ok Bill,
let circle the wagons and focus on the question
what do you plan on plugging this high efficiency charger into?
do you plan on recharging with mains power? or from a generator?
for whatever reason you don't want to answer? so lets move on
no one has ever said that a battery bank can't have a long and wonderful life, i know i haven't! however ...
a long and wonderful life might not be the most effective use of the battery or the best return on investment!
yes you can extend the life of the battery by fully recharging it very slowly and carefully vs. just slamming it full as fast as possible, maybe... maybe
maybe because we cannot recharge a battery (flooded cell) too slowly or we end up with stratified electrolyte and the bottom of the plates eaten away prematurely,, you got to heat them up with some regularity to get the electrolyte mixed up.... babying them along generally does not mix things very well.
then there is this,
if you are relying on a battery bank for power, when the hell are you going to have the lengthy time to carefully and slowly recharge them fully 3 times a week? can't very well do all this babying and pampering and use them at the same time now can we?
then there is the efficiency thing,
flooded lead acid batteries while being charged average about 90% efficient from 50-80% state of charge, (actually up to about 85%)
the last 15-20% ranges in efficiency from about 85 down to as low as 50% efficient near the top of the charging cycle.
that last 20% is not only hard to do, very time consuming but also very inefficient. so planning a system that requires 3 full recharges a week is probably going to be twice as costly as it needs to be, or is going to burn significantly more fuel than it needs to, and it is still debatable whether the end result is really going to extend the life of the battery bank and provide any real gain in our return on investment.
what good does it do to save X amount of money on our batteries by extending their lives if it takes 2X amount of money in fuel burned or 2X the amount of panels? and we still have to go without using these batteries during these pampering sessions 3times a week?
there is just a hell of a lot more to consider than simply focusing on getting the maximum lifespan out of a battery bank.
i know i can get 20 years out of a set of batteries if i simply keep them on float most of the time, cycle them very shallowly once a month, recharge them immediately afterward, and keep the electrolyte mixed, however when it is all said and done what have i gotten out of them for all the effort?? not very much power! yes i had some power available if i needed it, but what good is a battery bank to an offgrid installation if it sits there being pampered and not used?
the only way such use of a battery bank makes sense in an offgrid installation is "if" one has ample enough alternative energy coming in such as solar,wind, hydro or whatever. and he manages his loads to where they are less than and also concurrent with the power being supplied,, and the batteries are only used if all else fails. under this condition it might make sense, however how many folks can qualify this type of use? probably less than 1% can
most folks are not going to sit in the dark at night when the sun isn't shining or not do anything on days that are cloudy and the wind is not blowing. they are going to want to do things that require the power that they are either making or have made and stored in the battery bank.
i guess i don't agree with your philosophy as it relates to batteries, their use, and their care.
bob g
bob g