AFAIK the maximum recharge is listed as 27% or also seen-25% or also seen under 30%. I have not seen a "minimum" charging rate such as that 20% one for some (all?) AGMs, or to be above gassing voltage for FLAs. Not clear on LFPs--last heard it was 14.2 at least to get them to balance, but if not going for a balance then anything over 13.2? Whatever it is or isn't let the LFP guys fight it out. :)
If there is a minimum for SiO2s please let me know!
I use my 55 amper on the 200AH bank and am calling that as meeting the spec although it is over a tad. With one battery I was way over with the 55 amper, so I used a 20 amp portable, but no sweat with a 100AH FLA--it just accepts what it wants out of the 55.
I don't dare try that with my SiO2, because I don't know if it will damage it or if it just acts the same as a FLA