Batteries

Solar Batteries: How to Choose Lithium Storage for a Home, RV or Boat

Solar batteries store what your panels make during the day so you can use it at night or during an outage. Every battery in this collection is lithium iron phosphate (LiFePO4), which is why the cycle ratings run from 4,000 to 10,000 rather than the few hundred you get from lead-acid. The format varies a lot more than the chemistry: server rack modules, wall-mount units, outdoor cabinets, expansion packs for power stations, and 12V or 24V blocks that drop into a trailer or hull.

There are 43 batteries here from Pytes, Sungold Power, Bluetti, EG4, BigBattery and Rich Solar. The smallest is the 24V 100Ah Rich Solar ALPHA 4 LITE at $799; the largest single unit is the 16kWh EG4 WallMount at $3,750; the 4-pack of Sungold SG48100P modules gives 20.48kWh for $4,320.

How to choose a solar battery

• System voltage. 12V for small trailers and boats, 24V for larger RVs, 48V (51.2V nominal) for homes, cabins and any inverter above about 3kW. The Rich Solar 24V 100Ah ALPHA 4 at $899 covers the middle case with Bluetooth monitoring and self-heating. Almost everything else here is 48V.
• Capacity in kWh. A 5.12kWh module such as the Sungold Power 5.12kWh Powerwall SG48100M at $1,130 carries a fridge, lights and electronics overnight. A house with a well pump and electric water heater wants 14 to 16kWh, which is where the EG4 PowerPro 48V 14.3kWh at $3,124 and the 16kWh EG4 WallMount come in.
• Cycle life. Pytes V5 is rated 6,000+ cycles, Sungold 7,000+, EG4 PowerPro 8,000+, and the EG4 All-Weather 10,000. For a system that cycles daily, that difference is years of service.
• Mounting and location. Rack modules stack in a cabinet indoors. Wall-mount units bolt to a garage wall. The EG4 All-Weather is IP67 and the EG4 PowerPro IP65 for outdoor installs. The Bluetti B4810 51.2V 100Ah is built for 48V RV and off-grid systems and talks to Bluetti's RV5 Power Hub over CAN.
• Inverter communication. Closed-loop comms let the inverter read the battery's state directly. The HUSKY 2 INV, the EG4 units with Auto-ID and the B4810 all support this; a basic 12V pack does not.

Popular picks in this collection

Sizing tips

• Use the Solar Kit Calculator to turn your appliance list and ZIP code into a battery size in kWh, then divide by the module size to get a count. Two SG48100M units for a 10kWh target, for example.
• Use the recommended usable figure, not nominal. The EG4 16kWh units list 12.86kWh usable; plan around that number.
• Marine batteries need a sealed case. The IP65 HUSKY 2 INV and ALPHA 4 are the ones built for spray and vibration; rack modules are not.
• For motorhome batteries, check charge current against your converter. The ALPHA 4 accepts 100A max charge, which suits most RV chargers.
• Leave room to add modules. Most 48V units here parallel with more of the same model, so buy the inverter with the final bank size in mind.

Frequently asked questions

What size battery for a boat? Batteries for boat house loads are usually 12V or 24V: the 2,560Wh ALPHA 4 runs a fridge, pumps and electronics overnight. Larger 48V electric-drive or liveaboard systems use the HUSKY 2 INV.

Can I mix a 5.12kWh module with a 16kWh unit? No. Parallel only identical models. Pick one platform, Pytes, Sungold or EG4, and grow it with the same unit.

Do these work with any inverter? Any 48V inverter can charge and discharge them through voltage settings. Closed-loop communication is brand-specific; the HUSKY 2 INV, EG4 and Bluetti listings state which inverters they talk to.

All batteries ship free to the mainland US from partner warehouses in a few business days, with 30-day returns. Call us if you want to match a battery to an inverter or a vehicle before you order.