2012 Airstream International 16 Modifications

[Bruce B]

OK, we love our little Bambi Serenity but true to form I cannot leave well enough alone.
As we intend to do a little boondocking with the trailer one of the easiest places to begin was with the 12 volt system. Although I am new to the Airstream game, I have some very strong opinions about batteries and their care developed over 20 years of sailboat ownership. http://esmeralde.net
I understand the arguments both for and against AGM batteries but they have simply been the best power source I have ever owned. In the real world of deeper than intended discharges, partial re-charges and general abuse (and I work hard at treating my batteries well, it is just that life happens….) my AGM batteries have provided more amps, more voltage and more charge cycles than anything else I have used including Gell cells and conventional deep cycle batteries. I love them!
Now that I have that out of the way, it was quickly apparent that the little Group 24 AGM that came with the trailer was not going to cut it! After looking at the space, my desire to be able to run for some time without going lower than 50% of capacity led me to the conclusion that a Lifeline 4D was just what I required. I own an auto repair shop and I happen to have an employee whose welding talents surpass my own meager skills so yesterday I had Kurt weld up a new battery frame and attach it to the trailer. I have attached a few pictures so you can see the installation. I have now got more than 2 ½ times the battery capacity for the trailer along with an additional 70 lbs. on the hitch. On the subject of one large vs. 2 small batteries, I once asked this question of David Smead author of “living on 12 Volts with Ample Power” (a great read by the way!) and his answer was “bigger is better”. Thus as he is much smarter than I am, I listen to that advice.
Next on the list will be to replace the converter with the Ultra III (being delivered today) and to install a Trimetric 2025 battery analyzer. This will get me to the point where I am comfortable with the 12 Volt systems.
Bruce

[bnbsnive]

Very nice setup Bruce, done very professionally. Question - where did you come up with a battery box for the Lifeline 4D. I don't see anything on their website and a few quick googles have led me nowhere. Thanks in advance!

[mutcth]

Very nice Bruce! We've also done the Trimetric and the Ultra III upgrades - like you, it was a matter of feeling better. I forget - do you have factory solar?

Tom

[graysailor]

WestMarine boating supplies would be a good source for battery boxes.

[Bruce B]

Originally Posted by mutcth

Very nice Bruce! We've also done the Trimetric and the Ultra III upgrades - like you, it was a matter of feeling better. I forget - do you have factory solar?

Tom

Tom,
We do have factory solar. I like to think of it as helping delay the moment were we need to begin charging when we are off grid though as the panel is just a little one. I would consider adding panels mounted off the Bambi if I were to spend time in a single spot. The controller will handle a lot more capacity.

In the end, I bailed on the Ultra 3 and instead installed a Charles brand marine charger. It is made in the USA, has settings for AGM batteries, has plenty of capacity to run the 12volt systems if the battery is disconnected, it is temperature compensated and it is built like a tank. It made the installation more work but in the end I believe I have a superior solution.
Bruce

[resedaheat]

Wow thats a big battery, Im trying to figure out a better system for my bambi and reviewing cost vs longevity, Im only getting a max of 2 year life on my excide battery which costs about 90 bucks. How long do you get on a battery like this? I know there are a lot of variables, I use my airstream about 10x a year for a total of about 25 nights of boon docking.

[Bruce B]

So much of battery longevity depends on how you use and take care of your battery. Two important rules to remember. Number one, never discharge your battery more than 50% of its capacity. Number two, charge your battery properly and do not let it sit discharged or discharging for any length of time.
I chose the large battery so we could easily go two days with normal use while boondocking without hitting the 50% mark. I installed a battery monitor so I could determine the actual battery use. I ditched the converter as it is a lousy way to charge a battery.
I expect that we will get 6 or more years from our battery.
You will find that the cost of the changes I made exceed the cost of simply buying an inexpensive battery every two years. I was after battery voltage, system reliability and extended capacity.
Bruce

[Jim Flower]

Originally Posted by lsbrodsky

I could make a suggestion if I had a better idea of how your batteries are wired up. If they are all in parallel your controller is only going to tell you solar panel output when there is sun and the battery voltage of the "good" batteries when there is no solar panel output. % charged is not a useful parameter as it is really a proxy for voltage. A more useful device is something like the Trimetric that will let you better explore battery performance, but with 4 in parallel I do not know how you would see a problem in one battery.
Larry

Hi Larry
Old thread but I am just getting to fixing my battery performance problem. The inside battery + connects ( through a 100 Amp fuse) to the outside battery + via a shared connection at the battery side of the solenoid. The -s are connected at the - buss bar. The inverter connects only to the inside batteries.

So when I blew the 100 Amp fuse, there was no charge going to the outside batteries and they eventually died. This went undetected by the solar controller because it was just picking up the SOC of the inside batteries and all appeared ok.

I have now purchased a Trimetric 2025, following your excellent advice, since this will tell me (among other things) if my tank is really full or, under the current set up, just half full if I blow another fuse. My goal is to connect all batteries in parallel and monitor with the Trimetric.

My understanding of the Trimetric instructions is that only the battery -s from both banks connect to one side of the shunt and all other -s connect to the other side. The other -s would include the inverter and all other -s that are attached to the - buss bar under the setee.

My process would be to disconnect both battery -s from their existing location on the -buss and attach them to the shunt and then attach the - from the inverter to the other end of the shunt as well as adding a wire to connect that end of the shunt to the - buss bar. The result is that all other -s are on the same side of the shunt in accordance with the directions.
Does this sound like I am on the right track?

The batteries that I killed still seem to be holding up at 13.197 today although they have only been providing the power required when sitting in the "use" mode since the Airstream is still in storage (-12 this am) and they are being charged by the solar. Jim