I Hacked Bluetti Fridge Power — 100+ Hours of Runtime

The Bluetti Fridge Power is already one of the cleanest-looking backup systems on the market — thin, stackable or wall-mountable, and expandable with OEM batteries. But staring at the XT60 solar input on the side, I couldn't help wondering: what if we fed it something other than solar panels?

The hack

That XT60 port accepts 12–60 V at up to 1,000 W. So I ran a length of 10-gauge cable from a 51.2 V / 100 Ah golf-cart–style LiFePO₄ battery (with a proper DC-rated breaker inline), terminated in an XT60 connector, and plugged it straight in.

Flip the switch and the Bluetti app lights up: 995 W of “solar” coming in, happily charging the Fridge Power from a completely external battery pack.

Why this matters

• Massive runtime on a fridge. The Fridge Power unit + OEM expansion battery (≈ 4,000 Wh combined) ran my fridge over 50 hours in an earlier test. A single 5,120 Wh golf cart battery on the XT60 input alone carries more capacity than both OEM units combined — enough to push total system runtime past 100 hours.
• Better cost-per-watt-hour. OEM expansion batteries are convenient but expensive. A golf cart LiFePO₄ kit typically ships with a matching 56.8 V / 18 A charger in the box, so you can top it back off from a standard 120 V outlet after an event.
• Doubles your real solar ceiling. The built-in MPPT is capped at 60 V / 1,000 W. Pair the external battery with a standalone MPPT charge controller (up to 150 V and 40 A on the one I use), and you can pour 2,000+ W of solar into the external bank during the day while the Fridge Power sips a steady 1,000 W from it — perfect for running a high-draw workstation off-grid.

Gotchas & safety

• The XT60 port is input-only. The Fridge Power cannot charge the external battery back through it — that's why the included AC charger on the golf cart kit is such a nice-to-have.
• Use a properly sized DC-rated breaker on the battery side. The one in my demo was oversized for the cable; don't skip overcurrent protection.
• Stay under 60 V nominal. A 48 V LiFePO₄ pack maxes out around 58 V at full charge, which is fine. Higher-voltage packs will over-volt the input.
• A server rack battery works just as well — golf cart kits just tend to win on price and come with a charger.

Bottom line

This isn't the setup I'd run 24/7 — I still think of the Fridge Power as a UPS first. But for a long-duration outage, or for powering a 600 W desktop off-grid, cracking open that XT60 input turns a tidy 4 kWh appliance into a 7 kWh+ hybrid system for a fraction of the OEM expansion cost. Pretty wild for a cable and a battery you probably already own.

Watch the full demo on YouTube, then drop your pros and cons in the comments — I read them all.