Will I need a soft-start on my A/C? What does that entail?

A soft start is a device that reduces the electrical surge when your A/C compressor turns on. It applies only to air conditioning systems, not heating systems.

Whether you need one depends on your A/C unit's LRA (locked rotor amperage). If your A/C unit's LRA exceeds 100, a soft start is typically required. Here's why: when an outage occurs, your home loses power from the grid and the Base battery turns on. Your A/C compressor will try to restart at the same time and without a soft start, that startup surge can be too much for the battery to handle alongside the rest of your home's load.

Note: Your home must be using 11 kW or less for the battery to turn on during an outage. If high-draw devices like electric heaters push usage higher, you can use the Base App to turn on the battery after reducing usage.

If a soft start is required, Base will let you know during setup, and our licensed HVAC partners will handle the installation at no additional cost to you.

No. If your home requires a soft start, our licensed HVAC partners will install it as part of your setup at no additional charge.

Base works with licensed HVAC partners to install soft starts. If your home requires one, you should expect a text or phone call from our HVAC partner to schedule the installation. This outreach is not spam or a scam — it is coordinated by Base as part of your setup.

If you receive a message about a soft start installation and want to confirm it's legitimate, feel free to contact Base support and we'll verify.

Soft starts are typically installed after your battery system is set up — usually within a few weeks. In some cases, our HVAC partner may be on-site before or during your battery installation. Here's what to expect:

1. Base determines if you need one after reviewing your photos, or sometimes when our electricians are on-site during installation.

2. You'll receive an email from Base after your battery installation is scheduled, letting you know a soft start is needed.

3. Our HVAC partner will reach out to you directly by text or phone call to schedule the installation at a time that works for you.

Your battery system and A/C unit will still function normally. However, during an outage, you may have to turn your A/C unit off to allow the battery system to fully turn on. Your A/C may need to remain off for the duration of the outage until grid power is restored.

Once our HVAC partner installs the soft start, your A/C should run normally during outages without any action on your part.

Note on startup delays: After a soft start is installed, some A/C units have a built-in compressor protection delay (often around 5 minutes) before restarting after a power interruption. This is standard manufacturer behavior — not a problem with your Base system or the soft start. If your A/C doesn't immediately kick on during an outage, give it a few minutes.

If your A/C unit already has a soft start installed, let our HVAC partner know when they reach out to you. We'll verify that your existing soft start is compatible with the Base battery system. If it meets our specifications, no additional installation is needed.

A hard start and a soft start are different devices, and they cannot both be installed on the same A/C unit. A hard start boosts the compressor at startup by drawing more power, while a soft start reduces the startup surge — which is what the Base battery system requires. If your unit has a hard start, our HVAC partner will remove it and install a soft start in its place during your scheduled installation.

If your home has more than one A/C unit, each unit is evaluated when we review your photos or when our electricians are on-site. Some homes may need a soft start on more than one unit. Our HVAC partner will handle all installations — you don't need to schedule separately for each one.

If you'd prefer to have your own HVAC technician install a soft start, please contact Base support before proceeding so we can confirm compatibility and avoid a duplicate installation by our HVAC partner.

While soft starts handle power regulation, if you're concerned about protecting your A/C unit from grid voltage spikes (which Base unfortunately cannot control or prevent), you might want to consider installing a separate surge protector. Surge protectors focus on safeguarding the system from unexpected voltage spikes and are different from soft start devices.