40V 4.0Ah Lithium Battery

Features

  • Temperature-management material around each cell to help control heat
  • Designed to increase runtime and extend battery life
  • Compatible with PWRCore 40 40V tools
  • LED indicators for remaining charge
  • Shock-resistant construction
  • Includes one 4.0Ah battery

Specifications

Power Type Lithium-ion
Capacity 4.0 Ah
Battery Level Indicator Yes
Cooling/Temperature Management Yes
Weight (Lb) 3.62
Voltage (V) 40

A 40V 4.0Ah lithium-ion battery for the PWRCore 40 system. Each cell is enclosed in temperature-management material to help control operating temperature and reduce thermal stress, which is intended to increase runtime and extend service life. Green LEDs provide a battery charge indication. The pack has a shock-resistant design to protect cells and electronics.

Model Number: BY8708C-01

Skil 40V 4.0Ah Lithium Battery Review

1.3 out of 5

Diving into the world of battery-powered tools, I recently had the opportunity to test out the Skil 40V 4.0Ah Lithium Battery (BY8708C-01). As someone who frequently uses a variety of power tools, I was eager to see how this battery would perform, especially given its promise of extended runtime and compatibility with all Skil 40V tools. Here’s a detailed account of my experience with this battery.

First Impressions

At first glance, the Skil 40V battery feels robust and well-constructed. The shock-resistant design is a nice touch, providing some peace of mind that it can withstand the occasional drop or bump. The battery also features LED lights to indicate charge status, which is a convenient addition when you’re in the middle of a project and need to quickly check how much juice you have left.

Performance and Runtime

One of the main selling points of this battery is its cooling technology, which is supposed to enhance runtime. During my initial tests, I used the battery with a Skil leaf blower and a hedge trimmer. The battery performed adequately, providing a decent amount of power. However, I quickly noticed that the runtime was significantly shorter than advertised. On a full charge, the battery lasted about 30 minutes with continuous use on the leaf blower, which is far less than I expected for a 4.0Ah battery.

Charging the battery also took considerably longer than the 15 minutes advertised. In my experience, a full charge took over an hour. This extended charging time can be quite frustrating, especially if you’re in the middle of a project and need to get back to work quickly.

Durability and Longevity

Durability is a crucial factor for any battery-powered tool, and this is where the Skil 40V battery fell short for me. After about six months of intermittent use, the battery began to show signs of wear. It struggled to hold a charge and eventually stopped charging altogether. The battery also started leaking a black liquid, which I found quite concerning.

Customer Support and Warranty

While the battery comes with a two-year warranty, I found the customer support experience to be a mixed bag. On one hand, Skil did replace a failed battery for me without much hassle. However, the replacement process took about a week, which can be a significant downtime if you rely heavily on your tools. Additionally, the fact that the battery failed so soon after the warranty period is a red flag for its overall reliability.

Pros and Cons

Pros:
- Shock-Resistant Design: The battery is built to withstand minor impacts, making it suitable for tough work environments.
- LED Charge Indicator: The LED lights provide a quick and easy way to check the battery’s charge status.
- Compatibility: Works with all Skil 40V tools, offering versatility if you own multiple Skil products.

Cons:
- Short Runtime: The battery doesn’t last as long as advertised, which can be a significant drawback for larger projects.
- Long Charging Time: Despite claims of a quick charge, it takes over an hour to reach full capacity.
- Durability Issues: The battery showed signs of wear and leakage within a relatively short period.
- Warranty Limitations: The two-year warranty may not be sufficient given the battery’s tendency to fail just after the warranty period.

Final Thoughts

Overall, my experience with the Skil 40V 4.0Ah Lithium Battery has been less than satisfactory. While it has some useful features and is compatible with a range of Skil tools, its performance and durability leave much to be desired. The short runtime and long charging time make it impractical for extended use, and the durability issues raise concerns about its long-term reliability.

Given these factors, I cannot recommend the Skil 40V 4.0Ah Lithium Battery. For those who rely on battery-powered tools for their work or home projects, investing in a more reliable battery with a proven track record would be a wiser choice. The frustration of dealing with short battery life and potential leakage is not worth the initial convenience this battery might offer. Instead, consider exploring other options that provide better performance and longevity.



Project Ideas

Business

Quiet Early-Morning Landscaping

Offer HOA- and hospital-friendly lawn care using 40V tools for mowing, trimming, and blowing. Market the low-noise, zero-fume experience and schedule battery swaps using the pack’s LED indicator to maintain continuous operations.


Snow & Storm Response Subscriptions

Provide sidewalk/driveway snow clearing and post-storm debris removal with 40V snow throwers and blowers. Sell seasonal subscriptions; the battery’s shock-resistant build and thermal management support cold-weather reliability.


Event Cleanup and Venue Turnaround

Serve wedding venues and festivals with silent, cordless cleanup between events. Use a fleet of 40V blowers, hedge trimmers, and vacs to reset spaces quickly without generators. LED fuel gauges simplify fleet rotation and uptime.


Neighborhood Tool Library + Battery Share

Launch a membership-based tool library for PWRCore 40 tools. Maintain a charged pool of 4.0Ah packs, track checkouts, and offer on-site charging. Emphasize sustainability and cost savings versus owning rarely used tools.


Eco Handyman: No-Generator Service

Position as a green handyman offering quiet repairs, light carpentry, and yard tasks powered by 40V tools. Highlight clean indoor/outdoor work, reduced noise, and fast job turnover aided by runtime-extending, temperature-managed batteries.

Creative

Snap-In Camp Light Tower + Charger

Build a collapsible light tower that accepts the 40V battery as a base. Use a DC-DC converter to power high-output LED panels and a USB-C hub for phones/cameras. The battery’s LED fuel gauge makes it easy to manage runtime, and the shock-resistant pack is ideal for outdoor use.


Portable Garden Fountain/Pond Pump

Create a decorative, cordless fountain that docks the 40V battery and drives a low-voltage pump via a step-down controller. Add a simple timer and float sensor for safety. Great for patios or pop-up event decor where outlets aren’t available.


Cordless Shop Air Mover/Drying Stand

Design a compact air mover that clips onto a finishing stand or drying rack to speed cure times for paint/finish. The 40V pack’s longer runtime and thermal management help keep airflow steady without overheating during extended sessions.


Off-Grid Maker Booth Power Hub

Make a battery-docked power hub for craft fairs: step down 40V to multiple DC rails (USB-C, 12V) to run lights, a label printer, and small electronics. The LED indicator allows quick swaps so your booth stays lit all day without a generator.


Smart Tool Wall with Charge Status Windows

Build a custom tool wall that cradles the battery and mirrors its LED indicator through acrylic ‘windows’ so you can see charge levels at a glance. Integrate labeled docks for each 40V tool to streamline grab-and-go workflow in the shop.