This is a little random but in reviewing my thread I saw this and I've since learned that I can connect to single or split phase without reprogramming or power loss or anything special (e.g. works with standard RV dog bone adapters). I'm not sure if I mentioned that elsewhere in my thread. I can leave the Victron's set to NOT switch as group, and it works no matter what I connect it to. I've yet to find a downside of having "switch as group" turned off.
Cinergi's 28 kWh / 4 kW Solar / 10 kW inverter RV build
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This is a little random but in reviewing my thread I saw this and I've since learned that I can connect to single or split phase without reprogramming or power loss or anything special (e.g. works with standard RV dog bone adapters). I'm not sure if I mentioned that elsewhere in my thread. I can leave the Victron's set to NOT switch as group, and it works no matter what I connect it to. I've yet to find a downside of having "switch as group" turned off.
Yeah, I think the main issue comes when using a 120V generator. You can't feed a single phase from one of those generators into both inverters if they are in split phase, so people in that scenario only end up able to use "half" of the generating capacity.
I went up thread to look at this conversation, and I'm not sure how I got off on that tangent, since you didn't even specify whether you will have a generator in the first place.
(There is a secondary issue with "switch as group" disabled when loading a 240V generator: the decision-making is not guaranteed to be simultaneous, and timing variation could result in overloading the generator if one switches first and delivers a large, asymmetric load. I'm not sure in real life how often that occurs, but I've heard of people having trouble with it.)
Late in reacting...
I'll be jelly if you get your 2X 5kW Quattros in split phase before me... I've had one running for a year with the other sitting NIB. The single providing off-grid "shore power" to the single 5th wheel (L1 and L2 jumpered at the 50A shore connection) is almost always adequate - always able to run at least 2X high power items simultaneously (elec W/H, microwave, Rooftop A/C, coffee maker, induction cooktop) with enough reserve surge to handle a 3rd item long enough for me to identify and shut it down before the inverter objects.
Sounds like an awesome project. Good luck with the continued cell testing! There's less than a 5% difference between your 268-281Ah cells thus far. While the deviation from rated/expected is a little disappointing, that's a small variation, and should pose no issues.
Maybe I'm misunderstanding you -- but yes, you can charge from 120v generator with both hots going to both inverters -- that's what I mean to say. I'm able to charge from either 120 single phase or 240 split phase without reconfiguring. I use a dog bone adapter on my 20amp 120v plug which provides both hots of 120 to both inverters. The master unit will take the hot 120 and the other will ignore it and remain inverting.
Ah, I understand the switch as group downside. For what it's worth mine have always simultaneously switched anyway *and* it slowly ramps up power (since I have that feature turned on as well), so it would have to switch many many seconds out of sync and mine are nearly simultaneous.
Late in reacting...
I'll be jelly if you get your 2X 5kW Quattros in split phase before me... I've had one running for a year with the other sitting NIB. The single providing off-grid "shore power" to the single 5th wheel (L1 and L2 jumpered at the 50A shore connection) is almost always adequate - always able to run at least 2X high power items simultaneously (elec W/H, microwave, Rooftop A/C, coffee maker, induction cooktop) with enough reserve surge to handle a 3rd item long enough for me to identify and shut it down before the inverter objects.
Sounds like an awesome project. Good luck with the continued cell testing! There's less than a 5% difference between your 268-281Ah cells thus far. While the deviation from rated/expected is a little disappointing, that's a small variation, and should pose no issues.
I've been running them in split phase for at least a month now. It's been awesome. I've charged my Tesla with it (LOL) and I've plugged my existing RV into the Victrons (as if they're shore power) and turned on 12kW worth of stuff in my current RV and they handled it fine. Crazy awesome.
I've also run 8kW through the Quattro's with 1.5kW coming from shore and the other 6.5 coming from batteries (power assist). I would disconnect and reconnect that 1.5kW shore link while charging the Tesla and the Tesla was none the wiser. It's complete magic.
You can charge, but only at half of the capacity. Some people need that other leg to contribute as well.
I imagine they are pretty deterministic, yeah. I know of one rig where it was a big issue, but they had a device introducing a delay on one leg.
Gotcha, yes - of course true. I haven't determined my generator config yet. One option is a 3.5kva model capable of 2800w sustained so I can plug in a 30amp to 50 amp adapter and set the max AC power to about 20 amps so I'd get like 2.4kW going into my system. That would be plenty and only necessary if I've had really bad solar and I'm off-grid. On the other hand, I could just go with a built-in 6.5kW propane 240v split-phase ($$$$) and just set auto-start and never think about it again. Decisions decisions lol
JELLY!
I'm grinding through individual cell testing ... about the only other item of note is that I swapped out the GFCI breaker at the house because it's overly sensitive (I hate those damn things) so now I'm powering the Quattro's from a 50 amp plug and my existing RV from the Quattro's. I have the Quatto's set to limit "shore" power to 22 amps which means sometimes I'm charging the battery and sometimes I'm discharging the battery (power assist), as this RV does occasionally use 6.5kW of power in my current Winter setup.
I have a 120vdc variable power supply in hand now which I'll use to simulate solar panels because I really need to add solar into this mix and make sure it works properly. I'm going to pull the trigger on some Victron SCC's. It's looking like I can get 12 of these on the roof but I'm awaiting confirmation. I like these because their temperature coefficient is crazy low and they have excellent low-light performance. Would be 2 3s2p configurations (their Voc is over 70v so I'll need the MPPT 250/60's).
I'm still ruminating over the physical configuration of the battery (e.g. splitting the pack into pieces, connected with Anderson connectors) and bus bar design and compression design. I am amazed at how loose the cells are at ~0% SoC given how "tight" I tightened the wing nuts at ~50% SoC. Makes me worry about jostling at low SoC's as well as too much pressure at high SoC's. Good thing I have all this time to figure it out! I'm assuming RV delivery will be ~March, so ...
I have a 120vdc variable power supply in hand now which I'll use to simulate solar panels because I really need to add solar into this mix and make sure it works properly. I'm going to pull the trigger on some Victron SCC's. It's looking like I can get 12 of these on the roof but I'm awaiting confirmation. I like these because their temperature coefficient is crazy low and they have excellent low-light performance. Would be 2 3s2p configurations (their Voc is over 70v so I'll need the MPPT 250/60's).
I'm still ruminating over the physical configuration of the battery (e.g. splitting the pack into pieces, connected with Anderson connectors) and bus bar design and compression design. I am amazed at how loose the cells are at ~0% SoC given how "tight" I tightened the wing nuts at ~50% SoC. Makes me worry about jostling at low SoC's as well as too much pressure at high SoC's. Good thing I have all this time to figure it out! I'm assuming RV delivery will be ~March, so ...
Hedges
I See Electromagnetic Fields!
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Are you considering this?
Pack / Cell compression Optimized By Using Springs.
I am opening this thread to split it off from the general cell compression thread. That way those looking for info don't have to sort thru a thread that has many paths for pack compression. If you are new to this idea, it stemmed from an EVE cell specification that indicated a significant...
diysolarforum.com
Are you considering this?
Pack / Cell compression Optimized By Using Springs.
I am opening this thread to split it off from the general cell compression thread. That way those looking for info don't have to sort thru a thread that has many paths for pack compression. If you are new to this idea, it stemmed from an EVE cell specification that indicated a significant...
Yep -- been following all the compression/spring-related threads here...
Indeed. something like 500 vs 700 each. I would hit 152v at 0 degrees celsius (and I think max startup is 145) so that's a no-go anyway. I'm also trying to keep the number of paralleled strings to a minimum as I thought that was more shade-tolerant to do. I do also want 2 SCC's for redundancy purposes.
Gotcha. I had to go with 250/100 after a 150/100 due to not factoring in my cold weather voltage... definitely over 150V. Rather than rewire to 2S and get a second SCC, I went with a single 250/100. That kinda smarted.
Parallel is MORE shade tolerant than series. A single shaded panel in series affects all panels in series. Shaded panels have no effect on paralleled panels. In other words, if you're concerned about shading, 2S6P is the more favorable arrangement, and your Vmp is plenty high for optimal MPPT in that situation.
Parallel is MORE shade tolerant than series. A single shaded panel in series affects all panels in series. Shaded panels have no effect on paralleled panels. In other words, if you're concerned about shading, 2S6P is the more favorable arrangement, and your Vmp is plenty high for optimal MPPT in that situation.
I really need to go back and study panels and diodes and all that jazz now that I'm getting closer to implementing that side of the system
On a separate note, I'm thoroughly exercising my 48/12 DC-DC converter by charging up 4 cells that I've discharged through single-cell testing. At 280Ah and 30A rate, I'm running that converter at 100% for ~9 hours. I've done this probably 5 times now. It gets quite hot (over 130F) under that kind of load.
(I'm using the Chargery as a 4s BMS for those cells)
I then top-balance them and stash them away for later (when I create the big 560Ah battery).
(I'm using the Chargery as a 4s BMS for those cells)
I then top-balance them and stash them away for later (when I create the big 560Ah battery).
Do you have something between the batteries in your box? I've heard that if the batteries rub together long enough, that blue outer cover breaks down and the metal case is exposed and can short to its neighbor. I'm a newbie, so I'll defer to others, but this was told to me by a guy who runs a forklift battery company..lots of vibration.Spent some time at Lowes gathering what I needed to build a box. I had them cut the plywood but that turned out to be a bad idea. Thankfully I was able to borrow a circular saw that has a guide on it to fix everything up. I wish I had a shop with real equipment ... would have made this a lot easier
View attachment 25912
Here you see the compression box (I used the foam that the cells were packed in). 1/4" threaded rod covered with 1/4" tubing. 1/2" plywood. 1/4" nylon lock nuts and fender washers. This will go into an outer box which will fully enclose the compression "box", provide a place for the BMS and whatnot ... and the outside of THAT box will just have the battery terminals. This is going into a common storage area in the RV, so I need the battery to be fully enclosed (with some venting).
The compression box will be secured to the main box with L brackets and the main box will be secured to the floor of the basement in the RV. I will also have 2 more threaded rods above each string of cells (down their centers) so that they couldn't come out in the event of a rollover.
The lid to the main box will be hinged for access for maintenance and to be able to shut off the DCC (Chargery) which will de-energize the main battery terminals if needed.
This will weigh 200 pounds, so it can't be moved in its built form. I accept that. When I load it into the RV, I'll have to do it in pieces.
Fun thread!
--
Steve
Do you have something between the batteries in your box? I've heard that if the batteries rub together long enough, that blue outer cover breaks down and the metal case is exposed and can short to its neighbor. I'm a newbie, so I'll defer to others, but this was told to me by a guy who runs a forklift battery company..lots of vibration.
Fun thread!
--
Steve
Thanks!
I don't have anything between the cells. The compression/fixture prevents the cells from moving amongst themselves.
It's just leakage.Do you have something between the batteries in your box? I've heard that if the batteries rub together long enough, that blue outer cover breaks down and the metal case is exposed and can short to its neighbor. I'm a newbie, so I'll defer to others, but this was told to me by a guy who runs a forklift battery company..lots of vibration.
Fun thread!
--
Steve
Heltec BMS' (up to 350A) with Active Balancing & Independent Active Balancers | Page 5 | DIY Solar Power Forum (diysolarforum.com)
There is no mention of either of the terminals being tied to the aluminum shell in any of the spec sheets I have read.
