Found the fish and fried the trolling motor

Whelp, I finally got to my favorite city lake on Saturday at around noon. I rented a boat, 50 lb. thrust trolling motor and battery and we were off to the races! The trolling motor seemed a little sluggish but adequate. We started by throwing a shakey head with a trick worm and a texas rigged sweet beaver or reasonable facsimile (it was my partner's). Very slow bite, we both caught a few dinks and other fishermen told us the usual sad story "got most of my good fish/bites early in the morning". But 'tis the season for the easiest bass fishing so we perservered. Tried shallow and deep diving crankbaits with no luck, a spinnerbait with no luck, a carolina rig with no luck. Hey, at least I found a pattern! ... of no luck! lol! Finally, got a one pounder on my shakey head off a shallow main lake point. Many more nibbles but no fish. tried the back of long creek but still no luck! Then, as luck would have it, switched to a swimbait on ultralight tackle and tried another main lake point. Bingo! Hooked a decent fish. My partner said it was a big one but I'm thinking 2-4 lbs. Anyway, we'll never know because she broke my line! ****! And now it was time to go. But, I figured 'em out! The satisfaction of accomplishing that, even though it took all day and I didn't get to reap the rewards was worth it. By this time, the trolling motor was going slow on all speeds with both batteries even though we'd only used one. It had operated at the same speed for the top 3 settings anyway so I think the switch was already toast. I've gotten several bad trolling motors and batteries at this lake in the past and been chewed out for being late back to the dock so I decided to try something radical. I hooked both batteries together and connected them to the trolling motor. Wow! That thing moved like a small outboard! I didn't want to permanently damage it and the connection between the two batteries was heating up so I decided to try hooking it back up to only one battery. It worked like a charm with either battery! Better than it had all day. We made it back to the dock on time and I told the guy the switch on the motor was probably fried (it only worked on high after my little experiment) and made a comment about the equipment needing to be in working order when you BEGAN your fishing trip and went home. So, a fun interesting day!