As someone who regularly uses a variety of astronomical telescopes, GoTo mounts, and star-navigation devices that still rely on AA batteries, I’ve always wondered which batteries actually last the longest — especially in cold weather. I live at around 6,200 feet elevation, where nighttime temperatures often drop well below freezing, and batteries tend to drain far faster than their rated performance.

So, I recently decided to run a practical, real-world comparison between three types of AA batteries I had available:

• XTAR rechargeable 1.5V Li-ion AA batteries
• Duracell alkaline AA batteries
• EBL Ni-MH AA batteries

Note: this wasn’t a lab test — it was me using the batteries in actual astronomy gear during real observing nights. Here’s what I found.

Why I Did This Test

Several of my astronomy devices rely entirely on AA batteries:

• My Argo Navis navigation system uses 4 AA batteries
• My Orion StarSeeker 4 GoTo mount uses 8 AA batteries
• And many other telescopes — like the Celestron NexStar GoTo telescopes use 8 AA cells as well

Cold weather has always been a problem. Alkaline batteries in particular tend to drop voltage as soon as the temperature falls, leading to failed slews or devices simply shutting off. I wanted to know which batteries would actually hold up best outdoors.

The following are the specifications of the test battery:

Brand	XTAR	Duracell	EBL
Type	Li-ion	Alkaline	Ni-MH
Nominal Voltage	1.5V	1.2V	1.2V
Capacity	2500mAh	2850mAh	2500mAh
Energy	4150mWh	4275mWh	3000mWh
Discharge performance	1.5V constant output + 1.1V low battery alert	Gradual voltage drop	Gradual voltage drop
Cycle Life	1200+	/	500~800
Usage / Age	Brand new	Brand new	About two years old

In my experience:

• Rechargeables often handle cold better than alkalines
• Devices like GoTo mounts often fail because the voltage sags, not necessarily because the battery is truly empty
• A flatter discharge curve should help keep equipment stable throughout the night

So I suspected XTAR would do well, but I still wanted to test everything carefully.

Test 1: Real-World Runtime Test in the Orion StarSeeker IV

The Orion StarSeeker IV, a common beginner-to-intermediate GoTo telescope, runs on eight AA batteries. During testing, temperatures averaged around –2.2°C (29°F).

XTAR Results：

→ Runtime: 19.5 hours

This was the biggest surprise for me. It included four days of use in temperatures that dipped below freezing, and during that time the battery maintained a stable 1.5V output. Usually batteries just die when it gets this cold, so this performance was genuinely impressive.

Duracell Results

→ Runtime: 17.5 hours

But the way they “died” was very different. Instead of turning off cleanly, the mount simply couldn’t slew anymore. When I plugged in AC power, everything worked again immediately, confirming it was a voltage sag issue. 

Lastly, I didn’t test the EBL batteries in the StarSeeker because I didn’t have eight matching cells available.

Test 2: Real-World Runtime Test in the Argo Navis

The Argo Navis, used widely in Dobsonian and alt-az telescopes for accurate object location, relies heavily on stable voltage. In cold weather it has always been the first piece of equipment to fail for me during sky navigation.

XTAR Results

→ Runtime: 11.5 hours

The XTAR lithium-ion cells performed dramatically better: The screen stayed readable, and the device never shut down unexpectedly.

Duracell Results

→ Runtime: 4 hours

On a cold night, the alkalines lasted 4 hours. When I brought the batteries back inside, they worked again — which shows how severely cold weather affected them outdoors.

EBL Results

→ Runtime: 3 hours

The screen was still faintly lit, but I couldn’t read anything because the voltage had dropped too low. Even though they were fully charged before the test, they simply couldn’t handle the cold.

Summary of All Results

Devide Model	Battery Tested	Runtime/hrs	Performance Note
Orion StarSeeker 4	XTAR AA 4150	19.5	Longest lasting
	Duracell alkaline	17.5
Argo Navis	XTAR AA 4150	11.5	Outperforms by 3x
	Duracell alkaline	4
	EBL Ni-MH	3

This wasn’t a controlled lab experiment — it was a cold-weather astronomy test in the mountains. That’s exactly why the results felt meaningful to me.

• XTAR batteries consistently lasted the longest in both devices
• Alkalines were okay, but voltage sag caused functional failures before they were truly empty
• EBLs struggled the most in cold temperatures

Rechargeable AAs also help reduce waste — I had collected an entire bucket of used alkalines from the past year. I appreciated the convenience of not having to carry a big power tank or extension cords.

Final Thoughts

In the end, after seeing how well the XTAR batteries performed, especially in cold weather, I’ve decided to use them as my standard batteries for the Argo Navis and my other AA-powered astronomy gear. They’re lightweight, rechargeable, and most importantly — they didn’t leave me stranded halfway through a night of observing.