The Great Solar Generator Rip-Off (And How to Beat It)

Summary

The presenter argues that proprietary expansion batteries for portable power stations can be expensive and may have limited use outside their matching power station. Anker’s expansion battery is described as usable only with its main unit. The presenter says Bluetti’s B300K offers some standalone functionality and DJI’s battery includes an additional SDC port, but both remain limited.

As a lower-cost alternative, the video demonstrates a 51.2 V, 100 Ah LiFePO₄ golf-cart battery kit. The presenter cites a price of about $730 and a capacity of 5,120 Wh, compared with roughly $900 for Anker’s expansion battery and $999 for Bluetti’s B300K, which is listed at 2,764 Wh.

The kit also includes a smart charger, a Bluetooth module, and a display showing state of charge, current, voltage, temperature, estimated time remaining, cycle count, and individual cell voltages.

Connection Methods Demonstrated

DC-input method

For a power station whose DC input supports the battery’s voltage, the presenter uses a fused cable with ring terminals and a connector for the station, such as an XT60i. The cable should be at least 10 AWG. The station treats the battery’s output like DC or solar input; in the demonstration, input is limited to about 20 A, or roughly 1,000 W.

Direct battery connection

A more involved setup connects the external battery to a compatible power station battery system. The presenter emphasizes the need to:

• Match the 51.2 V nominal voltage and LiFePO₄ chemistry.
• Bring both batteries to a very similar state of charge.
• Keep the breaker or disconnect off until the connections are ready.

The presenter warns that a large charge imbalance could cause a heavy surge of current. In the demonstration, the external battery supplies part of the load, and the setup also works in the charging direction.

Other Uses

The presenter says the golf-cart battery can serve multiple purposes: expanding portable power stations for RV or mobile use, and later being used with a 48 V inverter as part of a home-backup system. The presenter also describes using the battery’s charger to buffer power from a gas generator, including “dirty” generator power, before supplying a power station.

Tests and Conclusions

• A capacity test using a Victron SmartShunt reportedly measured 105 Ah, at a discharge rate of about 20 A.
• A recharge test with the included charger took just over six hours to go from empty to full.
• The presenter’s overall conclusion is that the generic battery may offer more capacity and flexibility for less money, while proprietary expansion batteries are simpler to connect and avoid DIY wiring and compatibility decisions.

These are the presenter’s demonstrations and claims, not a general compatibility guarantee. The direct-connection approach requires careful matching and wiring. The presenter recommends proprietary batteries for users who prefer a plug-and-play setup.

Guides and Demonstrations Covered

1. Comparing proprietary expansion-battery prices and capacities with a golf-cart battery.
2. Connecting the battery to a power station’s DC input with a fused cable.
3. Demonstrating a direct battery connection, including voltage and state-of-charge checks.
4. Testing battery capacity and recharge time.
5. Discussing use with a generator, portable power stations, and a 48 V inverter.

Main speaker/source: An unnamed presenter from the There’s A Trick For That channel.