My car battery died after leaving the head lamps on for hours. I bought a heavy duty new battery charger but it would not charge the battery !
What I learned is that the new model battery chargers apparently will not charge a dead battery if the dead battery drops below 9 volts.
To get the dead battery to charge, you need to hook a GOOD charged battery in parallel to the bad battery (with jumper cables)
The dead battery will now take a small starting charge of 2 amps from the charger. Hopefully later today I can increase the amperage charge
Do you have an absorbent Matt battery? AGM battery will not charge off old chargers like lead acid batts. You have to use a new charger made for AGM batts. Joe R.
Go find the recent thread on exploding batteries.
David, I worked at a Volvo dealership for 8 years. One of the many school they send there tech,s to is one that includes battery,s. first always put the - cable on last and take it off first. It will reduce the chance of a spark. And a dead battery needs a trickle charger for 24-48 hours. The surface will sulfate and a trickle charger will break it down. After a long charge do a load test and then you will know if you can save the battery. Scott
I have had the same experience with my so called "SMART CHARGER". I put the battery on my old dumb charger for a while, and then the smart charger would work.