I have two light weight batteries (Deka etx12) that were discharged when I stupidly left it on the track car during off season storage. Can you recharge the batteries with a tender? Or once they are discharged, they will no longer charge? Both batteries have about 1.5yrs & 2k miles of use.

 

If I remember right Clyde Deka has a procedure for this. Try their site or Brailles as they are the same unit. GL!

 

I have discharged by odyssey pc680 before, put a battery powered jumper cable on it for about 20 minutes and it started and fully charged again. No issues for several years after that.

 

I've used a battery tender on my Deka batteries many times.

 

i have a p680 and i'm having this same issue, it discharged and my battery maintainer/trickle charger isn't doing the job. I guess i'll try a real battery charger and see how that works

 

This should help. Start reading at page 12.
http://www.odysseybattery.com/docume...1_0411_000.pdf

If it is deeply discharged down to <6V, I'd charge it at a high rate like 50 or 60 amps for an hour, then trickle charge it overnight. But I believe the definitive answer for iloveketchup and jsenclosure lies in that link.