Check the listing for details. EcoFlow DELTA 2 Max Smart Generator Extra Battery 2048Wh for Outdoor, LFP. Color: Black, Condition: New. Listed at 1099.00 USD. Please note that this is an extra battery of DELTA 2 Max Power Station. FAQ Q1: Can I stack more than one for more capacity? A: A DELTA Max can support up to two DELTA Max Smart Extra Battery to meet more extensive capacity requirements. Q2: Do I have to monitor it through APP? A: No. The app is optional, even if there is no app, you can monitor the battery status through the LED screen. Q3: Does it enable DELTA Max to plug in more powerful devices? A: The Smart Extra Battery just expands more capacity and supports your electrical appliances to have a longer use time, but DELTA Max itself can power very powerful equipment, it can support even 3400W appliances with X-Boost on. Q4: Is this product compatible with the DELTA/DELTA Pro? A: No, it only can be used with DELTA Max. NOTE: DO NOT connect the DELTA Max Extra Battery to DELTA Max while discharging or charging; if you need to remove the Extra Battery Cable, please make sure that the DELTA Max Extra Battery and DELTA Max are both powered off.