Using power station as primary battery

[jcwilde1]

I have something I have been researching and have gotten myself confused.

I have a 2013 TM and it needs a new 12v battery. I own a lithium phosphate power station and I know I can plug it into to the shore power plug with an adapter and everything works.

But I was wondering if anyone has tried to use the power station as the primary battery. I like the idea of this because I could hook a solar panel into it as well as take it out and use it for other things.

My confusion is more about how it would connect. I know it can charge using a 12v cigarette port and it has a 25amp DC 12v out, but with an existing battery it uses the same positive and negative cables for both discharge and charging so not sure this could work.

If not I realize replacing the existing converter to a lithium compatible one isn't terribly hard, just trying to save a few $$ and postpone getting a new battery.

[Shane826]

Unless you’re going to have the power station connected at all times, you need a battery in case the trailer gets separated from the tow vehicle to activate the break-away brakes.

[Bill]

I don't know much about these things, but we have discussed them before - see

https://www.trailmanorowners.com/for...ad.php?t=19759

My first thought was the same as Shane's. If you are going to use it as a primary battery for the TM, then you must do everything you would do with a real battery. And that includes connecting its 12-volt outlet to the primary battery terminals, and making sure that it is charged before you hit the road. In the event of a breakaway, the trailer brakes will immediately start to pull about 8+ amps from the battery, to activate the electric brakes and stop the trailer as quickly as possible. So be sure your unit can supply 10 amps for at least a minute. BTW, what make/model power station do you have?

If this is what you are thinking, then it may work. But if you are thinking of some less demanding use, like simply powering some lights, the radio/TV, and the water pump when you set up camp, I don't think it is a good idea.

Bill

[jcwilde1]

Bluetti 200 is the unit. The power consumption and keeping it connected when in motion is not as much of a concern as is the challenge of "connecting it to the trailer" part of it.

A normal battery charges and discharges from the same cables where as a power station has battery IN locations (for charging) and battery OUT locations (to power everything).

So I may be answering my own question and this may not be possible or at least not worth the hassle of trying to integrate into the existing wiring.

I have read that post and a host of others on various sites and it sounds like I really need to upgrade my converter to support Lifepo4 batteries or stick with Lead Acid and use my power station to extend that through its AC ports. The later is much much cheaper

[Wavery]

Originally Posted by jcwilde1

Bluetti 200 is the unit. The power consumption and keeping it connected when in motion is not as much of a concern as is the challenge of "connecting it to the trailer" part of it.

A normal battery charges and discharges from the same cables where as a power station has battery IN locations (for charging) and battery OUT locations (to power everything).

So I may be answering my own question and this may not be possible or at least not worth the hassle of trying to integrate into the existing wiring.

I have read that post and a host of others on various sites and it sounds like I really need to upgrade my converter to support Lifepo4 batteries or stick with Lead Acid and use my power station to extend that through its AC ports. The later is much much cheaper

You could literally just plug your TMs 30A cord into the Bluetti while camping and everything would work. You would need to do 2, things. 1, have a cut-off switch on your camper's L/A battery. 2, be SURE to turn off the breaker that controls your TM converter so that the converter is not trying to recharge your Bluetti and cause a weird looping situation.

As far as changing your converter charger, that wouldn't be necessary. You wouldn't be charging your Bluetti from that anyway. You would simply plug the Bluetti into a 110V power source or solar array.

I have been doing some research on running 12V L/A batteries in parallel with LiFeP04 batteries. Some people are already doing it successfully but there is some science behind it and should not be tried without doing your due diligence. You can't just hook a lithium into a L/A without doing some careful balancing.

[jagizzi]

Originally Posted by Wavery

I have been doing some research on running 12V L/A batteries in parallel with LiFeP04 batteries. Some people are already doing it successfully but there is some science behind it and should not be tried without doing your due diligence. You can't just hook a lithium into a L/A without doing some careful balancing.

I run a modified version of what you describe with both a FLA battery string on the tongue, and 2 206AH LiFePo4 batteries in the rear compartment. They are both charged by the converter/charger but do not exist in parallel with each other.

I placed a battery selector switch between the two strings so that I can charge, or operate, from one or the other, but not both. Progressive Dynamics chargers have a Boost function which manually, temporarily, outputs 14.4V for 4 hours and then reverts to 13.6V. I use the boost function to charge the LFP's and the normal function to charge the FLA.

Note that the solar charger is only connected in to the LFP batteries as that charger is not selectable. I will also only connect the inverter into the LFP's as well.

I set it up this way for 3 reasons: 1) I had just bought the trailer and it had dead batteries. The easiest, quickest thing to do was to replace the existing GC2's so I did. Two new GC2's sitting on the tongue that I didn't want to throw away. 2) Tongue weight is a factor as well. The GC2s weigh about 120# and sit way up on the tongue. My tongue weight is 350#. If I remove those batteries I am concerned that the tongue would be too light. 3) The GC2s give me an additional 2 days boondocking beyond the LFPs.

I am still trying to figure out how to integrate an inverter physically. The cables are heavy and don't bend easily in limited space, but I'll get there ;-)

[rich2468]

I can certainly see the attractiveness of having the ability to remove an expensive power source and have it available for other (non-TrailManor) uses....but when I look at trying to use a Bluetti device as a replacement for a power source for a TrailManor I see a number of shortcomings:

1st As Shane called out, it needs a secure connection to supply 12 volt DC for the trailer brakes under tow. (There's no compromise on that fact)

2nd The Bluetti device under consideration (AC200Max) weighs 61 lbs with a 40 Amp Hour capacity and costs (as of 2/14/2023) $1600. (That's not a tremendous amount of electrical capacity for that weight or cost)

3rd Integration Concerns- You could simply plug in the TrailManor's Shore Power Plug into the Bluetti's 120Volt outlet, but it's a little absurd to charge a Direct Charge storage device by Altering Current to then later use it as a 120 Volt Alternating Current source for a TrailManor under boondocking scenario (where 95% of your power needs for your camper are likely to be 12 volt DC). You'd still have a 12 volt TM battery under this scenario and would loose additional energy efficiency at the TM power converter.

You could certainly come up with ways to directly wire the Bluetti to remove the TrailManor's power converter from use, but in going through all the effort I think you'd find that you lost the flexibility to easily remove the Bluetti device and in the end any cost benefit is completely lost.

Bluetti's have their place as portable power stations, but I don't think they're really well suited for this use case.





Rich and Lynn
2021 2922KB

[Sienna]

I’ve been thinking about doing this with a Jackery.
Here is my thot process.
1. Have a break away battery on tongue hooked up exclusively to trailer brakes. Here is the e trailer link for the battery I am thinking.

https://www.etrailer.com/p-HM20008.h...ils=.questions

1a. I do have a battery tender that I use with my current lead acid batteries. That I would hook up in between trips to the trailer brake battery and hook up the trailer brake battery to the 7 pin to charge it while towing.

2. Jackeries do have a 12 volt 10 amp output. Hook this into the twelve volt system running wire to the back locked compartment.

3 Put in some vents in compartment just in case.

4. This way I can use the jackery for other things than camping in the TM.

Any body see any potential problems with this set up.

[Bill]

I don't see a big problem - I'll come back to that - but I don't see the point. If I am reading correctly, you re going to have two batteries, one on the tongue and one (the Jackerie in the rear compartment) serving as the TM main battery. You are going to wire them in parallel - that is, plus to plus, and minus to minus. The fact that you will use long round-about wires to do it doesn't change anything. With the batteries wired in parallel, they behave as a single battery. Your battery tender will charge both of them when you are camped and it is plugged in. And the 12-volt line from the truck will charge both of them, and power the TM loads (appliances in the camper, for instance) including the breakaway connection to the brakes, when you are driving. So I don't see that you have gained anything except a small increase in total battery capacity. The breakway function still works as desired, of course, powered by both the small battery and the Jackerie.

As to reasons not to do it? It is generally considered unwise (though not catastrophic) to connect two batteries of the same chemistry (lead-acid, for example) but different capacity together. Your TM battery problem has a capacity of 75 amp-hours or more, while the small battery has a capacity of 5 or 10 amp-hours. Not a good balance. If the two batteries have different chemistry, such as lead-acid for one and the lithium in the Jackery for the other, it is even more unwise.

The kit you are looking at is intended for utility trailers that have no main battery. In that case, the small battery is the only source of power for the brakes in the event of a breakaway.

And I've lost how the Jackery is involved. How does that fit into your plan? Are you thinking of three batteries - the TM main battery, the small tongue battery, and the Jackery? Maybe don't do that.

Bill

[Sienna]

I am proposing only two batteries not in parallel and not connected at all. The small battery isolated to the trailer brakes.

Sorry for the confusion I would be eliminating my current large lead acid batteries.

The jackery will be the TM main battery running the lights furnace water pump etc.

I believe I am solving these problems that I have by doing this.

I currently have two large lead acid on the tongue and need to remove some weight.

With the jackery I am removing the need to change out the WF electrical panel to lithium compatable.

I have some security for the jackery in the rear locking compartment.

I can use the jackery for other things besides the TrailManor.

I can easily add solar later.