Quattrohead
Solar Wizard
If you need 15 amps worth of cell balancing you have way bigger problems.
Mine is only 5A but it’s been left attached 24/7 for 3 weeks now and counting (to good effect)…15amp balancer...... will get it done ?
Andy also had videos for:
you can leave balancer attached and externally switch it on/off
use a voltage sensing relay
at x volts turn on a balancer
at y volts turn off
don't know if the 15amp is a candidate for leaving it permanently attached?
Take 280Ah cells, compute the %SOC mismatch you’d like your balancer to take care of daily, then calculate the delta voltage that translates to as far as one unbalanced cell versus all the others.If you need 15 amps worth of cell balancing you have way bigger problems.
No, it’s 100mV delta v to all other cells to get the full 5A balance current (never looked at the 15A active balancer).I’d be shocked 100mv was high enough delta to cause a 5a or 15a balancer to max out, I thought the delta needed to be much higher to max out these balancers.
With 8S, all 7 other cells need to be 100mV above or below the pit of balance cell to get the full 5A balance current (so 714.3mA balance current from each of the balanced cells).
I believe it’s actually total correlated imbalance of 700mV so one of the nearly-balanced cells can be higher than 100mV from the unbalanced cell compensated for by another neatly-balanced cell a bit under 100mV from the unbalanced cell.
100mA is a huge imbalance. In the flats (3.3V) it corresponds to ~40% SOC, above 3.4V it corresponds it corresponds to ~9.5% SOC and under 3.2V it corresponds to ~11% SOC…
Absolutely. Active balancers don’t do much until you’re pretty far into the upper knee of lower knee.I’ve always had the mindset a balancer adjusts small amounts over time, so if there is 100mv in the flat of the charge, there’s more to the story than an active or passive balancer can solve.
Thanks for the info, I’ve never tested mine but have seen 60mv max delta over all the cells with only about 30mv cell to cell. This was only observed at above 3.4v
No, it’s 100mV delta v to all other cells to get the full 5A balance current (never looked at the 15A active balancer).
See that’s where I was always under the mindset that balancing should only happen at the knees and balance frequently and balance often.