Before removing the existing batteries TURN IT OFF
do not turn it back on till the new ones are in palce.
Seriously that's all you HAVE to do in most cases.
NOW: Some Inverter/chargers have programmable charging pramaters. You can set the bulk voltage and current. abosorption voltage and current (and possibly time) and float voltage and last equalization voltage.
LIFELINE can give you suggested settings (IN fact I think they are on their web page) for their batteries.. But that said. I do not knwo what they are.
Some inverter/chargers have pre-sets one of which will be AGM
But AGM's are so close to flooded wet.. You do not absolutly NEED to make a change.. Might get oh say one more year out of 'em if you do though.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times