battery question

[Chrisper4694]

so i have a battery it's about 2.5 years old. When i used it the other day it seemed to loose power twice as fast as it usually does (while using it to power my trolling motor). then when i put it on the charger expecting to see it say 55% or less it said it was at 75%...this was strange considering how slow the trolling motor was going.

Then i noticed my charger kept trying to tell me it was charging a GEL battery rather than a STANDARD and i'd manually change the setting and it would then tell me the battery was at 57% and start charging it and then it switched back over to GEL setting when it reached 100%...

I'm pretty confused, but i guess this is my excuse to go buy a third interstate battery and just use this old one as a backup emergency one.

As far as i can tell the trolling motor seems fine and the charger does the other battery normal so i'm not really sure what the problem is, hopefully someone here knows or can give a suggestion.

also, i checked the fluid levels in the chambers and they seem plenty full, but there was some residue floating in there so i'm wondering if that is normal