Battery Upgrade and Relocation Advice

[WALL-E]

My Fellow Airstreamicans,

I have read countless posts on the topic of battery upgrades, and the best case scenarios are as varied as the individual applications. I implore your patience on this recurring topic, and would be happy to receive any advice in the form of links to articles or posts that might answer any of the following questions.

Use case: I'm convinced that AGM would suit our modest electrical needs (boon docking only a handful of days each year; running 12V accessories such as LED lights, pump, and furnace; hooked up to shore power (and solar) much of the time), budget, as well as my penchant for low maintenance, while allowing them to be relocated inside. Based on my research, 2 x 6V units would be my initial choice for, say, 150+ amp hours.

Model: 2006 Safari FB 25' (Special Edition)

Upgrades:
• Progressive Dynamics 4655 Converter
• 145W Solar Panel

1. What AGM options might you suggest? This could also be rephrased as, "What are some reasonable alternatives to Lifelines?" (GPL-4CT are presently on sale for $340, delivered; given these are the gold standard, this represents the ceiling, and any reasonable alternative would have to provide a substantial cost savings.)

2. Is there a non-stock size that would offer some advantage? I believe that the proposed area beneath the bed would offer some dimensional flexibility.

3. Would relocation back (toward the axles) require any safety calculations? I imagine there are some limits to how much weight can be safely transferred. The area beneath the front bed would allow a location 1/2 to 2/3 the distance between the stock battery compartment and front axle.

4. What other best practices do you recommend to accompany this project? I know that increasing cable size is generally desirable, but there are any steps, accessories, or additional upgrades that could be done make life better or otherwise take advantage of having everything apart?

As always, thank you in advance.

Michael T
Austin, TX

[waninae39]

most people go fwd with Lion, they don't look back.

Over a 10 year period , the TCO is much lower than std battery.

Most Lion go inside as they are much lighter

there are many threads on this,
i suggest you search the forum

[WALL-E]

Originally Posted by waninae39

most people go fwd with Lion, they don't look back.

Over a 10 year period , the TCO is much lower than std battery.

Most Lion go inside as they are much lighter

there are many threads on this,
i suggest you search the forum

There are no doubt countless threads. I read many, so many of them prior to posting. In fact, that is how I settled on pursuing the AGM option, with the Lifeline 6V in mind!

However, some questions remain — I encourage you to respond to any or all of the four questions posed.

Thanks,
Michael

[DaveP]

I have four of the Lifeline GPL-4CT batteries in series parallel. They have worked well for us the last four years. The only downside is that lead acid batteries take longer to charge the last 10% State of Charge (SOC) than lithium batteries, but they last almost as long as lithium (life span). Two lithium 100 AHr batteries would cost about $2000. Two 6 volt GPL-4CT (120 AHrs at 50% discharge) would cost about 35% of what 200 AHrs of lithium (at 150 AHr discharge) would cost. Go with the Lifeline. They would fit your stated budget and give you the power you need.

BTW, we are power hogs using lots of AHrs, and we have never have run below 60% SOC in a single night (even with the furnace running, coffee maker, microwave, etc). Also, we mounted the Lifelines on their sides under our front couch.

[WALL-E]

Originally Posted by DaveP

I have four of the Lifeline GPL-4CT batteries in series parallel. They have worked well for us the last four years. The only downside is that lead acid batteries take longer to charge the last 10% State of Charge (SOC) than lithium batteries, but they last almost as long as lithium (life span). Two lithium 100 AHr batteries would cost about $2000. Two 6 volt GPL-4CT (120 AHrs at 50% discharge) would cost about 35% of what 200 AHrs of lithium (at 150 AHr discharge) would cost. Go with the Lifeline. They would fit your stated budget and give you the power you need.

I believe yours was one of the journeys I’ve discovered in my recent perusing. My usage simply doesn’t demand either Li or AGM, but I’m looking to pay enough more for the latter to relax on the maintenance.

Originally Posted by DaveP

BTW, we are power hogs using lots of AHrs, and we have never have run below 60% SOC in a single night (even with the furnace running, coffee maker, microwave, etc). Also, we mounted the Lifelines on their sides under our front couch.

I’d love to hear more about why they are sideways and that process in general. Is this in an existing thread, by chance?

We’ve been lucky to get through the night with propane running our fridge and furnace (which, honestly, I enjoy more than the heat pump). We don’t even have an inverter (unless there’s a secret circuit that comes standard) or much of a use for it (yet). And, I don’t know how many amp hours “sleeping” takes, but 3/4s of that is what we are upgrading from.

[lsbrodsky]

One point of disagreement. Lifetime. I don't think we really know how long current Lithium batteries last in RV duty. They have not been around long enough; I have been RVing longer than Lithium's have been available. The manufacturers are predicting much longer life than AGM's.
My personal experience with AGM's in boating, where the batteries are truly cycled(sailing--no charging underway) is that 6 years was the point for Lifelines where performance started to significantly drop off. Sure they would last longer but I never could get the amp-hours out of them that they had for the first 6 years. So replacement was required.
If Lithiums last as long as projected today then the lifecycle cost for Lithiums is indeed lower because you may not need to replace them for the life of your RV. But, unknown for now.
Larry

[DaveP]

Originally Posted by WALL-E

I’d love to hear more about why they are sideways and that process in general. Is this in an existing thread, by chance?

I mounted the batteries on their sides because the GPL-4CT is to tall to fit under my couch standing up. Lewster (and Lifeline) assured me that the batteries would be just fine on their sides. No problems so far.

[DaveP]

Larry,

I agree with your assessment on lithium life spans. We don't know yet. I based my statement on the number of cycles stated by the manufacturers. They usually say 3000 or 5000 cycles which is probably low, but that is their assessment.

Lifeline says their batteries will last about 5000 cycles if you do not take their SOC below 50%. After 4 years, my batteries are working well (for lead acid batteries). But... I would guess my batteries have seen less than 1000 charge cycles, so they have not been too stressed.

I really want to get lithium for the quicker charging cycles, but the DW says NO.

[lsbrodsky]

Hmm, my wife is the one who wants to keep buying junk for the Airstream that we do not need, new curtains, new seat covers, and on and on.
Larry

[ROBERT CROSS]

^
Yeah....Like that useless Wine Wiz SWMBO got me.👍

Bob
🇺🇸

[lsbrodsky]

Hey it matches the Airstream skin, it seems. Better than a set of ugly Lithium batteries.
Larry

[MSL]

Originally Posted by DaveP

I mounted the batteries on their sides because the GPL-4CT is to tall to fit under my couch standing up. Lewster (and Lifeline) assured me that the batteries would be just fine on their sides. No problems so far.

Dave P: I'm curious if you added venting of your batteries. I have a 2019 Sport 22FB and added a 2nd AGM and wanted to move them inside. I spoke with Lifeline and they advised doing that only if venting was to be added. They acknowledged many peeople do not add venting, but that they could not recommend that. I understand likelihood of issues is very minimal. Just curious how you handled it.

[DaveP]

MSL,

According to what I was told at the time of purchase and by an expert, they do vent a very small amount of hydrogen gas occasionally. They said not to put them into a small, tightly sealed space without venting. I think they say this mostly for liability purposes. As you know, regular flooded batteries vent a lot of gas including hydrogen, so you would never put them inside.

As you can see from the picture, the batteries are not confined in a small space. Plus, I have a natural chimney effect going with air from the trailer coming in under the front of the sofa and venting upward behind the back of the sofa which is 6 inches from the wall. My charger/inverter is under there and provides the thermal drafting. So the batteries have the whole volume of the trailer to dissipate the hydrogen gas into if there is any venting. I also always keep the bathroom vent open for some turn-over of air inside the trailer. As you know, Airstream leak air like a sieve anyway.

Now, my trailer is stored at my house and I am in and out of it frequently, even during the winter so I get a lot of turn-over of the inside air in addition to the natural venting of the trailer. If you are concerned about the gas building up in the battery storage space, however, add some venting (particularly if it is confined). It is easy enough to do.

Cheers,

[dznf0g]

Do lifelines have a port where you can attach a vent hose. My car has an agm inside the cabin, but they run a vent hose out through the floor pan in the unlikely event of an overpressure through the valve.

[lsbrodsky]

AGM's don't really vent continuously; there is an overpressure relief valve that will release pressure in the event it is needed. It would be very abnormal for that to happen. Sure, the manufacturers and safety nannies provide the caution about installation, but 40 years of boating and Airstreaming I have never heard of that happening to anyone. You are safe installing them inside your Airstream...although I take no responsibility for your actions(required by my attorney).
Larry

[dznf0g]

Originally Posted by lsbrodsky

AGM's don't really vent continuously; there is an overpressure relief valve that will release pressure in the event it is needed. It would be very abnormal for that to happen. Sure, the manufacturers and safety nannies provide the caution about installation, but 40 years of boating and Airstreaming I have never heard of that happening to anyone. You are safe installing them inside your Airstream...although I take no responsibility for your actions(required by my attorney).
Larry

Just thought I'd ask. I do plan an interior install at next replacement.

[MSL]

Originally Posted by DaveP

MSL,

According to what I was told at the time of purchase and by an expert, they do vent a very small amount of hydrogen gas occasionally. They said not to put them into a small, tightly sealed space without venting. I think they say this mostly for liability purposes. As you know, regular flooded batteries vent a lot of gas including hydrogen, so you would never put them inside.

As you can see from the picture, the batteries are not confined in a small space. Plus, I have a natural chimney effect going with air from the trailer coming in under the front of the sofa and venting upward behind the back of the sofa which is 6 inches from the wall. My charger/inverter is under there and provides the thermal drafting. So the batteries have the whole volume of the trailer to dissipate the hydrogen gas into if there is any venting. I also always keep the bathroom vent open for some turn-over of air inside the trailer. As you know, Airstream leak air like a sieve anyway.

Now, my trailer is stored at my house and I am in and out of it frequently, even during the winter so I get a lot of turn-over of the inside air in addition to the natural venting of the trailer. If you are concerned about the gas building up in the battery storage space, however, add some venting (particularly if it is confined). It is easy enough to do.

Cheers,

Dave P: Thanks. Makes sense. For my 2019 Sport 22FB, they would be under the bed, which isn't as open as your under-the-couch installation, although it's certainly not sealed. I know the likelihood of AGNs outgassing is very minimal, and probably a lot more things going on to be concerned about if something happened to cause that. I guess I'm one of the "safety nannies".

[WALL-E]

Just to refocus the conversation: Assuming there are no issues with mounting the batteries under the front bed from a weight distribution standpoint, would the additional clearance afford me a battery size that would offer some advantage, from either a performance or cost standpoint? Does Interstate—or another reputable company—offer an alternative at a reasonable savings?

As I said initially, we only boondock a few times each year and have been getting by with, say, 10Ah for the last four years. Shelling out $700 for batteries, while admittedly not bad for the top of the line model, seems a bit silly for our modest needs. And, given all the updates I’ve been doing lately (LPG regulator and lines, cell signal booster, multistage converter, new faucets that allow you to easily get your hands under them, etc.), I’d like to give my better half some good news!

[WALL-E]

Originally Posted by WALL-E

Just to refocus the conversation: Assuming there are no issues with mounting the batteries under the front bed..

Then again, I’m asking you to invest your time so that I might save $200...and, to what end? I can only imagine how shortsighted that seems.

[DaveP]

I hear you. Sorry, your original question got kind of lost in the conversation.

It can be difficult depending on your financial analysis. I would spend the money for the 6 volt batteries as the least expensive alternative. For flooded batteries, I think Trojans are a good way to go. You already have the appropriate charger. Do you have the external space to mount them?

Originally Posted by WALL-E

Then again, I’m asking you to invest your time so that I might save $200...and, to what end? I can only imagine how shortsighted that seems.