Frequencyn/a (12 V 40 Ah LiFePO4 battery)
Bandsn/a (portable battery)
Power12 V 40 Ah LiFePO4 pack: max continuous discharge 40 A, peak 80 A for 5 s (about 480 W). Plenty to run a 100 W HF rig for a long field day.
Modes12 V LiFePO4 (LFP) battery with integrated PCM/BMS
Weight4.7 kg (10.4 lb) - About 8.4 x 6.3 x 3.2 in (213 x 159 x 80 mm) and only 10.4 lb (~4.7 kg) - a fraction of an equivalent lead-acid battery.
Connectors
outputAnderson Powerpole connectors.
chargeCharge with a LiFePO4-compatible charger (an optional Bioenno 110/220 VAC 6 A charger with Powerpole is available); do NOT use an SLA charger.
power reqSelf-contained rechargeable battery with a built-in Protection Circuit Module (cell balancing; over-current, over/under-voltage and short-circuit protection). Charge only with a LiFePO4 charger.
12 V 40 Ah lithium iron phosphate (LiFePO4) battery Max continuous discharge 40 A; peak 80 A for 5 seconds (~480 W) Built-in Protection Circuit Module (cell balancing + over/under-voltage, over-current and short-circuit protection) Anderson Powerpole output connectors Light for its capacity - 10.4 lb versus ~30 lb for a comparable lead-acid battery Clean, EMI-free DC with a long cycle life Optional 6 A LiFePO4 AC charger available
Strengths

A go-to field-day battery: 40 Ah of LiFePO4 will run a 100 W HF transceiver through a long operating session, the built-in protection module guards against the usual abuse, and at 10.4 lb it is a fraction of the weight of an equivalent lead-acid battery. Powerpole output and clean, EMI-free power make it plug-and-play for ham use.

Weaknesses

It is a substantial 40 Ah pack, so it is heavier and pricier than the smaller LiFePO4 batteries, and you must use a LiFePO4-compatible charger (an SLA charger can damage it) - the charger is often a separate purchase. Like all lithium chemistries, charging in freezing temperatures should be avoided.

Verdict

The Bioenno BLF-1240A is a workhorse 40 Ah LiFePO4 battery - enough to power a 100 W station all day, with built-in protection and Powerpole output at a fraction of lead-acid weight. An excellent field/emergency battery; budget for a LiFePO4 charger.

The Bioenno BLF-1240A is one of the most popular field batteries in amateur radio: a 12 V, 40 Ah lithium iron phosphate (LiFePO4) pack with enough capacity to run a 100 W HF transceiver through a long Field Day, POTA activation or emergency. It can deliver up to 40 amps continuously (and 80 amps in a 5-second peak), which covers a 100 W rig's transmit draw with room to spare, and it puts out clean, EMI-free DC.

Its big advantage over lead-acid is weight and life: at 10.4 pounds it weighs roughly a third of a comparable 40 Ah AGM battery, and LiFePO4 chemistry delivers far more charge/discharge cycles. A built-in Protection Circuit Module balances the cells and guards against over-current, over- and under-voltage and short circuits, and the battery terminates in Anderson Powerpole connectors - the de facto ham standard - so it is essentially plug-and-play.

The things to remember are that it is a sizeable 40 Ah pack (heavier and dearer than the small LiFePO4 batteries), and that lithium iron phosphate must be charged with a LiFePO4-compatible charger - never an SLA charger - which is often a separate purchase; avoid charging below freezing. For all-day field power it is a superb choice. Compare it with the smaller Bioenno BLF-1212A and the Bioenno LFP line.