has anyone had a battery die while hooked
up to a tender

 

It's possible. Batteries go bad while driving why not while being charged? The battery doesn't know the difference.

 

It happened to me last winter, the problem was that the battery tender died.

 

Or maybe if all of the water boiled out of the battery and made the water level low? Other than that, the Battery Tender shouldn't make the battery go bad. It just was in a state of going bad anyway..........

 

Same problem I had last year with my C5. Bought a Ctek for my C6 this winter.

 

To make a short story long, I've had several battery issues with my 2005 and I'm not sure we ever found out exactly what the problem was. The last occurrence was last Winter and had a 6 month old OEM Delco installed attached to a cigarette lighter Battery Tender Plus. All the lights on the charger looked good and it had been on the BT for about 2 weeks. Disconnected it and dead as could be. Called AAA and it wouldn't jump start, so decided(whoops) to buy one of their batteries, since they had one right there. Strange, it wouldn't start with the new battery. Decided to have it flat bedded to the dealer, but had this problem. The steering wheel was locked and I need to turn the front wheels to get it out of the garage and on the flatbed. The tow guy suggested that we remove the negative terminal cable and the steering worked, backed it out, put it on the flatbed and off we went. The dealer diagnosed the problem as a loose negative battery cable. Hmmmm, I knew that. It started like a champ and is still starting today fine, for the new owner. I've had folks tell me that the problem could have been the cigarette lighter adapter for the BT. The new owner is using a BT but using a connection direct to the battery. The car was on a tender from July through October in Florida and started perfectly the first time they cranked it up. I haven't decided what I 'm going to do with my new to me 2009 this Winter, but I did buy the BT direct to battery connector. I don't know, hoonose???eddie

 

this battery was 16 months old

 

I do believe battery tenders have a fuse in them as well.See if that's blown.

 

Batteries will die even when being float charged.