What battery to buy

[lennyl]

hello, I will need to buy a new 12v battery for the upcoming season and was looking at Exide Edge FP-AGM24DP Flat Plate AGM Sealed Marine Battery it sells on Amazon for $175
anyone has any experience using this battery?

thank you.

[seanmcpherson]

I'm having a Trojan AGM group 27 placed on a new 185RB Baja on order which I'll pick up later this year; figured if I was going to go to the expense of AGM I might as well get the group 27.

Sean

[lennyl]

what does group numbering mean?

[seanmcpherson]

It's mainly the dimensions, which in turn affects capacity. Here's a quick chart:

List of Common Battery Case Sizes | BCI Group Numbers

The 2015 SLX manual says it's set up for a group 27, so although a 24 fits fine and is what most RV places put on there (as they're cheaper), the weight difference isn't much and the extra 10+% capacity is useful for me.

[lennyl]

ok, just googled it group is a physical size of the battery

[oldmanAZ]

Originally Posted by lennyl

what does group numbering mean?

It is a relative size and capacity indication: A group 24 is physically smaller and has less capacity (amp hours) than a group 27.

There are group 27 Excide batteries. You could compare the size etc. to the group 24 you are considering.

[seanmcpherson]

My post about the sizes etc had a link so it was held for moderation If it pops up randomly later, my bad.

[GeraldNKathy]

I have never had a positive experience with ANY Exide battery. If available I would use an Interstate - or any brand but Exide.

[ninjahbob]

Not sure but there is something special about charging the AGM battery. You may need to make sure your on board charger will accommodate the AGM battery. Always had good luck with Interstate batteries.

[Mustang65]

The first question you want to ask before buying the battery is what it will be used for. If you are only camping at CG's with shore power there is no reason for a group 27 battery, or a DEEP CYCLE battery, the BASIC group 24 that comes with the TT is all you need, as it sole purpose is for emergency breaking (TT's electric break away switch activated) and will absorb any spikes that may be produced by the TT's battery charge controller (from a shore power spike). The new TT battery control centers suppress the spikes now. With proper maintenance, the standard RV/Marine battery that is standard on TT's will last for years.

If you are looking at a lot of dry-camping then the recommendation would be TRUE DEEP CYCLE batteries (not RV/Marine batteries which have CCA ratings). 12 Volt DEEP CYCLE batteries have less Ah ratings than (2) 6VDC batteries in series, so you may want to look at (2) 6VDC batteries in series. IE.. my (2) 6 volt batteries are rated at 260Ah rating, of which I can only use 130Ah of the 260Ah (12VDC minimum voltage level - 50%)

As for Flooded batteries vs AGM there is plenty of debate as to whether the extra money is worth it for the AGM. If your batteries are in an enclosed area, than AGM would be a good choice.

There are plenty of manufactures out there that have both flooded and AGM product lines.

Trojan
USBattery
Interstate (not sure about True DEEP Cycle Batteries, did not see any listed)
and many more....

Space is a driving factor on TT's as they have limited room to place your batteries. If you are looking for a true DEEP CYCLE battery, it should NOT have a CCA rating in the specifications. That is the easiest method for IDing non TRUE deep cycle batteries.

These are only a few thoughts regarding type of battery, I am sure that others will add to the list.

AGM battery charging (per the battery university):
AGM batteries are sensitive to overcharging. These sealed batteries can be charged to 2.40V/cell (and higher) without problem; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages).

Just my thoughts,

Don

[Northern Jay]

As far as batteries go, i still have the original 2 Magnum Energy RV/Marine batteries in our camper. They have been going strong for 7 years, and we mostly dry camp. We do have an 80W solar panel to maintain them. During winter the camper is always plugged in unless we happen to be winter camping.
We have the same batteries installed on the TT, but are installing a 250W solar system next month. Hopefully they will last as long as the batteries in the camper. They are 12V, not sure of AH capacity. Just FWIW.

[clubhouse]

I have been very happy with the batteries I purchased from Costco. I use dual Grp 24, but they have 27 and GC2 6v if you want to go that route.

[Imnaha.Mansion]

When comparing the Ah of 6V and 12V, remember to half the rated Ah of the 6V batteries since you will be running them at 12V. I have been vary pleased with my Lifeline AGM batteries. I went with four 6V (600Ah) since I'm a boondocker.

[AKGperson]

Speaking of 6v vs. 12v, why switch over to 6 volt batteries when the system is designed for 12 volt? Just curious.

Ken

[seanmcpherson]

I can't speak to all of the chargers, but the last couple of years of 185RB & 195RB are shipped with a WF8735P power center which bulk charges at 14.4, floats at 13.2, and loaded float charges (when loads are still present) at 13.6. All of those are fine for an AGM like the Trojan which calls for bulk charging at 14.1-14.7 and float at 13.2-13.8.

In regards to the exide batteries, I've had bad luck with them in other uses. I have had good luck with Deka/Penn, Trojan, and Concord/Lifeline.

[NVGun40]

I have a question regarding this topic. Having just experienced two brand new deep cycle batteries being dead on our new TT (haven't even taken it out yet); due to the constant draw of the entertainment system, the CO2 detector and refrigerator (I know... I should have pulled the fuse). However, colder temperatures wreak havoc on battery life anyway.
So I have decided to install a cutoff off switch. However, I am also looking into ditching the two 12V deep cycle batteries and changing to running two 6V batteries wired in series to provide the necessary 12V for the system. I am looking at:
Trojan 6v 189AH Deep Cycle Gel Battery T6V-GEL.
Gel batteries withstand the cold much better (actually all temperature extremes)
I had converted my fifth wheel over to running two 6V batteries. They actually last longer, which is why I did it; but that was 11 years ago. Does anyone still do this?
Pros, Cons?

[Mustang65]

Originally Posted by AKGperson

Speaking of 6v vs. 12v, why switch over to 6 volt batteries when the system is designed for 12 volt? Just curious.

I looked this up while researching which way I wanted to go... 12Volt vs 6 Volt. If we take a look at what is probably the most common 6 volt RV battery on the market, which is the Trojan T105 (220 Ah rating) and a 12VDC batteries (group 27 - 220 Ah rating).. both TRUE DEEP CYCLE. Originally I would have thought that there would not be much difference between the combination, only a bigger case, but I was wrong.

The T105 Deep Cycle plates and the 12 Volt battery plates are made of the same material, but the difference comes into play when you look at the thickness of the negative and positive plates of the T105 battery which are about 60% thicker than the 12 Volt counterpart. Given this information, if properly maintained, the T105's should have a longer life cycle than the 12 Volt batteries. The length of life of these batteries is determined by how much of the material is shed from the plates, which causes the eventual failure of the batteries.

There are more things to look at, like charging series connected batteries vs parallel connected batteries... the extra battery lead (circuit resistance)
needed to complete the 12 volt parallel battery connection. These may seem trivial but over time they play a part in the life cycle of a battery system.

The easy answer is that in a flooded battery system, there are less caps to check on a 6 volt system (6 caps - 2 batteries) vs (12 caps) on (2) 12 volt batteries.

To a normal RVer, the above is way past the information that they want to know, so they just purchase what ever the dealer makes the most money on, as they have no clue either.

Just my thoughts,
Don

[NVGun40]

Mustang65; Thank you for the technical information on this.

As of my last post regarding changing to 6V I did not notice the post from 'clubhouse'.

Technical aspects aside, I can only speak from lived experience. Like 'clubhouse', I am a boondocker. I have spent many hunting trips well off the grid. In fact one of the things my family currently loves about camping is that we usually go places away from cell service and get away from the computers and media etc. We 'unplug'. Anyway, my father had converted his trailer to 6V batteries a couple years prior. Now his TT was an older 1980 series 30 footer (I don't remember the make), meanwhile my 5th wheel was a much newer Komfort. During one hunting trip while camped side by side for over 3 weeks, and all things considered equal, the difference was as plain as the nose on our faces. His batteries were lasting longer than my 12V deep cycle on the fifth wheel. To further this, we spent most evenings after the hunt day was over, playing card in his trailer. Yet, his batteries lasted longer and his lights did not dim as quickly as mine did. As well, we noticed, when we fired up the generators (about every 3rd or 4th day) his batteries reached full charge level. Mind you, he was running two 6V batteries to my one 12V. After that trip, the first thing I did was change my fifth wheel over to 6V's.

Heavily considering doing the same with my new rig, but I will insist on using Gel batteries. Here in Alaska, I personally have seen to many times, batteries that go dead on vehicles over night when temps drop below zero.

[Mustang65]

Originally Posted by NVGun40

I have a question regarding this topic. Having just experienced two brand new deep cycle batteries being dead on our new TT (haven't even taken it out yet);

Don't write off your 2 batteries yet. Give them a FULL charge and take the specific gravity of each of the cells. Write them down. Take the batteries to a place that can do a TRUE EQUALIZATION of the batteries (connected together). Not the RV dealer, but a reputable battery outlet should be able to accomplish this. The TT's battery charger's equalization mode, is not at what most battery manufactures recommend. They should be EQUALIZED somewhere in the area of about 15.5 VDC with temperature monitoring. I am spoiled as my SOLAR charge controller does this for me, when I request it. Check with the mfr for the exact numbers. Oh, and do not add any of those battery rejuvenator products to the deep cycle batteries.

Have them check the specific gravity (SG) of each cell (write them down) after the EQUALIZATION and if the readings are all close to each other you should be good to go. The life of the battery may have been shortened but it should operate ok.

Keep these numbers (SG) as in a year or two you can compare them to the original numbers and be able to see how your batteries are doing.

You may be able to drop them off and they do the entire process, if you trust them.

Just my thoughts,
Don

[NVGun40]

Thanks Don, I am a do it yourself person, and have the equipment, so I will check the SG as you suggest. Then during my next R&R (I am retired from the military and work a job which I do two weeks on and two weeks off to keep me busy enough to put some extra fun tickets in our pockets) I will look into the equalization process. This sounds relatively inexpensive and easy to do.
BTW, I like the solar panel setup you have; I have checked out the pictures of your install. I am also thinking I will look into a similar setup in the future. Though I don't think I will be mounting the panel to roof considering the snows we get here. I will have to give it some thought. Does your system allow the TT to be run on solar power entirely?