2 power universal battery charger universal battery charger suitable for charging many types of low voltage battery packs for cameras camcorders mobile phones etc simply adjust the charging pins manually to correspond to your batterys contacts and plug in to the mains or dc car socket to begin charging the charger automatically senses positive and negative polarity and is suitable for charging 36v 37v 72v 74v lithium ion battery packs the unit is also able to charge aa aaa n