Sorry, the 100 amp shock treatment does not pass the sanity check with me. I initially charged my Optima with a 15 amp charger and in 15 minutes it got hot and started to whistle (gases escaping from the vent). I'm not going to try the 100 amp trick...sounds like a good way to blow up a battery.
I did some Googling of my own and found that Optima has a website and the manufacturer recommends the following charging procedures for redtop 6V batteries:
Alternator:
6.9-7.5 V, no amp/time limit
Charger
6.9-7.5 V, 10 Amp limit
6-12 hours (approx)
For a rapid recharge:
7.8V max
no amp limit but battery must remain below 125 degrees F
Charge to 1 Amp draw on charger
For a float charge:
6.6-6.9 V
1 amp max
no time limit
Here's the website address:
http://www.optimabatteries.com/produ...t/charging.php
Thanks for all the posts...