The Spectra S1 and S2 are essentially the same breast pump with one key difference: the S1 has a built-in rechargeable battery, and the S2 does not. They share the same motor, the same maximum suction (270 mmHg), the same pumping modes, and the same accessories. So the real question is whether portable, cord-free pumping is worth the extra cost to you.
The Only Hardware Difference: Battery
The S1 has a rechargeable battery that provides about 3 hours of pumping per charge. That means roughly 6 to 9 sessions before you need to plug it back in, depending on how long each session runs. You can also use it while it charges, so you’re never stuck waiting.
The S2 must be plugged into a wall outlet at all times. If you lose power or can’t find an outlet, the pump doesn’t work. This is perfectly fine if you pump exclusively at home in the same spot, but it becomes a limitation the moment you need to pump in a car, at a park, or anywhere without a convenient plug.
Pumping Performance Is Identical
Both pumps offer two modes. Massage mode runs at 70 cycles per minute to stimulate letdown, mimicking the quick, shallow sucking pattern of a newborn. Expression mode runs between 38 and 54 cycles per minute for steady milk removal. You control suction strength on a scale up to 270 mmHg on both models, so neither pump is “stronger” than the other.
Both are closed-system pumps, meaning a backflow protector sits between the milk collection kit and the motor. No milk, moisture, or mold can reach the internal tubing or motor. This makes them more hygienic than open-system pumps and easier to keep clean over months of daily use.
What Comes in the Box
The S1 and S2 ship with identical accessories:
- Two 24mm breast flanges and two 28mm breast flanges
- Two sets of tubing
- Two duckbill valves
- Two backflow protectors (each with a silicone membrane, uppercase, and lowercase)
- Two wide-neck storage bottles with nipples, caps, discs, and lids
- One 12-volt AC power adapter
The S1 weighs about 3 pounds, which is light enough to toss in a bag but noticeably heavier than wearable pumps. The S2 is slightly lighter since it lacks the battery, though the difference is small.
Cost and Insurance Coverage
Most insurance plans cover the S2 at no cost through a durable medical equipment provider. The S1 typically requires an out-of-pocket upgrade fee. That fee varies widely depending on where you order. Some parents report paying $95 through their insurance company’s default supplier, while others have found it for $25 to $50 by shopping through different retailers or DME providers like Pumping Essentials or Babylist.
If you’re considering the upgrade, it’s worth checking multiple suppliers before committing. The same pump can have dramatically different upgrade pricing depending on the retailer your insurance works with. A quick call to your insurance company to ask which DME providers are in-network, followed by price comparisons across those providers, can save you $40 to $70.
Warranty and Longevity
Both pumps carry a 2-year warranty on the motor, and accessories are covered for 90 days when purchased from Spectra directly, through insurance, or from an authorized retailer. The warranty covers manufacturer defects, starts on the date of purchase, and is non-transferable. That means buying a used Spectra from someone else leaves you without warranty protection, which matters since both are designated as single-user pumps.
Which One Should You Choose
Pick the S2 if you pump at home almost exclusively and always have an outlet nearby. It’s the same pump for less money, and you won’t miss the battery if you never need it. Many parents who work from home or pump on a predictable schedule at a desk find the S2 does everything they need.
Pick the S1 if you pump at work, travel, or simply want the flexibility to move around your house without being tethered to a cord. The battery also serves as a backup during power outages, which matters more than you’d think during late-night pumping sessions. Parents who pump in cars during commutes, in break rooms without convenient outlets, or while chasing a toddler around the house consistently say the battery upgrade was worth the cost.
For most people who will pump regularly for several months, the S1’s upgrade fee works out to pennies per session. Three hours of battery life is generous enough that you rarely need to think about charging. If the upgrade fee through your supplier is under $50, it’s an easy call. At $95, it still pays off if portability matters to your daily routine.