How much battery does RGB lighting drain on a wireless mouse?

About a quarter of your hours. Across nine pairs of manufacturer ratings from Logitech and ASUS, a wireless mouse with its lighting on is rated for 67 to 88 percent of its lights-off hours. In the middle of the range it keeps 75 percent. None of the nine loses half. Logitech's own three pairs cost 13, 25 and 27 percent.

What is being measured

RGB lighting means LEDs with red, green and blue parts that mix to make any colour. On a mouse they usually sit in the logo, the scroll wheel or a strip along the shell. The lighting runs an effect. Colour cycling steps through colours with the LEDs lit all the time. Breathing fades them in and out.

A lights-off and lights-on pair is two battery ratings for the same mouse under the same conditions, with only the lighting changed. Logitech states its pairs at a 1 ms report rate, which is 1000 Hz polling. ASUS does not state the rate on its spec pages. All of these figures are continuous use, as rated by the maker, not measured by us.

Stated hours, lights off and on

The last two columns are derived. "Kept" is lights-on hours divided by lights-off hours. "Cost per lit hour" is the extra share of a full charge that one hour of lighting uses, explained below.

One brief note on the Harpe Ace Aim Lab. TechPowerUp's review quotes ASUS at 70 hours with lighting. ASUS's own spec page now says 79 hours with the default breathing effect, and the table uses the spec page.

One mouse, worked through

Take a G903 and suppose you play four hours a night. Lights off, Logitech's 32 hours last eight nights. With colour cycling on, 24 hours last six. That is the whole cost in plain terms: two nights fewer between charges.

Now look at it per hour. Each unlit hour uses 1/32 of a charge. Each lit hour uses 1/24. The difference is what the lighting adds.

So on this mouse, every hour with the lights on spends about one extra percent of the battery.

Why the percentage changes from mouse to mouse

The Harpe Ace Extreme shows it best, because ASUS rates it on two radios. On 2.4 GHz the lighting costs 24 percent of the hours. On Bluetooth it costs 32 percent. Yet the cost per lit hour is almost the same in both: 0.46 and 0.47 percent of a charge. The lighting draws about the same power either way. Bluetooth draws less for everything else, so the same lights take a bigger share. (Bluetooth is also too slow for competitive play, as wireless versus wired explains.)

That is the rule. The lighting cost depends on two things: how much power the LEDs draw, and how much the rest of the mouse draws. More LEDs, more brightness and effects that stay lit all push the first number up. A thrifty radio or sensor pushes the second number down. Either one makes the percentage worse. It is not one fixed figure for every mouse.

The same logic runs the other way at high polling rates. Our polling rate battery life page shows 8000 Hz leaving 13 to 27 percent of the 1000 Hz hours. If the lighting's draw stays fixed, it becomes a smaller share of that much larger total.

Does RGB halve battery life?

Not on any mouse rating we found. The claim persists for three reasons, and each one is real in its own setting.

First, efficient mice give the lights a bigger share. SteelSeries' engineer writes that the Rival 3 Wireless "only has a single RGB LED in the scroll wheel". Yet out of the box it "draws almost 40% of the total power". Worked through, that means about 60 percent of the lights-off hours. That mouse runs on AAA batteries and is rated for up to 400 hours in its power-saving mode. Its Smart Mode turns the light off while the mouse moves, which SteelSeries says can bring the share down to about 10 percent in an FPS. The breathe effect brings it from 40 to about 35.

Second, small batteries make any loss feel larger. TechPowerUp ran the Aerox 3 Wireless at 1000 Hz with all lighting on, and it "shut off" after 10 hours. It has a 250 mAh battery. SteelSeries' 200-hour headline applies only to Bluetooth, which TechPowerUp says limits polling to 133 Hz. Set one figure beside the other and it looks like lighting wiped out 95 percent. But the two figures use different settings, so the gap says nothing about the LEDs alone. Trading battery for grams is a choice we cover in mouse weight.

Third, keyboards really do lose most of their battery. Logitech rates the G915 X TKL at up to 1000 hours with RGB off, 100 hours at 50 percent brightness and 42 hours at full brightness. Full lighting keeps about 4 percent of the hours. Worked back, the lights are about 96 percent of the keyboard's draw at full brightness. Logitech also notes that G HUB will show no more than 236 hours with the lighting off.

Where these numbers stop applying

These are makers' ratings, not our tests. Logitech and ASUS rate lighting under one named effect. Your brightness and effect may differ, so treat each pair as a guide to that mouse only. We left out mice whose lights-on figure we could not load from the maker. That includes Logitech's G502 X Plus, whose pair appears only in shop listings. Razer and Corsair mice are missing for a similar reason. The figures we found for them give hours without lighting, with no lit figure beside them. And the per-hour cost assumes the lighting draws steadily. Effects that switch off while you move break that, in your favour.

Sources

• Logitech support, G502 LIGHTSPEED battery life.
• Logitech support, Battery life for G900 and G903.
• Logitech support, Check battery status and charge the G403 or G703.
• Logitech G, G915 X TKL Wireless specifications.
• ASUS ROG, spec pages for the Harpe Ace Aim Lab Edition, Keris Wireless and Keris Wireless AimPoint.
• TechPowerUp, battery life sections of the ROG Harpe II Ace, ROG Harpe Ace Extreme, ROG Harpe Ace Aim Lab Edition, Aerox 3 Wireless and Aerox 5 Wireless reviews.
• SteelSeries, "Optimizing the Battery Life of the Rival 3 Wireless", Derek Brykowski.