I wanted to launch a new thread because the current thinking is buried in other threads after previous values were determined to be incorrect.
TL;DR - use 4Nm max to torque your M6 bolts (or the nuts on your studs).
Explanation
Many of us were all mislead by the spec sheet of the EVE cells...
circuit breaker and fuse testing. lots of bad breakers out there and there's the debate over class T vs. ANL etc. would be cool to compare LFP vs. AGM/FLA, too (as that goes towards AIC ratings). Probably would have to run some of those tests multiple times each. Over-current as well as full...
Just wanted to drop a note to say these busbars are continuing to perform well. I'm so happy I got these. My IR's continue to be amazing and the Orion BMS continues to report that the "State of Health" of the battery is 99% which it never did before (because it saw such variation in the IRs)...
I just purchased two of these and will install them into my motorhome and test them. I'll probably also take them apart. I have a youtube channel and can stick it on there... would love Will's input as well since he's done so many of these and I've done 0.
I love that you can purchase the guts...
Background
I'm having a new 5th wheel built and as part of that process, I'm designing and building the battery, inverter, and solar. I want to run as near as possible to 100% on solar for everything including A/C while boondocking (my new favorite activity). I live full-time in the RV (have...
It looks to me like the terminal & bus bar connection got hot probably due to a bad connection. The MDF, even under humidity, wouldn't have shorted anything out. Something went wrong with the battery. Without high rez pictures it's hard to tell (you'd need to upload elsewhere and link them here).
OK, discharged to 0% (2.000 volts each actually). Raw numbers are below. I'm pretty sure I heard the springs a few times. Maybe I'll capture a time-lapse of this some day. These springs really should have a 3/8" rod between them (not 1/4" like I do). The springs are deforming a bit as a...
Yup! This is my first heating season with the mini-split on solar in my 38' fifth wheel. Heating consumes more power (~2000 watts instead of ~1400) and energy (stays at max draw for a long time), is required for longer periods of time (night is longer than day), has a higher temperature...
I wanted to see how much solar I can produce ... I haven't been able to because my battery goes full on sunny days ... so I wasted a lot of power last night and today and ... drumroll ... 24 kWh of solar production on a sunny day in Connecticut in June. That's over 7 solar hours at rated output...
I'm currently testing each of my 36 EVE 280 cells at 15 amps. Results so far (23 of 36):
270
278
276
280
280
270
271
270
278
269
268
281
272
274
273
276
270
277
280
277
273
273
275
Varying C rates hasn't changed the capacity I'm getting.
Playing with springs and a new saw blade and guide etc so I can make 16 plywood panels. Got nice new plywood (project stock at Lowe’s). I’m shocked at the fact that I’m unable to tighten the springs down all the way with the wing nuts. I’m going to double check my calculations. That said the...
Look at the floor of the area where the cells were. ONE cell got very hot. Now look some more - there's a metal frame there. There's some blue plastic from the cell there. My guess is the cell shorted out against the RV frame.
New bus bars installed.
At 17 amps with old bus bars, I saw a 0.3mv drop across the long bus bars. With the new ones, it was 0.5mv. Expected - these aren't nearly as much copper. But I'd have to think they're copper based on how they're performing. I have no concerns there.
I charged and...
Victron might arrive tomorrow! :eek:
This is how far I got today. I'm quite sore haha. I shined up the terminals with 1000 grit sandpaper, blew it clean with air compressor, wiped down with anti-ox, loctite'd the grub screws, cut the insulation off the bus bars so I could double them up...
Got the SCC connected to the power supply and connected to the Cerbo with VE.Direct ... and it's doing EXACTLY what it should - the entire combined system is paying attention to what the BMS is asking for via the CAN Bus. Awesome!!!!
Here's my next prototype. Square bar on both sides, 5/16" rod, and I moved the upper and lower sets closer to the center. I'm also using deconstructed CALB flexible bus bars (2 pieces for each series connection). The battery is at about 0% and I set all springs to 30mm and I'll observe...
The pack I'm prototyping the springs with is 4s. Measurements are cell 1-2, 2-3, 3-4 .. which is why there are 6 measurements.
Spring and PSI info: https://diysolarforum.com/threads/cinergis-28-kwh-4-kw-solar-10-kw-inverter-rv-build.13786/post-189207
Terminals got closer together from 100 to...
I spent a few hours replacing the skimpy 1/16" x 3/4" bar with 1/8" x 3/4" ... and spent some time getting some nice bends. I also decided I should use the tinned 1/4" x 1" to join the "end" cells before connecting this -- both to match up the resistance of all my bus bars better and to prevent...
I prefer to operate based on facts for which I can provide evidence. There is more than sufficient evidence that AIC ratings are important: https://electrical-engineering-portal.com/3-overcurrent-protective-device-ratings-you-must-properly-select#3
If you can provide evidence that you can...
You definitely won't have heating problems from the cells themselves. At 200 amps discharge and 140 charge (100 - 0 - 100 percent SoC) I saw a 10F rise in temp.
8.4Ah left and I've got a cell-pair below 2.7 volts. Pack voltage is 48.2. I've configured it to connect to shore at 48v. Assuming the BMS calculation is the same as the CBA IV tester I used, I'm at 98.5% of my original capacity (likely higher). I now also know what pack voltage to use for...
You have no idea! LOL Plus I want to get my system back online.
https://diysolarforum.com/threads/36-eve-280-cells-capacity-tested.16540/
I'm going to match the capacities. I was originally going to pair highest with lowest but now I think that's a bad idea. I'd rather not have cell...
100% SoC
Spring travel: 1.0, 1.4, 1.5, 2.0
2 other things I did -- I tried using the CALB bus bars on my main battery to see how it would fit ... it's cleaner-looking and it's easier to compress the cells by hand (and I can observe the bus bar flexing up, as it should).
Second, I arranged an...
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...
Problem with this configuration is that it doesn't lie flat
And flipping the bolt around doesn't work because the washer hits the case.
I haven't done any functional testing yet ... that'll come soon.
I just want to thank everyone for the recent influx of testing and investigative work. I hope it's clear that I'm not particularly upset about these cells; as others have said, they provide a good value. All I want to accomplish here is to establish what's reality for these cells for everyone...
The last of 36 cells will have been tested tomorrow. Whew!
I've completely disassembled my battery and am toying with a completely different setup. I'm going to try 8 packs of 4 cells with molex and anderson connectors so I never have to unscrew a terminal again and to keep the system...
I recently drove 2000 miles so that put some physical stress on the batteries. They continue to perform admirably. I'm quite happy with these new busbars. Perfect solution.
It connected to shore at around 2.65v (nearly 400mv of deviation - expected, given I have cells that tested to 270Ah and others at 281) so 98.5% (probably higher due to my testing methods here) of my original capacity 1 year ago.
I got it fully charged about an hour ago. 125mv of deviation at...
It's alive! And I really need to go to sleep! I couldn't stop. ?
All wired up. Producing split-phase 240 VAC! Sending to my VRM portal. I'll plug it into AC tomorrow and start charging, and I'll test connecting to single-phase 120. I also still need to connect the DC-DC converter and...
I'd be worried that their long list of compatible inverters just means the inverter will run (a marketing technique), not that it will properly pay attention to the CANBUS. Each inverter has completely different protocol specs and the BMS would need to be explicitly configured to indicate that...
It was under 1Ah between 2.5 and 2.0 volts. Which is why I don't believe it's particularly damaging because we didn't really extract that many more electrons / move that much more LiFe around... and I immediately started charging the cells.
8mv of delta at that voltage is meaningless. You may be balancing at voltages that are too low which will mess up your balance. Don't balance below 3.4 (preferably 3.45) volts per cell. Which means you need to charge to at least that voltage for bulk and/or absorb; ok to float at 3.4vpc or...
I'm stoked! The last piece of the puzzle was the generator. I purchase the generator and give it the test. I love love love the Victron Power Assist feature!
My quattro charges its capacitors if I turn them on with AC connected and no battery. The lights in the house severely blinked! (2 5k quattro's at the same time - a lot of capacitance)
I'm still in CT ... COLD ... and I'm using electric for heat as much as possible (mostly the heat pump). I'm burning 40+ kWh/day. Yeah, way past what I can produce haha. My batteries haven't sat at 100% for weeks. So I plugged in and let it hit 100% .. I had almost 200mv of drift ... which...
We'll have to agree to disagree with those who think that applying 60v to a 12vdc FET-based Battery will reliably disconnect the battery. FETs don't work that way, period. The way FETs tend to fail is to continue passing current. That's why you see so many discussions about FET versus...
I got a little present today! My Orion BMS arrived early. So I got that going today and then launched my capacity test. Here's a little info on the Orion and how it interacts with the Victron, etc ...
It's pretty complex but it's very accurate. I'm still trying to get it to do the right...
I had a third mini-split cassette installed in the basement, so I can control the temperatures if I need to. It's the smallest size, 9k, which is way too much and causes cycling, which kills the performane of the entire system ... so I only use it when I really need it. I also need to install...
Cell balance and irregular/premature aging. The cells out the outer edge (left in your picture) will not take the same load as the cells closest to the battery +/- cables. The non-flat terminal contact means a high resistance connection which means a high degree of variability of resistances...
I received the studs and nuts. Before I went down the road of drilling/tapping/helicoil, I filed down the surface of the terminals (the aluminum had erupted out and caused an uneven surface) followed by 1000 grit sandpaper and then de-ox. I managed to get the studs all the way in and put...
I know I've been quiet. I'm so super busy with the RV pickup, working, traveling back home, etc ... but a brief update - the system is outperforming my wildest expectations. We've (we = my friend and I) had 0 sun for 3 days and I'm still at 25% battery. I don't have my generator with me so...
WRT worrying about cooling these cells .. my 280Ah cells increased all of 10F during a 220A discharge followed by a 130A charge. I wouldn't worry about it unless you're consistently pushing 1C through the cells.
The flat voltage curve is the best thing since sliced bread! Oh, and low voltage drop under load. Oh, and no peukert effect. Oh, and fast charging rates all the way to 100% ... Oh, and the weight and size. LOL
Except that this isn't normal atmospheric condition:
Look at what happens in the video below -- the connecting arc is small and requires close proximity. The disconnecting arc is shockingly enormous (no pun intended).
I worked on solving the issue with the 2 groups of cells that had high resistance and high voltage fluctuations as seen by the BMS. I solved it, and I'm in shock.
To recap - under load I would see about 4x the resistance between cell groups 4 and 5 (and between 12 and 13). It didn't show for...
I just completed testing 36 EVE 280AH cells purchased in the Group Buy thread.
Tester: https://www.aliexpress.com/item/32821857011.html
Wire gauge increased to 10. Connected to cell via lugs (in other words - a high quality connection, not the alligator clip method).
Amperage: 15
Temperature...
Oh, I forgot to mention that I also downsized my generator from the champion dual fuel 3400 to the honda 2200i with propane conversion kit. Runs my system just fine. I've only needed a generator once and I wanted to put a bike rack on the back of the RV instead of the cargo carrier with the...
Batteries installed. Arrived both at 13.08 volts (30-40% SOC). Charged at 100A combined (50 each - per recommendation) in a couple of hours. Was pretty fascinating to watch it charge at 100A and then as it got over 90%, the voltage spiked up to the 14.6 set point and amperage dropped down...
So it's about 82F outside, full afternoon sun (good heat load on the side of the RV), and I just set both cassettes to max and I'm drawing 700 watts. I can't wait to see what a 90+ degree day is like cuz that's awesome!
I haven't done anything in nodeRED but this reminded me of this recent announcement which is closely related: https://www.victronenergy.com/live/drafts:dynamic_ess
I've recently discovered that rigid bus bars are still put through stress -- and apparently to the point of causing higher resistance between the cell terminal and the bus bars as time goes by. The last maintenance I had to do required me to *pry* off the bus bar due to cell expansion (I did it...
You can permanently set up two of these in split-phase mode and then you can always connect to either single phase (15/20/30 amp service) or split phase (50 amp service) without doing ANY reconfiguration -- as stated in post 14, L1 will connect and provide DC power for the batteries and/or L2...
all cell wiring is done including BMS sense leads. Now I need to reconnect the relay, breaker, etc ... and then run that to the main bus bar and I’ll be back in business.
springs are delayed. USPS shipping delay ...
I've received the batteries. Hopefully I install them tomorrow. I'll take plenty of video and I'll do some testing ... I have a Victron BMV-712 so I can accurately test AH...
It’s alive!
I’m doing a full discharge so I can get all the cells flat again. Then I will do some heavy charge and discharge tests. I have the riden acting as a solar panel, too.
I’m gonna add anderson connectors (3 pairs) between the packs and I still need to insert the molex connectors for...
I've been playing with the Grafana/Victron integration and also using it to help me tune the Orion to do what I want ...
In the second graph (Battery Voltage) the Red line represents an arbitrary line at 58v and the blue another arbitrary line at 54.4. The dotted yellow is the max voltage...
On a separate note, it's been over 1 year since I put this into commission. The Orion BMS tracks the total # of pack cycles (a "cycle" is the sum of Ah discharged & charged - 2x the Ah rating - so for me, 1080 Ah on a 540 Ah pack). I never reset that number, so it includes all the testing I...
Some initial spring testing information on difference between 100% SoC and 0% SoC: https://diysolarforum.com/threads/cinergis-28-kwh-4-kw-solar-10-kw-inverter-rv-build.13786/post-195598
I am using red. I don’t see a need to remove the studs as I’m making them long enough to be flexible to any reasonable need.
edit: i let blue cure 24 hours and I was able to remove the stud very easily. After research I decided permatex brand red would be a better choice over loctite. Dunno...
+100, especially with 36 cells in the mix. I'm going to start a spreadsheet!
As for speeding up the process ... I think what I need is to get all my other cells fully charged so I can keep swapping cells in until I get reasonably close to 280 ... and then mark that battery as "good" and start...
My quick heating-with-minisplit notes that I just made in another thread: https://diysolarforum.com/threads/yes-rv-solar-li-and-ac-running-full-time.23979/page-10#post-348985
For me, this is why:
The only problem that is (in theory) resolved is the rapidly changing voltage and current values.
I've brought these problems up (including in PMs) and Jason ignored me. I had invested in TWO Chargery & DCC and ditched them.
It's completely crazy that I purchased 2 at the...
It's alive!
I've got the system back online. I haven't done a thorough job yet (e.g. heat shrink or cleaning terminals). I put a modest 1500 watt load on it and 1300 watt charge. I measured all the doubled-up serial cables between groups of 4 and the amperage was sharing pretty well (worst...
I'm like a kid in a candy store!
All my Victron equipment arrived today. This is how far I got:
I built the board and mounting most everything up. I still need to fully commission the battery (I started putting the BMS leads back on now that the loctite has cured for 24 hours) ...
Now that I've tested 11 and have a statistically relevant sample, I'm exploring my options with Michael (and Basen through Michael). We'll see what Basen says, where we draw the line with respect to calling it a "bad" cell, etc ...
and to that end, I decided to buy 4 Lishen cells and put them...
The EVE and Lishen cells we are getting here are not arriving with any form of balance. I've personally witnessed that. We're not buying from the factory, we're buying via Alibaba - so all bets are off.
Picking up tomorrow morning! I'll be busy as hell but I'll try to post pictures ... and try to remember to take video and document the installation etc.
Blue loctite didn't hold. I went with permatex brand red thread locker and those SS18 studs are nice and locked in. I sanded (1000 grit) the tops of the terminals, sprayed deox on it, and torqued to 7Nm. Amazingly easy to work with the studs as far as getting the lugs on and screwing down the...
If the cell voltage increases past their reconnect voltage (which is a separate setting), the DCC will turn back on. What happens after that is up to the connected equipment.
Depending on how much current was flowing at the time of disconnect, the cells can come back up to their reconnect...
Personally I don't need to perform the science experiment to decide what's safe to buy; I know my pack resistance is a couple of milliohms so I'm planning for ~20kA AIC fuses and breakers. This industry has been around a long time and these ratings exist for a reason. Who am I to say they're...
I don't think anyone here is using an active balancer to gain capacity. They're doing it to prevent a BMS HVD while doing an absorb charge to 3.5vpc which can easily cause another cell to hit 3.65+ with these EVE 280's we're all getting ... The faster active balancers reduces the chances of...
That information misses the point. There's a difference between creating a spark and extinguishing one. There's also a difference in how the fuse fails under extreme load. ANL (for example) may fail in such a way that there are small enough gaps to keep the current flowing via arc'ing. A...
SoH definition and implementation is up to the manufacturer. I have an Orion BMS. My SoH was dipping down quite a lot (by 10%+) ... as a result of high IR developing between the bus bars and cell terminals. Once I fixed that, my SoH has remained at 99% (450 cycles so far). From their site...
Check out the "DC System" graph (expand it to include at least all of yestrday.. so if you do this today, select 2 days at the top) here: https://vrm.victronenergy.com/installation/76892/advanced
SO much better.
Ultimately balancing is about being able to get your pack up to a ~100% SoC without causing one or more cells to go above 3.65. If you have 100mv of difference (even after doing a parallel top balance) when one of the cells is at 3.65, I wouldn't say that's cause for alarm, so long as it...