Silva Free 1200 S vs M: Battery, Runtime & Weight

Choose the tradeoff

Less carried weight, or more battery?

Both configurations here are rated at 1,200 lumens. The S and M difference is about the battery package, not which lamp has a higher maximum brightness.

Start here when weight matters
263g with battery

Free 1200 S / 3.35 Ah

The lighter of these two configurations. Compare it first for a shorter outing, provided your chosen light mode covers the full trip with a reserve.

Take a closer look at the S →
Start here when runtime matters
316g with battery

Free 1200 M / 5 Ah

A larger battery and longer published burn times, with a little more weight to carry. Compare it first when the outing calls for more battery capacity.

Take a closer look at the M →
The weight difference is 53 g. That is 316 g minus 263 g using the published configuration weights, not an Alpine Extreme weigh-in. Compare the runtime at the mode you will actually use before deciding whether that tradeoff works for you.

Compare like with like

Pick a mode. Then compare the hours.

A headline lumen rating cannot tell you how long a light will suit your outing. These are the published burn-time figures for the battery configurations below.

Swipe sideways to compare both headlamps.

Published burn times for the 3.35 Ah S and 5 Ah M configurations
Mode / output Free 1200 S Free 1200 M
Maximum / 1,200 lumens 1.5–3 hours 2 hr 15 min–4.5 hours
Medium / 500 lumens 4–8 hours 6–12 hours
Minimum / 80 lumens 25 hours 35 hours
Battery 3.35 Ah / 24.1 Wh 5 Ah / 36 Wh
Weight with battery 263 g 316 g
Plan a reserve, not a perfect-case finish. These figures do not promise constant maximum brightness for the entire stated duration. Temperature, battery condition, settings and use affect the result. Do not plan around the most optimistic endpoint with no margin.

Sources: Silva Canada, Free 1200 S and Silva, Free 1200 M. Figures describe the configurations identified here, not every product sold under an S or M name.

Think beyond the lamp

Build the setup around your outing.

A run, a ski session and a helmet-mounted setup can ask different things of the same modular lamp family.

Check what the package actually includes.

A complete headlamp package is different from a lamp unit, a battery or a mounting accessory. For off-head carrying, helmet mounting or bike use, confirm the compatible mount and cable supplied with your exact package.

The S and M suggestions are starting points, not a claim that either is right for every activity. Consider your pace, terrain, mounting position and lighting needs. Follow the product instructions and applicable lighting requirements.

A useful pre-trip check

Ticking this checklist is a planning aid, not a runtime guarantee. Ask us about your exact setup when a detail is unclear.

Before you head out

The questions behind the numbers.

Choose for the outing you actually have planned, not simply the largest number on the box.

Is the M brighter than the S?

Not in this comparison. Both are rated at 1,200 lumens. The M configuration has the larger battery and longer published burn times shown above.

Will the S run at 1,200 lumens for three hours?

Do not read the maximum-mode range as a promise of constant 1,200-lumen output for the whole period. Use the manufacturer's operating guidance and allow a reserve for real conditions.

Does the 53 g difference include the batteries?

Yes. It is calculated from the two published weights with their corresponding batteries: 316 g for the M and 263 g for the S.

Are all mounts included because the system is modular?

No. Check the exact package contents. A compatible accessory can still be sold separately.

Sources, model revisions and how to read the figures

Source review: September 18, 2026. This guide covers the linked 3.35 Ah Free 1200 S and 5 Ah Free 1200 M catalog configurations. Published weights and burn times are manufacturer information, not independent tests by Alpine Extreme.

Confirm the printed battery specification and supplied instructions before relying on a particular configuration. No specific runtime, mounting arrangement or suitability for every activity is guaranteed by this comparison.