I fished last weekend with no problems. I've had them hooked up to the charger since. I went in the garage today and smelled a strong rotten egg odor. I unplugged the charger and pulled out the batteries. The water level was low so I added some distilled water to both batteries. Are these batteries toast or is it possible they are ok to use? Thanks

It sounds like you either overcharged them or you had a plate come unglued and short on a neighboring plate. If just overcharged and boiled the water out, you should just be able to refill, charge and be ok. If shorted cell, goodnight irene.

Do you have an automatic charger? And is there an auto center nearby with a computerized battery tester?

Thanks, I've got an Autozone close. I'll see if they can test them.

Either it's bad or well on its way to being bad. Sounds like you cooked it pretty good. For an open top battery, I would prefer using a hydrometer over the electronic tester. The electronic tester is ok for sealed batteries but a hydrometer, load and voltmeter is a much better way of testing one.

Time for new batteries!

One battery was toast, I replaced both. Thanks....