1988 Limited - Installing lithium batteries/converter question

[88Limited]

Hello all, my wife and I recently came into possession of an '88 Limited. I have the interior skins out fixing subfloor and decided to look at the 12vdc system. The old batteries were interstate deep cycle and were over 10yrs old. They're out of the trailer. For the price per charge cycle etc I decided lithium is the way to go. I'm looking at the Progressive Dynamics PD9130LV for a converter. I don't plan on doing solar yet (one thing at a time and there's plenty on this trailer).

What I do have concerns with before installing the batteries is how the trailer is currently wired. I've attached some pictures of the current setup and how the manual shows it should be setup. I do know the dual 6AWG conductors coming from the battery kill switch need to be swapped out for the 4AWG conductor - that's a no no.

My other concern is the change in wiring from factory at the converter. The current setup has the converter 12v+ conductor going to the bus bar on the distribution panel, the factory wiring diagram has that conductor going to the battery side of the kill switch. Is that due to the original univolt system being replaced by the converter requiring the change? Will it damage anything to go back to the original wiring setup?

[88Limited]

And here's the diagrams from the manual just to confirm...

[88Limited]

So... doing some more reading and some time to absorb/think about it I believe I can answer my own question. When the newer converter was installed it was installed on the distribution panel side of the battery master switch as newer converters can provide 12vdc without batteries being present (I assume the original univolt system could not). I believe that otherwise the wiring is correct except for the two 6awg conductors and the extra breaker bypassing a potentially bad one.

So I believe my plan of attack is this:

1. Replace the two 6AWG conductors with a single 4AWG for safety sake.
2. Find out why there's an extra breaker that seems to be bypassing the bottom left breaker.
3. Install a DC to DC charger so that the lithium batteries are not drained by the TV batteries.
4. Install new lithium capable converter.
5. Install new lithium batteries.

Please, if anyone sees something wrong with this let me know. Don't want to burn the trailer down.

[daleyocum]

Originally Posted by 88Limited

So... doing some more reading and some time to absorb/think about it I believe I can answer my own question. When the newer converter was installed it was installed on the distribution panel side of the battery master switch as newer converters can provide 12vdc without batteries being present (I assume the original univolt system could not). I believe that otherwise the wiring is correct except for the two 6awg conductors and the extra breaker bypassing a potentially bad one.

So I believe my plan of attack is this:

1. Replace the two 6AWG conductors with a single 4AWG for safety sake.
2. Find out why there's an extra breaker that seems to be bypassing the bottom left breaker.
3. Install a DC to DC charger so that the lithium batteries are not drained by the TV batteries.
4. Install new lithium capable converter.
5. Install new lithium batteries.

Please, if anyone sees something wrong with this let me know. Don't want to burn the trailer down.

#3's necessity will depend on your tow vehicle. For example my new F150 puts out so little power while driving as to be almost useless charging the trailer batteries (we have solar so don't care.) It also has a bunch of electronics that prevent it from drawing any power from the trailer battery while parked.

I will say if you are installing Lithium, the Victron Multiplus 3000 is a great match. Sure it's more expensive than just a converter but it combines the converter & charger with a 3000w hybrid inverter and transfer switch all in one box. Super easy to install. It allows you to easily make every outlet in the trailer live all the time whether on the inverter or shore power. It also boosts limited shore power, like from a generator, with battery power when needed. The Victron BMV-712 battery monitor and a Victron Solar Controller all integrate with this. If you are going this route you'd want to run far heavier 02 wire from the batteries because the inverter can draw 150 amps at times.

Adding solar to this setup would be a natural step and not much more money. Unless you are SURE you never want it, at least add the 6ga wires to the roof while the interior skins are off. You'd also want to add a CAT6 wire for the inverter control and one for the battery monitor and maybe one for a Solar charge controller display (optional.)

[88Limited]

Originally Posted by daleyocum

#3's necessity will depend on your tow vehicle. For example my new F150 puts out so little power while driving as to be almost useless charging the trailer batteries (we have solar so don't care.) It also has a bunch of electronics that prevent it from drawing any power from the trailer battery while parked.

I will say if you are installing Lithium, the Victron Multiplus 3000 is a great match. Sure it's more expensive than just a converter but it combines the converter & charger with a 3000w hybrid inverter and transfer switch all in one box. Super easy to install. It allows you to easily make every outlet in the trailer live all the time whether on the inverter or shore power. It also boosts limited shore power, like from a generator, with battery power when needed. The Victron BMV-712 battery monitor and a Victron Solar Controller all integrate with this. If you are going this route you'd want to run far heavier 02 wire from the batteries because the inverter can draw 150 amps at times.

Adding solar to this setup would be a natural step and not much more money. Unless you are SURE you never want it, at least add the 6ga wires to the roof while the interior skins are off. You'd also want to add a CAT6 wire for the inverter control and one for the battery monitor and maybe one for a Solar charge controller display (optional.)

The TV is a 2010 Ram 2500 with a dual battery setup (diesel). I'm sure it doesn't have the electronics your newer F150 does to isolate the TV from the trailer.

I will take a look at the Victron Multiplus. I like your idea of future proofing by running larger conductors for solar/cat6. That is on the list of things to do, just not all at once. I may wait on the batteries and converter. I need to get the subfloor and leaks fixed first, axles, etc next. So far we've been staying at campgrounds but would like to boondock which will require solar. If you don't mind I'd like to give you a holler later when I get to that point?

[daleyocum]

Originally Posted by 88Limited

The TV is a 2010 Ram 2500 with a dual battery setup (diesel). I'm sure it doesn't have the electronics your newer F150 does to isolate the TV from the trailer.

I will take a look at the Victron Multiplus. I like your idea of future proofing by running larger conductors for solar/cat6. That is on the list of things to do, just not all at once. I may wait on the batteries and converter. I need to get the subfloor and leaks fixed first, axles, etc next. So far we've been staying at campgrounds but would like to boondock which will require solar. If you don't mind I'd like to give you a holler later when I get to that point?

Sounds like your TV will be great at charging batteries with the DC-DC unit from Renogy.

Feel free to reach out. Also check out AMSolar’s website for articles and tutorials on Solar. www.amsolar.com

[uncle_bob]

Hi

If you are going to put Lithium's in, put in a shunt based battery monitor at the same time. The Victron BMV-712 is one, there are others out there.

I would not go with a "single voltage" converter / charger or with one that can not be adjusted on a per stage basis. We simply don't know enough about fine tuning this stuff yet. From what I've seen, none of the fixed output devices really do it "right" ( based on current thinking ...).

I would also dump the manual kill switch and go to a latching relay. The Blue Sea 7xxx series parts are a good choice.

You don't mention how many batteries you are putting in. Two is probably the reasonable minimum. If you can plan for 4 (or 6) down the road. More is always better in this case ...

The value of the existing thermal breakers is debatable. They have a finite lifespan. If one of them got "exercised" a lot, it may be on it's last legs. If it makes more sense to fully re-wire the 12V stuff at this point, go for it !!

Bob

[Buckless]

I think the kill switch was on the battery side so to be sure battery would not be over charged and ruined.

[88Limited]

Originally Posted by uncle_bob

If it makes more sense to fully re-wire the 12V stuff at this point, go for it !!

Bob

Bob, I've been debating on this one. Do you have a recommendation for a new 12v distribution panel?

[daleyocum]

Airstream uses WFCO panels in their newer models. I’m happy with the stock one but they have a full line.

[uncle_bob]

Originally Posted by 88Limited

Bob, I've been debating on this one. Do you have a recommendation for a new 12v distribution panel?

Hi

If you want to go "fancy" the Blue Sea stuff is all pretty nice ....

For some of the stuff, you will want to use a self reset breaker. There are things that could go "pop" when in motion that you want to come back online if they can. Things like brakes and turn signals come to mind ....

In this day and age of automation, I'd put in some sort of monitor setup. Not anything crazy, but some way to signal that a circuit somewhere is in trouble. Might just be a single blinking light in an easy to spot location. The whole "breaker tripped / fuse blows and first indication is the freezer thaws out" thing is not ideal ....

Bob

[guskmg]

I would not use a self resetting circuit breaker anywhere. I have experienced fire from a low grade short igniting flammable objects due to the reset cycling acting like a heater element.
guskmg

[absinthe]

Originally Posted by 88Limited

Hello all, my wife and I recently came into possession of an '88 Limited. I have the interior skins out fixing subfloor and decided to look at the 12vdc system. The old batteries were interstate deep cycle and were over 10yrs old. They're out of the trailer. For the price per charge cycle etc I decided lithium is the way to go. I'm looking at the Progressive Dynamics PD9130LV for a converter. I don't plan on doing solar yet (one thing at a time and there's plenty on this trailer).

What I do have concerns with before installing the batteries is how the trailer is currently wired. I've attached some pictures of the current setup and how the manual shows it should be setup. I do know the dual 6AWG conductors coming from the battery kill switch need to be swapped out for the 4AWG conductor - that's a no no.

My other concern is the change in wiring from factory at the converter. The current setup has the converter 12v+ conductor going to the bus bar on the distribution panel, the factory wiring diagram has that conductor going to the battery side of the kill switch. Is that due to the original univolt system being replaced by the converter requiring the change? Will it damage anything to go back to the original wiring setup?

Hello there,

Did you ever complete this upgrade?

I ask because I have an 85 with nearly the same setup and am looking to also convert to a Multiplus 3k w/lithium batteries.

Thank you
-Rich