AAA Ni-MH 1.1V 1100mAh High-Capacity Rechargeable Battery for Remote Controls and DIY

Prototyping and Engineering Tips from Robogears

• Series Stacking: To achieve higher voltages for your robots, you can stack these in series. For example, 4 cells in series will give you a nominal 4.8V, which is safe for powering many 5V microcontrollers like an Arduino or ESP32 directly through their 5V pins (though a regulator is always safer).

• Smart Charging: To maximize battery life, use a "Smart Charger" that detects when the battery is full using the $-\Delta V$ (negative delta voltage) method. Charging a Ni-MH battery at a high current for too long can cause it to vent or lose capacity.

• The "Low Voltage" Myth: While these are rated at 1.1V–1.2V, most devices designed for 1.5V Alkaline batteries will work perfectly with Ni-MH. This is because Alkaline batteries drop to 1.1V very quickly under load, whereas Ni-MH stays at a steady 1.2V for almost its entire discharge.

• Storage Advice: If you aren't using your robot for a few months, charge the batteries to about 50% before storing them. Ni-MH batteries naturally lose a bit of charge over time; checking them every few months ensures they don't drop to 0V, which can be difficult to recover from.

Package Includes

• 1 x AAA 1.1V 1100mAh Ni-MH Rechargeable Battery

Disclaimer

Images are for reference; actual brand labeling or color may vary by batch. Specifications subject to change by manufacturer. Do not short-circuit or incinerate.