There is always the fairly polarised schools of thought. Some feel that is too high other pretty much run up at the top end like that. Thats 3.55v ish for each cell, so isn’t near the absolute limits of 3.65v per cell.
My view is if the manufacturer is asking for or allowing it. Then so be it if the battery isn’t misbehaving.
I have quite a few brands that run their cells that ‘high’ compared to other brands and they have been operating for 4-5 years with no visible cell swelling {internal check not case check} or other issues. SOH is still 98-99% with fairly crazy cycling (one site to 5% SOC pretty much every day).
Yes. But a low voltage event some say is more damaging that a HV. Its possible there is one cell going too close the threshold stopping the whole thing.
And maybe the SOC ‘calculating’ is also not so great.
I don’t know for sure i haven’t used many and the ones i have are not on systems that have any kind of real monitoring.
Getting very hot on balancing? Or hot in general use?
I have had one brand say it had high temperatures of -275°C… And then it would switch to low temps of 800°C… Fairly certain the owner never called because the house burned down
Kidding. Batteries were replaced as the cells had swelled after 2 years of use. Pretty disappointing as it was a well know brand they used much more conservative cell voltages aa well.
Last year in summer I noticed temperatures up to 32°C. Wondering if the slight voltage increase will increase the maximum temperature and that being an indicator of stressed and future swelling cells.
Depends on where the temp sensors are in the battery to what the information actually means. Of course cell inner temperature is always way higher than we are reading on their case.
For the most part in lithium its how long they spend hot that affects them.
And bulk charge or high amps is usually where the cells get hot, so being held at high voltage the cells should not be hot but the bms can get hot from bleeding off power ln hight cells. (Back to where the temps are being read. I have pulled apart exactly one dyness battery on my life so don’t have much experience with them (and i am a avid opener of all things i can get mey hands on).
As a reference one manufacturer we know actually base their commercial batteries on temps more than cycles, and their warranty slides from10 years to 7 if your batteries stay above 25°C. Stays at 7 if they operate closer to 35°C. (The secret to the 10 year warranty is fridge like conditions in the power room). And one manufacturer i know there is an immediate void of warranty if the battery ever records anything over 60°C.
