Solar wires to front slide

[jcwilde1]

I've been trying to read through the forum but haven't quite found what I am looking for. Does anyone have a link or information about the wire path if your battery is in the front? We have a 2922KS and I'm getting ready to mount two 100 watt panels and the slide out part is confusing me, my batteries and mppt will be below the couch in the front.

Also what would be a good spot for a shut off on this model? It would be great to have a shut off on the outside. Thanks!

[jagizzi]

I don't have a slide so can't help there but I mounted my battery cutoff switch to the side of the battery box. Remember to take into account the power for the emergency break cutoff switch when you wire in the cutoff switch.

[jcwilde1]

I think I got it figured out... Had the ah-ha moment by reading other posts that I should just wire the mppt to the main panel and thus not have to do anything special.

I will keep that in mind for sure, wouldn't want to have it completely disconnected.

[Bill]

Just think'n here. If your battery is inside, under the couch, is it a good idea to put the cutoff switch inside, on the battery box? I have occasionally found that outside access to the cutoff switch is handy. Perhaps you can reach it through the front access hatch?

Bill

[Shane826]

Just think'n here. If your battery is inside, under the couch, is it a good idea to put the cutoff switch inside, on the battery box? I have occasionally found that outside access to the cutoff switch is handy. Perhaps you can reach it through the front access hatch?

Bill

But if the camper is closed you still wouldn’t be able to reach the cutoff through the access hatch…

[jcwilde1]

I think would be easy enough to put the kill switch between the solar and the mppt and maybe another switch between the battery and inverter (where the mppt wires are going to splice in. But it would have to be on the front outside shell if I do it this way. No sense of running long wires to where the propane tank is.

[rickst29]

My MPPT is mounted on the lower front wall, but our situations are otherwise similar.

I brought my front-shell mounted solar wires down along the street side forward lift arm, with a bit of extra length at the bottom to allow for lifting and lowering the shells.(Just like TM does on the other lift arm, for the air conditioner cord and upper shell lighting wire). You can simply go down the curb side lift arm, ending very near your storage bench.

I then route the wires through the large frame holes which contain the torsion bars, and I used use a couple of screwed in wire clamps to hold the wires against the floor before reaching a hole (or two small ones), drilled through the floor to allow for their entry.

Be extremely careful drilling those holes, because the propane supply pipe for the stove is in the same area. I recommend that you drill from underneath, rather than above.

After pulling the solar wire ends, add fast-acting fuses on both leads. MPPT should already be connected to the battery first (and the battery connection powers the MPPT), only then connect solar "-" and finally connect solar "+". You must not leave solar connected if you disconnect the battery from the MPPT, the Solar "+" must always be disconnected first and connected last. You could use a 120V switch for that, although I'd use a heavy-duty switch (rated for 20A at 120V AC, rather than just 15A).


I assume that your batteries, if lead-acid, are within a tight and vented box. My own batteries are LFP, (they don't need venting) and never leave the Trailer. My TM is stored in the garage, and always plugged in, so I never worry about running the batteries down.

[jcwilde1]

Thanks for that information. I was thinking of splicing the mppt into the 12v wire that goes from the battery to the fuse panel (and adding a fuse at that stage), that way I can mount the mppt inside the cabin and not have to run the solar wires all the way to the front where the battery is located. Don't really see the difference in connecting it this way vs connecting it to the battery terminal directly.

I would love to put a LFP battery in there, but don't really want to change out the on board charge controller. From what I had read it may still work it just wouldn't ever charge them fully, but then again the solar would do that potentially. Thoughts on that?

[Bill]

But if the camper is closed you still wouldn’t be able to reach the cutoff through the access hatch…Of course you are right. Dunno what I was thinking. Too late at night, I guess. Thanks for the comment.

Bill

[rickst29]

Thanks for that information. I was thinking of splicing the mppt into the 12v wire that goes from the battery to the fuse panel (and adding a fuse at that stage), that way I can mount the mppt inside the cabin and not have to run the solar wires all the way to the front where the battery is located. Don't really see the difference in connecting it this way vs connecting it to the battery terminal directly.

I would love to put a LFP battery in there, but don't really want to change out the on board charge controller. From what I had read it may still work it just wouldn't ever charge them fully, but then again the solar would do that potentially. Thoughts on that?
That's a good idea in many ways, but I recommend against cutting and splicing the battery wire. If your solar power maximum "12v" output current is less than 30A, and therefore compatible with the 30A limit on TM's long AWG-10 wire between the battery and the power center, you could use a "power distribution block" like this one, installed behind the power center. You would ignore the the big input socket. The "battery wire" connection in the 12v fuse panel is already fused at the panel, you simply disconnect the current wire and replace it with a a short length wire (10-12 inches) reaching into one of the small distribution block ports. AWG-8 actually fits the distribution block better than AWG-10, and I upgraded that short segment in my own TM. The other two "small ports" are taken by your solar controller and the original battery wire. https://www.amazon.com/TOPSTRONGGEAR-Gauge-Copper-Distribution-Splitter/dp/B0919HX645

Because the original battery "+" wire has somewhat risky routing to reach your battery compartment, and because the current is bi-directional, I would (and did) add another fuse at the end of that wire before entering the distribution block. A couple of these wil handle both the MPPT and the battery wire: https://www.amazon.com/InstallGear-Gauge-Line-Fuse-Holder/dp/B079V7J839

[rickst29]

I would love to put a LFP battery in there, but don't really want to change out the on board charge controller. From what I had read it may still work it just wouldn't ever charge them fully, but then again the solar would do that potentially. Thoughts on that?
Many "Lithium Compatible" RV power converters implement a constant voltage charge of 14.6 volts, that's too much. Although lead-acid batteries should be kept as close to 100% full as possible, for the highest possible prportion of time, LFP batteries do not like being stored at 100% SOC. It degrades lifespan.

Changing out the power converter main board is not difficult, it is only costly. A "Converter" which can be re-set to do WHAT you want, WHEN you want it, is optimal - so a Progressive Dynamics converter with the controlling "charge wizard" pendant is the way to go. My own converter, a sightly modified PD, has that pendant. For long-term storage, including the entire winter, I let it settle into a low voltage "storage mode". Then, when I open the TM and pack for a trip, I push the button to force "boost mode" (which is only 14.4 volts, not 14.6). BMS in the battery packs stops charging at around 14.2 volts.

Interior LFP storage (under the couch) helps to prevent the issue of charging in extreme cold weather, the batteries cannot be charged below freezing (and really shouldn't be charged until at least a few degrees higher than that). But other TM owners have them elsewhere, and are pretty happy with their results.

The batteries cost a lot more than the converter replacement, but they last forever. With a "decent" converter, the 10-AWG wire between the load center/power converter will need to be replaced, because LFP batteries can be charged fast (with lots of current, too much for that small wire). My Converter can and does deliver nearly 60A into my batteries.

My most difficult "issue" in upgrading to LFP battery packs under the front couch was replacing that wire. From the batteries under the couch, I ran about 16 feet of liquid-tite conduit underneath the floor and into the curb-side frame (at the large torsion bar hole, exiting at one of the rear torsion bar holes. The liquid-tite is then clamped to the floor, crossing the underside and rising through a sealed hole (with a clamp above) behind the load center. It contains a single cable, AWG-6, THHN/THWN-2 .