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Steve_S
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# Posted: 9 Nov 2024 04:46pm
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I don't know that Label and wouldn't touch it. There are many well reviewed, torn part & beaten/tested ones that are worthy of being bought... Penny Wise & Dollar Foolish "CAUTION".
Damned shame you are not local to me, I'd load you up and set you on your way. Gotta clear everything unneeded out by next spring, as it will be listed for fast sale.
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gcrank1
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# Posted: 9 Nov 2024 05:21pm
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Paul, your bats seem to be working well. By the time they are actually dying there will likely be a whole new generation of 'storage' to choose from. Im thinking my LFPs will probably outlive me.
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Fanman
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# Posted: 10 Nov 2024 01:41am
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The charging current is a function of the voltage put out by the charger. If you're running two chargers both putting out the same voltage the charge current will be the same as with one charger.
If you're seeing a small (but not double) increase in charge current that means that one charger isn't quite enough to handle the battery's demand but two is more than enough.
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paulz
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# Posted: 10 Nov 2024 12:17pm - Edited by: paulz
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Quoting: Steve_S don't know that Label and wouldn't touch it. There
Thanks Steve. Good to hear it was an unknown, sure looked good. ;)
Quoting: gcrank1 By the time they are actually dying there will likely be a whole new
That’s the tough part. 50 years of car battery experience gives a pretty good clue of condition. How does it turn over, leave the lights on, does it take a jump… LFPs, whole new ballgame.
Quoting: Fanman The charging current is a function of the voltage put out by the charger. If you're running two chargers both putting out the same voltage the charge current will be the same as with one charger.
Hmm, interesting, if I understand. These Meanwells have parallel operation jumpers, which I have connected. What that does I’m not sure. They also have a voltage adjustment screw, up to 15 on mine.
Very sensitive, 14.2x about the closest I can get on each. The bank of course is at 13.
https://www.mouser.com/datasheet/2/260/scn-600-spec-1180098.pdf
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gcrank1
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# Posted: 10 Nov 2024 01:23pm
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This a lengthy thread so I don't remember if this has been mentioned...
Iirc the internal BMS can/will/does set the input limit for charging?
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paulz
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# Posted: 10 Nov 2024 02:57pm - Edited by: paulz
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Good question. These Valence batts don't have bms in the common (modern?) sense. They have an led that blinks green about every 30 seconds and also plugs that connect them together and connect to my laptup and provide the pictures I've been posting,. There is apparently additional Valence control software the hospitals used that I don't have. I do have a Victron low voltage disconnect.
All that said you would think a 140ah battery could take in more than 20 amps.
https://www.lithionbattery.com/wp-content/uploads/2019/12/Valence-U27-12XP-Data-Sheet -210623.pdf
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ICC
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# Posted: 10 Nov 2024 04:34pm - Edited by: ICC
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Quoting: paulz Thanks Steve. Good to hear it was an unknown, sure looked good. ;)
Spec sheets and ads with pictures can not be relied upon. In the factory supplied pictures of the Yugo, the car didn't look all that bad. The story was quite different once a person had one in their possession.
It may not be fair to compare the unknown name battery to a Yugo, but until something is proven to be good, remember the Yugo.
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gcrank1
Member
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# Posted: 10 Nov 2024 05:54pm
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Wise words Izzy
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ICC
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# Posted: 10 Nov 2024 06:03pm
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Quoting: paulz All that said you would think a 140ah battery could take in more than 20 amps.
You would think that. However, 20 amps would be quite safe. The user manual for my SOK 24v100A recommends a 20-amp charge but also states a maximum of 50 amps. My solar panel at the cabin seldom puts out more than 20 amps, so I am quite happy.
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gcrank1
Member
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# Posted: 12 Nov 2024 03:24am - Edited by: gcrank1
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I have both 12v 100ah lfp's back home now, pulled Bat2 from cabin at 12.6v. Ran an old headlight and found after 1.25hrs the lvd tripped at 11.8.
This is the bat that I found the hvd at 14.5 previously reported on this thread.
Bat1 has been sitting in my basement for the past 5? weeks at 13.1, and it has held that steady and fine.
Putting the light on it the v dropped quick to 13.0, 6hrs! later it was down to 12.2. Surprised me that much life left.
I kept going looking for the lvd, went all the way to 10v (2.5v/cell) and stopped, NO bms disconnect!
I charged it for 1.5hrs tonight at 13.8v on the Meanwell, will finish it off tomorrow looking for that hvd or 14.6 tops, whichever comes first so I Know just where it is. If I don't get a top trip like I didn't get a bottom trip I will be concerned about the bms.
My intent is to document the high/low for sure and certain.
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paulz
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# Posted: 12 Nov 2024 04:26am
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Interesting, if you have an amp gauge sitting around it would be nice to see how many amps are going in from the Meanwell.
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gcrank1
Member
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# Posted: 12 Nov 2024 01:43pm - Edited by: gcrank1
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Meanwell at 13.8 puts out about 20A on a low bat according to my old 'clamp on' automotive test meter(accuracy unknown).
At 14.4v it was 25A.
These were early stage charging when the bats take it easily.
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paulz
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# Posted: 12 Nov 2024 02:09pm - Edited by: paulz
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Hmm, it’s a 40 amper isn’t it? Mine seems to do 40, set in the 14s.
Getting back to the cabin today after several days of no sun. More fun ahead.
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gcrank1
Member
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# Posted: 12 Nov 2024 02:55pm - Edited by: gcrank1
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I have the 115/230v switch correctly set to 115.
Experimental check of output set at 14.6 (the recommended top for lfp) Ive never seen more than the 25ish amps. Ive also never checked it against another ammeter because as is it works just fine for me.
Ive been using the 13.8 no load setting per Steve_S for routine recharging though Im looking for the hvd now so when Ive stabilized at 13.8 under charge Im going to let it rest/settle then tweak up and watch.
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gcrank1
Member
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# Posted: 13 Nov 2024 02:17pm - Edited by: gcrank1
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So, bat1 has been sitting/settling overnight and still at 13.9v after taking it carefully to 14.6 last night. I did Not find the HVD but decided to not go farther.
I 'burned off' the surface charge with the headlight bulb, it dropped to 13.6 quickly.
Im going to put it in cabin again today.
Btw, my hashmarks show Ive only cycled this bat (1 of 2) 6 times since new! I bought them that prev 'new years' and put them in service, 2022, guess I better tag em with that rather than digging out the receipts.
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paulz
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# Posted: 13 Nov 2024 02:57pm
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Wow, that’s higher resting voltage than I ever see. Got back to the cabin yesterday after 3 days limited solar charging, power off. 13.3. This morning, after power on all night, 13.0. Not much sun today, probably generator time.
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gcrank1
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# Posted: 13 Nov 2024 03:23pm - Edited by: gcrank1
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Im pretty sure I can run down to 12.8 and be ok with just some led lights but with your loads, especially the fridge, no, the start up load would make enough sag that you hit the LVD or the inverter trip. Only one way to tell....but a good thing to know.
Other than the fridge, or any high load device, you can run light loads and led lights an hour or two? from 13.0.
Imo, to come back and find it at 13.3 isn't bad at all, neither is 13.0 in the morning after your normal living. But you know when to top up from your use experience, No substitute for that!
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paulz
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# Posted: 13 Nov 2024 04:19pm
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My fridge is 12v, no inverter. And it sits outside the front door. 42 degrees outside here now, fridge set to 40 so probably not kicking on much, can’t hear it from inside. But it was at 65 when I got here yesterday so it probably ran some then.
The soc graph we have all seen posted in places shows a deep falloff to zero after about 12.8. Up to there I’m getting more confident. I think it shows 13.0 as 30% Good rough numbers to follow, if accurate.
Btw, just looked at the Meanwells, says 40 amp right on the white label. I’m sure yours does too. When it delivers that much is another story..
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Steve_S
Member
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# Posted: 13 Nov 2024 04:23pm
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Sharing an observation / experience.
You all know I have a proper bench power supply $$$ but also Meanwells and others.
My Bench Supply outputs up to 15V@45A but I could never get that to the batteries, regardless of settings. Finally I put Super Fine Strand 6AWG Silicone wire with proper terminals crimped on, I got my 45A Charghe rate without problems and the charging improved as well (accuracy readings etc).
I had similar issues with the Meanwell Setup I have (Paired its for 24V) and with using SuperFine high-strand wire the output improved considerably and I'm getting everything they can deliver. PITA tweaking those POTS though).
Of course my Inverter/Charger & Solar gear is all wired extremely well so they always deliver everything they can. But the simplest thing like the quality & grade of wire makes such a difference in getting that power from the unit to devices, especially with real amperage should not be missed.
That's the biggy with DC, is all the "minutia" counts and adds up fast which can trickle down in loses & inefficiencies that end up costing you.
IMPORTANT TIP !
LFP = 0% Total GROSS SOC @ 2.500V per cell. 10.0/20.0/40.0 and that is Very Bad !
Safe Low Volt Cutoff that will generally prevent a Surge Load from shutting down the battery is at LOWEST 2.700vpc but best at 2.800 to 2.900 vpc.
11.2/22.4/44.8 to 11.6/23.2/46.4V
I have everything set to Low Volt Disconnect @ 2.800 V per cell but with Battery Shutdown (by BMS) at 2.700vpc to leave room to reboot & come up and to take a charge.
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paulz
Member
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# Posted: 13 Nov 2024 04:39pm - Edited by: paulz
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Thanks for chiming in Steve. And you’re right about those Meanwell pots, pita. Hey do you know what exactly the ‘pairing’ terminal does? Don’t see it explained in the doc I have.
Going to try my testing again with new cables and terminals, maybe today.
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Steve_S
Member
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# Posted: 13 Nov 2024 07:48pm
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Way back somewhere in this thread or another I posted a diagram with my paired set, which are a "Knock Off" Meanwell type supplies, very close but not quite the same.
Attached is the Diagram of how mine are setup.
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paulz
Member
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# Posted: 13 Nov 2024 09:14pm
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I goofed my verbiage, Meanwells calls it parallel operation, not paired. Looks about the same though. This is how mines wired. So what does “parallel” do?
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Steve_S
Member
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# Posted: 14 Nov 2024 12:00am
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The way mine is setup, it doubles the volts & amps out, otherwise they are 12V/25A max ea. I did download some actual meanwell manuals a ways back and I recall they have different models that can be wired in different combinations. Nature of "industrial" general purpose supplies I guess.
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gcrank1
Member
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# Posted: 14 Nov 2024 12:23am - Edited by: gcrank1
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I was wondering about that '40a' rating on the mean well tag with it being a 12/24v unit. Ive been thinking that at 12v it is about a 25a and maybe then at 24v it hits 40ish?
Since Im not using my set up for any high start up loads Im going to 13.0 as my useful bottom for my pair; 12.8 as my absolute bottom as they pretty much fall off the cliff after that.
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Steve_S
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# Posted: 14 Nov 2024 10:52am
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I ended up with these "Knock off Meanwells" way back when I bought an assembled LFP Pack that included this "setup". Of course no docs of any kind and similar but not quite the same as "Genuine" meanwells.
I've used that setup a couple of times for testing, including during my Thrash Tests. They do the CC/CV charging quite nicely & cleanly, especially after I cleaned up and upgraded the charging wires. The original wires go too hot to touch, way too small AWG to carry that current and No More "Aligator Clips either" bloody cursed things...
With LFP the voltage drop increases speed below 3.000 but below 2.800 it's a rock falling into a well (fast) and below 2.8, even a reasonable surge draw could drop the voltage to 2.500 or lower and cause a Low Volt Disconnect.
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paulz
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# Posted: 14 Nov 2024 02:11pm
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Yesterdays testing to report:
Bank was down flirting with 12.9. First off I added the third meeanwell with heavy cables like the others. Then, powered on one at a time, I adjusted them to 14.6, the charge voltage listed in the Valence spec. Then again one at a time I connected to the bank. Amperage read right at 40 each one. Plugged 2 in, 80 amps, same as usual. But, plugged in the third, still 80 amps! Thinking maybe it’s the genny, I fired up the old gas genny, moved just one over. Still 80. Maybe the cabling that runs from the chargers to the bank? The negative cable runs straight, the positive goes through a circuit breaker and Victron LVD. All connections clean and tight.
Giving up, I turned off the big lp genny and plugged all three in the old gas genny. Total charging about 60. Ran the voltage up to 14.0, and as it climbed the amperage went down to about 50. After shutting all down and cleaning up, bank dropped to 13.3. This morning at 13.2 and holding.
Verified a couple things at least. The Meanwells do put out 40. Secondly, as bank voltage rises, charging amperage drops. I suppose at this point I could try a second set of cables direct from chargers to bank. Again, 80 amps and two chargers is good enough..
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gcrank1
Member
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# Posted: 14 Nov 2024 02:17pm
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Wonder if your bat BMS's are charge limit set to 80A?
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Steve_S
Member
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# Posted: 14 Nov 2024 02:52pm
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Going from memory based on the massive valence threads on DIYS, the Valence Batteries internal BMS (they all have one BTW) are limited to 0.4C Charge Rate so meaning that a 100AH Battery will take 40A and not more. This makes sense given your observations. Battery Pack Resistance Rules ! No way around that and that's a good thing.
For kicks & giggles, just test each of your meanwells separately to make sure they are each actually capable of charging at XX Amps, or maybe you did to make sure all 3 are actually working & doing as they should.
BTW: Also on DIYS some folks had the valence Software for a PC and there was discussion on the software & versions etc. I di not follow that as I don't have any but did some cursory reading a while back. It may be prudent to look at the threads and gleen useful info out of them.
FYI: I don't spend much time there anymore, mostly observing a few things I have interest in. The place (owner included) and the type of people has changed and not for the better sadly. It got too much, especially after threats & stuff I figured I don't need that shit, so ...
Paul, just a point on Saturation. Feels a bit Deja-Vu.
Using a 12V/100AH Battery as example.
Charge it to 3.500vpc (14.0V) at 50A (0.5C rate)
batt will hit 14.0V taking 50A but as it saturated the Resistance increases and amps will drop accordingly. You can safely allow that to continue dropping to 5% of the capacity Rating or 5A at which point the cells will be at 100% Full & Saturated. When fully saturated the voltage drop after you disconnect incoming charge will not drop that much, a couple of % at best (while not pulling a load of course) but that drop should bring the battery pack down to 13.8-13.6 which is the Sweet Spot for 100% (just over the 3.400vpc)
The Cell Resistance Rules, you can never push more in than the physical cell chemistry will allow and should somehow that go wrong the BMS will shut it all down. Unlike good old Lead Acid which you could over charge & Cook off at High Amps (over spec without controls) and end up with a really nastry bad day. Do you remember that Percolating Sound when Boiling the FLAs during Equalization ? SCARY !
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paulz
Member
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# Posted: 14 Nov 2024 03:18pm
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Thanks guys. Still digesting your posts but for now, the Valence spec says 70 amp cccv per battery I think. And I did test the Meanwells individually, each putting out the 40amps.
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paulz
Member
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# Posted: 14 Nov 2024 03:58pm
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I think my plan for tonight will be to charge up to 14, 13.6 sitting, then unplug cabin power overnight so it doesn’t have the usual 6a draw and see where it’s at in the morning. The 13.6-8 you guys mention seems like a rarity to my bats.
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