Fit new AGM batteries

[gamana]

I am getting an Intl 27fb. How do you fit 2 AGM batteries of 200amp/hour in the battery compartment? I have asked the dealer to measure and he tells me the height is 9 1/4". All the batteries i found online (lifeline and MK) are over 10" of height.

[2airishuman]

what group size batteries are STOCK on the unit?

i'm guessing group 27s.

does the int only get group 24s??

the simplest way to replace is with the SAME group size.

lifeline grp 27 agms are ~9.25 inches tall.

spend a bit of time at there website...

Lifeline Batteries - Marine & RV Deep Cycle Batteries

post placement matters, but IF one sticks to the group size scheme,

sizing replacements is easy.

cheers
2air'

[olddog299]

2airis human is correct. You will not be able to stuff large AGM's into the (relatively) small space allocated within a standard issue Airstream Battery box. A custom install will likely be necessary. One option would be a marine dual battery box installed on the front tongue behind the propane tanks. That will require some modifications to the A-frame to support the weight without adversely affecting welds. Another possibility would be to install the desired batteries inside on the floor below the front window as space and support allows. Due consideration must be given to proper ventilation. AGM's may be sealed but catastrophic failures do come along once in a while. If they didn't, my career in the fire service would have floundered the first day...

[gamana]

Originally Posted by 2airishuman

what group size batteries are STOCK on the unit?

i'm guessing group 27s.

does the int only get group 24s??

the simplest way to replace is with the SAME group size.

lifeline grp 27 agms are ~9.25 inches tall.

spend a bit of time at there website...

Lifeline Batteries - Marine & RV Deep Cycle Batteries

post placement matters, but IF one sticks to the group size scheme,

sizing replacements is easy.

cheers
2air'

Yes. that one fits the max height of 9 1/4" but i can only put one.

The length of the box is ok for two batteries at 15 1/8" for a 13.9" battery. The width is unfortunately not at 11 3/4" in order to fit two 6.6" batteries.

100 amp/hour is a bit low for boondocking with solar. I am looking for 200amp/hour.

[gamana]

Actually, the one 2air sent could work but i would need to cut the back/AS side of the battery box to fit about 1 1/2" of the second battery.
I don't know if it would affect the integrity of the box. I remember the door being a it thin but i never checked the actual box.
The opening and the part of the battery sticking would need to been protected from the elements as well.
I am going to keep looking but this could be one option. Thoughts?

Cheers

[2airishuman]

what group size is OEM on the trailer?

24 or 27?

2 of the 27s IS ~200 amp/hours of available juice. and the 24s a tad LESS...

do you plan SOLAR or genset for recharging while boondocking?

are you planning a BIGGER charger/converter and do u plan to enlarge the wiring?

have you got ANY IDEA what the daily amp/hour consumption will be?

these are ALL important issues to sort out.

extra capacity is nice, but until you work through the consumption and REcharge issues...

there is NOT much point in DOUBLING capacity...

i LIKE agms but they don't provide MORE capacity in similar sizes,

what they do do, is take ABUSE better,

and they can be mounted in creative positions.

but at 2x the price of flooded wet cells.
___________

IF the trailer is ordered WITH SOLAR, it will include 2 agms.

details, details, details...

cheers
2air'

[gamana]

Originally Posted by 2airishuman

what group size is OEM on the trailer?

24 or 27?

2 of the 27s IS ~200 amp/hours of available juice. and the 24s a tad LESS...

do you plan SOLAR or genset for recharging while boondocking?

are you planning a BIGGER charger/converter and do u plan to enlarge the wiring?

have you got ANY IDEA what the daily amp/hour consumption will be?

these are ALL important issues to sort out.

extra capacity is nice, but until you work through the consumption and REcharge issues...

there is NOT much point in DOUBLING capacity...

i LIKE agms but they don't provide MORE capacity in similar sizes,

what they do do, is take ABUSE better,

and they can be mounted in creative positions.

but at 2x the price of flooded wet cells.
___________

IF the trailer is ordered WITH SOLAR, it will include 2 agms.

details, details, details...

cheers
2air'

I don't know about the group size. The owner's manual i downloaded online doesn't say and my dealer is trying to find out.

Are you certain about the 200amps? The dealer mentioned 100amps for the standard batteries. It would make a big difference as far as benefit to switch from flooded cells to AGM

I will use solar and genset, if needed.

The factory charger/converter is 55amp. isn't it sufficient?
The solar will have a dedicated charge controller

As far as daily consumption, the answer is no, i don't know, but for a family of four, I think 100amp/hour is a bit short.

I am not ordering the factory solar package. I think there are better and cheaper packages on the market than the Airstream boondocking package ($2,900). Their inverter is also not a sinewave so I will install one after delivery.

I prefer the low maintenance of AGM versus flooded cells but can live without. I was told by the dealer that the factory solar package included two AGM batteries for this reason, increase the capacity. That's the reason why i am looking to switch.

Cheers

[2airishuman]

group size = amp hours/capacity.

go back and read the basics on the lifeline site.

the AMP/hour stuff is there, just like all the other basics.

a dealer who doesn't KNOW battery size on a COMMON unit (there are EITHER 24s or 27s) may not be your best resource for electrical wisdom.

IF u wanna DOUBLE the battery bank/capacity NO the stock charger isn't adequate, nor is the wiring.

i have the agms and LIKE THEM, but they DO NOT provide MORE JUICE in the same size package as flooded wet cells.

if you plan to use a genset and are NOT running the furnace, 2 grp 24s or 27s is plenty of storage.

IF you ever plan to run the AC while boondocking, ADEQUATE generator capacity matters more than LARGER batteries.

YES the factor solar is a bit OVER priced.

but they have worked OUT the details.

you are a long way from that point it would seem.

and could easily speed the same/more getting this done correctly in the aftermarket.

it might be wise to just USE it as built, then change out the batteries LATER...

when the solar details are clearer.

cheers
2air'

[gamana]

The factory solar is WAY overpriced.

Look at this package from ALT E Store. Kyocera panels 135W, Unirac foldeable racks, BZ charge controller for $757.
You could almost add another panel for 270watts versus the 106watts of fact package AND still be cheaper.

Alt-E SOLARVOYAGER ™ Gold PV RV KIT - RV Solar Packages @ AltE

[gamana]

Originally Posted by 2airishuman

a dealer who doesn't KNOW battery size on a COMMON unit (there are EITHER 24s or 27s) may not be your best resource for electrical wisdom.

I know and they are supposed to install my solar package. I am sweating already...

[gamana]

ok. so I finally got the info from the dealer. The factory battery is a 24 group, Interstate SRM 24.

Interstate Batteries

It doe not specifically show the traditional amps/20hours rating. I realized that it is a "cranking" battery and not a deep cycle. I thought that those type of batteries were made to start engines, not really for household/rv use. Am I wrong?

[Bluto]

My old trailers have always had deep cycle batteries in them. The (my) new trailer will have the new type for solar from the A/S plant. I have never heard of using a auto battery in a trailer. I guess you could but I don't think it will last as long.

[thecatsandi]

Originally Posted by gamana

The factory solar is WAY overpriced.

Look at this package from ALT E Store. Kyocera panels 135W, Unirac foldeable racks, BZ charge controller for $757.
You could almost add another panel for 270watts versus the 106watts of fact package AND still be cheaper.

Alt-E SOLARVOYAGER ™ Gold PV RV KIT - RV Solar Packages @ AltE

Actually is it not, considering you get Lifelines, the Panels, the controller, the remote readout and the labor to connect it all. I called my solar guy before ordering the factory setup. He said considering all you are getting it is not out of line.

[gamana]

Originally Posted by thecatsandi

Actually is it not, considering you get Lifelines, the Panels, the controller, the remote readout and the labor to connect it all. I called my solar guy before ordering the factory setup. He said considering all you are getting it is not out of line.

Package ($800) plus batteries ($420) plus installation ($575) equals $1,795 versus $2,800 from AS. The difference covers cost for another panel and and inverter.

[2airishuman]

Originally Posted by gamana

ok. so I finally got the info from the dealer. The factory battery is a 24 group, Interstate SRM 24.

...I realized that it is a "cranking" battery and not a deep cycle...

the srm 24 IS a deep cycle battery...

at least it is interstate (or johnson controls who makes them) 's version of a deep cycle.

and the hours at various "amp loads" is another way comparing capacity.

so now compare these with agms GRP 24s for capacity.

cheers
2air'

[thecatsandi]

Originally Posted by gamana

Package ($800) plus batteries ($420) plus installation ($575) equals $1,795 versus $2,800 from AS. The difference covers cost for another panel and and inverter.

Ok, the price went up. My solar option was around $1800.

[Mexray]

Just a thought...if you've ordered a new rig to be built, perhaps AS has an 'option' to install a slightly larger battery box that will accommodate a pair of Group-27 batteries, to give you 200 AmpHr's...

Ray

[gamana]

Originally Posted by thecatsandi

Ok, the price went up. My solar option was around $1800.

That was a good price.

Cheers

[ostream]

Hard to beat this system from AM Solar - AM Solar's SunRunner RV100-22B Solar Electric System for RVs . Perhaps your dealer can install?

Attached is a the battery box lid design I had made to accomodate Lifeline (2) GPL-4C. Yields 220 amp hours @ 12V. Finished lid looks like it came from the factory! Any metal fabrication shop can make a similar lid with this design relatively inexpensively.

As was mentioned, a high quality 3-stage charge/converter is key to managing/maintaining healthy batteries. I went with the Xantrex XADC-80 and upgraded wiring, plus 2 more GPL-4C's inside for a total of 440 amp hours. With decent sun exposure, energy is never our constraint.

Good luck!

[gamana]

Ostream, thanks a lot for the drawings. I was thinking of cutting the side of the factory battery box but your set up is much better. I can now upgrade the amps/hours of my batteries.

I am still undecided between the AM Solar kit or the AltE store. They are similar in price but the AtlE store has 130 watts panels therefore 260 watts versus 200 watts on a 2 panel set up. The AltE panels are Kyocera which is a great brand. The charge controller of the AM Solar system seems better than the AltE store but still "weak" for future upgrades if need be.
I am still unsure if I have enough room on the roof the 27FB international to get two of the 130 watt panels. I tried to get drawings of the roof of my "under construction" 27FB Intl from Airstream but so far nothing...