New batteries

[Martin R]

i am looking to replace the original SRM-24 Interstate batteries in my trailer. I have been a little neglectful with the checking/maintenance of these batteries and suspect that if I replace them with similar I will not change.....any suggestions for an install and forget alternative battery type that will not require any cutting or modification of the battery box on my 2012 International 30 and has at least similar capacity?

[dznf0g]

Martin, are your batts in doors on either side of the tongue, like a Classic? If so group 27s fit easily. Interstate group 29s (which I have) will fit without any modification, but barely and you have to be very careful while sliding them in and out.

ooops, never mind, I see you want to get away from Lead acid.

[Martin R]

They are in a single box centred in the A frame behind the propane tanks. I have read elsewhere of others who have trimmed the lip of the battery box to enable 27's to fit (believe even up to 31's have been squeezed in) but I am happy to stick to 24's. Specifically, what is my best bet for similar (not necessarily better) from a maintenance free battery. I read a little about Optima AGM batteries but I think it may have been Lewster who cautioned that the Airstream electrical systems were not really compatible witness batteries without some upgrading and besides being expensive may not be as great as one would hope.......

[BoldAdventure]

Honestly, I'd stick with Lead Acid unless you are willing to upgrade the 1 stage converter. Otherwise throwing money down the drain. No point to AGM's for the cost with the single stage. Not to mention the extra cost + weight. And if you want to stick to that size, there is really no point in replacing your batteries with anything else. The whole reason to upgrade is more power/better discharge, maybe save weight with lithium batteries, but there is a cost investment with those.

Just my personal opinion on the matter.

[Martin R]

Originally Posted by BoldAdventure

Honestly, I'd stick with Lead Acid unless you are willing to upgrade the 1 stage converter. Otherwise throwing money down the drain. No point to AGM's for the cost with the single stage. Not to mention the extra cost + weight. And if you want to stick to that size, there is really no point in replacing your batteries with anything else. The whole reason to upgrade is more power/better discharge, maybe save weight with lithium batteries, but there is a cost investment with those.

Just my personal opinion on the matter.

I am not knowledgeable as to what alternatives to the lead/acid battery may exist as a simple switch over but your assessment is not really a surprise and probably right for us: stick with the type we have... (and pay more attention to them)..

[AnnArborBob]

The nice thing about AGM's is you never have to look at them to fill with water. The bad thing is that they cost more than standard batteries so when the piece of crap single stage charger that Airstream installed fries them, you feel worse.

Get a three stage charger and AGMs and then you'll be a happy camper!

[jcanavera]

The problem is the converter/charger will ruin any battery since it can't step down the charging power, once the battery is fully charged. So you have a few choices. Replace the existing unit with a multi-staged converter/charger. Perform more frequent checks of the fluid level to keep the plates submerged. Don't keep your trailer plugged into shore power when it isn't being used. I chose the last option and have never boiled the batteries since.

Jack

[lewster]

It's really a simple problem:

• keep the garbage constant voltage converter that your trailer comes with and use garbage, cheap batteries from Wal-Mart or other bargain outlet and just keep replacing them (lot's of folks seem happy with this solution and end up changing batteries every couple of years)

••••••••••••••OR••••••••••••

• replace that Parallax battery burner with a proper 'smart' converter/charger with 3 stage automatic charging (like a Progressive Dynamics unit made in the USA!) and upgrade to AGM batteries that will take NO MAINTENANCE and will likely last you 5-7 years if you don't deeply discharge them on a regular basis.

Lifeline group 27s will fit your battery box (group 31s will NOT FIT) IF you slice a small section out of the lip, and will give you a total of 200 amp/hours of reliable DC power. Optimas in the group 24 size (I don't think they make larger ones) are rated at 55 amp/hours each and you will be DECREASING the size of your present battery bank from 160 amp/hours to 110 amp/hours.

That's my take on your problem. It's your choice of maintenance vs. none and repeated replacements vs. none. Obviously, there are costs involved. Only YOU can decide which way to go and what the value of each option is TO YOU!

Have fun with your decision process.............

[TG Twinkie]

If you want to keep the converter you have and the wet cell batteries. And still have shore power when stored. Disconnect the positive lead of the batteries. Tape it off. The converter will provide 12 volt power to the coach when on shore power. By disconnecting the battery lead they won't be overcharged during storage.
My coach has only one group 24 battery. It does have a Progressive Dynamics Converter. But I still remove the battery when in storage. I have full time shore power while in storage. I can run any or all devices. Both AC and DC.


Sent from my iPod touch using Airstream Forums

[BoldAdventure]

Originally Posted by lewster

Lifeline group 27s will fit your battery box (group 31s will NOT FIT) IF you slice a small section out of the lip, and will give you a total of 200 amp/hours of reliable DC power. Optimas in the group 24 size (I don't think they make larger ones) are rated at 55 amp/hours each and you will be DECREASING the size of your present battery bank from 160 amp/hours to 110 amp/hours.

Is the battery box the same size on the 30 as it is the 27? Because Trojan Batteries 31xhs fit with the same modification as the 27's for 260ahs

31XHS | Trojan Battery Company

Photographic proof


But you did say Lifeline, maybe they're bigger. Not to dispute you.

[lewster]

Yep, just big enough not to fit.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[BoldAdventure]

Correction, the 31XHS is listed as fitment group size 30 in the technical specifications on the Trojan website. So I have been calling this battery the wrong size incorrectly.

My 27's didn't fit without trimming the box either. At least the ones from Costco with handles, I suspect with out the handles they would of dropped in.

[grizbear]

Lew has it right. I went with the PD4655 unit and made a 1 7/8" thick top extension to the battery box simple drilled four holes in top lip and used bolts to hold it on then replaced the top about one hrs work. Using 2 6 volt wet batts very happy with this set up. I was using cheap auto zone batts and a portable 3 stage charger and got 4 1/2 yrs out of the last set after I learned how to maintain batteries which is the key to battery life. Best of luck Rand

[dstalzer]

Originally Posted by lewster

It's really a simple problem:

• keep the garbage constant voltage converter that your trailer comes with and use garbage, cheap batteries from Wal-Mart or other bargain outlet and just keep replacing them (lot's of folks seem happy with this solution and end up changing batteries every couple of years)

••••••••••••••OR••••••••••••

• replace that Parallax battery burner with a proper 'smart' converter/charger with 3 stage automatic charging (like a Progressive Dynamics unit made in the USA!) and upgrade to AGM batteries that will take NO MAINTENANCE and will likely last you 5-7 years if you don't deeply discharge them on a regular basis.

Lew,
Which Progressive Dynamics converter/charger is the correct one to replace my Parallax 7455 in my 2005 Airstream Classic?

Thanks,

Dennis

[lewster]

Dennis,

If you have the deck mount unit from P/Lax, then the PD-9260 from Progressive Dynamics would be a good choice.

If you have the combo power center, then you need the PD-4655, which is a direct replacement.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[Meddle]

Originally Posted by BoldAdventure

Is the battery box the same size on the 30 as it is the 27? Because Trojan Batteries 31xhs fit with the same modification as the 27's for 260ahs

31XHS | Trojan Battery Company

Photographic proof


But you did say Lifeline, maybe they're bigger. Not to dispute you.

I am a bit confused, because when I compare the Trojan 31XHS with the Lifeline GPL-31XT, the dimensions of the Lifeline are actually marginally smaller than the Trojan.





This gives me hope that I could fit two GPL-31XTs in my 2012 27FB factory battery box, with a little modification of the lip, as BoldAdventure pointed out.

Has anyone had any success fitting a pair of GPL31XTs in their factory box?

[lewster]

They should fit. They are a bit shorter and a bit wider than the GPL-27T. I would still look into mounting them in a transverse orientation and compare the final position of the positive terminals relative to the edge of the battery box.

I never have requests for any Lifeline larger than the 27s at 100 amp/hours. The GPL-31T is not worth the extra expense for a mere 5 amp/hours of capacity.

If you look at the pricing in terms of dollars per amp-hour or $/amp-hour:

• GPL-27T @100A/H is $3.50/amp-hour (200 A/H per pair)
• GPL-31XT @125A/H is $3.44/amp-hour (250 A/H per pair)
• GPL-6CT @300A/H is $2.80/amp-hour (priced for a pair, as these are 6VDC)

This is why I sell more of the GPL-6CT than any other Lifeline product. They are also almost 100% mounted inside the trailers, reducing tongue weight as they are placed significantly rearward toward the axles by up to 3 feet.

One other thing. I would SIGNIFICANTLY increase the size of the parallel cables shown in the photo, and place the positive output cable on battery #1 and the negative output cable on battery #2 for complete, even charging and discharging of both batteries.

The purpose of these cables is to join a pair of batteries together as one unit. Do you think the solid metal connecting bus found inside a battery that joins the plates is as small as 6AWG???? I use a minimum of 1/0AWG for simple systems and as large as 4/0AWG for inverter systems, especially for series connections in 6VDC battery banks.

[guskmg]

Lew, the Optima D31M (75 AH) will fit the Classic battery boxes. The first set (4) I bought lasted seven years with the stock Airstream converter. I found replacements on line for $208 each. Airstream is now using the Parallax 4455TC Paramode with TempAssure in their Classic solar systems. I had to replace mine with the newer one after a power surge fried the old one. I agree that the factory solar system is marginal at best. I would be interested in your upgrade if you would PM me.

[rgwatkin]

Just replaced the single stage converter on my 2012 28' FC yesterday with PD4655. Manual says it will take two hours. Took me 1:45 so very straightforward. Only thing that took a little extra time was having to re-route the battery cables from the back of the DC compartment to the top as the connections on the new DC board have to come in from the top. I don't quite understand from a design point of view why they couldn't just keep the DC connection on the same place on the board. A couple of more pictures of the finished wiring would have been helpful.

[Tincampers]

If you pull the entire unit out you can loosen the clamps on the battery cables and pull a little more slack in there. That would put you right at 2 hours...��