Kastar BP-U90 Battery and Dual Fast Charger Replacement - High

In this review the Kastar BP-U90 replacement kit is tested as an alternative power solution for professional Sony camcorders. It is aimed at shooters who need long runtime and fast turnaround between takes, and the single biggest reason to consider it is the pair of high-capacity 8700mAh batteries combined with an LCD dual fast charger that can top up two batteries simultaneously. The review focuses on run time, charger intelligence and build compatibility with a range of PXW and PMW series cameras.

Key Features

• Ultra-high capacity: Each battery provides 8700mAh at 14.4V, giving extended runtime for long shoots and fewer battery swaps on location.
• Japanese cells: Uses high quality Japanese cells for longer battery life and reduced memory effect over repeated charge cycles.
• Dual fast charger: The Kastar LCD dual charger can charge two batteries at once and displays charge status and battery capacity on the screen.
• Wide voltage compatibility: The charger accepts batteries from 6.8V to 16.8V and the MCU automatically identifies voltage to deliver intelligent charging and prevent overcharge.
• Reliable charge method: Charging follows CC/CV with pre-charge and 0V activation for drained Li-ion cells, which helps recover and extend battery life.

Who It's For

The kit is best for professional videographers and ENG operators using Sony PXW and PMW series camcorders who need long runtimes and the convenience of charging multiple batteries overnight or between shoots. The high-capacity cells are particularly useful for handheld documentary work, event coverage, or any situation where AC power is limited.

Those who should look elsewhere include users who require manufacturer warranty support tied to OEM batteries or those who need lighter, lower-capacity batteries for smaller rigs; the Kastar pack is optimized for endurance and fast charging rather than compact weight savings.

Pros & Cons

Pros

• High 8700mAh capacity delivers noticeably longer run times versus typical OEM mid-capacity packs.
• Dual fast charger with LCD makes it easy to monitor two batteries and return to shooting faster.
• Smart MCU charging prevents overcharge and handles a wide voltage range for compatibility.

Cons

• The battery and charger are third-party components, so users seeking OEM-only support may prefer manufacturer-branded units.

Specifications

Battery type	Lithium-Ion
Battery voltage	14.4V
Battery capacity	8700mAh
Charger type	LCD Dual Fast Charger, CC/CV
Charger voltage range	6.8V - 16.8V
Special features	Pre-charge, 0V activation, MCU intelligent identification

Our Verdict

The Kastar BP-U90 battery and dual charger kit is a strong value for professionals who need extended runtime and reliable, fast recharging. With high-capacity Japanese cells and an intelligent LCD charger that handles two batteries at once, it reduces downtime on location and suits a wide range of Sony PXW and PMW camcorders. It is a practical choice for endurance-focused shooters who accept third-party components for better runtime and charging convenience.

Frequently Asked Questions

Will these batteries fit my PXW-FS7 camera?
Yes, the kit is listed as compatible with PXW-FS7 and related PXW/PMW models that use BP-U series battery plates.

Can the charger handle two batteries of different voltages?
Yes, the charger MCU automatically identifies battery voltage and supports charging batteries within the 6.8V to 16.8V range.

Does the charger support 0V activation for fully drained cells?
Yes, the charger includes pre-charge and li-ion 0V activation functions to recover and extend battery life.