Kastar NP-F550 NP-F570 4-Pack Battery and LTD2 USB Charger - Field

In this review the Kastar 4-Pack NP-F550 / NP-F570 battery set with the LTD2 USB charger is evaluated for videographers who use FEELWORLD and similar on-camera monitors. The bottom line: this bundle is for shooters who need reliable, high-capacity backup power and flexible charging on location. It combines four 2900mAh lithium-ion batteries with a compact dual USB charger that can top up two cells at once and supports both Micro-USB and Type-C inputs, making it a practical utility for multi-camera shoots or long monitoring sessions.

Key Features

• Long runtime: Each 7.4V 2900mAh lithium-ion battery delivers extended powering for monitors so the user can record and monitor longer without swapping batteries frequently.
• Dual charging: The LTD2 USB charger can charge two batteries simultaneously, which speeds turnaround when multiple spares are in use on set.
• Interchangeable plate: The charger can change plates to accept different battery plates, providing versatility for other compatible camera and monitor batteries.
• USB input options: With Micro-USB and Type-C input and a 5V 2-3A input rating, the charger runs from common power banks and USB adapters for convenient field charging.
• LED status indicators: Intelligent LED display shows charging status and approximate battery capacity so operators can see remaining power at a glance.
• Compact power draw: The charger accepts 15W input and provides 8.4V 800mA outputs, balancing charge speed and cell safety for frequent use.

Who It's For

The kit is best suited to independent filmmakers, run-and-gun shooters, and content creators who rely on FEELWORLD F6 PLUS, FT6, FR6 and other compatible field monitors and need several high-capacity spares. The included charger is especially useful for those who travel and prefer USB power sources over bulky mains chargers.

It is less appropriate for users who need extremely fast professional charging racks or those who require OEM-branded batteries for manufacturer warranty reasons. If a studio setup requires hundreds of cycles per day, a higher-end charging solution may be preferable.

Pros & Cons

Pros

• High 2900mAh capacity per cell provides noticeably longer runtime than many standard replacement batteries.
• Dual simultaneous charging and plate interchangeability add flexibility when managing multiple battery types on set.
• USB Micro-USB and Type-C inputs let you charge from power banks or common wall adapters while traveling.

Cons

• Charging speed is moderate at 800mA per channel, so full recharge of depleted cells can take a while compared with higher-power chargers.

Specifications

Battery type	Lithium-Ion
Battery voltage	7.4V
Battery capacity	2900mAh
Charger input	5V 2-3A (15W)
Charger output	8.4V 800mA x1 or x2
Inputs	Micro-USB and Type-C (includes Micro USB cable)

Our Verdict

The Kastar 4-pack plus LTD2 USB charger is a practical value for shooters who need several dependable NP-F550/NP-F570 style batteries and the flexibility to charge from USB sources. It is a sensible buy for on-location creators who prioritize capacity, portability, and convenience over the fastest possible charging times.

Frequently Asked Questions

Are these batteries compatible with FEELWORLD monitors?
Yes, they are listed as compatible with numerous FEELWORLD models including F6 PLUS, FT6, FR6 and several FW series monitors.

Can the charger charge two batteries at once?
Yes, the LTD2 charger supports charging two batteries simultaneously with independent LED status indicators.

What power sources can be used to charge the batteries?
The charger accepts Micro-USB or Type-C 5V 2-3A input, so common USB power banks and adapters can be used.