Flex Battery - Inergy

Flex Battery

We’re just going to come out and say it: the Flex Battery is the smartest, most versatile Lithium-ion expansion battery ever made.  Not only that, it is also the lightest, most compact Lithium-ion expansion battery you can find.

Important Note: Shipping will begin November 2022

AK,HI, PR, and Canada customers please call our team to place your order.

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  Questions? Call (877) 891-2657

What our customers are saying


  • Internal Battery: 1,000 Watt-hours nominal, Lithium-ion NMC, genuine LG, Samsung or BAK cells.
  • Charging:  Direct charge using Standard Wall Charger or Car Charger. Solar charge from Flex Power Console, Apex, or Kodiak Solar Power Stations. Accepts charge using any of the above methods simultaneously.
  • Lithium-ion Battery Expansion: Yes; the Flex Battery accepts up to 96 Flex Batteries (5 Flex Batteries per vertical stack maximum, connect multiple stacks with Flex Battery Adapter Plate—coming soon)
  • Automatic Battery Balancing: When connecting to a Flex, Apex, or Kodiak Power Station, the Flex Battery will auto balance with the connected power station to ensure safe and effective operation.
  • Connecting to Apex or Kodiak Power Stations: Connect using Flex Battery-to-Ring Terminal Adapter Cable (sold separately).
  • 5.5mm x 2.5 mm DC Input: User-friendly, plug-and-play interface for the Inergy Standard Wall Charger or Car Charger.


    • Dimensions: 14" x 8" x 4.7"
    • Weight: 16 lbs
    • Warranty: 2-Years
    • User Manual


    The Flex Battery is the smartest, most versatile Lithium-ion expansion battery ever made. The Flex Battery includes two Molex connector ports on the top and bottom panels for connecting to a Flex 1500 or Flex DC Power Console, MPPT Supercharger, to another Flex Expansion Battery or to a Kodiak or Apex power station.

    There are several important things you need to know about the Flex Battery:

    1. You can use it to expand the Flex 1500 Power Station and enjoy the most versatile plug-and-play portable solar energy storage device in the world.

    The Flex 1500 Power Station allows you to gather and store clean, renewable power whenever and wherever you need it. The Flex 1500 packs a huge punch in a compact, lightweight package with an efficient 1,500-Watt continuous (3,000 surge) pure sine wave inverter, so you can power dozens of 110-120VAC devices and appliances wherever you need it. You can expand the Flex 1500 with as many Flex Batteries as you need (up to 96)

    2. You can use it with the Flex DC Power Station as a powerful solar-powered, regulated DC power source. 

    If you are a DC-only user and you don’t need the AC power of the Flex 1500 Power Station, you can choose the Flex DC Power Station with as many Flex Batteries as you need (up to 96) and enjoy 13.8V of regulated DC output. You can now use the full capacity of your battery with 12V devices like portable refrigerators, water pumps, and DC appliances and devices.

    3. You have three ways to charge the battery with solar panels. 

    First, the MPPT controller in the Flex 1500 and Flex DC Power Stations will charge each Flex Battery in your stack at the same time. One single Flex Battery will charge in as little as 3 1/2 hours. More batteries in the stack will, of course, take more time. If you need faster charge times, you can add the Flex MPPT Supercharger, which triples the standard solar charge input to an unheard-of 90A input.

    4. You can use it with the Kodiak and Apex. 

    That’s right! The Flex Battery also is the Lithium-ion expansion battery for your Kodiak and Apex systems. It will nearly double your storage capacity with 1,000 Watt-hours of additional capacity. If you want, you could connect up to 96 Flex Batteries to one Kodiak or Apex for an unmatched amount of battery capacity.

    5.The Flex Battery is plug and play. 

    When you add Flex Batteries to a stack, they will automatically connect to each other when their voltages are within range of each other (about 0.8V). If your battery voltages are too far apart, you can still connect them, but each individual battery will only enable as it comes within range. As you use the Flex system, the batteries will automatically enable and equalize. Once connected, the power console display will show the combined state of charge for all currently enabled batteries in the stack.

    6. You can expand your system to an unmatched amount of energy storage. 

    This is worth mentioning once more. You can connect up to 96 Flex Batteries (approximately 96 kWh) to one Flex 1500 Power Station or Flex DC Power Station (or to an Apex or Kodiak) and enjoy the same plug-and-play functionality.



    Let’s just review this because the Flex Battery is so versatile, it might be easy to forget one.

      When connected to a Flex 1500 or Flex DC Power Station

      1. AC charging with a standard or Quick Wall wall charger
      2. Solar charging with up to 90V or 30A of solar panel input
      3. Solar charging with up to three strings of solar panels with up to 90V each (90A or 1,200W of total solar panel input) with the MPPT Supercharger
      4. Car charging with DC Car Charger

      When connected to an Apex or Kodiak portable power station

      1. AC charging with a standard or Quick Wall AC wall charger
      2. Car charging with DC Car Charger
      3. Solar charging through the Apex or Kodiak charge controller

      LCD Control Screen

      The LCD control screen allows you to track state of charge, voltage, and power output of each battery individually. 

      Battery Safety Features

      We use only genuine LG, Samsung or BAK cells, which hold to the highest safety standards in the industry. The Flex battery has several intelligent safety features:

      1. Multiple temperature sensors for smart cooling and battery protection
      2. Emergency shut-off control to protect all batteries in a stack from catastrophic damage. Any major failure in one battery can signal the rest to shut-off as a further precaution.
      3. Advanced BMS (battery management system) monitors all cell strings individually, protecting from events such as short-circuit, over/under temperature, over-charge and over-discharge.
      4. Smart data recording that tracks charge/discharge cycles, and other significant events that may affect the lifespan and capacity of the system.
      5. Rapid, automatic cell balancing during charge.

      California Residents: WARNING: Cancer and Reproductive Harm. www.p65warnings.ca.gov

      Customer Reviews

      Based on 177 reviews
      Karen Levarn

      We bought our Inergy Flex primarily for camping. We have used it inside the camper to plug in our TV and DVD player when boondocking and absolutely love it. Pretty nice to watch a movie in the middle of nowhere. Also looking forward to using it more with the solar panels.

      James Mika
      Reliable standby power.

      I have only needed to use my FLEX system once for a 4 hour power outage. It was easy to use to immediately provide back up power for some essential devices. It was comforting to know that it was ready to provide many more hours of power if it was needed.

      Solid battery

      Love how integrated the batteries are between each other. Good read outs on volume of charge.

      Michelle S
      Piece of Mind

      Having this set up gives us some piece of mind in the event of a power failure. We have been very happy with how it’s functioning and how quiet it is!

      Gary Thiemann
      Top Quality Solar Power Station

      I am very happy with my Flex 1500 Power Station purchase. The system works great and comes with very convenient DC power outlets for phone, computer and other 12V accessory power as well as an AC inverter section with multiple outlets. I was able to recharge my battery with the 4 solar panels I purchased as well within 1/2 day. Professional, quality and functional system.



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