PotusGobbleBottom
Corn Pop was a bad dude.
That would probably be the easiest way. Keep i mind, cell deviations are a lot more pronounced after the 3.45 mark. Also there insnt a ton of energy after 3.45 so it wont take too long. Couple days or so
Weird issue with 6000XP 🤷‍♂️
- Thread starter ChrisSwolls
- Start date
ChrisSwolls
New Member
So discharged the bank a bit more lastnight. They discharged unevenly for sure, I set charging amps to 5 for it to come back up. I’ll probably leave more lights on tonight when I go to work as I’m only getting into the 65-70% range SOC. Ideally, I should probably try and hit 30-40 I’m guessing?
ChrisSwolls
New Member
brucenolan
New Member
This was at end of the charge? cell delta at 53 volts is easy to get down, what is delta at 55 pack voltage? you are charging with a chargeverter? the cell voltage has to get high enuf to hit balanceForgot to attach, it was a long night at work
PotusGobbleBottom
Corn Pop was a bad dude.
Are you speaking of just SOC not matching or cell voltage?
Soc should be close but I have seen 5-10% difference in mine sometimes
registered-bum
New Member
ChrisSwolls
New Member
So discharged the bank a bit more lastnight. They discharged unevenly for sure, I set charging amps to 5 for it to come back up.
That was at the end or close to the end of discharge after lastnight. No chargeverter yet, it’s ordered but waiting for the next ship date. I’ve just been charging off PV for now. The cells were hitting BAL yesterday but I also have over voltage protection and alarm listed in BMS.
ChrisSwolls
New Member
Yeah, just the SOC difference and why one or 2 is getting drug down more than the others. It sounds like that might be normal though so no biggie there.
The Deltas are looking much better, still getting Overvoltage alarm and protection mode around 3.4xV per cell which seems off, but I’m guessing cycling them will help.
PotusGobbleBottom
Corn Pop was a bad dude.
It is kinda off but there is A LOT of energy between 3.40 and 3.49 That simply means that you might have a ways to go if most cells are at 3.45 and some hit 3.65. Cycling will fix this, but the best thing to do is hold the cells at just under protection activation voltage. The balancer is triggered at a specific voltage you need to stay at or above there. What I do periodically is watch cell voltages like a hawk, wait till the balancer starts, and then lower the current enough so that I am charging but only enough to hold the voltage, not necessarily to "charge" the battery. The idea is to minimize voltage gain and staying in the balancing V as long as possible.
Do you know when your battery starts balancing? The triggers are cell voltage and a 10mv delta usually.
ChrisSwolls
New Member
I missed it today, I believe around 98% total SOC they start or 3.4v per cell on average. I’ll watch it close tomorrow, I had to switch the house off the system and to grid tonight to run the jacuzzi. For some reason the jacuzzi does not like during on the XP. Not sure if it’s a load issue as I haven’t been actively watching when it trips or, if it’s a weird GFCI thing. I plan to play around with that tomorrow and check.
I think when I get home from work at 6am I’ll shut off the PV, run a little 800w heater while I sleep.
I want to get it to 90% total SOC-ish and charge real low like you mentioned at 2A
Attachments
PotusGobbleBottom
Corn Pop was a bad dude.
good plan!
PotusGobbleBottom
Corn Pop was a bad dude.
I do not like the fact that it is balancing at 3.385. I never start until a cell hits 3.45.
Probably just my preference, and possibly doesnt matter, I dont know. BUT if I am right, you may be chasing your tail a little bit.
Can you change the balance turn on voltage?
Probably just my preference, and possibly doesnt matter, I dont know. BUT if I am right, you may be chasing your tail a little bit.
Can you change the balance turn on voltage?
ChrisSwolls
New Member
I’m not sure, I haven’t played with any of the BMS settings, so they need a password to access? I did think that was weird also, I thought it should be mid 3.4x range. The cells should also be getting above 3.4x without hitting Over volt and the BMS cutting out I believe.
@EG4_Jared any thoughts?
ChrisSwolls
New Member
Alrighty, kicked on the load, gonna grab some shut eye for a bit. Do these cell voltages look low for 100% SOC? Everything within the pack balanced out pretty well though. It’s set for a 2A slowwww charge.
Attachments
PotusGobbleBottom
Corn Pop was a bad dude.
YES that looks right on target for a 17 amp draw on a 400 Ah battery.
You may not know, but If you charge a lifepo4 single cell to 100% It will (hopefully) stop charging when the cell reaches 3.65 and then if undisturbed with zero load it would settle around 3.45 or so.
This means that 3.33 with a 17 amp load on a 400 amp battery is perfectly fine.
This means the battery is fine, tho it doesnt mean it is balanced yet. 3.33 is not a good V to see imbalance.
The cell deviation really starts to show after 3.47 on a charger.
Cell deviation always looks fine at 3.33 with a healthy battery as it does with your batteries.
My goal is to have less than or equal to a .005 delta at 3.5v while charging. I believe that since I never charge to 3.65, why bother with any more than that..
You may not know, but If you charge a lifepo4 single cell to 100% It will (hopefully) stop charging when the cell reaches 3.65 and then if undisturbed with zero load it would settle around 3.45 or so.
This means that 3.33 with a 17 amp load on a 400 amp battery is perfectly fine.
This means the battery is fine, tho it doesnt mean it is balanced yet. 3.33 is not a good V to see imbalance.
The cell deviation really starts to show after 3.47 on a charger.
Cell deviation always looks fine at 3.33 with a healthy battery as it does with your batteries.
My goal is to have less than or equal to a .005 delta at 3.5v while charging. I believe that since I never charge to 3.65, why bother with any more than that..
ChrisSwolls
New Member
That was before I threw the load on it I believe.
PotusGobbleBottom
Corn Pop was a bad dude.
The second picture says it has a load. Were the pictures taken the same minute or so?
ChrisSwolls
New Member
The BMS pic was taken first. I wanted to see what they settled at after sitting for the night and topping off the charge after I left for work lastnight. The second was after I turned the heater on. If you check the pic, the current section has 0’s.
PotusGobbleBottom
Corn Pop was a bad dude.
I see now. Im still thinking everything is fine. This could imply that you are a little further away from balanced tho.
Need to see what it looks like when the cells are charging and around 3.48
brucenolan
New Member
As ScrousGB said, you need to see delta while charging at 3.48/cell and above. your cells are way out of balance and need to be held at balance voltage but below protection voltage for some time. The BMS in the Lifepower4 pack does not have much balance current, it took me a week of charging, (24/7) with a varible power supply pushing up the CV setting slightly as needed till I got to 3.6 per cell and under .020 delta on ONE pack. that is why I open and charge the low cells one at a time to balance new packs. if you continue as is the stock BMS will eventually balance out the cells, might take months !! however the 6000XP default CV (setting #7)is pushing you into protection. thats not helping. How are you holding voltage during charge to 2 amps?
