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Got a request for info, so I figured I'd bring this over here. I use a bunch of victron bits in my RV now and have added a raspberry pi running the victron venus image and I have a second pi that rocks a 4g card to provide internets. First up, the Internet Pi: This is a Pi 3+ that has a sixfab...

Double door RM1350. What's really ironic here is that I also have a compressor based CFX95 cooler that's fantastic. The absorption fridge is actually far more expensive from the factory. Anyhow, it appears that I can get a kit to convert it from JC refrigeration. I'm really liking the idea of...

After this weekends upgrades, I need to do a little bit of wiring cleanup. Before I really dig into that, I wanted to evaluate how things are working. It's been a beautiful day, about 70 outside. I ran one of my A/C units for about an hour just to really give things a chance to heat up.... and...

I believe the factory covering is sufficient. Since I've got them locked together, I don't believe that I'll have rubbing wear issues.

My process involved a couple shots of whisky and a few clicks on amazon. True story. Before that, I took a look at cost per watt, various panel reviews and the final cost. $80 per rich solar 100w poly panel with free amazon shipping won the day. I really liked the idea of the higher power 250w...

I built a simple clamp using plywood and four threaded rods. I protected the batteries from the rods with some white pex tubing that was handy.

Ok, finally have a matching set.

My batteries arrived today. I haven't opened them yet, but Paid on Oct 26, Arrived Dec 3. Considering there was a holiday in there, just a bit over a month isn't bad at all.

I'm going to disagree for a few reasons, but I will happily point them out. First up: energy. From the rec pro product page: The draw is "5.8 Amps and 78 Watts" That's really not that much energy. Seriously, think 1500 watt space heater vs 100 watt heating pad. To drive this further, the pad is...

Added foam insulation between the tension bars. Stuck until I get the hdpe spacers in so I can add the heaters, finalize the insulation and built the outer box.

Oh, I suppose I should comment on performance here. I use a firetv in the living room and have a roku tv in the bedroom. Both seem to work just fine over this system. I've successfully used it for video meetings and general online work as well. I've had issues in two locations. First, on the...

Allrighty, I've been making changes to my rig after using it all summer/fall. I figured this may be handy for anyone going the big camper solar route. My rig is a 37 foot Montana High Country 5th wheel camper. I'll try to keep this all electrically related for the moment. The house battery: My...

Testing overnight showed my expected results. That makes my happy since the battery seems to be working as planned. No change at all in AC load. I am starting to suspect it'll remain a constant. Of course, it looks like it's going to rain later so it'll be a bit of a shabby solar day. The test...

This is the first time that I've tried this with so much battery capacity. Previously, I only had around 3.5kwh of storage and I rarely ran it down more than a couple of Kwh. It's also the biggest constant load I've run... ever. That means that in general, my battery was topped off part way...

I've been using a gigavacs for some time, works very well. I just changed my main out for a 24v so I could feed it directly from my battery pack. If you want a no-power option, there are some high end tyco contactors that use power to open or close. Of course, the danger there is that you could...

So I'm just planning out my battery box builds for the new pack. After doing some winter camping with a crappy shore feed, I knew I had to add some battery heating for the new build. My batteries live in the unheated compartment of my 5th wheel camper.... The Batteries: 16x 280ah Lifepo4 cells...

I'm a fan of super lube silicone grease, it's an excellent dielectric grease.

New lesson today - It turns out that you cannot configure anything but the on/of/charge setting and the current limit on a multiplus using the bluetooth ve.bus adapter. You MUST have a usb interface to fully configure the multiplus.

Mine is fine without the aux battery for slides/leveling/etc. I do have a small SLA on my breakaway brake system. That uses a small charge controller and I just feed it off my 12v converter. The only time that battery gets used is if the camper tries to run away and the breakaway safety cable...

A good DC-DC converter/charger is the way to go. Even with SLA's it's helpful. On my rig, (2012 2500HD diesel and 5th wheel) I just added a Victron 12/24 DC-DC converter to directly charge my 24v solar bank. You'll need to size the voltage output to whatever you want. Note - I've put my...

Just to link things together a bit. I've now replaced the old Tesla pack with the LifePO4 pack. Battery order was: https://diysolarforum.com/threads/ordering-16x-280ah-cells-from-shenzhen-luyuan.13862/ Wrote up a bit about the RPi and monitoring here...

You *might* want one if.... You want to automatically have the charger turn off when the engine is off You plan to run a non-12v system (I use one for 12v to 24v) You want to regulate how much power is exiting your vehicle (fixed to the value of the charger) You want to check status/performance...

I almost forgot, thanks for your comments on this. It was helpful when I was deciding if I should just give up on ordering over the annoying verification.

Not so! If you do get a DC-DC charger like the victron, it will provide boost conversion to allow for the full range of charging. However, if you have enough battery capacity, even a full day of driving wouldn't fully charge. Example: I have a 12-24 charger. It provides 10a @24v (ok up to 28v...

This is one reason why I like the higher panel voltage that's accepted by MPPT vs PWM. PWM controllers - typical input voltage is like 17VDC for a 12V battery and 28VDC for a 24V battery. If the PV is less You can start generating usable power a bit earlier in the day =- Realistically, it's...

I love my BMV-712, simple, bluetooth app works great. Completely worth the $200 IMO. Easy to check status when I'm at the camper control center.

My combiner switch has a couple of modes. 1. each leg works normally but the multiplus is inline on one leg. 2. Both legs of the panel are bridged and fed from the multiplus. Only one leg from shore power is connected to the multiplus. The second is disconnected. To be clear, the multiplus is...

Yeah, you're good to put it wherever, just make sure that nothing grounds to the battery terminal - aka no connections between the shunt and the battery terminal.

The manufacturer specs said not to mount to metal - likely to prevent shorting. The hdpe is .187 thick. 12x24 pieces were about $15 each from amazon.

Welp, I used this system over the summer. Things I learned: 1) I love my dometic 12v fridge/freezer. I added it in when camping and used it as my outdoor fridge/ice bin at the beach. I'm going to add some accessory anderson connectors for that stuff. 2) I need to upgrade the inverter. I mostly...

Did you get your system together?

I’d swap in AGM cells, then use a battery protect to limit discharging. Keep all your loads DC/12v and no worries. If you want to add an inverter it’s a different deal, but that idea should get you started.

No worries, I murdered several starter solenoids years ago when rebuilding an old winch controller before I knew better.

Nice. How good was the deal? And yeah, it's a heavy one! Install is easy tho, the mounting bracket is pretty stout. When you crack it open you may note the big inductors tucked inside. This is very similar to high end audio gear - you'll get some very clean power from this thing.

Oh, by the way that little guy connecting the two terminals, wrapped in yellow is a diode to prevent surges when the coil field collapses.

You can also use a dual battery selector switch and a resistor. Less fiddly bits.

I'll go look in a bit. I just moved but I think I know where I shuffled things around to. Yes it has the hall effect sensor, amps are dependent on the contactor. The hard lesson I learned there was to make sure you buy one with the economizer.

In theory, the RV pad shouldn't let the bottom of the battery get over the 65 degree +_5 range. This is pretty darn acceptable and usable for most of these builds out of the box. Since I'm using an additional controller to reduce the load and provide finer temperature controls, I'm really not...

I bought these. Other than some fedex ground pain, it was a solid transaction. Thanks!

I actually have one, but I had to pick up the mk3 interface in order to actually program the multiplus. The app is nice, but certain family members are technologically... challenged.

Welp, I finally wired in my multiplus! I used Tom Morton's wiring idea for a contact switch. The switch disconnects shore power and bridges L1 and L2 for the multiplus to feed. I ended up buying 6/3 wire at HD and extending the main shore feed over to my battery bay, and a return run to feed...

Looking at your boat, I see you have a double backstay and quite a bit of boom shading. Model out the shading you'll get from those a bit to determine the ideal layout. Also, put a dedicated MPPT controller per panel. This will deal with shading better and you get redundancy - if you lose one...

I just did this but with a dedicated fuse block - I have three controllers on my boat, each called for a 25a fuse. That will feed into a battery protect that the BMS controls as a charging disable override.

Do you have numbers behind the compression concept? I was just planning to bolt mine up but I am curious about the need for spring loading. In mine, I've added some PEX around the allthread to protect the batterys from rubbing on it. (yes I read the flex numbers, I'm more concerned if I need to...

My 50a rv has two legs, l1 and l2. The switch combines them to be a single leg from the multiplus. When I'm on shore power and want full feeds the switch let's me. There is an automatic switch made but Its pricy enough that I'd just buy another multiplus over that.

Allrighty, I headed down and switched my fridge over to gas for tonight. The fridge would have absolutely killed my battery charge overnight if I'd left it on. I probably should have taken some temp readings, but I did find that my gallon of water in the freezer was mostly frozen, but not...

OK, let's try to get you an idea of how to size this thing. Let's say your AC want's 7 amps, at 115v thats right around 800 watts. Lets be lazy and round up to 1000w. (That'll give you a power budget for other things) So you'll want 6kwh of usable power (at 80%DoD) that means around 7.5kwh. I...

I’m going to second the above - do the math in watts and you’ll find that a minor charge isn’t really that much. A wind generator will serve you better than trying to pull 5a (@12v) is only 60 watts and only when running. Yeah it can help, but really it’s not much. I tow my camper all day and...

Yes. The balancer will have issues because of the extra inductance between the cells with the long cable. I am familiar with this as I built a bank of 16x 280ah cells in an 8s2p setup. I'm using a SBMS0 and when discussing the design this was called out to me by Dacian, who designed the SBMS0...

I use a 70A victron unit. I have a biggish 37ft fifth wheel and the slides/leveling system all use 12v. I was using a 40A but a failing house battery murdered it (blown fuses were easy to replace) But I took the opportunity to install the 70A since I wanted bolt terminals instead of the spades...

Howdy, I bought a new 5th wheel camper to live in while I build my house. I've decided to add a 1200 watt solar system for the RV, using 12x 100w rich solar poly panels. ($80 each on amazon) I'm going to upgrade the battery pack to something with a lot more capacity later, but for now it'll be...

I don't regard my truck as a charging source for my 5th wheel. That's covered by solar/shore power. In fact, pretty soon I'm separating out the 12v battery system entirely and setting it up with a small SLA for the break away brake system. The hitch connection is only really good for maybe 10a...

Today I kicked of a test of my system with a few ideas in mind. Discharge testing of my new 14Kwh battery pack Energy consumption and offset when using my Absorption fridge Getting used to the discharge numbers and behavior of my new pack Evaluate just how off-grid I can be with the current...

Don't use a battery protect on the inverter. It will fail.

Yup, 30a service is one legged, so it's super easy for you. 50a is only annoying because it cost extra copper and the manufacturer was too cheap to provide generator prep by default. Interestingly, both of my A/Cs are on the same leg. Bit silly.

That's an interesting use of space with the stair idea. I've also seen the multiplus mounted sideways for better air flow. (in the same area) While you're under there, mouse proof the pass through where your black pipe goes out. I found droppings in my kitchen island (where all my silverware...

I tested one heating pad on my bench. It's comfortable to touch. Car heaters would definitely require care and controllers. After doing bench testing, I think the RV heater pad is just about perfect. I'll get more data once I have the pack built. I can easily test time to heat since I live in...

I'll admit, I chose my panels because I could get them shipped free on amazon. (100w poly rich solar's which are $80 each right now) I arranged them into 4s3p so I get 60-70v (70 on really cold days) and it kept amps well under 20. This was partly to utilize the 10awg factory solar wiring...

I wrote this up for this recurring cause. :) http://burningflux.com/blog/index.php/2021/03/15/simple-pre-charging-to-avoid-sparks/

Couple of no-so-quick notes. To protect the contactor, I'm going to add a precharge circuit - aka big a$$ resistor on a relay. This will be used to precharge capacitors before the battery is fully connected. This will reduce the surge that could potentially fuse the contactor. I'll post more...

Then you can use the old command line instructions. You need to stick the card in, identify which disk it is then use the dd command to copy it over. https://www.raspberrypi.org/documentation/installation/installing-images/mac.md

True sine should do the trick. I grabbed a silvia for my setup - total wattage is 1100 on it but the boiler is only like 800. (I also use a kettle for presses, works great)

Mine is screenless - I have it installed down in my electric bay. It also offers remote access - you have to turn it on but I can access all the gx menu bits from the internet if I want to.

Been busy playing.... Anyhow. It’s more about load division and management. The start surge of A/Cs units is hard on inverters. I am willing to run one, but both of them wouldn’t be a good idea without soft starts on both. Once in a while, I manage to trip the main breaker at a site when I’m...

So I've been playing with keeping my 12/24v Dometic CFX95 cooler/freezer running in my camper. (I tend to make a pizza for lunch when I'm working on it in storage) First run, I had both sides of the cooler set to freezer mode - something like 0f. I was seeing quite a bit of draw, to the point...

Enjoy.

The main thing is that inverters have large capacitors that smooth the power feed. The pre-charge prevents arcing inside things like breakers, contactors or battery switches. Even if you don't use an inverter, some loads can cause sparking. (Ever replaced a battery in a car?) So yes, if you...

In this weeks episode of Will's odd ideas, I'm considering building a custom slideout awning. I got the idea when reviewing specs of the flexible panels that are available. The things are very light - 5lbs each. I could build (weld) an aluminum frame that's hinged and mounted above my large...

And to round this out... My pack dropped a few percent over a couple of bad solar days. Today was much better (with rain later on in the afternoon) For today, My pack went from 44 to 72% (so up 28%). It probably would have it 75 or so if I hadn't been there for a while. I ran off propane for a...

Final thoughts - in my 5th wheel, there isn't a single device that actually uses split phase power. I have a 50a feed, L1 and L2, but nothing uses both sides for anything. I suspect that you don't actually need split phase service, so you can just use the parallel configuration rather than the...

Trying to log some updates as I go along here. It's been a poor solar day so far. Only 1.5Kwh generated and none of that time actually exceeded the load. Bleh. On the 'bright' side (sorry, I'm a dad) I get to continue capacity testing my battery pack. This is great for validating my pack's...

Damn, I just ran across your build. It's like mine on steroids. (2020 37ft fifth wheel, 1200W, single 3k multiplus, one set of 16x 280, SBMS0)

Stick a small starter battery in there, then add a dc-dc charger between the starter and lifepo4 pack. Victrons can sense when the engine is running. The small battery will act as a buffer.

Depends. I could make it lock out the slide control when engaged.

Few more things: The mk3 is talking via victron bus. You only really need it the one time unless you're modding things or hooking up to a venus pi. One could take advantage of easy returns at a particular online superstore.

Some decisions have been made! I've decided that I want a bit more than 3kw on the boat, I'm aiming for a 5000VA inverter this time. It'll be either a quattro or a multiplus, depending on what kind of deal I can find. This means I'm opting for 24v to keep amperage on the battery wiring run...

You need to understand the function of the BMS. It should be monitoring individual internal cell voltages. If a cell is going too high or too low, it'll cut out charge or discharge respectively. Once you give up on the company, you may want to consider adding a different BMS. Either way, I'd at...

I grabbed some footage of my PV layout the other day. Figured I'd share. Right now, I'm using 12 100w rich solar poly panels (yeah, the ones reviewed by Wil in one of his comparison vids) As you can see, the main line of 9, fits really nicely, although that antenna can cause shading. I should...

Yup, if I want more it's getting a second multiplus. For $30 I'll deal with having the switch for a while.

I used a tesla battery last year in my RV. SBMS0 balanced it and worked great. I only used about 3.5kwh of capacity on that pack with the limits that I enforced on it. The most annoying thing is the voltage range of the packs - I couldn't take full advantage until I got a multiplus that would...

Ok so my pads arrived. I can clearly trim the length down, which is nice. There's a good five inches of foam at the end.

After lots lessons learned, I figured I'd talk about my latest build changes in my 46 foot sailboat. #1: 24V Inverter/solar battery pack. The solar pack is a ~600Ah 24v lifepo4 pack. Its managed by a REC Q BMS, which talks canbus to my victron Cerbo. The REC has a pre-charge controller with a...

I will second the victron gear - I have the smartsense, a bmv712 and smartsolar charger - all work very well together. I'm finally adding a 24/3000 multiplus to the mix - it too has temperature sensing. Now that I have more time with the gear, I have to say that victron works well. I added a 12v...

Victron supports it on the newer multiplus units. Cutoff is 19v iirc

I could just break out my TIG for aluminum. I was digging the plastic idea for the non-conductive nature of the material.

Just be careful about letting it sit at cutoff for long. Recovering an over discharged battery is a pain.

Here you go. http://burningflux.com/blog/index.php/2021/03/15/simple-pre-charging-to-avoid-sparks/ I'm building an automated version with my new controller, but I'll be using the manual version as a backup to my automatic one.

Oh and regarding fire risk... I blew a tire on my trailer coming up the interstate last year. It was smoking huge - my very first thought was: Oh crap the tesla pack lit off.

I'm going to admit that I also gave arizona wind and sun a call. I wanted to make sure I wasn't overlooking another product and they even pulled up my solar cell specs and double checked the calculations. (I even told them I'd gotten them off amazon, but was shopping for a controller) Bet you...

The boat? 1973 Ericson 46. It. Is. Yuge. Currently, it has an older Xantrex 2000w inverter/charger. Sadly, It doesn't support lithium charging profiles. Here's what I'm leaning toward: Multiplus 12/3000 (110v) Inverter Charger. (May add a 230v auto transformer on the input later on) I have a...

I just flip off the breaker for my factory shore to 12v converter. It makes a handy backup if you have an issue with your 24/12 converter or need to take your solar battery offline but want to keep the lights on, etc.

Latest lesson: No parallel SBMS0/electrodacus, according to Dacian. I have about 14kwh of battery on the way from Shenzen. (That's 16 280Ah LifePo4 cells) I have fedex tracking for the US segment, so whenever they hit the US I'll know. I was planning on a pair of electrodacus BMS units and...

This should be useful for you: https://diysolarforum.com/threads/changes-to-my-build-after-this-summer-fall-of-usage.16962/ 24v battery, using a 24/12 70a converter now. Old 12v FLA is gone, I added a breakaway SLA and charger to run the breakaway brakes.

Very nice. If you don't have one, add a cover over those battery terminals to prevent shorts from falling objects. I didn't see a precharge circuit, be careful when you turn on the battery cutoff.

Half of the build coming together. The open end will butt up against the other half to keep the connection short enough to keep inductance low enough. The entire assembly slides into the outer shell.

Is there an inverter after this switch? You may want to build a precharge circuit to prevent the surge.

The idea was the direction of flow. BPs don't like reverse charging, so you can't just stick one in front of a battery. It has an IN and OUT terminal. So.... Charger->IN OUT->Battery Battery->IN OUT->Load I picked up an inexpensive 3kw inverter to mess with. I expect that I'll get a big...

Depends on what you're after. I use a contactor (with precharge circuit) as a main cutoff. I'm also use control inputs on my chargers and load circuits to control things. Currently I'm building an integration circuit based on an arduino to fine tune my controls and add specific features I want -...

@jwelter99 Bit more info would be great. I use the multiplus with SBMS0 pretty easily. What features are you getting by using the REC which is... pricy.

I have been using a Tesla module in my RV for a bit. It works but it's got some issues. 1) Working voltages are odd. Most 24v inverters don't like the lower voltages 2) BMS is needed. 3) Price is usually too high - I've seen prices coming down a bit but I only chose to use mine thanks to the...