I bought an Interstate cranking batter a little over a year ago that came w/ a 2-yr warranty. Recently, the battery isn't holding a charge long enough to crank my motor after ~4 hours on the water. All the electronics on the boat are hooked up to that battery and I hadn't had any problems w/ it until a month ago. The onboard charger and charging system on my motor are functioning properly. How do I go about proving that the battery is bad so I can get a new one through the warranty if the battery works on a full charge but discharges too much during the course of my fishing trip to achieve its main purpose?

take it back to the one you bought from. they can run a test if they can't. tell them you want a new one

I don't know where you live or where you bought it but Interstate has been good to me on replacements. I have one in the garage (about 2 yeas old I guess) that kept discharging like that too.

I need to return it on my next trip to Dallas.

(469) 221-4500
10200 Plano Road, Dallas, Texas 75238
Or Bass Pro Shops.

If you have a reputable business they should replace it if it is only 1 yr old. I had the same issue with my deep cycles. They worked fine for 8 months then the next thing you know they would only hold up for about 4 hrs. I took them back and they supposedly tested good. I told them that the batteries had definitely been compromised some how because I had been out 3 times in a row and the holding power was 4hrs. at best. They replaced them. The new batteries they replaced with have lasted twice as long so far. Both batteries tested good according to them. As a result no one was certain which one was the culprit so they replaced them both.

Mine went completely dead yesterday. Battery was just a year old.

Another Interstate?

This will get you home when you do have battery issues. Been using one for three years. http://tournamentsaverpro.com/