Quick answer

The two batteries are not interchangeable. The 2000mAh 10.8V pack fits Velux 946933, 846933 and 946930 solar shutter motors, while the 865103 2000mAh battery fits Velux Integra Solar and KSX 100K lighting units. Match the battery to the model printed on your Velux unit, not to the window type.

Why the model number decides the fit

Velux uses different battery packs across its solar window and blind ranges, and the model number on the unit is the only reliable way to tell them apart. A 946933 or 946930 solar shutter motor takes the 2000mAh 10.8V pack, while an Integra Solar or KSX 100K lighting unit takes the 865103 2000mAh battery. Both packs share the same 2000mAh capacity, so capacity alone will not tell you which one you need. Check the label on the motor or control unit before ordering, and treat the voltage rating as a hard requirement rather than a preference.

What each replacement covers

The 946933/846933/946930 battery is a 10.8V, 2000mAh replacement aimed at Velux solar shutter motors. That 10.8V figure is the detail that separates it from the 865103, which is listed for Integra Solar and KSX 100K lighting units. If your unit is a solar shutter motor, the 865103 is the wrong part even though both are 2000mAh. If your unit is an Integra Solar or KSX 100K lighting unit, the 10.8V pack is the wrong part. Use the model list, not the window size or age, to choose between them.

How to confirm before you order

Open the battery compartment and read the model number directly off the unit or the old battery. Velux numbers can appear as 946933, 846933 or 946930 on the same family of shutter motors, so note every number you see. If the label shows Integra Solar or KSX 100K, order the 865103 battery. If it shows a solar shutter motor model, order the 10.8V pack. When a specification such as connector type or exact compartment dimensions is not listed in the product data, measure the old battery and compare it before ordering rather than assuming a fit.

Trade-offs at a glance

  • Fit certainty: Both packs are model-specific. The 10.8V pack covers three shutter motor numbers; the 865103 covers Integra Solar and KSX 100K. Neither is a universal Velux battery. Match the model number on your unit before buying.
  • Capacity versus voltage: Both are 2000mAh, so capacity will not separate them. The 10.8V rating on the shutter motor pack is the meaningful difference. Check voltage, not just mAh.
  • Price and guarantee: The 865103 is listed at USD 21.51 and the 10.8V pack at USD 25.13, both with a 3-year guarantee and fast UK delivery. Pick by fit first; the price gap is small.

Product facts

Which one should you buy?

Best for

  • Velux 946933, 846933 or 946930 solar shutter motor owners
  • Anyone replacing a 10.8V, 2000mAh Velux shutter motor battery

Not for

  • Velux Integra Solar or KSX 100K lighting units, which take the 865103 battery
  • Units where the model number cannot be confirmed before ordering