I agree... but he probably figured this out 4 years ago. :willy:

Not for him. But for others who might search on this topic.

just a heads up for the future. if you have a gel cell type battery (optima etc) that has gone dead (and that charger is a digital one with an automatic sensing system) it is possible that the charger won't even recognize it has been attached to a battery to switch to the charging mode. (don't ask how i know this, lol). i solved the problem by hooking the battery (still in the car) to a running car via jumper cables for about 20 minutes or so to give the dead gel cell some life. then the digital charger recognized it was attached to a somewhat dead battery and flipped automatically to the charging function. it took approximately 36 hours to bring the optima back to a normal full level and was still going strong when i sold the car about a year later. just something to be aware of if your charger is one of those that automatically senses the function to perform. glad you got your problem solved.

I have seen that before also....a battery is dead and the trickle charger will not charge it...so I have hooked it up to a full size charger and charged that way and I have also pulled a battery before and take to the auto parts store and let it sit on their charger for a couple days.

When I worked at the NAPA store we had the battery tester that checked for both available charge and load tested the battery. Unless technology has changed you can't load test a battery that has no charge.

Back in the 60's the way you trickle charged a battery was to remove the battery from the vehicle and sit it on a piece of 2x10 wood. Then you removed the caps, made sure the acid level was to the correct level and hooked up the trickle charger. A couple days later when all the cells were bubbling and some liquid had spit onto the top of the battery and the battery was warm to the touch you checked the voltage. Of course you can't do this with an AGM battery.

With my 2000 I run the NAPA battery tender. If the car sits a week without being driven it can take three days to achieve full charge according to the tender lights. The battery is less than three years old and is a NAPA 770 CCA battery.

Thanks for the input.

I just wanted to add that my battery tender appears to be defective in that the light doesn't always go green after a day or so of charging. But if I jiggle the cables or remove them and re-attach them the light will go green! Then when I reconnect the car's cable the battery appears to be fully charged and my Vette will turn right over.
So All I'm saying is that that I can't trust the red light on my charger that indicates the battery requires more charging time. Partially defeats the purpose of the little bugger.

Spend the $30.00 or so,and get a new tender.

Interesting to see this thread on the first page. I'm wondering the same thing.

6 weeks ago, it went completely dead after I left it sitting in an airport parking lot for 4 days. Got a jump and drove it for an hour before getting home and it seemed to be fine ever since.

But now it just sat for less than 48 hours and went dead again. I didn't leave the lights on, and confirmed the radar detector was unplugged. :crazy2:

Yesterday morning, I removed the battery from the car and put it on my battery tender jr.

Here I am 24 hours later and it's still got a solid red light. The jr model only puts out 750ma. So I guess it will need another 24 hours at least.

O'Reilly's has a battery tender power charger that puts out 5amps but it costs more than a new battery. I guess I will tough it out and charge with what I've got. Then go down and have the battery load tested and maybe check the alternator.


edit: got sick of waiting, bought an 8amp Schumacher charger at Walmart for $37. Hooked up for barely 2 hours and it's already done. :)