Overland

Thanks for the post. IMO, that's a worrying number of initial quality problems.

Makes me wonder about those Airstream owners. He even got complimented for having 'thought everything through'. If I run into that particular Darwin Award applicant at a campground, I'll have to remember not to touch his truck or trailer - that could be a nasty shock.

For curiosity sake, I had to go out and hook my truck up to see where the electrons ended up. Here's where things stood with the solar disconnected, no shore power, and unhooked from the truck: Now, with the truck connected, but not turned on: Then finally, with the truck turned on: Well, that's revealing. Yes, the trailer was definitely connected since the running lights were on. And the alternator was running - here's the truck voltage, both on and off: Interesting that while the truck doesn't draw anything from the trailer's batteries, it is drawing from the house battery installed in the truck. Makes me wonder what the deal is with the trailer. I checked the ground wire - it's there. I get 13.35v from power to both ground and frame at the plug, and 14.5 from the same on the truck. So...huh.

Trucks are definitely changing, especially with the shift to hybrid charging, so I won't deny that you're getting a charge, but I do have questions. First, I'm curious how many amps of charge you're seeing and how that changes over time vs just at startup when the alternator is charging the start battery. My alternator will give 14.6 volts for a bit, but only until it senses that the starting battery is recharged, then it drops into, if I remember right, the low 13's, which isn't enough to charge lithiums even without taking into consideration the .3 to .5 drop in voltage that you'd see over the distance to the batteries. This happens even with a house battery in the truck, connected with 2 awg cables. That behavior seems pretty common for modern truck electrical systems, but of course with hybrids that could be different. The ideal test, but also the most inconvenient, would be to disconnect your solar while driving for a day and then take a look at the day's chart from the Victron app. Also, what gauge wiring do you have between the truck and trailer? If it's standard 12 gauge, and 18' to 25'+ of wiring from truck to trailer (depending on where it starts in the truck), and the Norcold fridge pulls 15 amps, then already I think your wiring is undersized (assuming you're charging from the truck at the same rate). My guess though is that your solar is providing the bulk of what you're seeing to the batteries/fridge. Still, traveling at night or rainy days, I think I'd want at the very least 10 awg wiring, and if I'm swapping it out for that, then of course I might as well swap it out for something more.

To get a charge from your tow vehicle, you’ll need heavy gauge wiring and a battery to battery charger. The existing wiring is too small for the distance between the alternator and the trailer batteries, and modern truck electrical systems will not supply a continual voltage from the alternator high enough to charge a bank of batteries. It’s a wiring/electronics issue and not a battery issue.

On the other hand, I found this Victron video, where at 5:10 he explains why connecting the panels in series would be beneficial. So there’s definitely a trade off. If you spend most of your time in full sun conditions, then maybe rewiring your panels in series would be wise. Of course, your MPPT controller would work automatically with either, which has me wondering if you could create a simple way to switch between the two configurations to match whatever conditions you’re in.

Still on the list. You should see the list I have for the house.

Well you’ve definitely gotten me interested and thinking about this again. I would definitely like to get more out of my solar panels, especially in the winter. This past trip was a bit painful being in full sun and seeing at most about half of the rated capacity. I know that the most effective modification would be to make my panels tiltable, but I always seem to plant the trailer on a north south axis for some reason.

A higher voltage array will undoubtably give more opportunity for the MPPT to provide a charge to the batteries, but I’ve never read that there’s no advantage to using an MPPT with 12 volt panels. I think the reverse is true for sure - if you have 24 volt or higher panels then you really need to use an MPPT. I’m betting that the advantage that you’ll see is that your batteries will start charging a little earlier in the morning and will continue a bit later in the evening. I doubt you’ll see much difference the rest of the day. Like I said, I’m still learning as well so I’m eager to see if you find a real advantage, and there’s no downside to trying it out other than time spent rewiring. I’d be thrilled if it works well since it would mean an easy and free upgrade for me.

You could try bending out the clip a little for a tighter fit. We had trouble with ours coming loose but the solution had nothing to do with the blinds - I just lowered the tire pressure down from the absurd level that Oliver used to use.

It turned out that wasn’t the issue, rather the batteries themselves have problems. Hopefully I’ll find out what exactly it was after Battleborn takes a look. You are correct that theoretically (and perhaps practically) it shouldn’t make a difference. You’ve in essence created a bus bar with the cables and it shouldn’t make any difference where along a bus the power is connected. I could see it being a problem with marginal or undersized cables, but with 4/0 like I have there’s just the tiniest smidge of added resistance between the first battery and the others. After hearing that from Battleborn I’ve tried to find some other reference to properly wiring the battery bank but can can only find one, from a company called Iota. But looking at the photos from their test, it’s obvious that the battery interconnects are undersized. So my take is that theoretically you could have a problem with the batteries wired that way, but practically, I doubt you’d have a problem unless your interconnects were undersized. I’ll certainly make sure they’re connected like Battleborn wants, but yeah, I don’t think it really matters.

Your Victron will do fine with 12 volt panels. It’s definitely not a requirement to do 24 volt - perhaps a recommendation?

Yes and no. I did replace mine while doing my plumbing refit but I didn’t bother to preserve the bath duct. And in three weeks on the road without it, neither my wife nor I could tell any difference at all. My plan was to reroute the duct down the other side (possible since I’ve previously removed my unused black tank drain), but I don’t think it’s worth the trouble. The bath just doesn’t get appreciably colder than the main cabin. With the bath duct gone, the two cabin vents blow a bit stronger - probably due as much to having the ductwork pulled tighter. I replaced the remaining duct with insulated flex duct. I experimented with rigid duct but there’s too many ins and outs with the plumbing to make it work. I guess I could have done the duct first and worked the plumbing around it but that would have made for a real rats nest of plumbing. But the insulated flex duct is huge and I don’t really like it. I think that I’ll go back with semi rigid like you said. The old duct that I pulled out was just nasty with caked on fiberglass dust.

I was thinking of doing something similar. But maybe with a dense foam to help cushion the batteries. Of course there’s not much room for me to add much of anything. I’m surprised though how beat up my batteries look from just a few years of small vibrations against the tray and each other.

The series/parallel trade off is a bit tricky. Like John said, in parallel lower voltage from one panel will bring down the voltage of the entire array. In full sun, that’s never really an issue since panel voltage stays pretty consistent until a steep drop off with very little light. It’s the amperage that varies with stronger or weaker sun and in parallel, the amperage is additive. In series, it’s the opposite, low amperage from one panel is a bottleneck to the others while the voltage of the panels is additive. Again, not a problem in full sun even if the amperage is changing, since the amperage of each panel should track pretty closely with the others (so long as your panels are all alike - adding in a half size zamp panel like I have would cut the current of the larger ones in half!) Also, as John points out, the panels themselves are made up of modules of grouped cells connected with bypass diodes that allow current to go around a shaded module to minimize current loss. I think the problem with running panels in series though is that you won’t have bypass diodes between the panels so if one panel has reduced amperage, the other will as well, and that can affect total power even more than the loss of voltage. The advantage of running them in series is typically smaller wiring, but in this case you’ve already got the heavier gauge wiring in place. I guess you’ll get less resistance nonetheless and possibly more headroom for the MPPT to do its thing? Of course in the end you have to ask how often it is in the Ollie, with a fairly small array of two adjacent panels, that you’re going to see significant shading on one panel and not the other. Certainly it will happen on occasion, but my personal experience is that we’re almost always either in deep shade or full sun. I’m not sure it’s worth the trouble myself but I’m definitely curious to see the results and maybe learn something new.

Does the LifeBlue app tell you the battery temp?

After spending three weeks without the bathroom furnace vent connected, and not being able to tell a lick of difference, I’m thinking that instead of trying to reroute that vent back to the bath like I’d planned, that I’ll just run it to the battery box. I have one of those seed mats and while it does get slightly warm to the touch it doesn’t seem like it would have much capacity to warm anything that it isn’t touching directly. Maybe that’s just my particular mat, but I’d worry that if you’re trying to warm the air in the battery box to heat the batteries, that it might be a losing battle between the mat and the cold door, even with insulation.

Also check the available height since you can stand the Battleborns on end if they won’t lie flat.

The tray that Oliver uses in the Elite II is the MorRyde SP60-042 Utility Tray, inside dimensions 14" x 21" x 2.75". There's 12.75" clear from the floor of the tray to the bottom of the aluminum catch for the lock. 4 Battleborns will fit, but you have to stand them on end. It’s tight. I’m pretty sure that Battleborn’s dimensions include the tabs for straps, since I’ve got about a half inch clearance between my batteries and the latch. I cut off the tabs on one side so that they’d lie flat on end in the tray.

The LifeBlue batteries that Oliver uses do have a built in heating system. But according to at least one post here by someone who’s spoken with Oliver, they’re disabling that feature due to overheating and are instead installing a heat mat. The temperature limit appears to be an advantage of the Battleborn batteries, since they allow charging at an internal temperature of as low as 24 F. Why the difference? No idea. Perhaps they’re just less conservative or maybe they use a different type of cell. I do suspect that Victron’s 41 F degree limit (5 C) is probably due to their typical conservatism. The typical limit seems to be ‘don’t charge below freezing’, but my guess is that’s just a convenient reference since there’s nothing special about the freezing point of water that should be relevant to the battery. So what’s the real limit and does it vary among batteries or is it universal to all LFPs? I assume that since Battleborn’s limit is very specific that they’ve tested it - I can’t see them pulling 24 degrees (-4.44 C) out of a hat. Another point worth mentioning is that I don’t think that the Victron BMS will cut off charging at low temperatures, like the Battleborn will. I haven’t read the full Victron manual, but from their description and spec sheet, that seems the case. So it’s really up to the user to make sure that they don’t kill their batteries. From what I understand, all it takes is once, since what happens is that the anode doesn’t soak in the lithium ions at cold temperatures and as a result gets plated with lithium, rendering it useless.

Glad you got it working but I’m curious too what caused it to stop.

Parts of it. All brass fittings and stainless crimps. And also a better quality PEX except for a few bits I reused. I tried as best I could to make it modular so that sections could be pulled out easily to repair. It’s so difficult in places to maneuver a crimper, pipe, arms, etc. inside the hull. Everything stayed tight though on our recent trip, even with some good bumping around. Feels so much more solid, though it’s definitely an overkill project and one that I’d never have done had it not been one of those ‘if I’m doing this, then I may as well do that’ sort of things. Nor would I have done it if I’d actually bothered to count all the friggin fittings and crimps ahead of time.

It sounds like they’re using the hybrid battery to power the 12 volt system while the truck is off, rather than the start battery. That would be a sensible design in all cases except the one you’re describing. If that’s the case, then I doubt there’s a fix outside of some sort of smart relay to cut the trailer power, which would be more trouble to install than just remembering to unplug. FWIW, I always unplug for the opposite reason, to keep my trailer batteries from draining the truck’s. You might look through the Victron catalog - they make a number of products for interconnecting dual battery systems on ambulances and the like. Perhaps they make something with a diode or something similar that would only allow power to go one way. Thanks for bringing it up - I suspect we’ll see issues like these come up as more hybrid trucks come onto the market.

They say drop in replacement but their batteries are slightly larger, so I’d check the dimensions to make sure they fit.

I think I’d go ahead and splice them since it would give you a chance to shorten the wires to the right length at the same time. Mine are way too long.