Selmarturbo4batterychargerinstructions Link Verified Review

A slight hum is normal. A very loud vibration might indicate the unit is old or the internal transformer is loose.

Once the needle settles at a very low level (near zero) and stays there for an hour, the battery is as charged as the unit can take it. 4. Charging Duration selmarturbo4batterychargerinstructions link

As the battery fills up, the needle will slowly drop toward zero. A slight hum is normal

Attach the red positive clip to the positive (+) terminal of the battery. selmarturbo4batterychargerinstructions link

If the battery feels hot to the touch or smells like rotten eggs (sulfur), stop charging immediately. The battery may have a shorted cell.

8–12 hours (often an overnight charge).