WTF-J

Batteries are one of those things that you don’t really think about until they fail.  Having been caught by a failed battery at O-Dark-thirty one evening, I vowed to never again go cheap.  The result for the Jeep formerly known as WTF-J was an Optima Yellow Top (Deep Cycle) from Quadratec.  (Note: Wow, in building the link for this article, I was stunned by how much they cost now.) 

During the construction phase, the  Optima was installed and kept on a trickle charge while powering the radio and the occasional test start-up.  One day I hit the starter and had the unmistakable sound of a dead battery.  Evidently failing to reconnect the charger while leaving something on overnight is a bad thing.  No big deal, as the charger would bring it back to life.  Wrong! 

Tried to recharge it 2-3 times and the BatteryMinder would flip into protection mode after about 20-30 min.  Off the charger, the battery would quickly fall back to ~5v.  The high priced Optima was dead!

Having read about Optimas pre-mature failures I was concerned that I had a real expensive paperweight.  The good news is that the Internet is a wonderful place and found that if you discharge an AGM (Absorbed Glass Mat) battery too far, “intelligent” chargers will not be able to deal with them, but if you add a regular battery in parallel, it will trick the charger into doing its job. 

Sure enough, the addition of the battery from the pickup worked and the Optima was back in business.  (You wonder how many AGM batteries have been scrapped because the owner didn’t find the parallel battery ploy?)

BTW, the BatteryMinder in the picture is probably the ideal charger for the WTF-J.  It will act as a trickle charger to keep the battery topped off all winter, has a setting to refresh (desulfate) AGM batteries, and provides a quick(er) boost charge when needed.  The high tech charger developed a problem after ~1yr of use in the garage.  When I made a warranty inquiry, the company’s customer service operation had me send the defective unit and they returned a new charger .  No hassles whatsoever.  

Life is good when you have power!