Anything below 9-volts will result in the smart charger acting like a paperweight and giving you an error light.
Only when that surface charge is recognized will it begin to pump in a current to bring the battery to a full charge.įor chargers like a Deltran Battery Tender, seen here on Amazon, the minimum is 9-volts (for a 12-volt battery) or 1.5-volts per cell. When you hook up the leads to the battery, the smart charger attempts to sense an initial surface charge so that it recognizes that it is indeed connected to a battery. While these are nice, and the pros definitely outweigh the cons, there comes the frustration when your smart charger won’t recognize a legitimate battery. How to Make a Smart Charger to Recognize a Dead BatteryĪs I mentioned above, smart chargers are built with several safety features to prevent you from shocking something that isn’t a battery, from frying your charger by touching the leads together, and to prevent you from charging a battery when the incorrect leads are connected to the incorrect battery terminals.
