I think I understand your question. You have an outside light that has an AA battery in it and it is charged by a small solar panel. Generally, those batteries are standard AA rechargeable so they can be put into a wall charger. Verify that the voltage on the battery says from 1.2 to 1.5, in that range to be sure it is not some other specialty battery. I have done it several times for similar lights. Also, note that that NiCds are notorious for failing so you may find that it is only a temporary measure. If you end up replacing it, try to get Nickel Metal Hydride NiMH. They are more reliable.