While we hope that you use your Voltaic charger and battery regularly, we do have three quick suggestions for storage.
1. Charge the battery to full either from the sun or your wall or AC charger, feel free to leave it connected to the solar panels during storage.
2. Re-charge the battery every 5-6 months. Lithium-Ion cells can get damaged if they stay in a completely drained state for a long period of time.
3. Try to avoid extreme high or low temperatures (e.g. don't leave it stored your car during a Texas summer)