We ship every Kestrel 4000 Series Meter exclusively with Made in the USA Energizer® Brand Ultimate Lithium AAA batteries for improved reliability, capacity, cold-weather performance and weight. Our Kestrel 5000 Series Meters are shipped with 1 Ultimate Lithium AA battery. We strongly recommend that you use only Energizer Ultimate Lithium batteries in your Kestrel Meter. If you choose to install alkaline batteries, we recommend that you do NOT store your Kestrel with these batteries installed and that you check your batteries for leakage and corrosion a minimum of every 30 days. Damage due to leaking alkaline batteries is not covered under warranty.

Why the switch? There are some definite benefits to using lithium batteries:

• They are lighter.
• They offer a much longer life with Bluetooth applications.
• Lithium batteries offer better cold-weather performance.
• Most importantly, lithium batteries WILL NOT LEAK in storage applications, even with the low-level power drain of data logging. They protect an expensive Kestrel Meter from internal damage due to inexpensive and leak-prone alkaline batteries