How often are you supposed to check the electrolyte level in your batteries? Just in the last year I've gotten an on board charger and have left them hooked up 24/7 to keep them charged. I left them on in the dead of winter for nearly 2 months without checking them and when I did they were pretty low (tops of plates exposed). Now I'm paranoid and checking them every few days.

And if I leave my maintanence-free starting battery (a dual-purpose type) hooked up, will it loose water, too? There's no way to check that battery. So should that one be charged until full then disconnected?

I check them at least once a month is the summer and then when I put the boat away for the winter. I don't recharge during the winter or in the spring until I have checked the water level. I don't leave my on-board charger hooked up during the winter because I am not disiplined enough to check the water frequently.

I check my trolling batteries about every 45-60 days. I use an auto charger and most times plug it in in the evening when I get home and then unplug it the next morning. Occasionally I have left it plugged in for a couple days in a row but I don't usually do that.

My cranking battery is also a maintenance free. I usually don't do anything with it unless I am fishing an electric only lake. In that case I put on a trickle charger when I get home and leave it on until I go out again.

New batteries don't lose much fluid or do batteries that are not charged a lot. Older batteries or frequently used and charged batteries tend to need distilled water a lot more often. Most of the time you can pick an easy day like the First of the month and check them and do just fine.

I have finally gotten tired of it and the mess that goes along with battery acid and made the plung to AGM batteries. Time will tell if that has been a good decision.