I agree with Peter, charge trolling motor batteries when you get off the lake. I use battery chargers 6/10 amp on mine when I back it into the garage.I hit mine once every three weeks during the winter months. Currrently I am running Duracell's that I got at Sam's Club. Tollers are 18 month free with 36 monthprorated replacement. I am using a group 65 Duracell 1080 Cold crankin amps 3yr free replacement and 86 month prorated for the starter on my E-tec. I have a Walmart deep cycle 4 years old that I use as a backup and to run my power sprayer for weeds and brush. Hope this helps.