There are many good batteries out there. What people neglect to do is proper maintenance. Deep cycle batteries form a memory depending on how you charge them. Always charge them as soon as possible after use. Make sure your extension cord is large enough to supply correct voltage to the charger. 12 or 10 gauge should do it. Long pulls like when you are out of town at hotels are not good for chargers with small gauge drop cords. Make sure your charger has the proper setting for the type battery you have. Gel and some of the newest high tech batteries require a special charger. A standard charger will charge but not to the max of some batteries and this forms a memory in the battery. One solution is to buy from a retailer that has free 12 month or 18 month replacement and get a new battery each spring. Check connections not just at battery but every connection from trolling motor to battery including inline charger and keep them clean and tight. This will allow max recharging. Proper wire gauge is critical for on board chargers. Keep proper water levels for those type batteries you don't want to cook it. Hope his helps.