Pick your player, battery edition

‍Batteries aren’t exactly groundbreaking technology — Volta’s first battery dates back to 1800. But over the last 200ish years, a lot of investment has gone into creating increasingly safe, durable, and space-saving modern batteries.

So there are a lot of options to choose from when you start a battery-integrated appliance company. And naturally, the stakes are high.

At Impulse, we’ve chosen to use the LFP battery (shorthand for Lithium Iron Phosphate). We think it’s the best battery for the job, but we don’t want you to just take our word for it. So today, we’re going to quickly run you through the battery landscape — the types, their strengths, and their weaknesses — to show you why an LFP battery is the perfect one for your home (and stove).

The battery landscape 

Most modern batteries use the same basic building blocks as the batteries of centuries ago.

Today’s battery landscape is dominated by lithium-ion batteries, which emerged onto the commercial landscape in the 1980s. They’re a class of batteries that use some sort of lithium ion to carry charge back and forth between the cathode and the anode.

There are lots of types of lithium ion batteries, which are differentiated by the lithium ion that they use (shocker, we know). But there are a few players that dominate the field:

1. NCA (Lithium Nickel Cobalt Aluminum Oxide): popular for use in EVs, particularly Tesla’s Model S and X.

2. NMC (Nickel Manganese Cobalt Oxide): also popular for use in EVs across a bunch of car brands.

3. LTO (Lithium Titanate): used in low-temperature specialty applications

4. LFP (Lithium Iron Phosphate): our choice of battery, and also popular across home energy storage systems like Tesla Powerwalls.

Each battery type has its own strengths and weaknesses, which makes some of them a better fit for applications like EVs while others are better for home energy storage.

How to pick a battery

There are a few features that we can use to distinguish between battery technologies to pick the right man for the job:

• Safety

• Durability

• Energy density (or, storage capacity/size)

• Charging speed

Here’s how the batteries stack up against these criteria:

As you can see, there’s no one perfect battery. But when you’re making battery-powered appliances, some things are higher priority than others.

For example, even though we care a lot about how quickly our battery discharges, we don’t care too much about how fast it charges. (This is because our stoves can charge for 23 hours of the day before they’re used for an hour of cooking.) And while energy density keeps our appliances small and tidy, it isn’t as important as it might be in EV.

When it comes to major home appliances, we’re looking for something safe and long-lasting. The average stove is expected to last 10-15 years in your home, so we need our batteries to last just as long. And of course, it’s imperative that the batteries don’t introduce any new risks into the home, especially fire risk.

When we weigh these priorities, we have a clear winner: LFP batteries.

What makes LFP batteries so special

Durability

The main limit on the lifespan of a rechargeable battery (like an LFP) is how many times it can be charged and discharged before its performance degrades. So let’s do some quick math.

As we mentioned, the average stove is expected to last 10-15 years. Let’s say you charge and then use your battery roughly once per day, for 365 days a year. Over the lifetime of your appliance, your battery will probably go through ~3500 - 5500 charging cycles.

This math happens to work out great, since LFP batteries last somewhere between 2000-6000 cycles. That’s way more than NMC batteries, which have been tested to 1500 and 2000 cycles.

Safety

At Impulse, the safety of our appliances is our top priority. So we selected a battery that would maximize your family’s safety at home.

This is especially relevant given recent concerns about fires caused by batteries in e-bikes and e-scooters. When you buy an Impulse product, you deserve the peace of mind that comes with knowing that your battery and appliance are designed to keep you safe.

Any time you store a lot of energy in a compact way — whether that be in a battery or in gas — there is a risk of fire. Luckily, our choice of LFP batteries are chemically optimized for safety. 

(If you want to know the details, LFP batteries boast an extremely stable iron-phosphate bond. This stability reduces the internal stress of the battery, and also prevents oxygen from being released by the phosphate. Both of these factors contribute to decreased risk of thermal runaway — a self-perpetuating cycle of overheating that can lead to fire.) 

That all boils down to an ultra-stable battery that keeps your home and your family safe. Plus, electrification helps eliminate both your everyday exposure to unhealthy gas and the risk of gas leaks in your home.

How Impulse is putting LFP to use 

Beyond choosing the best stationary battery technology out there, we’re designing the Impulse cooktop with your safety, convenience, and peace of mind first. Because we believe that transitioning to an electrified future should be filled with delight, not stress.

In an industry first, we’re meticulously pursuing safety testing and certifications for our battery and every component in our stove, paving the way for a new class of battery-powered appliances. Plus, our modular design means that if your battery ever needs servicing or replacement, it’ll be safe and easy.

Our designs also ensure that your charger and battery are matched to each other. Mismatched components can increase fire risk, and it’s an issue we’ve seen with (perhaps less carefully made) e-bikes and e-scooters. Luckily, the integration of the battery into our inherently solves this issue, adding another layer of safety. 

There are a lot of good battery options out there, but only one of them has the potential to usher in a new era of clean energy storage, power never-before-seen appliance performance, and meet the safety and durability standards you deserve: LFP.