+1 on what the other posters said..I would like to add if you let the batteries set for long periods of time ,Go to your local parts store or even cheaper Harbour freight pick up one of those battery tenders.It's just a little 'bout 2 amp battery maintainer.tha way you are always getting a little bit of juice going to you battery.If you plan on fishing give her a quick overnight jolt with your regular charger .I have always found that if you charge on lower amps (takes longer) they hold the charge better than a quick hot(10 amp) charge.What I usually do is chage on 2 amp untill complete then a couple of hours before I go I will give it a "hot" shot on 10 amps for a little while untill time to go......JMHO