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dr67
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# Posted: 3 Feb 2020 15:41 - Edited by: dr67
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the problem is that external BMS isnt available to us. I have 4 in parallel for about a month now and so far they are staying balanced. I made sure they were all at 100% charge before connecting them up. So far so good, but only time will tell.
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somewhereinusa
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# Posted: 3 Feb 2020 16:23
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I think you will find that being in parallel will keep them pretty even. Mine do.
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mitchk1303
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# Posted: 4 Feb 2020 08:05
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Ok, that sounds good. As long as the internal cells within each battery are being kept even I don't think I should have any issues. I can pretty easily check to make sure that the batteries within the parallel system are staying even with each other and if not I will charge them individually to the same voltage.
Now I just need to figure out what charge/ discharge protection I am going to implement as well as temp control.
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SHACKENIT
Member
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# Posted: 26 Feb 2020 21:08
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Howdy folks, I ended up here doing a deep Valence search as well some others and thought I would inquire with the "experts" on how bad a deal I got. I got 2 batteries off of the bay for my camper and I am pretty sure the one with the 35.29 SOC is toast? It shows 13.8 volts ...
Also wondering if you can throw an eyeball of the other battery/picture as well which shows a good SOC. They both have one under voltage flag and extremely very little use it seems although advertised off an electric vehicle with 7500 miles. Anyway any help with the autopsy is greatly appreciated. And great site by the way 
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dr67
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# Posted: 27 Feb 2020 09:49
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I have found the SOC on that app to be a little quirky. I have 2 batteries that never change the SOC using that app. I tested one with a 1000 watt Heat gun and let it run for over an hour and the SOC never changed. I think its a bug in the BMS or maybe the app. Real world tests have shown me the batteries are fine.
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paulz
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# Posted: 27 Feb 2020 10:11
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I'd still like to feel confident hooking up mine to my 100w HF solar controller instead of dragging it home to charge. The programmable settings are still in the default positions as shown for lead batteries. I'm guessing it would not hurt the Valence but may not charge 100%, which I don't seem to need anyway.
But if anyone has better parameters I'm all ears.
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FishHog
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# Posted: 27 Feb 2020 11:36
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can't read you diagram Paul as it won't blow up, but lithium batteries don't like or need a float charge. Lead does, so if you can take that out of the charging profile that would be best. If you can program your controller search for the charging profile for your batteries and program it to match.
I wouldn't use a lead program on a lithium battery
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paulz
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# Posted: 27 Feb 2020 17:20
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Yeah I did that from my phone, here is a better photo. Dang, I left Valence on the solar charger when I left today but from the limited sun I get and only 100w panel hopefully it won't hurt it. I'll remove that float next time. Thanks
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SHACKENIT
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# Posted: 27 Feb 2020 20:55
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Thanks for chiming in dr67. So ignore the SOC... I drained and re charged both batteries today with a heat gun. About 2 hours+ each pulling about 45 amps. and yup the SOC on both batteries it totally different but nothing unusually noted other than below..
Is it normal or ok to have a high amount of errors such as 1400 errors on a battery charged/discharged only 8 times? Is it normal or ok to have a 400 cell voltage difference in between the four cell banks after recharge?
I am wondering what my new numbers will be after I put these two batteries in parallel later...
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SHACKENIT
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# Posted: 28 Feb 2020 23:02
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Update... I matched up the voltages on the two U27 batteries separately and then paralleled them together. They are now tethered together and everything looks good especially the two batteries cell voltages. I apparently was overcharging with the Progressive Dynamics camper lithium charger. It hit them at 14.6 and that seems a bit high at least for my cells.. If I could somehow control the charge to 13.5 max I would be golden as they would hardly vary in balanced charging. I guess I got keepers
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Brettny
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# Posted: 29 Feb 2020 09:29
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Shack how did you get the software and hardware to connect these batteries to your computer so you can get that info?
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paulz
Member
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# Posted: 29 Feb 2020 09:57
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Shack, my lithium specific charger gets mine to 14.6. If you find the Valence spec sheet earlier in this thread I believe that is the spec.
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SHACKENIT
Member
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# Posted: 29 Feb 2020 10:20
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Brettny. The link to software is posted on page 3 or 4 by "somewere..." You have to order some parts to do this. It works good aside from the SOC anomalies reported by a number of people including myself.
Paulz. Im guessing my cells might have some issues when I charge to 14.6. Maybe a bad cell somewhere or maybe not?? What I am seeing after charge on both batteries is a drastic cell imbalance of approx 400 then it takes a long time to balance as well as energy. Hopefully it works itself out. If not I will have to live with charging to less than 14.6..
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Brettny
Member
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# Posted: 29 Feb 2020 15:43
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Thank you.
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paulz
Member
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# Posted: 5 Mar 2020 15:50 - Edited by: paulz
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Well I figured I'd screw up sooner or later..
Last week when I left the cabin I put one of my Valence batteries on the solar controller instead of packing it home for the first time. Unfortunately, I forgot to unplug it from the cabin, so it powered my router, tablets and what not. When I returned Tuesday the green flashing light had gone to solid red. Gulp. Luckily I had brought another battery to use. Plugged it into the charger a little while ago, it's flashing red now. Fingers crossed.
It could also be that the solar controller was discharging it too, I guess, but never seems to hurt flooded batteries.
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SHACKENIT
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# Posted: 5 Mar 2020 16:07
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Probably wont hurt nothing. I forgot if you have the software? If you do I would be interested in what your cells read. Not sure about the light codes but it sounds like its charging. You may have to trickle charge it with milliamps for a while if it doesnt take. good luck
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FishHog
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# Posted: 5 Mar 2020 16:13
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Quoting: paulz It could also be that the solar controller was discharging it too,
are you hooked direct from your panel to your battery or do you have a solar charge controller in there? If direct then yes they can back flow to the panel. But even the cheapest charge controller should prevent that.
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paulz
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# Posted: 5 Mar 2020 18:32
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Hooked to the HF controller that comes with the 100 amp kit. Parameters are in the pic above but I lowered the float charge to 12.8, as low as it would go.
I do have the software and should have hooked it up before I put it on the charger but didn't think of it. It's reading 13.1 with a DVM on the charger now but still blinking red.
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paulz
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# Posted: 6 Mar 2020 09:41
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Encouraging news. Last night the battery LED went to it's normal blinking green, 13.3 on the dvm. This morning still blinking green 13.5. Never taken more than overnight to charge but that's understandable.
Charger still charging, fingers still crossed.
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Brettny
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# Posted: 6 Mar 2020 12:20
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Your using a HF solar chsrge controller on a +$300 battery? They do make lithium compatable chsrge controllers and there not that costly.
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paulz
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# Posted: 6 Mar 2020 12:52
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My solar capability is very marginal. They sit out on the deck, as in this photo. The trees surround my cabin 360 degrees and are 150' or so tall. Anytime they are in the sun it's only for a brief period. Plus I'm on a north slope. So I haven't invested much in solar. Believe me, if I could figure out a way I would, I have been lugging batteries around for so long my arms are a couple inches longer.
Battery's at 13.6, still inching upward.
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Brettny
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# Posted: 6 Mar 2020 16:12
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O geez and I thought my site is bad for solar. I'm putting more effort into hydro at the moment...I have owned 2 235w panels for years and have never hooked them up.
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FishHog
Member
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# Posted: 6 Mar 2020 17:01
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Might not be great for solar paul, but sure looks nice nestled in all those big trees.
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paulz
Member
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# Posted: 6 Mar 2020 17:21
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Thanks Fish, yeah it's pretty neat in nice weather. All quite by accident, I started out just building some kind of shack we could sleep in.
So the charger shut off, Valence at 14.4. Now to see if it holds a charge. Maybe I got lucky. The manual says the solid red LED means less than 2v per cell. I know that's bad..
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paulz
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# Posted: 7 Mar 2020 11:25
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Battery holding overnight at 13.4. I've had many lead batteries that hold a charge but die the second you put a load on. We'll see, are lifepos like that?
Don't mean to over report but since this thread, oddly, seems to be a go to place for Valence info. To recap, battery status LED solid red, no output, able to recharge seemingly all the way.
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SHACKENIT
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# Posted: 8 Mar 2020 14:27
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Data update information and question(s).
I paralleled my two U27's together in my camper and got a couple cycles through them. Surprisingly I have noticed the SOC has aligned together on both batteries at 99.61.
I confirmed that when I charge at 14.6 with the on board camper Progressive Dynamics converter LIfepo4 charger it is too much voltage as it overshoots by approximately 400mv consequently commencing a long rebalance down to the weak link cell bank voltage in bank #1. Which is the case for both batteries (cell bank #1). I ordered a 10A charger (from Ali) that will be here one day maybe which allows up to a 10% variance in charge amount. Hopefully I can throttle it down to low 14 volts area? Ill advise. I got the 10 amp charger so I can use it with my little 2000 gen out in the field.
All that said I am wondering if this is the "Valence" normal for charging numbers to end up with around 13500 volts (see pic) and around 3.35 per cell. Someone else mentioned 3.34 ish is approximately 90%. Being 90% is better for batt life so I guess this could be a good thing? These batteries have an unfortunate history in the minimal voltages log of 2035MV per cell (see pic). So way below 10 volt minimal drain recommended. But seemingly ok...? I guess I am just looking for confirmation these are good numbers? I paid a grip for these batteries and have a week left to where I can return them if they seem damaged, which I really still don't know. My first camping trip test with these batteries is next weekend. Ill advise how they hold up.
So back to Paulz question of being at 13.4 after a good drain. I think you should be ok. Plug in the software and see if you beat my minimum cell voltage of 2035mv (if that data is even accurate?). If you didn't and you have what you started with (3.4) you should be golden again. My old rc LIPO batteries would do weird stuff after over drains but I think this chemistry can take a lot more of a beating. Just try not to beat it any more
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paulz
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# Posted: 8 Mar 2020 15:17
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Shack, do you have the Valence manual? Somwherein usa posted it earlier in this thread and I think on his web page. If you can't find it I can send it to you. It has tons of tech info, more than I will ever understand.
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SHACKENIT
Member
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# Posted: 8 Mar 2020 15:26 - Edited by: SHACKENIT
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I think I got it. Is it 61 pages long U charge xp REV2 user manual? Can you direct me to a specific page for educational purposes
I keep seeing this in the manual: "The U-Charge® XP modules must be charged under the control of the Valence U-BMS . "
Cant wait until someone gets the BMS hack finalized! Probably sell a thousand of them overnight!
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paulz
Member
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# Posted: 8 Mar 2020 19:51
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Here's the readout from the battery that went red, unused since recharged. Mostly Greek to me but I see 1 under voltage count.
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SHACKENIT
Member
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# Posted: 8 Mar 2020 21:46
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Looks like you beat me at minimum cell volt of 2000mv. Cells look nice and balanced at 3.4. So I think were lucky to have this Valence software. I would monitor the battery while simultaneously testing a good draw, like a heat gun pulling 40A. I havent heard any horror stories with this chemistry but then I havent looked. Now regular LIPO batteries I could tell you some stories... Go for it
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