Help with locating components in battery upgrade

[jranck]

We just purchased a used 2018 25 FB twin and the batteries are shot (among other things). I've decided that I might as well switch from the lead acid to Li, which is something that has been on the upgrade path for whatever trailer we ended up with.



I have spent days going over the Li conversion threads in the forum and going over the owner's manual, but can't seem to find the info I'm looking for.


Before I start tearing into things in my trailer, can anyone tell me where the existing inverter and converter are located in my trailer?


The upgrade will not include solar at this point, and will only include a couple of batteries, a new inverter/converter, a monitoring system so we can see state of charge, etc., and something to protect our TV so it doesn't burn anything out trying to charge Li batteries. We may later add solar and more capacity if I can ever satisfy myself that it would be helpful to us.


My plan is to locate stuff under one of the twin beds. However, if anyone has made a similar conversion, I'd love to see a description/pictures of what you have done. May help me in choosing components and figuring out how much space to take for the installation.


Jeff.

[akerr]

I am just new to this as well so others can chime in, but I don't believe airstream installs power inverters unless you purchase the solar package. My 2012 even had a factory installed inverter put on later and they didn't install an inverter.

For monitoring the power there are a couple of options that you could install wherever is convenient. If you plan on going solar you might consider just going ahead and installing a solar controller. This will monitor your batteries, and the solar input will just read 0 until you get around to putting in solar, but you'll be all wired up. Airstream in 2016 was installing zamp, I just looked at their web site and the "40 Amp 5-Stage PWM Charge Controller" is $110 right now, so not bad.

Another thing to consider, that I am considering as well, is that while I have roof mounted panels if I park my camper in the shade, which is preferable when possible because hey - you can't run your AC on batteries - the panels also don't get as much light. You could, instead, get some portable panels that fold up like a folding table - wire up a plug near your batter compartment/front jack/whatever is convenient, and plug in the panels as part of your setup. This way you can point them right at the sun in a convenient location while keeping the camper in the shade. The only down sides are slightly more work, power cable in your camp site, and the possibility of theft if left unattended. But you can get a rottweiler (or in my case, chihuahua) to guard them

[akerr]

Just to follow up on this, despite not having an inverter built in, I really don't care. There is a 12v cigarette outlet near the tv, under my table, and with the radio. All you need an inverter for really is the TV and maybe laptop charger. A cheap one on amazon, from costco, etc has been more than enough to power my small LCD TV and power my laptop at very minimal cost, and its more obvious for me to remember to unplug them than it is turning off a remote inverter.

Also, I forgot to mention, my solar controller is mounted behind my TV on my 23FB. That gave easy wiring access to the roof, under the trailer, and the back of the controller is exposed in the closet should I need any easy access to it for some reason.

I also like having the controller behind the TV because it hides it and I can't see any lights when sleeping, etc. But I can peek back there to check the voltage, or swing the TV out if I need to push buttons or get more serious. You cloud probably put it IN the closet as well if you fabricated a box, but mine was just cutting a hole. I'd suggest somewhere convenient and eye-level, you're going to be looking at it a lot.

[jranck]

My 2018 does have an inverter. Half of the 110 outlets are labeled "inverter" and half aren't. Weird way to do it if you ask me, but airstream didn't.

[jranck]

Originally Posted by akerr

You could, instead, get some portable panels that fold up like a folding table - wire up a plug near your batter compartment/front jack/whatever is convenient, and plug in the panels as part of your setup. This way you can point them right at the sun in a convenient location while keeping the camper in the shade. The only down sides are slightly more work, power cable in your camp site, and the possibility of theft if left unattended. But you can get a rottweiler (or in my case, chihuahua) to guard them

We may pick up one of the suitcase panels at some point, but so far there is no port to plug them in. If we add solar in the future, that is something we'll add.

[1StreamDream]

I don’t have the same trailer as you but It’s close. I have a 25’ RB (twin) and my inverter is under the longer of the 2 bench seats, toward the center of the trailer. A little trick that might help you locate it is simply turn it on and listen for the cooling fan noise. The on off for the inverter is a separate panel near the tank display in the kitchen area in my trailer. Mine is a 2015 and the fan always runs when the inverter is on. The noise is faint so you will need quiet conditions to have the best chance of hearing it (says the old guy who can’t hear very well in general)

[Wazbro]

I don't know exactly where the inverter and converter are in your trailer. In general they are as close to the batteries as practical. The wires to connect to the batteries need to be heavy, the longer they are the heavier and more expensive they need to be. So in a front twin they should be under one of the beds or in the front compartment.

[uncle_bob]

Hi

The converter / charger is likely near or behind the DC fuse panel. The inverter could be just about anywhere in the front of the trailer. First step would be to look under the beds / night stand. Then work back from there. It's a good bet that the inverter is mounted to the floor.

Bob

[Wayne&Sam]

Originally Posted by 1StreamDream

I don’t have the same trailer as you but It’s close. I have a 25’ RB (twin) and my inverter is under the longer of the 2 bench seats, toward the center of the trailer.

I also have a rear bedroom 25. Just lift that cushion and open the panel you will find. It's in there.

[jimdelane]

A solar controller provides information relative to the solar charging system. To properly monitor lithium batteries, you need a coulomb counter type battery monitor. This requires a shunt to be placed on the negative side of the bank terminal and basically counts the electron flow. This provides an accurate state of charge as well as other information. Victron puts out the 712 and SmartShunt. Both work with the Victron Connect app which you put on your smartphone. The 712 comes with a gauge hand has more range. The SmartShunt is just a shunt and sender. Nice thing about the bluetooth is you can look at it anytime day or night - my wife loves that. There are other shunt based battery monitors out there as well.

[GammaDog]

Uncle Bob has my answer.

Our 2014 25’ FB is a queen, not twin, so yours will be a bit different, but our inverter is mounted to the inside of the bed frame on a horizontal surface. Accessing it requires removing the mattress and removing the screwed-in panel under the head of the bed.

I’d recommend you (or anyone working n their own trailer) email Airstream and ask for the applicable wiring diagram for your year/floorplan. It’s free, reasonably detailed and helpful for questions like this.

I moved the batteries inside when I upgraded to LiFePO4 this past winter. It’s been a great upgrade for us. The wiring diagram was essential.

[jranck]

A lot of good information here and I want to thank everyone. I think that I have enough to at least start looking for everything.


I've ordered everything that I need, including the Victron BMV-712 battery monitor and the bluetooth dongle.


The user manual also has the wiring diagram for my trailer and I've printed off all the relevant pages. I think between everything, I'll hopefully have enough to find what I'm looking for.


I'll attempt to document with pictures in case anyone else tries to upgrade the same model trailer.


Thanks!
Jeff.

[uncle_bob]

Hi

While you have the trailer someplace you can do this and do that: take it all apart. Look behind this and behind that. Look under the beds. Pull all the drawers and look behind / under them. Pop open any screw down panels and see what's behind them. It's a fun way to spend a day or two with your trailer.

For bonus points, take pictures of everything with your phone. That way two years from now, you won't have to pull all the panels off again

No, this really is not rewiring specific. It's something you should do even if you don't plan to do any work. If you are out at a campsite at 3AM with a problem .... that's not the time to wonder where this or that might be.

Fun !!

Bob

[jranck]

Originally Posted by uncle_bob

Hi

While you have the trailer someplace you can do this and do that: take it all apart. Look behind this and behind that. Look under the beds. Pull all the drawers and look behind / under them. Pop open any screw down panels and see what's behind them. It's a fun way to spend a day or two with your trailer.

For bonus points, take pictures of everything with your phone. That way two years from now, you won't have to pull all the panels off again

No, this really is not rewiring specific. It's something you should do even if you don't plan to do any work. If you are out at a campsite at 3AM with a problem .... that's not the time to wonder where this or that might be.

Fun !!

Bob

Good suggestion!

[guskmg]

If you are going to upgrade to Li batteries, you might as well get a 3000 inverter and rewire for the heavy duty option. The nice thing about that is the batteries will recharge in no time. Plus you will be ready for all the solar you want. Contact AMSolar.com for any sugestions. They sell kits for about anything you want to do. They are most reliable and have techs available if you get in over your head.
guskmg

[Wayne&Sam]

And please, tell us when the inverter was found.

[uncle_bob]

Originally Posted by Wayne&Sam

And please, tell us when the inverter was found.

Hi

If you have an older trailer, spending time to find this and that is even *more* worth doing ..... Airstream loves to move around the locations of this stuff year to year and maybe even during a year.

Bob

[Oreg52]

Should be under the curb side bed. The inverter is mounted to the front, converter to the rear.

When installing a larger than stock inverter or converter ensure the input/output wiring matches the power requirements of both