AGM batteries - are they better?

BFL13 wrote:
Ignoring all questions of why in the world you would want to operate in the 80-100 SOC zone where you have such slow charging AGMs or Wets, which is why people do 50-80s instead, then:

I don't want to operate there, but the longer you keep the battery discharged below 100%, the more of the plate is subject to sulfation. I run 70% to 90% for several days, with perhaps and occasional drop to 60%, then I try to get to 100% to maximize battery life. What I should probably do, is get some solar to top off the last bit, instead of trying to do it with generator, which is inefficient and slow. I'm happy with my present bulk charge rate of 80A. It's the slow climb to 100% that annoys me. It takes too long, but I know it's good for the batteries to get there.

To get higher amps for shorter time in the 80-100 SOC zone, you need a higher absorption voltage (within reason)
Might be easier to get a charger with a higher Vabs than the existing 80amper than to go AGM even if they would charge a little faster.

I've already modified the PD9280 to increase the charge voltage to 14.8, It made a huge difference in the performance of the bulk charging region.

AFAIK from previous threads, AGMs taper the same as Wets during the Absorption Stage.

Thanks.

To get a 14.8v Vabs for my 458AH bank of four wet 6s, I set 15v on the charger. ( A PowerMax 100amper with adjustable voltage) I do a 50-90 in about two hours and ten minutes.It takes about 50 minutes to do the 80-90 part with amps tapering from about 60a to about 20a in that time (I call 5 amps per 110AH 90% as when to stop the gen)

That sounds similar to what I get. Here's my chart - the dark blue is charge amperage and the dark red is voltage (for my modified PD9280). Charging starts at 50% SOC for 460AH battery bank. Ignore the 105 volt test data for the unmodified PD9280.:

If you want faster charging for the 50-80 part than the 80 will do just buy a VEC1093DBD and add it on for 120a initial charging. 460AH bank accepts that no problem (unless the gen can't run that much)

I have a VEC1093DBD, but seldom use it in combo. The 80A bulk charge rate is as fast as I want to go with my FLAs. That's already at C/5.75, and the Vectra shuts down in the above 80% SOC region where the battery voltage is at 14.7, thinking the charging is done.

I appreciate all the comments here. I'm starting to think I should just stick with my current system, and buy some solar to do the top off that extends battery life. I just don't see much advantage from AGMs for me.