Thank you Tom! I may just take you up on that offer. Leo still has the coach. I may pass by to see him today. He was waiting on airbags to arrive. Ironically I have been leaving Morgan messages on returning the bags I bought at Newell when we were there. They are incorrect and need a return label to send them back.
Regarding the hydraulic crimp tool, I just bought one from Amazon! That's ok, I can return it. I've been meaning to just stop by even by car to say hello. With work slowing down I may just have more time to do so. (Not really a good thing for slow times in any business)
(10-27-2022, 07:59 AM)encantotom Wrote: jack and simon,
you are the cause of me spending several hours watching will's videos. really interesting.
hope it doesnt cost me any money.
tom
LMAO! I tend to spend needless money when I get crazy ideas... I've seen Will's videos for a few years. I believe he is the authority on solar and lithiums. Love that he cuts stuff open to see their quality and comparison. One thing my wife and I are onboard with, is to be as self sufficient as possible. So Richard, if that last sentence gives you an idea of our intended use, that would best describe our goals!
--Simon
1993 8v92TA #312
(This post was last modified: 10-27-2022, 08:08 AM by BusNit.)
Simon,
I've been busy with a project but I just logged-in with my wife's account to confirm that everything Jack wrote is what I had explained or alluded to in my Facebook discussion with you.
The Growatt inverters are exactly the type of "Chinese" transformer-less inverter that I recommended. While the Growatt is a more popular/marketed name, you can also buy a variety of identical hardware under lesser known names for even less. In addition, you would go with a split-phase unit and you'd be able to parallel for more wattage if required. Not only are the transformerless units smaller, lighter and less expensive -- they also run more efficient, which is crucial in your application / extending the kWh of the battery bank.
I've also had very good luck with the prismatic batteries that Jack uses. There have also been more recent / long-running studies on cycle-count where you'll far exceed 5000 cycles if applying the charge-curve Jack mentioned (not that you should ever need that many 80% DoD cycles). However, you can also buy nearly new, often no more than a dozen cycles, battery backup recovery cells, military/hospital recovery cells, EV cells that were never shipped, etc. Many of these can be the highest quality despite being a bit aged in years (largely irrelevant in this specific context/these high-end cells). I am also a big fan of buying Tesla packs from people that buy salvage Teslas and sell-off the parts. These are exceptionally well-built, energy-dense packs, and you'll be able to re-work the house battery compartment to accommodate.
Richard mentioned going with a higher voltage. In my humble opinion, Richard is spot-on and this is a no-brainer. Parallel a few DC-buck units to provide 12v from your bank, but ultimately go with a 48v or similar bank, strictly for your 110v (220v split-phase), if that's possible. The Growatt-style inverters have large voltage ranges; for example, the 48v will run anywhere from 38v to 60v (that's a very rough estimate based on memory; double-check the exact numbers before buying). What this means is that if you buy a Lithium pack that has a nominal of 52 volts (eg LiFePO4 15s bank) with a range of 58v to 45v across the charge-curve, you'll have no problem (lithium chemistries also have very flat discharge curves which further reduces this issue).
Speaking of paralleling batteries... You asked whether you can parallel more than 4. While it's true that many manufacturers (eg BattleBorn) recommend against paralleling too many batteries, this is not a concern when you design your bank properly. A big part of this is how you wire and whether you start by testing every cell's life. I mentioned this in the Facebook post; be sure you wire in a manner where the batteries are forced to discharge evenly. This form of wiring is a bit confusing at first; however, you only have to wire your batteries once; it's not something you have to commit to memory, etc.
I also do not feel that someone needs an excuse to go with Lithium chemistry battery banks. For example, even if someone doesn't do extensive boondocking, there remain hundreds of reasons that make modern-chemistry the far better choice at current prices. They're almost 3 times as energy-dense (aka 1/3 the weight) and technically more if you consider their DoD, which at a 15-95 curve (optimal lifetime/DoD curve) gives you 80% of their rated energy, versus an SLA at 50%.
Better yet, they have (essentially) no self-discharge, they are not permanently damaged by a situation where they run down, the required BMS provides a great deal more care/longevity than you'll get without, contrary to SLA or AGM batteries, they don't have limited "lifetimes" based on a number of years similar to SLA's (at least not for real-world RV purposes), etc.
In our class-B, we go so far as to run LiFePO4 as our chassis battery as well, simply because it's stored without power and we can go six months without using, without any issue whatsoever.
If you're considering LiFePO4 or Li-on solely as an alternative for standard battery use, without boondocking, they are absolutely the way to go at current pricing (anywhere from $120 to ~$440 per kWh all-inclusive with tax/shipping). NMC is also very easy to come by and in many ways that would work better in a Newell battery bank configuration, if you're doing a higher-voltage unit.
I could go on for pages on the benefits and reasons for going with modern chemistries over SLA or AGM; this is just the tip of the iceberg. I can provide far more detail on any of the areas where you're interested in digging deeper.
It's also worth reading the posts related to the battery isolator, which my wife posted along with some of my input, just a couple days back. This explains the benefits / trade-offs of the DC-DC charger that I had also recommended to you.
Thank you! I appreciate the write up. I have been gathering mental data (Filling my head with ideas) while the coach is out with Leo. I will be returning the Magnum inverter in favor of designing a higher voltage system. As an electrical contractor (Yet nothing related to low volt stuff) I realize higher voltage will make smaller gauge wiring possible. My largest consideration is locating where the alternator for generator and coach go to in terms of charging the batteries and intercepting those leads while separating the starting batteries from house batteries. In my experience I tend to just remove everything and start over...
Simon,
I think the best way to start is probably to have very specific parameters/priorities.
This will help assure that any information provided will go to helping you, versus merely "throwing spaghetti" to see what sticks.
For starters, your budget and whether you prefer to get the most kWh for your money -- or you're more concerned about things like warranty and trusted-brands, etc.
For example, some people are less about the cost and far more about buying a product that is exceptionally reliable. Those people typically buy Battle Born batteries. Some other people look for the best trade-off and they are willing to do a lot of hands-on work to create their own battery banks; those people often buy used EV batteries. Another group prefers something in between where they buy new cells and combine with their own BMS (as Jack has done).
The same goes for your inverter; if it were me, I'd go with something similar to Jack's Growatt or the inexpensive no-name alternatives. They all have similar quality materials and they are so inexpensive that if one doesn't last or has issues, the cost to replace is less than going a step-up in price.
The more parameters you can provide, the easier it will be to share information that is valuable to you, with less noise or wasted effort.
Absolutely. Not really concerned about warranties. I figure a decent system to be around the 10k mark. I'd like to be able to run at a minimum one of the basement Dometics all through the night along with fridge and still have power when we wake up to use the breville toaster oven and Keurig coffee maker. TV and laptops as well. I was curious what you thought of this system although its a little more than I want to spend but seems to cover quite a bit. (A little short on battery for my needs) (over 16k) 48v system with 5.12kw batteries
I like the server battery system and cabinet set up. I emailed for dimensions on the cabinet and panels. Not sure how many will fit up on the roof. Now with Starlink, we would like that up there too.
Wow a lot of chat here! My wife and I are 68, we gauge everything we do on how long do we have to be alive and functional, I like to have comfort and performance as long as I can afford it after all we don't live forever. The batteries I've built should last the rest of my life but hopefully I'll be alive to see them belly up, if you look at the cost of 8D over a period of years you might come close to the cost of lithium but remember you only can use 50% of the amp hours of glass and wet cell batteries, so you can't compare 100 ah of wet cell to 100 ah of lithium because you can use 80% of lithium. So your getting 30% more battery with lithium of the same size, this means a lot if your really using your system.
Yes 52v lithium will be the way I will go in the future, wire size is much smaller and easier to work with below is a picture of my nephews golf cart that I converted to lithium, 200ah@52vdc = 10.4kw hour and the cost was $1680 which included freight from China. There is a heavy rubber mat that covers all those batteries up, plus they are strapped together, sometimes space is an issue so thats why it looks like that.
Richard the new mini splits (1 ton) have are inverter type units, they use a 3 phase DC compressor that draws 9 amps at full tilt. The difference is amazing compared to the old scroll type compressors that draw 17 amps for the same amount of cooling. If I where to design a new heat and air system for our Newell it would be inverter tech all the way and I would use remote cassettes rather than duck the air all the way to the back. Dometic now makes a roof mounted inverter AC which is easy on energy for those who have roof air. The beauty of inverter is it ramps the compressor speed down the closer you get to your set point which you can't do with old type scroll compressors. If you get into your RV and its 100 degrees inside and you have the temp set at 72 then the compressor runs full speed but the closer it gets to 72 degrees it ramps down speed and amperage so at set point temp the compressor draws half of the current, in my case 450w and I had 770w of solar so in full sun I could run the AC of the panels on the roof and everything in the van without battery usage.
Almost forgot, Growatt and many other all in one systems can be linked together, my 2 growatts are not linked but If I wanted 6kw at 220vac spit phase I could do it.
@Jack Houpe - we're on the exact same page, I explain the all of these same points to everyone that will listen, lol. I also have some additional info on these points (which I'm sure you're aware but for sake of aiding Simon or others stumbling upon this) ...
* Your Depth-of-Discharge point with wet-cell versus Lithium, was one of my key points and I absolutely agree. Even more importantly, that depth-of-discharge remains. After 4 years, if treating Li properly, the total capacity will be around 92% if you use them very frequently (higher if you do not cycle as much), meanwhile the wet-cells will be on their last leg (at least as far as kWh).
More importantly -- in the event you do fully discharge a Lithium battery, you've decreased its potential by about 0.0005% whereas with an SLA a full DoD is reducing the lifetime by 50% in every instance its fully discharged.
This is one of the important reasons that I say (and agree with you) that Li is a no-brainer, boondocking or not.
-
* You're using prismatic cells; with prismatics, it's very important to strap them as you mentioned, not for sake of holding them together, but to actually use a rigid end-plate on each side and compress them firmly. The reason for this is that prismatics will expand and this reduces their effective lifetime.
-
* Most of the transformerless 6kW-level solar inverters are currently split-phase. IMHO, the best way to parallel them is by using split-phase (not one per leg) because it makes it easier to expand beyond two if you need. This is not crucial with RV's but moreso with home setups. Also, remember that because it's AC, the parallel feature has to be a documented capability (the inverters have to explicitly mention it / sync their sine via rs485 or similar). In short, just double-check that you're buying an inverter that supports paralleling, which about 70%+ modern/transformerless options do support.
If we could get a group-buy going for those new Inverter-based Dometic units, I'd swap-out all of my existing working units in a heartbeat. I wonder if others are interested in something like this?
-
* The best feature of the inverter-driven, three-phase, ECM compressors (in my humble opinion) is not only the far more efficient electric motors or ramping to better maintain temperature, but alleviating the huge hit with compressor startup. Inverter-based systems are so much easier on your off-grid system as a result. Also, the low-volume ramped-down option you mention is great in RV's because it is far more effective in reducing humidity.
-
QUESTION for others: While on the topic of running new electronics, etc -- how difficult is it to snake wire in existing conduit within Newells? In the manufacturing videos, I've noticed Newell runs large conduit (4"?) down the center between the frame. Has anyone used this conduit for running their own wiring or is there a common approach when running wire in Newells?
(This post was last modified: 10-28-2022, 06:30 AM by SouthernDevGirl.)
I have those conduits but from my quick inspection appear to be carrying fuel lines and other hoses. The length of run of the conduit with the snaking of the hoses may make it tough to pull in additional wiring. I thought of that too by using those conduits. Something I may need to look at again when I'm under the coach.
I was looking at videos on the EG4 inverter and Will shows it to use 165 watts at idle. Seems high. Victron is about 60 watts idle but is more than double the cost. Not sure what to do. I guess I would need to measure roof space and panel size to add another panel or two to help offset the losses but I'd hate to know the parasitic loss is that high.
68 is not old. In fact, I don't even see that as advanced age. My wife and I lost a combined 130lbs 5 years ago and kept it off. We are both in our early 50's and no longer take any medications. We quit sugar, dairy, fried foods and complex carbs. Made a difference and hopefully we can keep going into our 90's.
Love the mini split in the Sprinter van. Simply outstanding!
I was looking at a Facebook feed that showed a high velocity air conditioning system for houses that uses a series of 2" ducts. Might be a great solution for guys like me who want to keep the basement a/c unit to save roof space. I also love the clean lines of an uninterrupted ceiling space.
