CHOICE verdict
From the moment you put them in the device until the batteries are spent, Tenavolts rechargeable AA lithium batteries deliver a consistent current at around 1.5V. This means they can power high-drain devices for longer periods compared to your standard single-use alkaline and NiMH rechargeable batteries. With a faster charge time than regular rechargeable batteries (we clocked it at just under two hours), the Tenavolts battery pack could be a good option if you find your existing rechargeable batteries aren't powering your devices like they used to or are powering them for shorter periods than you'd like.
Price: $55.99
Contact: tenavolts.com
On this page:
- Do you need a rechargeable lithium battery?
- Why is voltage important?
- What's in the Tenavolts kit?
- How do Tenavolts batteries perform?
Do you need a rechargeable lithium battery?
If used well, rechargeable batteries are an undeniably better environmental option compared to single-use alkaline batteries. But the inability for traditional NiMH (nickel metal hydride) batteries to reach the voltage of a single-use alkaline battery at 1.5V or even maintain their 1.2V level for the operating life of the battery is an issue for some, particularly if you're powering devices that house four or more AA or AAA batteries.
Tenavolts AA lithium rechargeable batteries deliver 1.5V from the moment you put them in the device until they stop, and they can then be recharged to full capacity in just under two hours.
Why is voltage important?
The two most important things to consider in a battery are voltage (volts) and current (amps). A simple analogy to understand the two components is to imagine water moving through a pipe.
Think of voltage as the water pressure supplied to the pipe while the current (measured in amps or mAh) is the flow rate. If the battery can maintain a consistent voltage, then the current or flow rate remains the same for the life of the battery.
If the voltage for a single battery drops during operation, which can happen for most alkaline and NiMH rechargeable batteries, then the aggregated effect can lead to an inability to power the device even if there's still energy left in the batteries.
For example, if a toy requires a certain amount of current to operate and the toy needs four or more batteries, then any drop from the 1.5V you can get from a single-use alkaline battery to the 1.2V you can get from a rechargeable NiMH battery leads to a quick drop in your ability to power the toy.
They may look like normal rechargeable batteries but these AAs can deliver 1.5V from a fully charged state to completely spent.
What's in the Tenavolts kit?
The package includes four lithium rechargeable AA batteries, a charger cradle and a micro USB cable that can be connected to your laptop or smart device power supply. The cable is quite short, but you can also use a longer micro USB cable if you have one that came with a smartphone, speaker or other smart device.
It's important to note that this charge cradle should not be used with any of the NiMH batteries you may already have at home. Keep the Tenavolts system away from your other rechargeable batteries and you'll have an ideal option for the devices that really need that extra boost.
The front of the cradle shows a blue LED to indicate the charge condition of the battery when it's in the charger, and the LED turns off when the battery is fully charged.
The kit includes four AA batteries, a charging cradle and small micro USB cable.
How do Tenavolts batteries perform?
Tenavolts batteries consist of a 3.7V/2.8Wh lithium-ion cell, which would make them incompatible with standard AA batteries. However, a 3.7V to 1.5V voltage converter/voltage regulator circuit board allows the Tenavolts batteries to be used on devices that require standard AA batteries. The board is located within the battery cylinder under the negative terminal cap.
The Tenavolts AA high-capacity rechargeable batteries are pre-charged up to 2775mWh, and are fully charged in a bit less than two hours, which is faster than the traditional quick charge NiMH rechargeable batteries which need at least three hours to be fully charged.
The batteries deliver a consistent 1.5V from fully charged to completely spent, providing the voltage required for some devices that need the best possible performance in heavy load discharge. Our tester, Carl Mihailovich, found some small variance over the life of the battery, but no more than 0.02V, which wouldn't be noticed in day-to-day use of the batteries.
In this voltage vs current comparison, the Tenavolts' performance was superior to the NiMH and alkaline batteries.
The measured capacity of the batteries is 1825mAh at 1.5V, which compares favourably to the rated capacity of 2775mWh (1850mAh). The load current for this test was 0.35A, which was used as the load for the NiMH rechargeable (Eneloop) and single-use alkaline (Duracell) batteries.
Our tester noted that the overall capacity of the Tenavolts batteries compares well with the Eneloop rechargeable and single-use Duracell alkaline batteries. The impressive voltage regulation of the Tenavolts batteries also makes them more versatile over loads ranging from low (0.1A) to very high (2A).
While the battery voltage remained very stable at each load current, there was a slight reduction with increased load. At 2A load (heavy) the voltage was >1.27V.
If you want to keep your high-drain devices powered for longer or cut down on single-use batteries (without compromising on performance), consider introducing your toys and devices to some Tenavolts AA lithium batteries.
Stock images: Getty, unless otherwise stated.
