My Elcon PFC 1500 for my nominally 72V pack charges to 86.4V @ 14 amps then does an absorption phase at this voltage with diminishing ampage. It then does a balance at a low ampage (which is adjustable) but I turn it off when it reaches this point.
I think, if you havenot bought one already, you need to invest in an intelligent charger. It will treat your batteries kindly and extend their life. Mine cost around $500 so if you ruin a set of batteries with a seemingly simpler and cheaper system it is likely to cost you more money in the long run. I also have a Ctek 12V charger which is useful to charge batteries individually. It charges to 14.4V and was good for initially charging the batteries when I got them to try to make them as equal as possible. It cost <£50.
As a further caution from someone who didn't listen to advice, because I trusted to luck and my own instincts, I have managed to cut the achievable range of my vehicle by being far too hard on the batteries.
I now beleive that if you intend your FLA pack to last any time you should not let your voltmeter drop below 12V per battery ie. 144V in a 144V pack. This figure is not the resting voltage, but the voltage under load. Any lower than that may be OK in the short term, or very occasionally, but it will shorten the life of your pack. I could go over 25 miles when I got the pack but only half this distance before I saw <72V uphill or during accelleration. If I had used this figure as my range and not done 25 miles on about 20 trips, where the voltmeter dropped to as low as 60V, I would expect that my pack would still seem to perform much as it did in those early days.
Andrew