Thank you for telling me about the bug with picking the item up. This has now been fixed in 0.1.3. I chose not to use batteries in the recipe so that the lamps are available early game. I feel that adding batteries would delay it's access far too much.
The Solar Lamp recipe now requires 2 batteries per lamp in the recipe as opposed to none. This can be toggled in the Mod Settings, and is on by default. Thank you for your suggestion.