Ok, all cells are disconnected.Each cell voltage is the same since they are in parallel.
At 3.078V, you are at extremely low state of charge. Less than 10% remains.
Recommendation stands. Disconnect all cells immediately.
So is there any reason to not assemble the battery and charge it using my solar while monitoring to ensure voltages stay close together? And then stopping the charging if there is an excessive voltage differential?
My power supply should arrive today, but if my math is correct at 10 amps it will take about 15 hours to fully charge each 150ah cell, 120 hours for the entire pack, so 5 days of charging?
I have a BMS, and I put all cells in parallel for half the day yesterday to bring them to within a few millivolts of each other. I need to go measure them this morning though and see if anything changed overnight.If you don't have a BMS, the reason is that a cell is likely to run the moment you aren't watching closely.
If you have a BMS connected which monitors each cell and disconnects charger, then it's fine.
But if one cell is particularly low, could use the supply to charge it up to same voltage as the rest.
I have a BMS, and I put all cells in parallel for half the day yesterday to bring them to within a few millivolts of each other. I need to go measure them this morning though and see if anything changed overnight.
Please let us know the results.
Could I rebuild the pack and charge them with my solar to get them closer to full before using the power supply to top balance them? I would of course be monitoring them the entire time they're charging to watch for voltage discrepancies.That's encouraging. Based on those results, I would conclude it's safe to put them in parallel again and charge when the power supply arrives.
Yes, my SBMS0 would still be controlling everything.Only if you install the BMS. Human BMSs routinely fail.
I don't believe it malfunctioned. It was use error, I had the inverter on and wasn't watching my SOC, and my inverter isn't low-voltage protected. So the BMS turned off my 12 volt loads, and then low voltage locked and shut down charging as well, but of course couldn't turn off a load it doesn't have access to. I've been meaning to wire the BMS into the inverter switch, but I use my inverter so rarely that it was a low priority task.Ah. Forgot. Given that it's possibly malfunctioned, I would be hesitant to trust it unless you stare at it the whole time. Your call.
I've been meaning to wire the BMS into the inverter switch, but I use my inverter so rarely that it was a low priority task.
That all sounds awfully complicated....Has a "BMS test" process been developed that doesn't risk damage?
My first thought is connect BMS to battery, then swap cells for adjustable power supply one at a time. But things not all connected has been known to blow BMS.
Second though add resistors in series with all BMS sense lines, and use a power supply (maybe through additional resistor) to impose higher/lower voltage and check where BMS does disconnect.
Have your priorities been readjusted?
Has a "BMS test" process been developed that doesn't risk
I don't believe it malfunctioned. It was use error, I had the inverter on and wasn't watching my SOC, and my inverter isn't low-voltage protected. So the BMS turned off my 12 volt loads, and then low voltage locked and shut down charging as well, but of course couldn't turn off a load it doesn't have access to. I've been meaning to wire the BMS into the inverter switch, but I use my inverter so rarely that it was a low priority task.
Thats also something I should have explained better. Again, user error. I had the temp set too high, so I lowered it to allow charging at a lower temp. For example it wasn’t charging until about 10C, which is about as warm as it gets here this time of year. So I reduced the cutoff temp, without double checking or calibrating the temperature probe. So it was really my fault, after increasing the cutoff temp it’s been performing properly.I guess I'm missing the whole point of this thread. Didn't the BMS permit charging in low-temp conditions?
I'm sorry to hear that, but it's nice that it was covered under warranty.This is pretty much what happened to me too ckent. I have a bloated 210ah cell though which they replaced under warranty since my BMS has low temp cutoff. The one cell just failed weirdly and bloated and I didn't notice it till all the cells were less than 2v. The rest recovered and are back to full capacity with the replacement cell