Replaced original rechargeable batteries with Energizer Recharge Power Plus batteries; now the lights on the charger base won't light up. Yes, batteries are in correctly.

Iron

• 3018 Answers
• Posted on May 23, 2011

SOURCE: cobra pr 3850wx bought new NiMh 800mAh 1.2v

• A Cobra 3850wx Radio requires 4x600mAh NiMH 1.2V AAA Part # GA-3ANH rechargeable batteries.
• Not just any AAA rechargeable battery will charge in the unit.
• All will work in the radio but not all will charge inside the radio. It has to be a specific battery.
• This is an example of what you need. GA-3ANH batteries which will charge inside your radio. http://www.tomsawyer2wayradios.com/catalog/item/3823249/5076887.htm

SOURCE: cobra pr 3850wx bought new NiMh 800mAh 1.2v

The higher capacity batteries are fine (they'll just take longer to reach a full charge), the problem is that the original batteries have the negative contact extended as a band around the bottom of the battery. The charging tab at the bottom of the unit makes contact with the negative end of the first battery through a springy contact inside the battery compartment that touches this band. You don't have to buy expensive Cobra batteries. The easy fix is to wrap some aluminum foil around the bottom of the battery that touches the springy bottom side contact. Be sure the foil also covers the bottom end of the battery), or you could cut away the outer plastic battery cover (at the bottom) to expose the metal shell like this: http://www.walkie-talkie-radio.co.uk/replacing-cobra-walkie-talkie-rechargeable-batteries.html