Just switched to two 6V batteries: amazing results

[Aolani]

After researching battery options and boondocking limitations tied to battery capacities, we just invested in upgrading from the (2) factory-supplied 12V batteries to (2) Lifeline 6V batteries.

So far, amazing difference!

Background:
Our 2010 25FB Airstream was shipped with (2) Interstate Group 24 12V batteries, wired in parallel. While the setup worked fine for normally-connected camping, we found a substantial drain on the batteries even over one evening while boondocking.

We tried the normal things:
* Didn't run the furnance at night and turned off pretty much everything, except the freezer (running on propane).
* Swapped out the majority of the halogen interior (and exterior) bulbs for LEDs (purchased through airstream.com)
* Invested in a solar panel - not to help with battery drain per-se, but to enable non-generator recharging.

New Battery Setup:
After MUCH research online and calling vendors, we settled on the Lifeline GPL-6CT batteries, wiring them up in series. I won't go into the pros/cons on Lifeline vs other good brands, but we decided that our camping style will have a large mix of boondocking for several days in our local state parks. Yes, we have a generator and know we can use it when needed, but prefer not to need to use it.

Thanks to many of the posts here, we went forward with the GPL-6CTs, knowing that a battery box modification would be necessary: both in height, and in modifying the post to clamp the batteries down. I've attached pictures to show what it ended up looking like. We're pretty pleased, but may re-do the C-channel later, doing it differently to address the problems we had with the corners (I'm not a metal-worker!).

* The GPL-6CT batteries fit inside the battery box from a length/width standpoint perfectly. All that is required is to make the battery box about 1" taller, and increase the height of the retention rod.

* We used standard C-channel aluminum to create a 1" "ring" around the top of the battery box, securing it to the battery box with standard sheet-metal screws. Was kinda' tough to get to the screw heads given the C-channel, but doable. We painted the aluminum with a rustoleum product prior to attaching to the battery box (aesthetics).

* The existing battery box cover came off simply by drilling out the rivets. We re-attached it to the C-channnel with rivets later. That part was easy.

* To make the retention rod higher, we used a 3/8 coupler nut and a short section of 3/8 threaded rod that we cut to desired height. Both were available from a local hardware store.

* Instead of continuing to use the factory wing-nut, we just used a normal 3/8" nut with a nylon sleeve to prevent loosening. We figured there's no real reason to need to take the batteries out quickly (wing-nut) anyway, and the wing nut is pretty tall.

That was it. The results are amazing, compared to our previous batteries. Before, our factory batteries were typically down to mid-40% in the mornings after very slight furnace use, lights, etc. This was after a confirmed full charge during the day. Now we wake up to a mid-90% charge level with the two new batteries - nothing else had changed that would account for that dramatic change in reserve capacity.

Also, we have a dealer-installed 110W solar panel. Coupled with the two 6V batteries we can already tell we'll rarely have to run the generator when camping on a sunny trip when in a reasonable non-shaded site.

This forum was great for all the background research, so I figured I'd add something to the discussion, hopefully useful for the next person considering battery conversion choices.

[RickDavis]

A nice job. You may also be rewarded with longer life. We never did much better tha 4 years on a pair of 12 volt batteries. We changed to a pair of 6 volt golf cart batteries and they are still going strong. Will be 7 years old in June.
Almost all our charging is done by solar and we never leave the 110 charger on full time when hooked up.(which isn't often)

[bryanl]

You get new, bigger batteries, swapped out the incandescent lights, installed solar and then notice an amazing difference?

IMHO It is really misleading to drop this down as amazing and imply that it is due to 6v batteries.

What you did was to increase your battery energy capacity by ten to twenty percent (and your battery weight as well). You added perhaps a half a battery's worth of energy as a daily solar addition. Replacing the halogens with LED's could make a significant reduction in your energy use profile. This collection of things implies that there were other use changes that would enhance energy efficiency as well. i.e. many unlisted variables of unknown significance.

Of course, with all this going on, you are going to realize a difference in battery capacity over stock. With the AGM's, you might also get up to a 50% longer battery life if you don't run them down too far very often and maintain them properly.

No wonder so many get hornswoggled into spending a whole lot of money on things they may not really need. The lesson is that one needs to be a critical reader when it comes to things technical in these sorts of discussions.

[Aolani]

To be clear, I was pretty precise in my explanation of the series of events... The two 6V batteries do make an exceptional difference as opposed to the stock 12V ones.

In summary (see original post for specific), we did all the other stuff first - switched to LEDs, installed solar. Still have a pretty substantial drain on batteries overnight - after a confirmed full charge.

THEN, we switched to the new batteries, doing nothing else - and overnight noticed the difference.

In combination, it all adds up, each of the various modifications. But it's clear - and I leave the math and disagreements to others who have tried these specific steps - that the two 6V Lifetime batteries provide much better results for those, like me, who wish to maximize non-generator time.

Sure, they're expensive, but so are Airstreams. I suspect for a reason.

[Fyrzowt]

No wonder so many get hornswoggled into spending a whole lot of money on things they may not really need. The lesson is that one needs to be a critical reader when it comes to things technical in these sorts of discussions.

Really.
?

[Inland RV Center, In]

Originally Posted by Aolani

To be clear, I was pretty precise in my explanation of the series of events... The two 6V batteries do make an exceptional difference as opposed to the stock 12V ones.

In summary (see original post for specific), we did all the other stuff first - switched to LEDs, installed solar. Still have a pretty substantial drain on batteries overnight - after a confirmed full charge.

THEN, we switched to the new batteries, doing nothing else - and overnight noticed the difference.

In combination, it all adds up, each of the various modifications. But it's clear - and I leave the math and disagreements to others who have tried these specific steps - that the two 6V Lifetime batteries provide much better results for those, like me, who wish to maximize non-generator time.

Sure, they're expensive, but so are Airstreams. I suspect for a reason.

The difference in performance, is because of the type battery you now have.

Changing from 2 12 volt batteries to 2 6 volt batteries, has nothing to do with the better performance.

Amp hours are just that, amp hours.

Andy

[FreshAir]

Originally Posted by RickDavis

A nice job. You may also be rewarded with longer life. We never did much better tha 4 years on a pair of 12 volt batteries. We changed to a pair of 6 volt golf cart batteries and they are still going strong. Will be 7 years old in June.
Almost all our charging is done by solar and we never leave the 110 charger on full time when hooked up.(which isn't often)

Where did you make room for your 6 volt batts?
Neil.

[Ellie & Carl]

I was quite happy to read your post. I'm planning on doing the two six volt conversion on my '69 as part of the restoration. As someone who has researched and studied so-called "off the grid" living over a span of nearly 20 years, I've learned that greater battery capacity equals longer battery life and longer time between charging. Two group 24 12 volts cannot hope to compete with a pair of golf cart batteries. I'm glad it worked out as it did for you... but I really would never expect it to work out any other way.
You tried other methods to reduce your overnight battery draw-down. Not much change... Increase your storage capacity and voila! With that one change, you've still got batteries in the morning! How cool is that?
It's always interesting to see that those who don't do things like this are the most vociferous nay-sayers of actually doing them. It happens in other areas, as well. I've been a motorcycle enthusiast for a long time, and the folks who poo-poo others (on the motorcycle forums) for trying things always seem to read with a decided slant any accounts from those that DO do them. The advice given should be taken by the giver: "one needs to be a critical reader when it comes to things technical in these sorts of discussions". In other words, read what's written.... not what you'd like it to say.

[2airishuman]

welcome aolani...

the basic point is that MORE CAPACITY results in less % used for any given need.

the pair of oem flooded wet cell batteries were about 250$ total and about 105 lbs.

while the pair of "amazing" 6volt glp 6ct lifelines run 7- 800$ and weigh ~190 lbs...

so YES one should expect more JUICE given the cost and weight factors for the 2x6volt set up.

the one caveat being HOW one is measuring % used or charge state.

IF using a typical surface charge gizmo the readings are misleading and not accurate relative to true charge state.

the 2nd caveat being what was the ambient TEMPERATURE when the before/after comparisons happened?

COLD batteries have less capacity/reserve as do HOT HOT cells...
__________

it's often posted here that the BIGGEST gain in electrical capacity comes from adding a battery or 2...

and that's basically what has been done by going to the heavier 6v cells...

however the OP suggests "nothing else" was done.

the issues then become...

what bits are part of the solar setup (wire size/solar charger)

is the primary charger/converter ADEQUATELY sized for these batteries?

and again HOW is the battery level measured?

it's great u r happy with the change and the pictures are nice for those considering this...

but there really isn't anything "amazing" about larger/heavier/more expensive batteries having MORE capacity.

a 3rd (or 4th) gp 24 could have been added to the original batteries for MUCH less $ and the gains would be similar.

with a bit more space needed for the 3rd battery.

___________
a 2x6volt setup like this means a tad LESS packaging relative to the plates/fluid

so there is a tad more juice per LB of cell...

but if ANY one cell craps out, you got NO 12v juice.

and while it's rare, that can and does happen.

http://www.airforums.com/forums/f449...ain-64036.html

i like the agms and have 5 years duty so far

but the primary advantage of these is INSIDE mounting in any position.


cheers
2air'

[Inland RV Center, In]

There is nothing magic about "WATTS".

The DC formula is watts=voltage X current(amps)

If a battery given battery last longer, with a given load, it must have a greater current rating (amps).

Obviously repalcing 2 12 volt batteries with 2 6 volt batteries that have a higher amp/hour ratings, will provide more "watts", therefore with a given load, will last longer.

Nothing is "free" from batteries.

You get what you pay for, in watts, nothing more.

Different types of batteries, of course have different characteristics.

Comparing a couple of cheap 12 volt batteries to the AGM's, has no merit, in that comparing a Chevy to a Rolls Royce, has the same no merit.

There is no question that the AGM's are a better battery, and that goes with their price.

Again, it's an individual choice of quality, not performance when it comes to "WATTS".

Andy

[Minnie's Mate]

Thanks for sharing your experience with us. It gives additional information for consideration when replacing batteries.

I agree with 2Air's point about one of the batteries going out. A couple of years ago I had reason to store our Airstream without shore power for about two months. I had forgot to change over to "storage" mode and had left the power to the stereo on and the digital readout for the time/source (maybe other items) had drained the batteries dead. Not good for a battery. The following Spring when I was prepping the Airstream for a trip I discovered that one of the batteries had frozen and burst. This was probably a result of the complete draining of the batteries and lack of experience on my part in storage protocols. The end result is that I had only one battery to supply power to the fridge and incidental lighting on the over the road portion of the trip.

[bryanl]

I've learned that greater battery capacity equals longer battery life and longer time between charging.

If you look at the life cycles versus depth of discharge (DoD) curves you will find an optimum cost effectiveness at about 50% DoD. That is where the battery replacement costs and battery capital costs tend to balance at minimal overall expense over time. This is why you often see recommendations not to run your batteries below half charge as a general thing.

Buying too much battery capacity can be cost inefficient as well because they won't get proper 'exercise' and will still age out.

Another consideration many seem to overlook is that battery capacity is quite limited. Each RV type battery (about 60# or so) has about a half kilowatt hour of usable energy. Compare and contrast that to your typical household use. What that means is that the RV is quite energy constrained and, once you get down to meeting those constraints, very small changes in use habits are going to have much more of an impact than incidental efficiencies.

As for the 6v vs 12v rationalizations, I suggest you look for things that can be actually measured. If you do that, you'll find that there is no significant difference between batteries correlated to voltage. They all have about the same energy density by weight and they all have about the same life spans when voltage is the variable.

One should also note that there are many variables that influence available battery capacity by ten to twenty percent. These include cycle to cycle variance, temperature, age, and use profile. For this reason, any differences in this range have no substance to guide decision making.

The first priority for battery happiness should be charging, use, and maintenance. Make sure you don't abuse your batteries by running them down too far, recharge promptly with a good three stage battery charger, and use a battery maintainer that will keep a top charge and inhibit suflation on your batteries when they are not in use. Once you have that handled, then you can start looking at how to get a silk purse from a sow's ear by adding a few pounds of battery or a few watts of solar.

[Gator113]

Great thread. The posts have been very helpful to me.

[hhendrix]

Aolani, very interesting post. I'm having similar problems with battery usage and want to start by switching out the lights in my 2009 27FB, so I found your information useful. Don't be discouraged by the naysayers and nitpickers. Even though I'm also new to this board, one thing I learned very quickly is to post your info and walk away. Don't look back. It seems there is often someone laying in wait to attack or demean meaningful attempts to provide information and experiences here.

[Ellie & Carl]

I thing the gist of all of this is: 12 volts = 12 volts. I don't remember anyone trying to point out that two 6 volts somehow provided a different voltage. The potential is ALWAYS the same. I don't recall any argument about there being a difference in voltage or that contributing to more battery. We're simply talking about deliverable juice.... amp hours. There can be no argument that the new batteries are better than the old for doing that.
We're also talking about a group 24 "deep cycle" battery vs a true (golf cart) deep cycle battery. One is designed to be drawn down deeper, while providing more amps. This means more amp hours. The bigger plates in the 6 volt batteries are designed from the ground up to provide more juice than the 12 volts.
Yes, there IS a trade-off in weight. Why is it, do you think, that golf cart batteries are 6 volt instead of 12? Anyone? I served 6 years in the US Navy's submarine service. When you want truly deep cycle-ability, you go to smaller voltage ratings per cell. This gives you deep cycle and flexibility. The ideal situation, whether you're in a mountain cabin, completely off the grid, a golf cart on the back nine, a submarine operating in "enemy" waters (without a diesel or reactor for power) or in a 30-some foot Coors can by a stream in Montana is to be able to drop a cell (or group of cells) from your battery and continue to operate. Translation: Having both series and parallel hook-ups in your "battery" by having more than two six volts or having two six volts and a 12 volt or something like that gives you that kind of flexibility.
Now let's consider what is realistic. For many, the A/S is not a full-time home. If it were mine, I'd have 4 of those 6 volt batteries in it, with an appropriate charge controller/inverter and at least a couple photovoltaic panels. Do you "need" the power to run a microwave and a big screen TV from just your battery? Or is it just convenience? If you are draining your group 24s down below 35 - 50% on a regular basis, then you need to make adjustments. The golf cart 6 volts are a great step. Reducing consumption is also a great step, and maybe the most important one.
Tearing someone down or hinting they've bought into some snake oil scheme for being able to make what most would have to consider an improvement is not productive. Getting information out is.

[2airishuman]

Originally Posted by hhendrix

...It seems there is often someone laying in wait to attack or demean meaningful attempts to provide information and experiences here.

yeah and there is OFTEN some1 claiming this crap has happened...

when it hasn't.

info/experience IS valuable here and so are EXPLANATIONS of why/how the info OR experience applies.

and that's all i read so far (except for a bit of ranting from the ranters)

Originally Posted by Ellie & Carl

I thing the gist of all of this is: 12 volts = 12 volts...

entirely true, but the notion promoted in many for 6v vs 12v threads is that there really IS some magic in the swap.

when in reality it's extra WEIGHT = extra juice.

ruggedness is largely not a factor for tongue mounted batteries (or inside/upfront)

ruggedness might be a minor issue for REAR mounted batteries but that's largely on old trailer issue.

Originally Posted by Ellie & Carl

...Tearing someone down or hinting they've bought into some snake oil scheme for being able to make what most would have to consider an improvement is not productive...

NO ONE is tearing down the o.p., it's all just an exchange of info, with suggestions to UNDERSTAND the relevant factors...

(weight, size, cost, amp hours, agm/flooded and so on)

but the assertion that "most" consider the change an improvement is categorically UNproven opinion, not fact.

with 1 battery we're committed to 12v and adding a 2nd is easy.

with 2 batteries i consider 2x6v as NOT an improvement and with the potential for NO juice.

with 4 batteries 6v vs 12v is largely a zero sum gain but with POSITIVES for either set up (or a combined set up)

with 6 batteries 6v may be a MUCH better approach, IF one has the space/weigh capacity and NEEDs that much juice.

1 can also buy/use one GIANT 12v agm (like the 250LB offering from lifeline) and that's another ok approach.

it's all about carrying the weight and having the space.
__________

i'd rather have MORE lp gas gadgets and carry lp gas, because there is a LOT more bang for every pound of fuel vs electricity.

Originally Posted by Ellie & Carl

... Getting information out is.

which IS the entire reason for the replies viewed as opposing the "amazing" results...

the op (new and their 1st post) use of the title term 'amazing' is part of the reason for ANY reply.

otherwise it's just a "i spent money, added weight and got more juice and i'm happy!" report...

happy reports are great stuff, especially with pictures.

but OFTEN these are product/vendor generated threads, designed to CONFUSE and ENCOURAGE the unsuspecting reader...

2 spend money...

CLEARLY that may not be THIS OP's intent, but it is very very common here.
____________

besides there are LOTS of of these threads with REALLY good info and maybe even MORE HEATED exchanges...

http://www.airforums.com/forums/f449...olt-14234.html

http://www.airforums.com/forums/f449...2-a-31854.html

http://www.airforums.com/forums/f449...lel-36595.html

http://www.airforums.com/forums/f449...ies-35364.html

http://www.airforums.com/forums/f449...ind-40614.html

http://www.airforums.com/forums/f449...ery-60141.html

http://www.airforums.com/forums/f449...ies-20633.html

http://www.airforums.com/forums/f449...ies-32463.html

http://www.airforums.com/forums/f449...ies-57392.html
_________

OFTEN the confusion is about some magik PEUK' effect in 6s vs 12s, and THAT is source of much heat and debate...

especially clear/useful info in posts 3 and 7 here...

http://www.airforums.com/forums/f449...ies-52395.html

http://www.airforums.com/forums/f449...ion-40065.html

http://www.airforums.com/forums/f448...nce-37921.html
________

so chill folks.

this 6 vs 12 thing is like solar/genset, axles or tires or corrosion or polish/clearcoat or MANY other common themes here...

folks LIKE what they like, and vendors SNEAK in sales crap a lotta wayz.

folks OFTEN don't wanna understand the basics and hope for magic from some new approach...

and often that magic is spread by members that WANT yer money...

other folks like to CLARIFY the important details and issues...

the goal being to PROMOTE clarity where hype is often a lot more exciting and interesting.
________

this thread is totally cupcake...

so far

((although i'd wager the REAL sellin' is happening via PM now...))

cheers
2air'

[2airishuman]

to summarize the op and point out the questionable parts....

Originally Posted by Aolani

So far, amazing difference!

....we found a substantial drain on the batteries even over one evening while boondocking.

After MUCH research online and calling vendors, we settled on the Lifeline GPL-6CT batteries, wiring them up in series.

The results are amazing, compared to our previous batteries.

Before, our factory batteries were typically down to mid-40% in the mornings after very slight furnace use, lights, etc. This was after a confirmed full charge during the day. Now we wake up to a mid-90% charge level with the two new batteries - nothing else had changed that would account for that dramatic change in reserve capacity...

there is a learning curve to energy management and that is undoubtedly part of the amazing turn around.

1 night with furnace cycling in moderate temps shouldn't take them down to 40% on 2x12v unless...

it's really cold (batteries are cold)

or the reading is from a SURFACE voltage sensor ((the 40% will AMAZINGLY rise to 60-70% after an hour or so of NO use and some warming...)

what is a "confirmed full charge" ?

batteries truely at 40% will take up to 2 days of charging to be at 100% on shore power (with the oem p-lax c/c)...

and 8-12 hour or MORE of generator charging to be at 100%.

while only 2-3 hours may get them UPTO 80-85%...

and that 80-85% will SHOW at 100% charge/voltage on the typical gauge right after charging...

but turn on a light or WAIT 2 hours (with no use) and the gauge will show a more realistic equalized charge/voltage of 80-85 %...

this is a common point of confusion on the sunexplorer OEM wall meter and MOST wall meters reading surface charge/voltage.
____________

the GREATER reserve capacity is simply a result of starting with MORE JUICE (bigger heavier cells) , temperature variations

and the learning curve of power management.

cheers
2air'

[mello mike]

For years I used two 6v golf cart batteries and was quite happy with them until.... two months ago when one failed. No 12v power the last day of my camping trip really sucked.

Bottom line: 6v batteries have more amperage and can handle more deep discharges than your standard 12v battery, so I do think they are better batteries, but only if you have room for four or more. If you have room for only two, I'd go with two 12v, size 27s.

Just my 2 cents...

[Ellie & Carl]

Good points on the possible fallibility of a two 6 volts tied for 12 volts system. I totally agree. In fact, I agree with most of 2airishuman's .... (ahem) ... comments. What I don't agree with is the second post in reply to a new poster saying "No wonder so many get hornswoggled into spending a whole lot of money on things they may not really need". This is not getting info out. This is a nay-sayer trying to belittle someone who was trying to think outside the box (or tin can, in this case).
Another point: I do NOT have forward mounted batteries... I don't have tongue mounted batteries. Mine was originally a single 12 volt mounted under the bathroom sink. I've moved them forward, some. It is my intention to keep a 12 volt battery on board and to use a dual charging switch (marine) so that in the unlikely event I drop a cell or a whole 6 volt battery, I can still function. There are solutions and constructive ideas to solve any of the perceived shortfalls in what the OP did.
Oh! One more thing... in response to 2airishuman's comment "but the assertion that "most" consider the change an improvement is categorically UNproven opinion, not fact", I'd have to refer you to the HUGE off-the-grid community and the factual data derived from their long-term experimentation. I was not claiming that most A/S owners on the forum agree with this. I was relating information from documentation that has been building outside of the aluminum tube community for over 40 years. True deep cycle batteries cost more and weigh more and take up more space but can produce more amp hours, be drawn down further and recover more quickly than any of the 12 volt batteries out there. If I had the room, I'd have nickel metal hydride cells! But that's even more rediculous than a couple of golf cart batts.

As to the philisophical aspects of this discussion (as compared to the technical) I suggest reading Robert M. Pirsig's 1974 tome Zen and the Art of Motorcycle Maintenance. A great read!

[2airishuman]

ok time for a group hug...

series or parallel?

((but don't suggest fixin my fancy bmw handle bars with a beer can shim))

cheers
2air'