SEYVUM Mini CS-BM21 750W Chainsaw: In-Depth Review and Customer Opinions

The Seyvum Mini CS-BM21 is a compact yet powerful chainsaw designed for light pruning and cutting tasks. Seyvum is a Chinese manufacturer established in 2016 focused on producing electric power tools. The Seyvum Mini chainsaw is notable for its lightweight and easy handling, fast yet quiet cutting, and battery-powered convenience.

Overall, the Seyvum Mini CS-BM21 offers a good balance of power, portability, safety features, and value for homeowners and DIYers looking for an entry-level electric chainsaw for light tasks. Key advantages of this model are its compact size, cordless battery operation, tool-less chain adjustments, and automatic oiling system. Downsides to consider are the short 20-30 minute runtime per charge, potential quality control issues, and lack of brand reputation compared to leading manufacturers. The Mini CS-BM21 performs well for incidental pruning jobs and should meet the needs of most casual users if handled properly, though more demanding tasks may require a higher-powered gas chainsaw.

Design

The SEYVUM Mini CS-BM21 chainsaw features a compact and lightweight design perfect for using one-handed. Weighing only 4.4 lbs with the bar and chain attached, this is one of the lightest gas-powered chainsaws on the market.

The petite 10-inch bar and chain are easy to maneuver in tight spaces and quick trimming jobs. The wraparound front handle has an ergonomic rubber grip that allows you to comfortably support the saw with one hand.

An additional handle is positioned at the rear of the body for two-handed operation. The rear handle can be installed on either side for left or right-handed users.

The chainsaw is very well balanced, with most of the weight positioned over the grip hand. This balance makes it easy to control the saw without excessive arm fatigue. The narrow body profile aids in getting into tight spots around trees or cutting near the ground.

Overall, the portable size and smart handle design of the SEYVUM Mini Chainsaw allow for effortless control and handling. The lightweight body brings maneuverability without sacrificing power.

Motor Power

The SEYVUM Mini CS-BM21 chainsaw is powered by a 750W brushless motor that delivers high torque for cutting through logs up to 25 cm in diameter. This battery-powered motor provides similar power to a gas chainsaw without the noise, fumes, and maintenance of a gas engine.

The motor uses a 36V 2.0Ah lithium-ion battery that provides up to 30 minutes of continuous runtime. While not as long as some gas models, the battery can be quickly swapped out for extended cutting sessions. The battery takes about 2-3 hours to fully recharge.

A key advantage of the electric motor is how quiet it operates compared to gas models. It produces just 80 dB of noise, similar to a vacuum cleaner, versus 95-115 dB for a typical gas chainsaw. This makes the electric saw much better suited to residential use where noise pollution is a concern.

The brushless motor design requires less maintenance as there are no brushes to replace like on brushed motors. It delivers consistent power throughout the battery cycle, right up until the battery is depleted. This gives you full cutting capability every time you use it.

Overall, the battery-powered brushless motor provides ample power for most small to medium sized cutting tasks, with significantly less noise and maintenance than a gas motor. Just be sure to have extra batteries on hand for longer projects.

Cutting Features

The SEYVUM Mini chainsaw comes equipped with a 10 inch bar and chain, providing good reach and cutting capacity for limbing and basic tasks. The bar length is ideal for a compact saw like this. Longer bars can bog down smaller motors.

It uses a low profile 3/8 inch pitch Oregon chain, which is easy to sharpen and replace. The chain speed is 12 m/s, which is typical for an electric saw of this size. Higher chain speeds allow faster cutting but require more power.

This electric chainsaw can handle logs up to 10 inches thick, making it suitable for cutting small limbs, saplings, and branches. While it can buck smaller logs, you'll want a more powerful gas chainsaw for felling large trees and major storm cleanup. The mini is best for modest cutting jobs and doesn't have the power of a pro-grade model.

Overall the cutting features allow you to take care of typical property maintenance needs and small projects around the yard. It's a handy backup saw to have around for emergencies or when you need a nimble electric tool.

Safety Features

The CS-BM21 comes equipped with several important safety features to help prevent injury.

Chain Brake

This chainsaw has an automatic chain brake that engages if the chainsaw experiences a kickback. The brake stops the chain instantly to prevent further contact. This is an essential safety feature for consumer chainsaws.

Kickback Protection

In addition to the chain brake, the CS-BM21 has a reduced kickback bar and chain. This helps reduce the chance and intensity of potential kickbacks. The bar tip guard also deflects kickbacks down and away from the operator.

Additional Safety Mechanisms

Further safety features include a front hand guard to protect the left hand and prevent accidental contact with the chain. There is also a safety lock that must be disengaged before the trigger can be activated to prevent accidental startup. The chain cover fully encloses the bar and chain when not in use for added protection.

Ease of Use

The SEYVUM Mini Chainsaw is designed for straightforward operation and maintenance. Starting the saw is simple with the side-mounted throttle trigger and lockout button to prevent accidental starts.

Adjusting the chain tension is tool-free and can be done by hand. Just turn the knob on the side cover counterclockwise to loosen the bar, adjust tension, and turn clockwise to tighten back up. The side cover can also be easily removed without tools for chain and bar changes.

Replacing the chain and bar is a quick process. Just remove the side cover, take off the old bar and chain, replace with the new one, and reinstall the cover. The chain has a self-tensioning system so getting the correct tightness is hassle-free. Make sure to lubricate the new bar and chain before use.

Overall, starting up, adjusting chain tension, and swapping out the chain and bar is intuitive and can be done rapidly without needing any tools. This makes the saw very convenient for those looking for simplicity when getting set up and making adjustments.

Runtime

The SEYVUM Mini chainsaw is powered by a built-in 1500mAh 20V lithium-ion battery. This provides sufficient power for the small 14-inch bar and chain, making the saw ideal for light duty trimming, pruning and cutting tasks.

The battery takes around 2-3 hours to fully charge. Actual runtime will vary depending on the thickness and hardness of the material being cut, but most users report getting 20-30 minutes of cutting time per charge. This is reasonable for a battery-powered chainsaw of this size.

One of the advantages of the electric design is no need to mix fuel or deal with the mess of gas. Simply charge the battery when needed and you're ready to go. The battery also retains its charge well when not in use.

For extended run times, an extra battery can be purchased so one can be charging while the other is in use. But for basic property maintenance tasks, the standard battery should be adequate on a single charge. Just be sure to monitor battery level and stop to recharge when running low.

Maintenance

Proper maintenance is key to ensuring your chainsaw runs safely and efficiently over time. Here are some tips for caring for your SEYVUM Mini CS-BM21 chainsaw:

Air Filter Cleaning

• Check and clean the air filter regularly to prevent dust and debris from entering the carburetor. Remove the air filter cover and gently brush off built-up dirt. Replace the filter if it's excessively dirty or damaged.

• Avoid using compressed air to clean the filter, as this can push dirt further into the fibers. Instead, gently tap the filter to remove particles.

Lubricating the Chain

• The chain needs constant lubrication to prevent friction and overheating. Use high-quality chain oil and check the oil tank level before each use.

• When refilling the oil tank, take care not to overfill. Too much oil can be flung off the chain onto the operator.

• Inspect the oil delivery system periodically to ensure oil is flowing properly to the chain. Clean out any blocked ports or passages.

Storing and Preventative Upkeep

• After each use, allow the chainsaw to fully cool before storing. Empty the fuel and chain oil tanks before longer-term storage to prevent gumming.

• Wipe off any dirt, sap, or debris from the saw body, chain, and guide bar. This helps prevent corrosion and wear.

• Store the chainsaw in a clean, dry location out of direct sunlight. Avoid temperature extremes.

• Replace the spark plug and air filter as specified in the owner's manual. A well-maintained engine will extend the life of your saw.

• Sharpen or replace the chain periodically to keep it cutting efficiently. Use the correct file size and follow sharpening angles.

Accessories

The SEYVUM CS-BM21 comes with several key accessories including a blade guard, chain cover, 41.3 cm (16 inch) bar and chain, and hex key wrench set.

Included Accessories

• Blade guard - Helps protect the user from flying wood chips and debris while sawing. Made from durable plastic.
• Chain cover - Keeps the chain protected when saw is not in use. Prevents accidental contact with the sharp cutting chain.
• 41.3 cm (16 inch) bar and chain - Offers good cutting capacity for small to medium jobs. Hardened steel resists wear.
• Hex key wrench set - Allows for tensioning the chain and general maintenance.

Optional Add-ons Available

• Longer guide bars - Up to 50.8 cm (20 inches) available for cutting larger pieces of wood.
• Spare chains - Good to have extras on hand for quick chain changes when working extensively.
• Carrying case - Provides safe transport and storage for the saw and accessories. Water resistant fabric.

Compatibility with Attachments

The CS-BM21 uses industry standard mountings and attachments. Compatible accessories include:

• Depth gauges - For setting precise cutting depths.
• Felling wedges - For helping guide the fall direction of trees.
• Chainsaw mills - Allow the saw to function like a small portable sawmill for milling lumber.
• Pole saw attachments - Extend the saw's reach for high branches.

The universal compatibility gives owners flexibility to customize their saw setup for different needs.

Conclusion

The SEYVUM Mini CS-BM21 750W chainsaw offers a compact, lightweight design perfect for home DIY projects. Its powerful 750W motor can cut logs up to 6 inches thick, while the 12 inch Oregon bar and chain provide smooth, efficient cutting.

Overall, the chainsaw's biggest pros are its portability, ease of startup, and safety features like the chain brake and front hand guard. The electric model also requires less maintenance than gas chainsaws. The runtime could be longer, but the 2Ah batteries are swappable for continuous working time.

For light-duty trimming, pruning, and firewood cutting, the SEYVUM Mini is an excellent choice. It may struggle with thick hardwood logs over 6 inches. Larger 16-20 inch gas chainsaws would be better suited for frequent heavy-duty use.

Consider the SEYVUM Mini if you need an occasional-use electric chainsaw for your property. It packs plenty of power while remaining easy to handle and transport. Just be mindful of the limited runtime per charge. For extended cutting jobs, have extra charged batteries on hand.