Hi,
I using a 500Ah 48v VRLA battery bank(20x Ultracell UCG 100-12 100Ah) with multiplus II 48/5000 inverter, Smart Solar Mppt 150/70Tr + Smart Solar Mppt 150/100 and i want to know what is the max absortion time and I can't find this information. Please help me.
Hi @pfloryann
There's no straight answer for this. Too many factors, like Temperature, how far you've discharged them, etc. And with solar 'creeping up' on Absorb and varying each day, even harder to determine.
What I use daily to terminate Abs is the Amps the battery can accept. Not gels like yours, fla's. But I chose ~3% (A vs Ah). For you that's 15A.
I note from other posts you also have GX capability and a BMV, so you can network your mppts to do this with their Tail function. You'll find it very reproducible (against SOC), and far better than a Fixed or Adaptive value.
It seems you have 5x parallel battery strings. And may well have a special charging regime to deal with that, like a lower V Abs setting. So the A value you choose needs to reflect that. Please ask again if you need more explanation. This is a great feature.
All this aside, I wouldn't ever subject my floodeds to more than 2 hours of Absorb. Ever! Your setup and batts are different, so you need to determine yourself what's suitable for them. Choose well..
