I've used wet cell with gel for 1.5 years in a pinch. All seemed fine when I returned to the states.
Technically not good to charge a gel at wet cell
charging voltages. Maybe check your
charging voltage with a Volt Ohm Meter.... or many
instruments have a voltage meter built in. See what you are running.
How is your battery switching set up? Do both charge automatically? or do you switch to charge each bank?
So many questions.....