Rep Power: 0

This past Monday morning I was cleaning out the interior and accidentilly turned on the drivers' side reading lamp. That evening, I went to start the car and it was dead. I jumped it with my AC Jump Starter and away I went. A couple of days later it would not start again. I took the battery to a local store and they could not test it because it was not charged. I put on the AC Charger for 11 hours. Installed it; the car fired right up. I decided to take it back and have them test the battery and Alternator. With the car off, 12.26v - reported the battery fine. Started the car with no load, measured 12.46v. According to the repersentative the alternator was bad. I had it towed to the Honda Dealer that I trust (rare). The Service Manager called me and asked what had happened because everything looked fine; here is where the learnng started. He explained to me that the new charging systems are more intelligent those from older vehicles. If the battery does not need a charge, the system will not turn the charging system on. The way to test the alternator is while the car is running, turn on the lights; this will automatically turn on the charging system to ~ 14,5 volts. Try it sometime. Good talk. Hope this helps someone.

 
Rep Power: 308

Yes, ELD. Electronic Load Detector.

How old is battery ??

I would think it would take a while for a single map light to drain a healthy battery. 3.5 - 5 years on a battery these days is the norm. And deep cycling does not help matters.

 
Rep Power: 518

Yep... Honda has been doing things like this since the 80s, maybe earlier than that.