wrote WFCO tech support to ask "Whatup?"

To their credit, they responded promptly to confirm the typo and clarify that the converter "should kick into bulk mode at around 12.2V."