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gcrank1
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# Posted: 14 Nov 2024 04:44pm
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Mine don't stay there long at all, just right after a full charge and settle.
They drop quickly to 13.4 then fair quick to 13.3.
They stay longest in the 13.3-13.0 range.
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paulz
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# Posted: 14 Nov 2024 05:55pm
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Ok, that’s a relief! Mine do the same, unless solar is kicking around. Pretty scarce these days.
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paulz
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# Posted: 14 Nov 2024 08:56pm - Edited by: paulz
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Couple more things:
Came inside after a few hours this morning and saw the voltage at 13.4, after 13.1 this morning! Solar says 16 amps coming even though not a patch of blue in the sky, just quit raining matter of fact. Maybe that washed the panels off. or blue sky not necessary, light gray ok.
The Epever Tracer controller display says 13.5 I know, but it always reads higher than a VOM, which matches the 13.4.
Next thing, speaking of Epever solar controllers, I have a second one down at the shop with just a couple panels and FLA car battery hooked to it. Again minimal sun and the battery only supplies a couple led lights and motion detection trail camera. But the fla keeps going dead, tried a couple known good ones. My question is can a controller use that much juice? I do get a decent spark from it when I hook it to a battery. Something wrong with it maybe? I do have a spare little Renogy controller, one of those little black things, maybe I’ll try swapping that in.
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paulz
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# Posted: 15 Nov 2024 07:02pm - Edited by: paulz
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Yay! I had left all 3 chargers hooked up after quitting the other night. This morning I figured I would run them one more time. Bank was low, about 13.0-1, sunny day with some solar coming so no big deal. So I fired up just the big genny, plugged in all three and 101 amps! After 5 minutes of that it had dropped to 86, battery resistance going up I guess. Turned off the genny, bank now at 13.2.
Gonna leave em all hooked and test again tomorrow morning.
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gcrank1
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# Posted: 16 Nov 2024 12:18am
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Wow!
Im sure no expert, but my gut tells me that the bat-bank voltage is 'reading off' and that your bank isn't near as depleted at it looks like.
Why? Because I would not expect the bats to come up that fast to that reduction of amps; ie, the recharge in 5ish min to that kind of internal resistance doesn't seem right.
Now, where is Steve......
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ICC
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# Posted: 16 Nov 2024 02:05am
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Quoting: gcrank1 Because I would not expect the bats to come up that fast......
A battery that seems to recharge very quickly can also be a battery that is failing. If it doesn't have much good capacity left it can seem to recharge fully quite quickly, but when used not have the full rated capacity.
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Steve_S
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# Posted: 16 Nov 2024 12:09pm
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Snickers snickers... have a seat !
Nothing Wrong there ! No they are NOT worn out.
Here's the deal and this is where MANY get confabulated with the new chemistries.
You charge your batteries to the proper 100% Voltage regularly and the cells within balance out quite nicely (valence always used great cells). The chemistry is "Fully" active since commissioning and you've kept them that way and haven't abused them (frozen, deep discharge to 0% or super high stress loading etc). HAD this not been the case, charging at Higher Amps would take longer.
There is a few things at play which causes some confusion.
- Charging from 2.500 to 2.900 volts per cell is quicker due to the chemistry curve. It's that "cliff fall" segment of the curve.
- Charging from 2.900-3.500 is slower because the curve there is very very flat, it "looks" slower due to the slow incremental gain. Remember 3.0-3.4 is the "delivery segment" of the curve.
- Charging from 3.400 to 3.650 speeds up as that is the other side of the Hockey Stick curve (beyond the working/delivery range). This is also were the Resistance climbs FAST and drops the Amps being taken in.
* This is where it gets a tad confusing if you are "Eagle Eyeing" the charge process because you see the change in Voltages & the Amps taken change fast .
Again, remember that the Deliverable Amp Hours come from that 3.000-3.400 (12.0-13.6) Volts per cell range and most use down to 2.8/2.9 volts per cell (moderate usage profile).
The PARALLEL GOTCHA ! Ohh yeah, like everything, gotcha's lurk to get ya ! Ohhh such fun ! 
-- Assume you have 3 Packs, all identical (age, wear and "tested" AH Capacity).
(A) These will all charge equally and take the same Amperage per pack nicely. They will lower amps taken in unison and top-off balance politely. That would be monitorable at the pack terminals.
(B) Packs with different wear/tear & slight AH Capacity Loss. These will all take full Amps when low, but as the charging progresses, the packs with lower capacity will hit their "full" first and drop amps taken while the Fresher Packs will take more amperage (think of it as saturating a sponge, more capacity = more sponge) and ultimately they will lower the amps taken till Endamps is reached.
* This can be monitored & replicated. IE put a 100AH & 120AH pack in parallel and you can replicate the effect. 100AH will fill & drop Amps while 120 will take some more & follow suit as it fills.
PSST: remember I was running 1x105AH, 2x175AH & 3x280AH in my bank for quite some time, and other combos & setups as well. Some PITA factors to work out when doing so.
Paul, we do not know the true status of these batteries because you haven't been able to do a full & proper capacity test on each battery individually. They are all likely fairly close but not exactly (you don't know what kind of life they had before). It's likely safe to assume that they likely have slightly different "true" AH capacities, maybe 5AH difference or so.
I suspect, what you saw was they were already 13.0V/3.250vpc (3.200 = 50% SOC) and the 101A was split and delivering 33.6A to each pack. So the Internal Resistance was already in play (@ 12.0V/3,000vpc they would have taken 40A). Now if "A" cell or cells are diminished a bit, they will increase resistance a bit faster & lower the input amps accepted. The Batteries in Parallel will try to share/divide all incoming & outgoing power and by chemistry, they do this proportionately relative to their actual capacity.
Confused yet ? Sorry I think I got a tad circular but letting it stand.
Simple IE using my old bank config mentioned above with regards to Proportional related to Capacity. Assume I am pulling 130A from that bank.
105AH pack dumps 10.5A
175AH packs dump 17.5A ea (35A)
280AH packs dump 28.0A ea (84A)
- 0.5A inefficiency drop.
It works identically but inverse for Charging.
If "Eagle Eyeing" that, at pack level you can actually watch the entire cycle and how the different packs float up/down slightly as they balance the delivery between themselves. You can ONLY SEE this with Advvanced chemistries using BMS'. It's quite a dance really !
CHEATING Capacity Loss Testing !
A fast "Cheat" to give an approximation of Capacity Loss can be done if you want to waste some time & fill your curiosity.
- Charge a single Battery Pack to 14.00V (3.500vpc)
- Allow to "saturate" to Endamps. 100AHx0.05=5A and cutoff charge when down to taking only 5A.
- Allow to sit "disconnected" for 1 hour, note the voltage at the terminals (2/3 decimal accurate)
- Connect inverter and find a load that will pull 0.3C (30A from a 100AH Batt) and let it rip. NOTE the Time of Start & Time of Cutoff.
!!! Set the Cutoff to where you would normally cutoff like 2.800-2.900 vpc 11.2-11.6V
OPTION: You can use something like a Kill-A-Watt meter between inverter & device pulling the 30A and that will give a good read in Wh, kWh & pending on model AH. There is some losses in that process but it's pretty close.
Remember that Battery Temp affects capacity. Optimal Temp is 25C/77F - optimal temp range is 15C-35C, either side of those temps, capacity delivery decreases slightly.
Sorry for the Novella
Hope it helps.
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paulz
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# Posted: 16 Nov 2024 03:38pm - Edited by: paulz
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Thanks Steve. I’m headed back to the grid for the weekend (we seem to be doing the opposite of working age cabin folks, quiet cabin life all week and hustle and bustle city life on the weekends). Anyway I will try your single battery test next week. I suspect you’re right though, they will last at least until the day that import duty goes in, hopefully much longer.
In the mean time, I repeated yesterday’s test just now since all still plugged in. Bank was at 13.1, been there all night, didn’t pay attention to second decimal place. As soon as I waddled inside after firing up the genny, less than one minute, it was at 103 amps. Verifies that all three Meanwells are in fact working, and cabling/genny too. In 10 minutes the amperage had dropped to 82. Turn off genny, voltage now at 13.2.
Sunny weekend predicted, should be at 13.3 from solar when I get back Monday. We really didn’t need the genny all week, voltage stayed between 13.0 and 13.2 just from solar. Hit the high 30 degrees this morning, fridge outside stays off a lot I’m sure.
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Steve_S
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# Posted: 16 Nov 2024 03:55pm
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Gosh... I would really love to see Screen Captures from the Valence BMS Software for PC. I know that software is out there and some folks have it available but not sure where.
Sorry, I spend as Little Time as I can now on DIYSolar, as I am only following 2 threads till the issues are resolved and then I am totally out of there. That placed changed as have some of the people (themselves) and it's not for me anymore.
Possibles ?
https://www.brewskynet.com/valence/
A video on using the tools.
https://www.youtube.com/watch?v=7C3rHbR90I8
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paulz
Member
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# Posted: 17 Nov 2024 01:40pm - Edited by: paulz
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Quoting: Steve_S Gosh... I would really love to see Screen Captures from the Valence BMS Software for PC. I know that software is out there and some folks have it available but not sure where
I also made a USB wire setup that attaches to the bank like the video you posted and connects to the Valence software I have and have been posting photos.
I don’t know if it’s the same software though and I myself am limited by the laptop I have. It’s a small old Dell I’ve had for years and only use for this. It has Windows 7 or 8, upgrade no longer supported. It won’t show the bottom part of the Valence screen shown in your video. I have tried turning orientation sideways, shrinking text, scrolling down.. won’t do any of that so I don’t know if there are additional display or BMS entry options I’m not seeing, again as shown in your video.
Again thanks for helping Steve. If I get a newer laptop I’ll try that. I’ll be giving that laptop away when the batteries die, package deal!
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Steve_S
Member
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# Posted: 17 Nov 2024 02:04pm
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Win 7 Forward came with a tool called SNIPPING TOOL. It lets you capture the screen or just a part that you highlight. After Win-10 they added a few more similar tools but with some extra funds. That is what I use for my screen grabs that I post.
You can save the Screen Captures as JPG, PNG etc to your desktop or a folder.
the Valence APP should have the std icons on top right to allow you to go from Full Screen to Windowed which will then let you scroll through the entire APP screen and even shift it around a bit or scale it by dragging the sides or corner tabs.
You can see those Icons (I see them on the photo) so give that a try.
I forget is Win7-8 can use the CTRL - combo (reduce screen size font/display) and CTRL+ combo to increase same.
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paulz
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# Posted: 17 Nov 2024 02:33pm
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I’ll try your suggestions on that laptop when I get back to the cabin late Monday. Mean time I’m at the grid house, desktop PC, space heater, TV, fridge all plugged into the wall, the easy life. I’m paying a PGE minimum bill here I’m sure, might as well use it.
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paulz
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# Posted: 17 Nov 2024 05:19pm
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Quoting: gcrank1 This a lengthy thread so I don't remember if this has been mentioned...
And the big question, going back to post #1, did Dave Bell ever get his lawn mowed?
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paulz
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# Posted: 19 Nov 2024 03:55pm - Edited by: paulz
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Back at the cabin last night. Voltage was at 13.3, now 13.1 and holding after 6a draw all night.
Playing with that old laptop Steve. I can move the app a little, only by holding cursor on the blue bar. It will go left and right, up and down but won’t raise the bottom. Ctrl plus or minus doesn’t do anything. It does min and max with those icons you mention.
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Steve_S
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# Posted: 20 Nov 2024 06:14pm
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Hmmm Haven't used Win 7/8 in a very long time... subtle differences.
When you move the cursor over the sides of the App Window, it should change to something like this: <--> which would let you stretch/shrink the app window.
I tried answering before but a 403 Error came up & the site poofed for a bit.
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paulz
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# Posted: 20 Nov 2024 07:01pm
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Hi Steve,
It does show those arrows, left right and top, and I can move the valence screen in those directions, but no arrows at the bottom where I really need it. Windows 7.
I’m ok though. Big rainstorm going on, solar panels covered in duff, generator iffy but still at 13.1.
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paulz
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# Posted: 21 Nov 2024 03:46pm - Edited by: paulz
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Quoting: gcrank1 Im going to 13.0 as my useful bottom for my pair
Same hear. We have a big windy rain storm going on. Heard a limb hit the roof but haven’t gone up there yet.
No solar coming in and my generator and chargers got wet from the wind, need to build a better enclosure. Afraid to use them now, leaving for the grid until this blows through.
Anyway bank was down to 13.1 last evening. This morning still at 13.1 with usual stuff on. Sounds low but I’m getting used to it being a fat spot in the soc.
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gcrank1
Member
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# Posted: 21 Nov 2024 04:18pm
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Takin the chargers home to dry out in front of a heater?
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paulz
Member
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# Posted: 21 Nov 2024 05:39pm - Edited by: paulz
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Ha, I would have done that yesterday here but just the day before I finalized the wiring and screwed them to the outer wall. Should have finished the enclosure.
Found that falling limb bang from yesterday on the way out. It went through the shop roof, loud enough that it sounded like the cabin. Just put buckets under, more work next week.
That redwood duff is everywhere, including the solar panels. Oh well, if we’re going to sell the house and live here year round better get used to it. It was kinda nice last night, rain beating on the roof, fire going.. Until venturing out this morning….
https://amp-cnn-com.cdn.ampproject.org/v/s/amp.cnn.com/cnn/2024/11/21/weather/bomb-cy clone-atmospheric-river-west-coast-hnk?amp_js_v=0.1&_gsa=1#webview=1&cap=swipe
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gcrank1
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# Posted: 21 Nov 2024 05:12pm
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Bummer Paul, but it could have been Sooo much worse.
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FishHog
Member
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# Posted: 22 Nov 2024 07:03am
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Quoting: gcrank1 Bummer Paul, but it could have been Sooo much worse.
No kidding. Still sucks, but its just mother nature making sure you don't get bored at the cottage.
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paulz
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# Posted: 30 Nov 2024 11:23am - Edited by: paulz
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Well been back at the cabin 3 days now. Quite a storm it was. On the bright side, no additional damage, cabin pulled through well. A few minor things gave me a workout:
The cover of the pop up awning covering my gas genny blew off, I guess some water found its way in and it took some time, carb rebuild, to get it going.
Same with the washing machine. Wife’s pile of laundry died halfway through. Just after I hand rinsed everything the stupid washer lights started working again. Right after I dug out the manual that said “unplug for five minutes and try again”…
Then it was down to the shop to pull the branch out of the roof and patch. Did that, but plywood still wet and no rain expected for a week so letting that dry out more.
Stopped on the walk back up to pick and shovel a rut the rain put in my nice asphalt gravel driveway. Did about ten feet but slipped and hurt a hip joint. Limped back to the cabin and called it a day.
Let the battery bank go since our return, bank got down to 12.9 when I fired up the chargers. Charging amps showed 110, about the max my chargers will put out. Ran it up to 14v (on charge) but at that point only about 40 amps going in. Quickly down to 13.3 after turning off genny, remained there for a while, 13.2 this morning.
Didn’t cook much. Did make a good ham dinner for thanksgiving, just the two of us. We did have a nice party at my school before leaving, friend cooked a turkey by dumping in a bucket of boiling oil. Turned out great, along with all the trimmings.
That’s about it for cabin life this week. Back to the grid for medical again next eeek. Oh, speaking of grid power, got a text last night from my next door neighbor, “power out over here, you ok?” “Heck yeah, lights on, watching TV, cold beer in the fridge!”… Rare moments when off grid makes me smile.
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paulz
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# Posted: 2 Dec 2024 07:41pm - Edited by: paulz
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Not to let this ‘cyber weekend’ pass empty handed, I finally jumped today and got a 100ah Lfp. I plan to try it at my shop, instead of the old car FLA it usually has, just powering a camera and shop LEDs using a couple solar panels for charging. It’s just a Wangbang or some such, bud did say grade A cells. $120 shipped. If it works satisfactorily I’ll knock the cabin down to one of my old Valence bats, then swap this in for comparison.
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paulz
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# Posted: 11 Dec 2024 02:23pm
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Been at the cabin trying this new 100a Lfp. So far just ran the TV and modem for a few hours.
I’m thinking about trying to start my cart with it. It has a Honda Vtwin, 20 hp or so. Runs off the magneto once started. I don’t have the charging system hooked up, just hook it to the solar when sitting.
I don’t see a CCA rating, it does have a 100a BMS it says. Will that come into play if I try and it has a problem? I see they sell Lfp motorcycle batteries, maybe they are different.
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Fanman
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# Posted: 11 Dec 2024 05:08pm
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If a LFP battery doesn't have a CCA rating, it's not suitable for engine starting. The instructions for the LFP battery I'm using to power the fuel pump in my plane explicitly say not to use it for engine starting.
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ICC
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# Posted: 11 Dec 2024 06:25pm
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I believe it's the BMS that can be damaged by too high a current surge when used as a starting battery if the LFP battery is not rated for cranking.
As an aside and FWIW. I have an LFP battery in a dirtbike and an ATV. When it is cold, like now, it fails to crank the engine because the battery has reduced output when cold. That issue can be sidestepped by turning on the headlight before cranking. It takes a few minutes for the discharge current to warm the battery sufficiently to crank the cold engine. That takes a leap of faith as it goes against everything I grew up with regarding cold weather starting.
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paulz
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# Posted: 11 Dec 2024 06:31pm - Edited by: paulz
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Thanks Guys. Nothing in the manual about CCAs or engine starting. It does list Over Current Discharge Protection as 300 amps. Best I could find for Honda GX batteries was 18ah minimum.
Sounds like it would work, or at least turn off if not. But I have no great need, the little LA cycle battery it has in it works fine.
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paulz
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# Posted: 12 Dec 2024 11:06am - Edited by: paulz
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Curiosity got the better of me so I tried it. Started right up, however I did give it its usual 15 second turnover on the choke first with the old LA motorcycle bat. Lfp was already down to 13.1 from cabin testing.
I figured these Lfp bats have to have the umph to do other small things, water pumps etc and this engine can be started with a rope pull start, not like a car engine.
I’ll try it again tomorrow on a stone cold turnover.
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