Hey Guys,
I found this thread and thought I would say a few things here.
First, thanks drockstar for the OP. Optima and other AGM batteries are different from your standard flooded lead/acid batteries and have to be charged differently. The method you describe and that is explained on Optima's you tube video shows how to recharge a deeply discharged battery, using a standard charger. We do recommend that you keep an eye on it as you recharge to be sure you don't overheat and ruin the battery. Just be sure it isn't too hot to touch. Warm is ok and expected but if you can not touch it, it is being overcharged.
Goingdef, I read your replies too. Question, when you vented your battery, was it on a charger by itself? No battery in parallel? My guess is you were charging at an amp rate over 10amps and yes that will cook an AGM battery. My guess too is your battery was at 10.5 amps or close and it did not need the battery in parallel for the charger to recognize it. You are correct and if you recharge an AGM like you normally do a regular battery, it will over charge and possibly ruin your battery. So many Optima batteries are ruined this way simply because people don't know the proper way to recharge.
As far as what type of charger to use, you can you your old charger as long as it will charge at a rate of 2 amps. It is ok to charge at 10amps for a short period of time, as long as you are there, keeping a close eye on the battery, again to be sure it isn't getting too hot.
Preferably though, a newer, microprocessor style charger with an AGM setting. There are several on the market. Optima has just released our own charger that obviously is designed with AGM in mind. I have tested/used one for a good while now and really like how simple it works and tests all kinds of batteries. The really good thing I have found about it is once it recharges the battery, it switches over to a maintain mode and keeps the battery at proper voltage, rather than just keep charging and overcharging the battery.
Beat-down69, I will try and address your post. You don't have to use the AGM charger, but you must keep an eye on a standard charger if you use it. The main reason for the AGM setting on newer chargers is they are programed to know the difference and monitor the amperage closely when charging an AGM. You are on the right track with your trickle charger and usually it will be fine to use to recharge a deeply discharged AGM battery. Just be sure the charger knows when to shut off and not over charge. Something else you said that bares pointing out. You are right, most cars (some new systems require AGM ) don't know the difference in a regular and AGM battery. However, something that most people think and are wrong about, a 20 minute drive probably won't properly recharge a discharged battery. You car charging system has regulators that won't let it overcharge as long as everything is working right, but any deeply discharged battery really should be recharged properly with a battery charger. Alternator were designed to recharge the normal drain of the battery during normal driving demands, not fix a deeply discharged battery. This can cause strain on the car's charging system also. This is more and more important with newer cars and all the new electronics we see added to them yearly.
Guys, I hope this helps, but feel free to ask if you have other questions.
Thanks,
Bill Howell
eCare Manager, OPTIMA Batteries, Inc.
